CD8+ T cells provide immune protection against murine disseminated endotheliotropic Orientia tsutsugamushi infection.

Directory of Open Access Journals (Sweden)

Guang Xu

2017-07-01

Full Text Available Scrub typhus, caused by a Gram-negative obligately intracellular coccobacillus, Orientia tsutsugamushi, is a long neglected but important tropical disease. Orientia tsutsugamushi causes illness in one million people each year, and 1 billion people are at risk. Without appropriate diagnosis and treatment, the disease can cause severe multiorgan failure with a case fatality rate of 7-15%. The current gaps in knowledge of immunity include the unknown mechanisms of host immunity to O. tsutsugamushi. Using an intravenous (i.v. disseminated infection mouse model, we observed that more CD8+ T cells than CD4+ T cells were present in the spleen of infected mice at 12 dpi. We also determined that Treg cells and the proportion of T cells producing IL-10 were significantly increased from 6 dpi, which correlated with the onset of illness, body weight loss, and increased bacterial loads. We further studied CD8-/-, MHC I-/- and wild type control (WT C57BL/6J mice to determine the importance of CD8+ T cells and MHC I molecules. After infection with an ordinarily sub-lethal dose of O. tsutsugamushi, all CD8-/- and MHC I-/- mice were moribund between 12 and 15 dpi, whereas all WT mice survived. Bacterial loads in the lung, kidney, liver and spleen of CD8-/- and MHC I-/- mice were significantly greater than those in WT mice. Interferon-γ (IFN-γ and granzyme B mRNA levels in the liver of CD8-/- and MHC I-/- mice were significantly greater than in WT mice. In addition, more severe histopathologic lesions were observed in CD8-/- mice. Finally, adoptive transfer confirmed a major role of immune CD8+ T cells as well as a less effective contribution by immune CD8 T cell-depleted splenocytes in protection against O. tsutsugamushi infection. These studies demonstrated the critical importance of CD8+ T cells in the host immune response during O. tsutsugamushi infection.

Extensive immune-mediated hippocampal damage in mice surviving infection with neuroadapted Sindbis virus

International Nuclear Information System (INIS)

Kimura, Takashi; Griffin, Diane E.

2003-01-01

Viral infections of the central nervous system and immune responses to these infections cause a variety of neurological diseases. Infection of weanling mice with Sindbis virus causes acute nonfatal encephalomyelitis followed by clearance of infectious virus, but persistence of viral RNA. Infection with a neuroadapted strain of Sindbis virus (NSV) causes fatal encephalomyelitis, but passive transfer of immune serum after infection protects from fatal disease and infectious virus is cleared. To determine whether persistent NSV RNA is associated with neurological damage, we examined the brains of recovered mice and found progressive loss of the hippocampal gyrus, adjacent white matter, and deep cerebral cortex associated with mononuclear cell infiltration. Mice deficient in CD4 + T cells showed less tissue loss, while mice lacking CD8 + T cells showed lesions comparable to those in immunocompetent mice. Mice deficient in both CD4 + and CD8 + T cells developed severe tissue loss similar to immunocompetent mice and this was associated with extensive infiltration of macrophages. The number of CD4 + cells and macrophage/microglial cells, but not CD8 + cells, infiltrating the hippocampal gyrus was correlated with the number of terminal deoxynucleotidyltransferase-mediated dUTP nick end-labeling positive pyramidal neurons. These results suggest that CD4 + T cells can promote progressive neuronal death and tissue injury, despite clearance of infectious virus

Postlactational changes in cadmium retention in mice orally exposed to cadmium during pregnancy and lactation

International Nuclear Information System (INIS)

Bhattacharyya, M.H.; Sellers, D.A.; Peterson, D.P.

1986-01-01

Mice were continuously exposed to 109Cd in drinking water (0.03 microCi/ml; 0.11 ppb total cadmium) during pregnancy and lactation. After cessation of exposure, 109 Cd retention and distribution were examined during a 4-week postlactational period. At the start of the postlactational period (0 time), the fraction of oral 109 Cd retained by the dams was 2.4 times greater than that retained by similarly exposed nonpregnant mice. 109 Cd concentrations at 0 time were greater in the dams than in the nonpregnant mice in kidney (5-fold), liver (2.6-fold), mammary tissue (greater than 28-fold), and duodenum (13-fold). No changes in 109 Cd content of the whole body (minus gastrointestinal tract) occurred during the 4 weeks after cessation of exposure in either the dams or the nonpregnant mice; i.e., pregnancy-dependent increases in 109 Cd contents of individual organs were maintained during the 4 weeks of observation. An indication of translocation of 109 Cd from liver to kidney was observed in the dams but not in the nonpregnant mice. 109 Cd concentrations in the mammary tissue of the dams increased 2-fold during the postlactational period concomitant with a 3-fold decrease in mammary tissue mass. 109 Cd in the duodenum of the pregnant/lactating mice decreased, with a half-life of 14 days. Results indicate that multiparous women exposed to environmental levels of cadmium may takeup and retain in their kidneys, livers, and mammary tissue a greater fraction of their dietary cadmium than women with few or no children. Such results may bear on the etiology of Itai-Itai disease, a disease of the skeleton potentially related to oral cadmium exposure, with an incidence predominantly among postmenopausal women with a history of multiple childbirths

Endogenous jasmonic and salicylic acids levels in the Cd-hyperaccumulator Noccaea (Thlaspi) praecox exposed to fungal infection and/or mechanical stress.

Science.gov (United States)

Llugany, M; Martin, S R; Barceló, J; Poschenrieder, C

2013-08-01

Sensitivity to Erysiphe in Noccaea praecox with low metal supply is related to the failure in enhancing SA. Cadmium protects against fungal-infection by direct toxicity and/or enhanced fungal-induced JA signaling. Metal-based defense against biotic stress is an attractive hypothesis on evolutionary advantages of plant metal hyperaccumulation. Metals may compensate for a defect in biotic stress signaling in hyperaccumulators (metal-therapy) by either or both direct toxicity to pathogens and by metal-induced alternative signaling pathways. Jasmonic acid (JA) and salicylic acid (SA) are well-established components of stress signaling pathways. However, few studies evaluate the influence of metals on endogenous concentrations of these defense-related hormones. Even less data are available for metal hyperaccumulators. To further test the metal-therapy hypothesis we analyzed endogenous SA and JA concentrations in Noccaea praecox, a cadmium (Cd) hyperaccumulator. Plants treated or not with Cd, were exposed to mechanical wounding, expected to enhance JA signaling, and/or to infection by biotrophic fungus Erysiphe cruciferarum for triggering SA. JA and SA were analyzed in leaf extracts using LC-ESI(-)-MS/MS. Plants without Cd were more susceptible to fungal attack than plants receiving Cd. Cadmium alone tended to increase leaf SA but not JA. Either or both fungal attack and mechanical wounding decreased SA levels and enhanced JA in the Cd-rich leaves of plants exposed to Cd. High leaf Cd in N. praecox seems to hamper biotic-stress-induced SA, while triggering JA signaling in response to fungal attack and wounding. To the best of our knowledge, this is the first report on the endogenous JA and SA levels in a Cd-hyperaccumulator exposed to different biotic and abiotic stresses. Our results support the view of a defect in SA stress signaling in Cd hyperaccumulating N. praecox.

Apocynin and ebselen reduce influenza A virus-induced lung inflammation in cigarette smoke-exposed mice.

Science.gov (United States)

Oostwoud, L C; Gunasinghe, P; Seow, H J; Ye, J M; Selemidis, S; Bozinovski, S; Vlahos, R

2016-02-15

Influenza A virus (IAV) infections are a common cause of acute exacerbations of chronic obstructive pulmonary disease (AECOPD). Oxidative stress is increased in COPD, IAV-induced lung inflammation and AECOPD. Therefore, we investigated whether targeting oxidative stress with the Nox2 oxidase inhibitors and ROS scavengers, apocynin and ebselen could ameliorate lung inflammation in a mouse model of AECOPD. Male BALB/c mice were exposed to cigarette smoke (CS) generated from 9 cigarettes per day for 4 days. On day 5, mice were infected with 1 × 10(4.5) PFUs of the IAV Mem71 (H3N1). BALF inflammation, viral titers, superoxide production and whole lung cytokine, chemokine and protease mRNA expression were assessed 3 and 7 days post infection. IAV infection resulted in a greater increase in BALF inflammation in mice that had been exposed to CS compared to non-smoking mice. This increase in BALF inflammation in CS-exposed mice caused by IAV infection was associated with elevated gene expression of pro-inflammatory cytokines, chemokines and proteases, compared to CS alone mice. Apocynin and ebselen significantly reduced the exacerbated BALF inflammation and pro-inflammatory cytokine, chemokine and protease expression caused by IAV infection in CS mice. Targeting oxidative stress using apocynin and ebselen reduces IAV-induced lung inflammation in CS-exposed mice and may be therapeutically exploited to alleviate AECOPD.

[Oxidative damage effects induced by CdTe quantum dots in mice].

Science.gov (United States)

Xie, G Y; Chen, W; Wang, Q K; Cheng, X R; Xu, J N; Huang, P L

2017-07-20

Objective: To investigate Oxidative damage effects induced by CdTe Quantum Dots (QDs) in mice. Methods: 40 ICR mice were randomly divided into 5 groups: one control group (normal saline) ; four CdTe QDs (exposed by intravenous injection of 0.2 ml of CdTe QDs at the concentration of 0、0.5、5.0、50.0 and 500.0 nmol/ml respectively) . After 24 h, the mice were decapitated and the blood was collected for serum biochemically indexes、hematology indexes, the activities of SOD、GSH-Px and the concentration of MDA were all detected. Results: The results showed in the four CdTe QDs exposure groups, the level of CRE、PLT and the concentration of MDA were all significantly lower than those of the control group ( P control group ( P <0.01) . Conclusion: It was suggested that CdTe QDs at 0.5 nmol/ml could induce Oxidative damage effects in mice.

Memory CD8 T cells mediate severe immunopathology following respiratory syncytial virus infection.

Directory of Open Access Journals (Sweden)

Megan E Schmidt

2018-01-01

Full Text Available Memory CD8 T cells can provide protection from re-infection by respiratory viruses such as influenza and SARS. However, the relative contribution of memory CD8 T cells in providing protection against respiratory syncytial virus (RSV infection is currently unclear. To address this knowledge gap, we utilized a prime-boost immunization approach to induce robust memory CD8 T cell responses in the absence of RSV-specific CD4 T cells and antibodies. Unexpectedly, RSV infection of mice with pre-existing CD8 T cell memory led to exacerbated weight loss, pulmonary disease, and lethal immunopathology. The exacerbated disease in immunized mice was not epitope-dependent and occurred despite a significant reduction in RSV viral titers. In addition, the lethal immunopathology was unique to the context of an RSV infection as mice were protected from a normally lethal challenge with a recombinant influenza virus expressing an RSV epitope. Memory CD8 T cells rapidly produced IFN-γ following RSV infection resulting in elevated protein levels in the lung and periphery. Neutralization of IFN-γ in the respiratory tract reduced morbidity and prevented mortality. These results demonstrate that in contrast to other respiratory viruses, RSV-specific memory CD8 T cells can induce lethal immunopathology despite mediating enhanced viral clearance.

The Role of LAT in Increased CD8+ T Cell Exhaustion in Trigeminal Ganglia of Mice Latently Infected with Herpes Simplex Virus 1▿

Science.gov (United States)

Allen, Sariah J.; Hamrah, Pedram; Gate, David; Mott, Kevin R.; Mantopoulos, Dimosthenis; Zheng, Lixin; Town, Terrence; Jones, Clinton; von Andrian, Ulrich H.; Freeman, Gordon J.; Sharpe, Arlene H.; BenMohamed, Lbachir; Ahmed, Rafi; Wechsler, Steven L.; Ghiasi, Homayon

2011-01-01

Herpes simplex virus (HSV) infection is a classic example of latent viral infection in humans and experimental animal models. The HSV-1 latency-associated transcript (LAT) plays a major role in the HSV-1 latency reactivation cycle and thus in recurrent disease. Whether the presence of LAT leads to generation of dysfunctional T cell responses in the trigeminal ganglia (TG) of latently infected mice is not known. To address this issue, we used LAT-positive [LAT(+)] and LAT-deficient [LAT(−)] viruses to evaluate the effect of LAT on CD8 T cell exhaustion in TG of latently infected mice. The amount of latency as determined by quantitative reverse transcription-PCR (qRT-PCR) of viral DNA in total TG extracts was 3-fold higher with LAT(+) than with LAT(−) virus. LAT expression and increased latency correlated with increased mRNA levels of CD8, PD-1, and Tim-3. PD-1 is both a marker for exhaustion and a primary factor leading to exhaustion, and Tim-3 can also contribute to exhaustion. These results suggested that LAT(+) TG contain both more CD8+ T cells and more CD8+ T cells expressing the exhaustion markers PD-1 and Tim-3. This was confirmed by flow cytometry analyses of expression of CD3/CD8/PD-1/Tim-3, HSV-1, CD8+ T cell pentamer (specific for a peptide derived from residues 498 to 505 of glycoprotein B [gB498–505]), interleukin-2 (IL-2), and tumor necrosis factor alpha (TNF-α). The functional significance of PD-1 and its ligands in HSV-1 latency was demonstrated by the significantly reduced amount of HSV-1 latency in PD-1- and PD-L1-deficient mice. Together, these results may suggest that both PD-1 and Tim-3 are mediators of CD8+ T cell exhaustion and latency in HSV-1 infection. PMID:21307196

Dual function of CD70 in viral infection: modulator of early cytokine responses and activator of adaptive responses1

Science.gov (United States)

Allam, Atef; Swiecki, Melissa; Vermi, William; Ashwell, Jonathan D.; Colonna, Marco

2014-01-01

The role of the tumor necrosis factor family member CD70 in adaptive T cell responses has been intensively studied but its function in innate responses is still under investigation. Here we show that CD70 inhibits the early innate response to murine cytomegalovirus (MCMV) but is essential for the optimal generation of virus-specific CD8 T cells. CD70-/- mice reacted to MCMV infection with a robust type I interferon and proinflammatory cytokine response. This response was sufficient for initial control of MCMV, although at later time points, CD70-/- mice became more susceptible to MCMV infection. The heightened cytokine response during the early phase of MCMV infection in CD70-/- mice was paralleled by a reduction in regulatory T cells (Treg). Treg from naïve CD70-/- mice were not as efficient at suppressing T cell proliferation compared to Treg from naïve WT mice and depletion of Treg during MCMV infection in Foxp3-DTR mice or in WT mice recapitulated the phenotype observed in CD70-/- mice. Our study demonstrates that while CD70 is required for the activation of the antiviral adaptive response, it has a regulatory role in early cytokine responses to viruses such as MCMV, possibly through maintenance of Treg survival and function. PMID:24913981

Glycosylphosphatidylinositol-Anchored Anti-HIV scFv Efficiently Protects CD4 T Cells from HIV-1 Infection and Deletion in hu-PBL Mice

Science.gov (United States)

Ye, Chaobaihui; Wang, Weiming; Cheng, Liang; Li, Guangming; Wen, Michael; Wang, Qi; Zhang, Qing; Li, Dan

2016-01-01

ABSTRACT Despite success in viral inhibition and CD4 T cell recovery by highly active antiretroviral treatment (HAART), HIV-1 is still not curable due to the persistence of the HIV-1 reservoir during treatment. One patient with acute myeloid leukemia who received allogeneic hematopoietic stem cell transplantation from a homozygous CCR5 Δ32 donor has had no detectable viremia for 9 years after HAART cessation. This case has inspired a field of HIV-1 cure research focusing on engineering HIV-1 resistance in permissive cells. Here, we employed a glycosylphosphatidylinositol (GPI)-scFv X5 approach to confer resistance of human primary CD4 T cells to HIV-1. We showed that primary CD4 T cells expressing GPI-scFv X5 were resistant to CCR5 (R5)-, CXCR4 (X4)-, and dual-tropic HIV-1 and had a survival advantage compared to control cells ex vivo. In a hu-PBL mouse study, GPI-scFv X5-transduced CD4 T cells were selected in peripheral blood and lymphoid tissues upon HIV-1 infection. Finally, GPI-scFv X5-transduced CD4 T cells, after being cotransfused with HIV-infected cells, showed significantly reduced viral loads and viral RNA copy numbers relative to CD4 cells in hu-PBL mice compared to mice with GPI-scFv AB65-transduced CD4 T cells. We conclude that GPI-scFv X5-modified CD4 T cells could potentially be used as a genetic intervention against both R5- and X4-tropic HIV-1 infections. IMPORTANCE Blocking of HIV-1 entry is one of most promising approaches for therapy. Genetic disruption of the HIV-1 coreceptor CCR5 by nucleases in T cells is under 2 clinical trials and leads to reduced viremia in patients. However, the emergence of viruses using the CXCR4 coreceptor is a concern for therapies applying single-coreceptor disruption. Here, we report that HIV-1-permissive CD4 T cells engineered with GPI-scFv X5 are resistant to R5-, X4-, or dual-tropic virus infection ex vivo. In a preclinical study using hu-PBL mice, we show that CD4 T cells were protected and that GPI-scFv X5

CD8 T cells protect adult naive mice from JEV-induced morbidity via lytic function.

Science.gov (United States)

Jain, Nidhi; Oswal, Neelam; Chawla, Amanpreet Singh; Agrawal, Tanvi; Biswas, Moanaro; Vrati, Sudhanshu; Rath, Satyajit; George, Anna; Bal, Vineeta; Medigeshi, Guruprasad R

2017-02-01

Following Japanese encephalitis virus (JEV) infection neutralizing antibodies are shown to provide protection in a significant proportion of cases, but not all, suggesting additional components of immune system might also contribute to elicit protective immune response. Here we have characterized the role of T cells in offering protection in adult mice infected with JEV. Mice lacking α/β-T cells (TCRβ-null) are highly susceptible and die over 10-18 day period as compared to the wild-type (WT) mice which are resistant. This is associated with high viral load, higher mRNA levels of proinflammatory cytokines and breach in the blood-brain-barrier (BBB). Infected WT mice do not show a breach in BBB; however, in contrast to TCRβ-null, they show the presence of T cells in the brain. Using adoptive transfer of cells with specific genetic deficiencies we see that neither the presence of CD4 T cells nor cytokines such as IL-4, IL-10 or interferon-gamma have any significant role in offering protection from primary infection. In contrast, we show that CD8 T cell deficiency is more critical as absence of CD8 T cells alone increases mortality in mice infected with JEV. Further, transfer of T cells from beige mice with defects in granular lytic function into TCRβ-null mice shows poor protection implicating granule-mediated target cell lysis as an essential component for survival. In addition, for the first time we report that γ/δ-T cells also make significant contribution to confer protection from JEV infection. Our data show that effector CD8 T cells play a protective role during primary infection possibly by preventing the breach in BBB and neuronal damage.

CD8 T cells protect adult naive mice from JEV-induced morbidity via lytic function.

Directory of Open Access Journals (Sweden)

Nidhi Jain

2017-02-01

Full Text Available Following Japanese encephalitis virus (JEV infection neutralizing antibodies are shown to provide protection in a significant proportion of cases, but not all, suggesting additional components of immune system might also contribute to elicit protective immune response. Here we have characterized the role of T cells in offering protection in adult mice infected with JEV. Mice lacking α/β-T cells (TCRβ-null are highly susceptible and die over 10-18 day period as compared to the wild-type (WT mice which are resistant. This is associated with high viral load, higher mRNA levels of proinflammatory cytokines and breach in the blood-brain-barrier (BBB. Infected WT mice do not show a breach in BBB; however, in contrast to TCRβ-null, they show the presence of T cells in the brain. Using adoptive transfer of cells with specific genetic deficiencies we see that neither the presence of CD4 T cells nor cytokines such as IL-4, IL-10 or interferon-gamma have any significant role in offering protection from primary infection. In contrast, we show that CD8 T cell deficiency is more critical as absence of CD8 T cells alone increases mortality in mice infected with JEV. Further, transfer of T cells from beige mice with defects in granular lytic function into TCRβ-null mice shows poor protection implicating granule-mediated target cell lysis as an essential component for survival. In addition, for the first time we report that γ/δ-T cells also make significant contribution to confer protection from JEV infection. Our data show that effector CD8 T cells play a protective role during primary infection possibly by preventing the breach in BBB and neuronal damage.

CXCL10/CXCR3-Dependent Mobilization of Herpes Simplex Virus-Specific CD8+ TEM and CD8+ TRM Cells within Infected Tissues Allows Efficient Protection against Recurrent Herpesvirus Infection and Disease.

Science.gov (United States)

Srivastava, Ruchi; Khan, Arif A; Chilukuri, Sravya; Syed, Sabrina A; Tran, Tien T; Furness, Julie; Bahraoui, Elmostafa; BenMohamed, Lbachir

2017-07-15

Herpes simplex virus 1 (HSV-1) establishes latency within the sensory neurons of the trigeminal ganglia (TG). HSV-specific memory CD8 + T cells play a critical role in preventing HSV-1 reactivation from TG and subsequent virus shedding in tears that trigger recurrent corneal herpetic disease. The CXC chemokine ligand 10 (CXCL10)/CXC chemokine receptor 3 (CXCR3) chemokine pathway promotes T cell immunity to many viral pathogens, but its importance in CD8 + T cell immunity to recurrent herpes has been poorly elucidated. In this study, we determined how the CXCL10/CXCR3 pathway affects TG- and cornea-resident CD8 + T cell responses to recurrent ocular herpesvirus infection and disease using a well-established murine model in which HSV-1 reactivation was induced from latently infected TG by UV-B light. Following UV-B-induced HSV-1 reactivation, a significant increase in both the number and function of HSV-specific CXCR3 + CD8 + T cells was detected in TG and corneas of protected C57BL/6 (B6) mice, but not in TG and corneas of nonprotected CXCL10 -/- or CXCR3 -/- deficient mice. This increase was associated with a significant reduction in both virus shedding and recurrent corneal herpetic disease. Furthermore, delivery of exogenous CXCL10 chemokine in TG of CXCL10 -/- mice, using the neurotropic adeno-associated virus type 8 (AAV8) vector, boosted the number and function of effector memory CD8 + T cells (T EM ) and tissue-resident memory CD8 + T cells (T RM ), but not of central memory CD8 + T cells (T CM ), locally within TG, and improved protection against recurrent herpesvirus infection and disease in CXCL10 -/- deficient mice. These findings demonstrate that the CXCL10/CXCR3 chemokine pathway is critical in shaping CD8 + T cell immunity, locally within latently infected tissues, which protects against recurrent herpesvirus infection and disease. IMPORTANCE We determined how the CXCL10/CXCR3 pathway affects CD8 + T cell responses to recurrent ocular herpesvirus

Control of mucosal virus infection by influenza nucleoprotein-specific CD8+ cytotoxic T lymphocytes

Directory of Open Access Journals (Sweden)

Couch Robert B

2007-06-01

Full Text Available Abstract Background MHC class I-restricted CD8+ cytotoxic T lymphocytes (CTL are thought to play a major role in clearing virus and promoting recovery from influenza infection and disease. This has been demonstrated for clearance of influenza virus from the lungs of infected mice. However, human influenza infection is primarily a respiratory mucosal infection involving the nasopharynx and tracheobronchial tree. The role of CD8+ CTL directed toward the influenza nucleoprotein (NP in defense against influenza virus infection at the respiratory mucosa was evaluated in two separate adoptive transfer experiments. Methods Influenza nucleoprotein (NP-specific CD8+ CTL were generated from splenocytes obtained from Balb/c mice previously primed with influenza A/Taiwan/1/86 (H1N1 infection or with influenza A/PR/8/34 (H1N1-derived NP plasmid DNA vaccine followed by infection with A/Hong Kong/68 (H3N2 virus. After in vitro expansion by exposure to an influenza NP-vaccinia recombinant, highly purified CD8+ T cells exhibited significant lysis in vitro of P815 target cells infected with A/Hong Kong/68 (H3N2 virus while the CD8- fraction (CD4+ T cells, B cells and macrophages had no CTL activity. Purified CD8+ and CD8- T cells (1 × 107 were injected intravenously or interperitoneally into naive mice four hours prior to intranasal challenge with A/HK/68 (H3N2 virus. Results The adoptively transferred NP-vaccinia-induced CD8+ T cells caused significant reduction of virus titers in both the lungs and nasal passages when compared to CD8- cells. Neither CD8+ nor CD8- T cells from cultures stimulated with HIV gp120-vaccinia recombinant reduced virus titers. Conclusion The present data demonstrate that influenza NP-specific CD8+ CTL can play a direct role in clearance of influenza virus from the upper respiratory mucosal surfaces.

Influenza virus-induced alterations of cytochrome P-450 enzyme activities following exposure of mice to coal and diesel particulates.

Science.gov (United States)

Rabovsky, J; Judy, D J; Rodak, D J; Petersen, M

1986-06-01

We have investigated a relationship between two detoxication systems, metabolic detoxication through the cytochrome P-450 (P-450) pathway and resistance to infection through interferon (IFN), in mice infected with influenza virus following exposure to coal dust (CD) and diesel exhaust (DE) particulates. Mice were exposed by inhalation to filtered air (FA; control), CD, or DE for 1 month and then inoculated intranasally (IN) with influenza virus. During infection, 7-ethoxycoumarin deethylase (7ECdeEt'ase) and ethylmorphine demethylase (EMdeMe'ase) (monooxygenases), and NADPH cytochrome c reductase (NADPH c red'ase) were measured in liver microsomes. Temporal patterns of enzyme activities were observed with control animals. EMdeMe'ase and NADPH c red'ase exhibited peak values at Day 4 postinfection (27.6 and 482 nmole/min/mg protein, respectively), compared to initial activities (9.1 and 307 nmole/min/mg protein, respectively). 7ECdeEt'ase activity decreased between Days 1-3 postvirus infection and thereafter returned to the original value (1.7 nmole/min/mg protein). When the mice were first exposed to CD or DE particulates for 1 month prior to influenza infection, changes in enzyme temporal patterns were observed. The increased EMdeMe'ase activity at Day 4 was not observed in mice exposed to CD and was reduced in mice exposed to DE. Preexposure to either particulate resulted in the abolition of the increased Day 4 activity of NADPH c red'ase. The 7ECdeEt'ase postinfection temporal pattern was not affected by a preexposure to either particulate. Estimates of the enzyme activities after the 1-month exposure to FA, CD, or DE but before virus infection indicated no changes due to particulate exposure alone. Under these conditions of particulate exposure and virus infection, serum IFN levels in the mice used in this study peaked at Days 4-5 and were unaffected by the 1-month preexposure to CD or DE (Hahon et al., (1985). The data suggest the relationship that exists

Whole-body aerosol exposure of cadmium chloride (CdCl{sub 2}) and tetrabromobisphenol A (TBBPA) induced hepatic changes in CD-1 male mice

Energy Technology Data Exchange (ETDEWEB)

Chen, Yuanhong; Hu, Yabing; Liu, Shuyun; Zheng, Huiying; Wu, Xiaojuan; Huang, Zhengyu; Li, Hao; Peng, Baoqi; Long, Jinlie [Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou 325035 (China); Pan, Bishu [Taizhou Center for Disease Control and Prevention, Taizhou 318000 (China); Huang, Changjiang, E-mail: cjhuang5711@163.com [Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou 325035 (China); Dong, Qiaoxiang, E-mail: dqxdong@163.com [Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou 325035 (China)

2016-11-15

Highlights: • Hepatotoxicity of TBBPA and Cd aerosol co-exposure was evaluated in CD-1 male mice. • Hepatic changes include focal necrosis, increased organ weight, and elevated enzymes. • TBBPA group exhibited highest hepatic toxicity followed by co-exposure and Cd groups. • We did not observe any synergistic effect of hepatic toxicity between TBBPA and Cd. • TBBPA/Cd suppressed antioxidant defensive mechanisms and increased oxidative stress. - Abstract: Cadmium (Cd) and tetrabromobisphenol A (TBBPA) are two prevalent contaminants in e-waste recycling facilities. However, the potential adversely health effect of co-exposure to these two types of pollutants in an occupational setting is unknown. In this study, we investigated co-exposure of these two pollutants on hepatic toxicity in CD-1 male mice through a whole-body aerosol inhalation route. Specifically, mice were exposed to solvent control (5% DMSO), Cd (8 μg/m{sup 3}), TBBPA (16 μg/m{sup 3}) and Cd/TBBPA mixture for 8 h/day and 6 days a week for 60 days. Hepatic changes include increased organ weight, focal necrosis, and elevated levels of liver enzymes in serum. These changes were most severe in mice exposed to TBBPA, followed by Cd/TBBPA mixture and Cd. These chemicals also led to suppressed antioxidant defensive mechanisms and increased oxidative stress. Further, these chemicals induced gene expression of apoptosis-related genes, activated genes encoding for phase I detoxification enzymes and inhibited genes encoding for phase II detoxification enzymes. These findings indicate that the hepatic damages induced by subchronic aerosol exposure of Cd and TBBPA may result from the oxidative damages caused by excessive ROS production when these chemicals were metabolized in the liver.

Hesperidin Inhibits Inflammatory Response Induced by Aeromonas hydrophila Infection and Alters CD4+/CD8+ T Cell Ratio

Directory of Open Access Journals (Sweden)

Abdelaziz S. A. Abuelsaad

2014-01-01

Full Text Available Background. Aeromonas hydrophila is an opportunistic bacterial pathogen that is associated with a number of human diseases. Hesperidin (HES has been reported to exert antioxidant and anti-inflammatory activities. Objectives. The aim of this study was to investigate the potential effect of HES treatment on inflammatory response induced by A. hydrophila infection in murine. Methods. A. hydrophila-infected mice were treated with HES at 250 mg/kg b.wt./week for 4 consecutive weeks. Phagocytosis, reactive oxygen species production, CD4+/CD8+ T cell ratio, and CD14 expression on intestinal infiltrating monocytes were evaluated. The expression of E-selectin and intercellular adhesion molecule 1 on stimulated HUVECs and RAW macrophage was evaluated. Results. Percentage of CD4+ T cells in the intestinal tissues of infected treated mice was highly significantly increased; however, phagocytic index, ROS production, CD8+ T cells percentage, and CD14 expression on monocytes were significantly reduced. On the other hand, HES significantly inhibited A-LPS- and A-ECP-induced E-selectin and ICAM-1 expression on HUVECs and ICAM-1 expression on RAW macrophage. Conclusion. Present data indicated that HES has a potential role in the suppression of inflammatory response induced by A. hydrophila toxins through downmodulation of ROS production and CD14 and adhesion molecules expression, as well as increase of CD4+/CD8+ cell ratio.

Aggravation of Allergic Airway Inflammation by Cigarette Smoke in Mice Is CD44-Dependent.

Directory of Open Access Journals (Sweden)

Smitha Kumar

Full Text Available Although epidemiological studies reveal that cigarette smoke (CS facilitates the development and exacerbation of allergic asthma, these studies offer limited information on the mechanisms involved. The transmembrane glycoprotein CD44 is involved in cell adhesion and acts as a receptor for hyaluronic acid and osteopontin. We aimed to investigate the role of CD44 in a murine model of CS-facilitated allergic airway inflammation.Wild type (WT and CD44 knock-out (KO mice were exposed simultaneously to house dust mite (HDM extract and CS. Inflammatory cells, hyaluronic acid (HA and osteopontin (OPN levels were measured in bronchoalveolar lavage fluid (BALF. Proinflammatory mediators, goblet cell metaplasia and peribronchial eosinophilia were assessed in lung tissue. T-helper (Th 1, Th2 and Th17 cytokine production was evaluated in mediastinal lymph node cultures.In WT mice, combined HDM/CS exposure increased the number of inflammatory cells and the levels of HA and OPN in BALF and Th2 cytokine production in mediastinal lymph nodes compared to control groups exposed to phosphate buffered saline (PBS/CS, HDM/Air or PBS/Air. Furthermore, HDM/CS exposure significantly increased goblet cell metaplasia, peribronchial eosinophilia and inflammatory mediators in the lung. CD44 KO mice exposed to HDM/CS had significantly fewer inflammatory cells in BALF, an attenuated Th2 cytokine production, as well as decreased goblet cells and peribronchial eosinophils compared to WT mice. In contrast, the levels of inflammatory mediators were similar or higher than in WT mice.We demonstrate for the first time that the aggravation of pulmonary inflammation upon combined exposure to allergen and an environmental pollutant is CD44-dependent. Data from this murine model of concomitant exposure to CS and HDM might be of importance for smoking allergic asthmatics.

Poliomyelitis in transgenic mice expressing CD155 under the control of the Tage4 promoter after oral and parenteral poliovirus inoculation.

Science.gov (United States)

Khan, Shaukat; Toyoda, Hidemi; Linehan, Melissa; Iwasaki, Akiko; Nomoto, Akio; Bernhardt, Günter; Cello, Jeronimo; Wimmer, Eckard

2014-08-01

An important step in poliovirus (PV) infection by the oral route in humans is replication of the virus in lymphatic tissues of the gastrointestinal (GI) tract, thought to be mainly in the Peyer's patches of the small intestine. No immunocompetent transgenic (tg) mice that express human PV receptor (CD155) under the control of different promoters can be infected orally. The mouse orthologue of human CD155 is Tage4, a protein expressed at the surface of enterocytes and in the Peyer's patches. We describe here the generation of a tg mouse model in which the Tage4 promoter was used to drive expression of the human PV receptor-coding region (Tage4-CD155tg mice). In this model, CD155 expression was observed by immunostaining in different regions in the Peyer's patches but not in their germinal centres. Although a similar pattern of staining was observed between 3- and 6-week-old Tage4-CD155tg mice, poliomyelitis was only seen in the younger mice after PV infection by the oral route. When compared with TgPVR21 mice that expressed CD155 driven by its human promoter, 3-week-old Tage4-CD155tg mice were more susceptible to gut infection and paralysis following feeding with PV. Also, Tage4-CD155tg mice exhibited higher susceptibility to poliomyelitis after parenteral inoculation of PV. Remarkably, the LD50 after intracerebral inoculation of PV was similar in both CD155 tg mouse strains. The CD155 tg mouse model reported here, although moderately susceptible to oral infection, may be suitable to study mechanisms of PV replication in the gastrointestinal tract and to dissect important aspects of PV neuroinvasiveness. © 2014 The Authors.

Eosinophils Promote Antiviral Immunity in Mice Infected with Influenza A Virus.

Science.gov (United States)

Samarasinghe, Amali E; Melo, Rossana C N; Duan, Susu; LeMessurier, Kim S; Liedmann, Swantje; Surman, Sherri L; Lee, James J; Hurwitz, Julia L; Thomas, Paul G; McCullers, Jonathan A

2017-04-15

Eosinophils are multifunctional cells of the innate immune system linked to allergic inflammation. Asthmatics were more likely to be hospitalized but less likely to suffer severe morbidity and mortality during the 2009 influenza pandemic. These epidemiologic findings were recapitulated in a mouse model of fungal asthma wherein infection during heightened allergic inflammation was protective against influenza A virus (IAV) infection and disease. Our goal was to delineate a mechanism(s) by which allergic asthma may alleviate influenza disease outcome, focused on the hypothesis that pulmonary eosinophilia linked with allergic respiratory disease is able to promote antiviral host defenses against the influenza virus. The transfer of eosinophils from the lungs of allergen-sensitized and challenged mice into influenza virus-infected mice resulted in reduced morbidity and viral burden, improved lung compliance, and increased CD8 + T cell numbers in the airways. In vitro assays with primary or bone marrow-derived eosinophils were used to determine eosinophil responses to the virus using the laboratory strain (A/PR/08/1934) or the pandemic strain (A/CA/04/2009) of IAV. Eosinophils were susceptible to IAV infection and responded by activation, piecemeal degranulation, and upregulation of Ag presentation markers. Virus- or viral peptide-exposed eosinophils induced CD8 + T cell proliferation, activation, and effector functions. Our data suggest that eosinophils promote host cellular immunity to reduce influenza virus replication in lungs, thereby providing a novel mechanism by which hosts with allergic asthma may be protected from influenza morbidity. Copyright © 2017 by The American Association of Immunologists, Inc.

Influenza virus-induced alterations of cytochrome P-450 enzyme activities following exposure of mice to coal and diesel particulates

Energy Technology Data Exchange (ETDEWEB)

Rabovsky, J.; Judy, D.J.; Rodak, D.J.; Petersen, M.

1986-06-01

We have investigated a relationship between two detoxication systems, metabolic detoxication through the cytochrome P-450 (P-450) pathway and resistance to infection through interferon (IFN), in mice infected with influenza virus following exposure to coal dust (CD) and diesel exhaust (DE) particulates. Mice were exposed by inhalation to filtered air (FA; control), CD, or DE for 1 month and then inoculated intranasally (IN) with influenza virus. During infection, 7-ethoxycoumarin deethylase (7ECdeEt'ase) and ethylmorphine demethylase (EMdeMe'ase) (monooxygenases), and NADPH cytochrome c reductase (NADPH c red'ase) were measured in liver microsomes. Temporal patterns of enzyme activities were observed with control animals. EMdeMe'ase and NADPH c red'ase exhibited peak values at Day 4 postinfection (27.6 and 482 nmole/min/mg protein, respectively), compared to initial activities (9.1 and 307 nmole/min/mg protein, respectively). 7ECdeEt'ase activity decreased between Days 1-3 postvirus infection and thereafter returned to the original value (1.7 nmole/min/mg protein). When the mice were first exposed to CD or DE particulates for 1 month prior to influenza infection, changes in enzyme temporal patterns were observed. The increased EMdeMe'ase activity at Day 4 was not observed in mice exposed to CD and was reduced in mice exposed to DE. Preexposure to either particulate resulted in the abolition of the increased Day 4 activity of NADPH c red'ase. The 7ECdeEt'ase postinfection temporal pattern was not affected by a preexposure to either particulate. Estimates of the enzyme activities after the 1-month exposure to FA, CD, or DE but before virus infection indicated no changes due to particulate exposure alone. Under conditions of particulate exposure and virus infection, serum IFN levels peaked at Days 4-5 and were unaffected by the 1-month preexposure to CD or DE.

CD151, a novel host factor of nuclear export signaling in influenza virus infection.

Science.gov (United States)

Qiao, Yongkang; Yan, Yan; Tan, Kai Sen; Tan, Sheryl S L; Seet, Ju Ee; Arumugam, Thiruma Valavan; Chow, Vincent T K; Wang, De Yun; Tran, Thai

2018-05-01

Despite advances in our understanding of the mechanisms of influenza A virus (IAV) infection, the crucial virus-host interactions during the viral replication cycle still remain incomplete. Tetraspanin CD151 is highly expressed in the human respiratory tract, but its pathological role in IAV infection is unknown. We sought to characterize the functional role and mechanisms of action of CD151 in IAV infection of the upper and lower respiratory tracts with H1N1 and H3N2 strains. We used CD151-null mice in an in vivo model of IAV infection and clinical donor samples of in vitro-differentiated human nasal epithelial cells cultured at air-liquid interface. As compared with wild-type infected mice, CD151-null infected mice exhibited a significant reduction in virus titer and improvement in survival that is associated with pronounced host antiviral response and inflammasome activation together with accelerated lung repair. Interestingly, we show that CD151 complexes newly synthesized viral proteins with host nuclear export proteins and stabilizes microtubule complexes, which are key processes necessary for the polarized trafficking of viral progeny to the host plasma membrane for assembly. Our results provide new mechanistic insights into our understanding of IAV infection. We show that CD151 is a critical novel host factor of nuclear export signaling whereby the IAV nuclear export uses it to complement its own nuclear export proteins (a site not targeted by current therapy), making this regulation unique, and holds promise for the development of novel alternative/complementary strategies to reduce IAV severity. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Influenza Virus-Induced Lung Inflammation Was Modulated by Cigarette Smoke Exposure in Mice

Science.gov (United States)

Han, Yan; Ling, Man To; Mao, Huawei; Zheng, Jian; Liu, Ming; Lam, Kwok Tai; Liu, Yuan; Tu, Wenwei; Lau, Yu-Lung

2014-01-01

Although smokers have increased susceptibility and severity of seasonal influenza virus infection, there is no report about the risk of 2009 pandemic H1N1 (pdmH1N1) or avian H9N2 (H9N2/G1) virus infection in smokers. In our study, we used mouse model to investigate the effect of cigarette smoke on pdmH1N1 or H9N2 virus infection. Mice were exposed to cigarette smoke for 21 days and then infected with pdmH1N1 or H9N2 virus. Control mice were exposed to air in parallel. We found that cigarette smoke exposure alone significantly upregulated the lung inflammation. Such prior cigarette smoke exposure significantly reduced the disease severity of subsequent pdmH1N1 or H9N2 virus infection. For pdmH1N1 infection, cigarette smoke exposed mice had significantly lower mortality than the control mice, possibly due to the significantly decreased production of inflammatory cytokines and chemokines. Similarly, after H9N2 infection, cigarette smoke exposed mice displayed significantly less weight loss, which might be attributed to lower cytokines and chemokines production, less macrophages, neutrophils, CD4+ and CD8+ T cells infiltration and reduced lung damage compared to the control mice. To further investigate the underlying mechanism, we used nicotine to mimic the effect of cigarette smoke both in vitro and in vivo. Pre-treating the primary human macrophages with nicotine for 72 h significantly decreased their expression of cytokines and chemokines after pdmH1N1 or H9N2 infection. The mice subcutaneously and continuously treated with nicotine displayed significantly less weight loss and lower inflammatory response than the control mice upon pdmH1N1 or H9N2 infection. Moreover, α7 nicotinic acetylcholine receptor knockout mice had more body weight loss than wild-type mice after cigarette smoke exposure and H9N2 infection. Our study provided the first evidence that the pathogenicity of both pdmH1N1 and H9N2 viruses was alleviated in cigarette smoke exposed mice, which might

Influenza virus-induced lung inflammation was modulated by cigarette smoke exposure in mice.

Directory of Open Access Journals (Sweden)

Yan Han

Full Text Available Although smokers have increased susceptibility and severity of seasonal influenza virus infection, there is no report about the risk of 2009 pandemic H1N1 (pdmH1N1 or avian H9N2 (H9N2/G1 virus infection in smokers. In our study, we used mouse model to investigate the effect of cigarette smoke on pdmH1N1 or H9N2 virus infection. Mice were exposed to cigarette smoke for 21 days and then infected with pdmH1N1 or H9N2 virus. Control mice were exposed to air in parallel. We found that cigarette smoke exposure alone significantly upregulated the lung inflammation. Such prior cigarette smoke exposure significantly reduced the disease severity of subsequent pdmH1N1 or H9N2 virus infection. For pdmH1N1 infection, cigarette smoke exposed mice had significantly lower mortality than the control mice, possibly due to the significantly decreased production of inflammatory cytokines and chemokines. Similarly, after H9N2 infection, cigarette smoke exposed mice displayed significantly less weight loss, which might be attributed to lower cytokines and chemokines production, less macrophages, neutrophils, CD4+ and CD8+ T cells infiltration and reduced lung damage compared to the control mice. To further investigate the underlying mechanism, we used nicotine to mimic the effect of cigarette smoke both in vitro and in vivo. Pre-treating the primary human macrophages with nicotine for 72 h significantly decreased their expression of cytokines and chemokines after pdmH1N1 or H9N2 infection. The mice subcutaneously and continuously treated with nicotine displayed significantly less weight loss and lower inflammatory response than the control mice upon pdmH1N1 or H9N2 infection. Moreover, α7 nicotinic acetylcholine receptor knockout mice had more body weight loss than wild-type mice after cigarette smoke exposure and H9N2 infection. Our study provided the first evidence that the pathogenicity of both pdmH1N1 and H9N2 viruses was alleviated in cigarette smoke exposed

Sm29, but not Sm22.6 retains its ability to induce a protective immune response in mice previously exposed to a Schistosoma mansoni infection.

Directory of Open Access Journals (Sweden)

Clarice Carvalho Alves

2015-02-01

Full Text Available BACKGROUND: A vaccine against schistosomiasis would have a great impact in disease elimination. Sm29 and Sm22.6 are two parasite tegument proteins which represent promising antigens to compose a vaccine. These antigens have been associated with resistance to infection and reinfection in individuals living in endemic area for the disease and induced partial protection when evaluated in immunization trials using naïve mice. METHODOLOGY/PRINCIPALS FINDINGS: In this study we evaluated rSm29 and rSm22.6 ability to induce protection in Balb/c mice that had been previously infected with S. mansoni and further treated with Praziquantel. Our results demonstrate that three doses of the vaccine containing rSm29 were necessary to elicit significant protection (26%-48%. Immunization of mice with rSm29 induced a significant production of IL-2, IFN-γ, IL-17, IL-4; significant production of specific antibodies; increased percentage of CD4+ central memory cells in comparison with infected and treated saline group and increased percentage of CD4+ effector memory cells in comparison with naïve Balb/c mice immunized with rSm29. On the other hand, although immunization with Sm22.6 induced a robust immune response, it failed to induce protection. CONCLUSION/SIGNIFICANCE: Our results demonstrate that rSm29 retains its ability to induce protection in previously infected animals, reinforcing its potential as a vaccine candidate.

Diet-induced obesity in mice reduces the maintenance of influenza-specific CD8+ memory T cells.

Science.gov (United States)

Karlsson, Erik A; Sheridan, Patricia A; Beck, Melinda A

2010-09-01

Obesity has been associated with increasing the risk for type 2 diabetes and heart disease, but its influence on the immune response to viral infection is understudied. Memory T cells generated during a primary influenza infection are important for protection against subsequent influenza exposures. Previously, we have demonstrated that diet-induced obese (DIO) mice have increased morbidity and mortality following secondary influenza infection compared with lean mice. To determine whether the problem resided in a failure to maintain functional, influenza-specific CD8(+) memory T cells, male DIO and lean mice were infected with influenza X-31. At 84 d postinfection, DIO mice had a 10% reduction in memory T cell numbers. This reduction may have resulted from significantly reduced memory T cell expression of interleukin 2 receptor beta (IL-2R beta, CD122), but not IL-7 receptor alpha (CD127), which are both required for memory cell maintenance. Peripheral leptin resistance in the DIO mice may be a contributing factor to the impairment. Indeed, leptin receptor mRNA expression was significantly reduced in the lungs of obese mice, whereas suppressor of cytokine signaling (Socs)1 and Socs3 mRNA expression were increased. It is imperative to understand how the obese state alters memory T cells, because impairment in maintenance of functional memory responses has important implications for vaccine efficacy in an obese population.

Cytotoxic CD4 T Cells—Friend or Foe during Viral Infection?

Science.gov (United States)

Juno, Jennifer A.; van Bockel, David; Kent, Stephen J.; Kelleher, Anthony D.; Zaunders, John J.; Munier, C. Mee Ling

2017-01-01

CD4 T cells with cytotoxic function were once thought to be an artifact due to long-term in vitro cultures but have in more recent years become accepted and reported in the literature in response to a number of viral infections. In this review, we focus on cytotoxic CD4 T cells in the context of human viral infections and in some infections that affect mice and non-human primates. We examine the effector mechanisms used by cytotoxic CD4 cells, the phenotypes that describe this population, and the transcription factors and pathways that lead to their induction following infection. We further consider the cells that are the predominant targets of this effector subset and describe the viral infections in which CD4 cytotoxic T lymphocytes have been shown to play a protective or pathologic role. Cytotoxic CD4 T cells are detected in the circulation at much higher levels than previously realized and are now recognized to have an important role in the immune response to viral infections. PMID:28167943

Multi-level Strategy for Identifying Proteasome-Catalyzed Spliced Epitopes Targeted by CD8+ T Cells during Bacterial Infection

Directory of Open Access Journals (Sweden)

Anouk C.M. Platteel

2017-08-01

Full Text Available Proteasome-catalyzed peptide splicing (PCPS generates peptides that are presented by MHC class I molecules, but because their identification is challenging, the immunological relevance of spliced peptides remains unclear. Here, we developed a reverse immunology-based multi-level approach to identify proteasome-generated spliced epitopes. Applying this strategy to a murine Listeria monocytogenes infection model, we identified two spliced epitopes within the secreted bacterial phospholipase PlcB that primed antigen-specific CD8+ T cells in L. monocytogenes-infected mice. While reacting to the spliced epitopes, these CD8+ T cells failed to recognize the non-spliced peptide parts in the context of their natural flanking sequences. Thus, we here show that PCPS expands the CD8+ T cell response against L. monocytogenes by exposing spliced epitopes on the cell surface. Moreover, our multi-level strategy opens up opportunities to systematically investigate proteins for spliced epitope candidates and thus strategies for immunotherapies or vaccine design.

Infection with Porphyromonas gingivalis exacerbates endothelial injury in obese mice.

Directory of Open Access Journals (Sweden)

Min Ao

Full Text Available BACKGROUND: A number of studies have revealed a link between chronic periodontitis and cardiovascular disease in obese patients. However, there is little information about the influence of periodontitis-associated bacteria, Porphyromonas gingivalis (Pg, on pathogenesis of atherosclerosis in obesity. METHODS: In vivo experiment: C57BL/6J mice were fed with a high-fat diet (HFD or normal chow diet (CD, as a control. Pg was infected from the pulp chamber. At 6 weeks post-infection, histological and immunohistochemical analysis of aortal tissues was performed. In vitro experiment: hTERT-immortalized human umbilical vein endothelial cells (HuhT1 were used to assess the effect of Pg/Pg-LPS on free fatty acid (FFA induced endothelial cells apoptosis and regulation of cytokine gene expression. RESULTS: Weaker staining of CD31 and increased numbers of TUNEL positive cells in aortal tissue of HFD mice indicated endothelial injury. Pg infection exacerbated the endothelial injury. Immunohistochemically, Pg was detected deep in the smooth muscle of the aorta, and the number of Pg cells in the aortal wall was higher in HFD mice than in CD mice. Moreover, in vitro, FFA treatment induced apoptosis in HuhT1 cells and exposure to Pg-LPS increased this effect. In addition, Pg and Pg-LPS both attenuated cytokine production in HuhT1 cells stimulated by palmitate. CONCLUSIONS: Dental infection of Pg may contribute to pathogenesis of atherosclerosis by accelerating FFA-induced endothelial injury.

Superior induction and maintenance of protective CD8 T cells in mice infected with mouse cytomegalovirus vector expressing RAE-1γ.

Science.gov (United States)

Trsan, Tihana; Busche, Andreas; Abram, Maja; Wensveen, Felix M; Lemmermann, Niels A; Arapovic, Maja; Babic, Marina; Tomic, Adriana; Golemac, Mijo; Brinkmann, Melanie M; Jäger, Wiebke; Oxenius, Annette; Polic, Bojan; Krmpotic, Astrid; Messerle, Martin; Jonjic, Stipan

2013-10-08

Due to a unique pattern of CD8 T-cell response induced by cytomegaloviruses (CMVs), live attenuated CMVs are attractive candidates for vaccine vectors for a number of clinically relevant infections and tumors. NKG2D is one of the most important activating NK cell receptors that plays a role in costimulation of CD8 T cells. Here we demonstrate that the expression of CD8 T-cell epitope of Listeria monocytogenes by a recombinant mouse CMV (MCMV) expressing the NKG2D ligand retinoic acid early-inducible protein 1-gamma (RAE-1γ) dramatically enhanced the effectiveness and longevity of epitope-specific CD8 T-cell response and conferred protection against a subsequent challenge infection with Listeria monocytogenes. Unexpectedly, the attenuated growth in vivo of the CMV vector expressing RAE-1γ and its capacity to enhance specific CD8 T-cell response were preserved even in mice lacking NKG2D, implying additional immune function for RAE-1γ beyond engagement of NKG2D. Thus, vectors expressing RAE-1γ represent a promising approach in the development of CD8 T-cell-based vaccines.

Vaccination against lymphocytic choriomeningitis virus infection in MHC class II-deficient mice

DEFF Research Database (Denmark)

Holst, Peter Johannes; Christensen, Jan Pravsgaard; Thomsen, Allan Randrup

2011-01-01

response could be elicited in MHC class II-deficient mice by vaccination with adenovirus encoding lymphocytic choriomeningitis virus (LCMV) glycoprotein tethered to MHC class II-associated invariant chain. Moreover, the response induced conferred significant cytolytic CD8(+) T cell-mediated protection...... against challenge with a high dose of the invasive clone 13 strain of LCMV. In contrast, vaccination with adenovirus encoding unlinked LCMV glycoprotein induced weak virus control in the absence of CD4(+) T cells, and mice may die of increased immunopathology associated with incomplete protection. Acute...... mortality was not observed in any vaccinated mice following infection with the less-invasive Traub strain. However, LCMV Traub infection caused accelerated late mortality in unvaccinated MHC class II-deficient mice; in this case, we observed a strong trend toward delayed mortality in vaccinated mice...

CD8 Knockout Mice Are Protected from Challenge by Vaccination with WR201, a Live Attenuated Mutant of Brucella melitensis

Directory of Open Access Journals (Sweden)

Samuel L. Yingst

2013-01-01

Full Text Available CD8+ T cells have been reported to play an important role in defense against B. abortus infection in mouse models. In the present report, we use CD8 knockout mice to further elucidate the role of these cells in protection from B. melitensis infection. Mice were immunized orally by administration of B. melitensis WR201, a purine auxotrophic attenuated vaccine strain, then challenged intranasally with B. melitensis 16M. In some experiments, persistence of WR201 in the spleens of CD8 knockout mice was slightly longer than that in the spleens of normal mice. However, development of anti-LPS serum antibody, antigen-induced production of γ-interferon (IFN-γ by immune splenic lymphocytes, protection against intranasal challenge, and recovery of nonimmunized animals from intranasal challenge were similar between normal and knockout animals. Further, primary Brucella infection was not exacerbated in perforin knockout and Fas-deficient mice and these animals’ anti-Brucella immune responses were indistinguishable from those of normal mice. These results indicate that CD8+ T cells do not play an essential role as either cytotoxic cells or IFN-γ producers, yet they do participate in a specific immune response to immunization and challenge in this murine model of B. melitensis infection.

The Acute Phase of Trypanosoma cruzi Infection Is Attenuated in 5-Lipoxygenase-Deficient Mice

Directory of Open Access Journals (Sweden)

Adriana M. C. Canavaci

2014-01-01

Full Text Available In the present work we examine the contribution of 5-lipoxygenase- (5-LO- derived lipid mediators to immune responses during the acute phase of Trypanosoma cruzi infection in 5-LO gene knockout (5-LO−/− mice and wild-type (WT mice. Compared with WT mice, the 5-LO−/− mice developed less parasitemia/tissue parasitism, less inflammatory cell infiltrates, and a lower mortality. This resistance of 5-LO−/− mice correlated with several differences in the immune response to infection, including reduced PGE2 synthesis; sustained capacity of splenocytes to produce high levels of interleukin (IL-12 early in the infection; enhanced splenocyte production of IL-1β, IL-6, and IFN-γ; rapid T-cell polarization to secrete high quantities of IFN-γ and low quantities of IL-10; and greater numbers of CD8+CD44highCD62Llow memory effector T cells at the end of the acute phase of infection. The high mortality in WT mice was associated with increased production of LTB4/LTC4, T cell bias to produce IFN-γ, high levels of serum nitrite, and marked protein extravasation into the peritoneal cavity, although survival was improved by treatment with a cys-LT receptor 1 antagonist. These data also provide evidence that 5-LO-derived mediators negatively affect host survival during the acute phase of T. cruzi infection.

Single-epitope DNA vaccination prevents exhaustion and facilitates a broad antiviral CD8+ T cell response during chronic viral infection

DEFF Research Database (Denmark)

Bartholdy, Christina; Stryhn, Anette; Christensen, Jan Pravsgaard

2004-01-01

Induction of a monospecific antiviral CD8+ T cell response may pose a risk to the host due to the narrow T cell response induced. At the individual level, this may result in selection of CD8+ T cell escape variants, particularly during chronic viral infection. Second, prior immunization toward a ...... with escape variants. These findings underscore that a monospecific vaccine may induce efficient protective immunity given the right set of circumstances....... of DNA vaccines encoding immunodominant epitopes of lymphocytic choriomeningitis virus (LCMV). We analyzed the spectrum of the CD8+ T cell response and the susceptibility to infection in H-2(b) and H-2(d) mice. Priming for a monospecific, CD8+ T cell response did not render mice susceptible to viral...... variants. Thus, vaccinated mice were protected against chronic infection with LCMV, and no evidence indicating biologically relevant viral escape was obtained. In parallel, a broad and sustained CD8+ T cell response was generated upon infection, and in H-2(d) mice epitope spreading was observed. Even after...

CD4+ T regulatory cells from the colonic lamina propria of normal mice inhibit proliferation of enterobacteria-reactive, disease-inducing Th1-cells from scid mice with colitis

DEFF Research Database (Denmark)

Gad, M; Brimnes, J; Claesson, Mogens Helweg

2003-01-01

Adoptive transfer of CD4+ T cells into scid mice leads to a chronic colitis in the recipients. The transferred CD4+ T cells accumulate in the intestinal lamina propria (LP), express an activated Th1 phenotype and proliferate vigorously when exposed ex vivo to enteric bacterial antigens. As LP CD4......+ T cells from normal BALB/c mice do not respond to enteric bacterial antigens, we have investigated whether colonic LP-derived CD4+ T cells from normal mice suppress the antibacterial response of CD4+ T cells from scid mice with colitis. LP-derived CD4+ T cells cocultured with bone marrow......-derived dendritic cells effectively suppress the antibacterial proliferative response of CD4+ T cells from scid mice with colitis. The majority of these LP T-reg cells display a nonactivated phenotype and suppression is independent of antigen exposure, is partly mediated by soluble factor(s) different from IL-10...

Antibody response is required for protection from Theiler's virus-induced encephalitis in C57BL/6 mice in the absence of CD8+ T cells

International Nuclear Information System (INIS)

Kang, B.-S.; Palma, Joann P.; Lyman, Michael A.; Dal Canto, Mauro; Kim, Byung S.

2005-01-01

Intracerebral infection of susceptible mice with Theiler's murine encephalomyelitis virus (TMEV) induces immune-mediated demyelinating disease and this system serves as a relevant infectious model for human multiple sclerosis. It was previously shown that β 2 M-deficient C57BL/6 mice lacking functional CD8 + T cells display increased viral persistence and enhanced susceptibility to TMEV-induced demyelination, and yet the majority of mice are free of clinical signs. To understand the mechanisms involved in this general resistance of C57BL/6 mice in the absence of CTL responses, mice (μMT) deficient in the B-cell compartment lacking membrane IgM molecules were treated with anti-CD8 antibody and then infected with TMEV. Although little difference in the proliferative responses of peripheral T cells to UV-inactivated TMEV and the resistance to demyelinating disease was observed between virus-infected μMT and control B6 mice, the levels of CD4 + T cells were higher in the CNS of μMT mice. However, after treatment with anti-CD8 antibody, 100% of the mice displayed clinical gray matter disease and prolonged viral persistence in μMT mice, while only 10% of B6 mice showed clinical symptoms and very low viral persistence. Transfusion of sera from TMEV-infected B6 mice into anti-CD8 antibody-treated μMT mice partially restored resistance to virus-induced encephalitis. These results indicate that the early anti-viral antibody response is also important in the protection from TMEV-induced encephalitis particularly in the absence of CD8 + T cells

Depletion of CD4+ T cells precipitates immunopathology in immunodeficient mice infected with a noncytocidal virus

DEFF Research Database (Denmark)

Christensen, Jan Pravsgaard; Bartholdy, C; Wodarz, D

2001-01-01

investigated whether CD4(+) Th cells are required to establish and maintain this new equilibrium. The absence of IFN-gamma does not impair the generation of IL-2-producing CD4(+) cells, and depletion of these cells precipitates severe CD8(+) T cell-mediated immunopathology in IFN-gamma(-/-) mice, indicating...... an important role of CD4(+) T cells in preventing this syndrome. Analysis of organ virus levels revealed a further impairment of virus control in IFN-gamma(-/-) mice following CD4(+) cell depletion. Initially the antiviral CTL response did not require CD4(+) cells, but with time an impaired reactivity toward...... especially the glycoprotein 33--41 epitope was noted. Enumeration of epitope-specific (glycoprotein 33--41 and nucleoprotein 396--404) CD8(+) T cells by use of tetramers gave similar results. Finally, limiting dilution analysis of CTL precursors reveal an impaired capacity to sustain this population in CD4...

Music exposure induced prolongation of cardiac allograft survival and generated regulatory CD4⁺ cells in mice.

Science.gov (United States)

Uchiyama, M; Jin, X; Zhang, Q; Amano, A; Watanabe, T; Niimi, M

2012-05-01

In clinical practice, music has been used to decrease stress, heart rate, and blood pressure and to provide a distraction from disease symptoms. We investigated sound effects on alloimmune responses in murine heart transplantation. Naïve and eardrum-ruptured CBA/N (CBA, H2(K)) underwent transplantation of a C57BL/6 (B6, H2(b)) heart and were exposed to 1 of 3 types of music-opera (La Traviata), classical (Mozart), and New Age (Enya)-or 1 of 6 different single sound frequencies for 7 days. An adoptive transfer study was performed to determine whether regulatory cells were generated in allograft recipients. Cell-proliferation, cytokine, and flow cytometry assessments were also performed. CBA recipients of a B6 graft exposed to opera and classical music had significantly prolonged allograft survival (median survival times [MSTs], 26.5 and 20 days, respectively), whereas those exposed to 6 single sound frequencies and New Age did not (MSTs, 7, 8, 9, 8, 8, 8, and 11 days, respectively). Untreated and eardrum-ruptured CBA rejected B6 grafts acutely (MSTs, 7 and 8.5 days, respectively). Adoptive transfer of whole splenocytes, CD4(+) cells, and CD4(+)CD25(+) cells from opera-exposed primary recipients resulted in significantly prolonged allograft survival in naive secondary recipients (MSTs, 36, 68, and >50 days, respectively). Cell-proliferation, interleukin (IL)-2 and interferon-γ were suppressed in opera-exposed mice, whereas IL-4 and IL-10 from opera-exposed recipients were up-regulated. Flow cytometry studies showed an increased CD4(+)CD25(+)Foxp3(+) cell population in splenocytes from opera-exposed mice. In conclusion, exposure to some types of music may induce prolonged survival of fully allogeneic cardiac allografts and generate CD4(+)CD25(+)Foxp3(+) regulatory cells. Copyright © 2012 Elsevier Inc. All rights reserved.

Inhibition of HIV transmission in human cervicovaginal explants and humanized mice using CD4 aptamer-siRNA chimeras

Science.gov (United States)

Wheeler, Lee Adam; Trifonova, Radiana; Vrbanac, Vladimir; Basar, Emre; McKernan, Shannon; Xu, Zhan; Seung, Edward; Deruaz, Maud; Dudek, Tim; Einarsson, Jon Ivar; Yang, Linda; Allen, Todd M.; Luster, Andrew D.; Tager, Andrew M.; Dykxhoorn, Derek M.; Lieberman, Judy

2011-01-01

The continued spread of the HIV epidemic underscores the need to interrupt transmission. One attractive strategy is a topical vaginal microbicide. Sexual transmission of herpes simplex virus type 2 (HSV-2) in mice can be inhibited by intravaginal siRNA application. To overcome the challenges of knocking down gene expression in immune cells susceptible to HIV infection, we used chimeric RNAs composed of an aptamer fused to an siRNA for targeted gene knockdown in cells bearing an aptamer-binding receptor. Here, we showed that CD4 aptamer-siRNA chimeras (CD4-AsiCs) specifically suppress gene expression in CD4+ T cells and macrophages in vitro, in polarized cervicovaginal tissue explants, and in the female genital tract of humanized mice. CD4-AsiCs do not activate lymphocytes or stimulate innate immunity. CD4-AsiCs that knock down HIV genes and/or CCR5 inhibited HIV infection in vitro and in tissue explants. When applied intravaginally to humanized mice, CD4-AsiCs protected against HIV vaginal transmission. Thus, CD4-AsiCs could be used as the active ingredient of a microbicide to prevent HIV sexual transmission. PMID:21576818

Impaired immune responses in the lungs of aged mice following influenza infection

Directory of Open Access Journals (Sweden)

Toapanta Franklin R

2009-11-01

Full Text Available Abstract Background Each year, influenza virus infection causes severe morbidity and mortality, particularly in the most susceptible groups including children, the elderly (>65 years-old and people with chronic respiratory diseases. Among the several factors that contribute to the increased susceptibility in elderly populations are the higher prevalence of chronic diseases (e.g. diabetes and the senescence of the immune system. Methods In this study, aged and adult mice were infected with sublethal doses of influenza virus (A/Puerto Rico/8/1934. Differences in weight loss, morbidity, virus titer and the kinetics of lung infiltration with cells of the innate and adaptive immune responses were analyzed. Additionally, the main cytokines and chemokines produced by these cells were also assayed. Results Compared to adult mice, aged mice had higher morbidity, lost weight more rapidly, and recovered more slowly from infection. There was a delay in the accumulation of granulocytic cells and conventional dendritic cells (cDCs, but not macrophages in the lungs of aged mice compared to adult animals. The delayed infiltration kinetics of APCs in aged animals correlated with alteration in their activation (CD40 expression, which also correlated with a delayed detection of cytokines and chemokines in lung homogenates. This was associated with retarded lung infiltration by natural killer (NK, CD4+ and CD8+ T-cells. Furthermore, the percentage of activated (CD69+ influenza-specific and IL-2 producer CD8+ T-cells was higher in adult mice compared to aged ones. Additionally, activation (CD69+ of adult B-cells was earlier and correlated with a quicker development of neutralizing antibodies in adult animals. Conclusion Overall, alterations in APC priming and activation lead to delayed production of cytokines and chemokines in the lungs that ultimately affected the infiltration of immune cells following influenza infection. This resulted in delayed activation of the

Influenza A facilitates sensitization to house dust mite in infant mice leading to an asthma phenotype in adulthood

KAUST Repository

Al-Garawi, A

2011-08-31

The origins of allergic asthma, particularly in infancy, remain obscure. Respiratory viral infections and allergen sensitization in early life have been associated with asthma in young children. However, a causal link has not been established. We investigated whether an influenza A infection in early life alters immune responses to house dust mite (HDM) and promotes an asthmatic phenotype later in life. Neonatal (8-day-old) mice were infected with influenza virus and 7 days later, exposed to HDM for 3 weeks. Unlike adults, neonatal mice exposed to HDM exhibited negligible immune responsiveness to HDM, but not to influenza A. HDM responsiveness in adults was associated with distinct Ly6c + CD11b + inflammatory dendritic cell and CD8α + plasmacytoid (pDC) populations that were absent in HDM-exposed infant mice, suggesting an important role in HDM-mediated inflammation. Remarkably, HDM hyporesponsiveness was overcome when exposure occurred concurrently with an acute influenza infection; young mice now displayed robust allergen-specific immunity, allergic inflammation, and lung remodeling. Remodeling persisted into early adulthood, even after prolonged discontinuation of allergen exposure and was associated with marked impairment of lung function. Our data demonstrate that allergen exposure coincident with acute viral infection in early life subverts constitutive allergen hyporesponsiveness and imprints an asthmatic phenotype in adulthood.

Ultra-low dose of Mycobacterium tuberculosis aerosol creates partial infection in mice.

Science.gov (United States)

Saini, Divey; Hopkins, Gregory W; Seay, Sarah A; Chen, Ching-Ju; Perley, Casey C; Click, Eva M; Frothingham, Richard

2012-03-01

A murine low dose (LD) aerosol model is commonly used to test tuberculosis vaccines. Doses of 50-400 CFU (24h lung CFU) infect 100% of exposed mice. The LD model measures progression from infection to disease based on organ CFU at defined time points. To mimic natural exposure, we exposed mice to an ultra-low dose (ULD) aerosol. We estimated the presented dose by sampling the aerosol. Female C57BL/6 mice were exposed to Mycobacterium tuberculosis H37Rv aerosol at 1.0, 1.1, 1.6, 5.4, and 11 CFU presented dose, infecting 27%, 36%, 36%, 100%, and 95% of mice, respectively. These data are compatible with a stochastic infection event (Poisson distribution, weighted R(2)=0.97) or with a dose-response relationship (sigmoid distribution, weighted R(2)=0.97). Based on the later assumption, the ID50 was 1.6CFU presented dose (95% confidence interval, 1.2-2.1). We compared organ CFU after ULD and LD aerosols (5.4 vs. 395CFU presented dose). Lung burden was 30-fold lower in the ULD model at 4 weeks (3.4 vs. 4.8 logs, pLD aerosols had greater within-group CFU variability. Exposure to ULD aerosols leads to infection in a subset of mice, and to persistently low organ CFU. The ULD aerosol model may resemble human pulmonary tuberculosis more closely than the standard LD model, and may be used to identify host or bacterial factors that modulate the initial infection event. Copyright © 2011 Elsevier Ltd. All rights reserved.

CD4+CD25hiFOXP3+ cells in cord blood of neonates born from filaria infected mother are negatively associated with CD4+Tbet+ and CD4+RORγt+ T cells.

Science.gov (United States)

Ateba-Ngoa, Ulysse; Mombo-Ngoma, Ghyslain; Zettlmeissl, Eva; van der Vlugt, Luciën E P M; de Jong, Sanne E; de Jong, Sanne; Matsiegui, Pierre-Blaise; Ramharter, Michael; Kremsner, Peter G; Yazdanbakhsh, Maria; Adegnika, Ayola Akim

2014-01-01

Children who have been exposed in utero to maternal filarial infection are immunologically less responsive to filarial antigens, have less pathology, and are more susceptible to acquire infection than offspring of uninfected mothers. Moreover children from filaria infected mothers have been shown to be less responsive to vaccination as a consequence of an impairment of their immune response. However, it is not well known how in utero exposure to parasite antigens affects cellular immune responses. Here, 30 pregnant women were examined for the presence of microfilaria of Loa loa and Mansonella perstans in peripheral blood. At delivery, cord blood mononuclear cells (CBMC) were obtained and the CD4+T cells were phenotyped by expression of the transcription factors Tbet, RORγt, and FOXP3. No significant difference was observed between newborns from infected versus uninfected mothers in the frequencies of total CD4+T cells and CD4+T cells subsets including CD4+Tbet+, CD4+RORγt+ T and CD4+CD25hiFOXP3+ T cells. However, there was a negative association between CD4+CD25hiFOXP3+T cells and CD4+Tbet+ as well as CD4+RORγt+ T cells in the infected group only (B = -0.242, P = 0.002; B = -0.178, P = 0.013 respectively). Our results suggest that filarial infection during pregnancy leads to an expansion of functionally active regulatory T cells that keep TH1 and TH17 in check.

CD11c controls herpes simplex virus 1 responses to limit virus replication during primary infection.

Science.gov (United States)

Allen, Sariah J; Mott, Kevin R; Chentoufi, Aziz A; BenMohamed, Lbachir; Wechsler, Steven L; Ballantyne, Christie M; Ghiasi, Homayon

2011-10-01

CD11c is expressed on the surface of dendritic cells (DCs) and is one of the main markers for identification of DCs. DCs are the effectors of central innate immune responses, but they also affect acquired immune responses to infection. However, how DCs influence the efficacy of adaptive immunity is poorly understood. Here, we show that CD11c(+) DCs negatively orchestrate both adaptive and innate immunity against herpes simplex virus type 1 (HSV-1) ocular infection. The effectiveness and quantity of virus-specific CD8(+) T cell responses are increased in CD11c-deficient animals. In addition, the levels of CD83, CD11b, alpha interferon (IFN-α), and IFN-β, but not IFN-γ, were significantly increased in CD11c-deficient animals. Higher levels of IFN-α, IFN-β, and CD8(+) T cells in the CD11c-deficient mice may have contributed to lower virus replication in the eye and trigeminal ganglia (TG) during the early period of infection than in wild-type mice. However, the absence of CD11c did not influence survival, severity of eye disease, or latency. Our studies provide for the first time evidence that CD11c expression may abrogate the ability to reduce primary virus replication in the eye and TG via higher activities of type 1 interferon and CD8(+) T cell responses.

Trichomonas vaginalis infection induces vaginal CD4+ T-cell infiltration in a mouse model: a vaccine strategy to reduce vaginal infection and HIV transmission.

Science.gov (United States)

Smith, Jeffrey D; Garber, Gary E

2015-07-15

Complications related to the diagnosis and treatment of Trichomonas vaginalis infection, as well as the association between T. vaginalis infection and increased transmission of and susceptibility to human immunodeficiency virus, highlight the need for alternative interventions. We tested a human-safe, aluminum hydroxide-adjuvanted whole-cell T. vaginalis vaccine for efficacy in a BALB/c mouse model of vaginal infection. A whole-cell T. vaginalis vaccine was administered subcutaneously to BALB/c mice, using a prime-boost vaccination schedule. CD4(+) T-cell infiltration in the murine vaginal tissue and local and systemic levels of immunoglobulins were measured at time points up to 4 weeks following infection. Vaccination reduced the incidence and increased the clearance of T. vaginalis infection and induced both systemic and local humoral immune responses. CD4(+) T cells were detected in vaginal tissues following intravaginal infection with T. vaginalis but were not seen in uninfected mice. The presence of CD4(+) T cells following T. vaginalis infection can potentially increase susceptibility to and transmission of human immunodeficiency virus. The vaccine induces local and systemic immune responses and confers significantly greater protection against vaginal infection than seen in unvaccinated mice (P infection that could also influence the incidence of human immunodeficiency virus infection. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Experimental infection of Balb/c nude mice with Hepatitis E virus

Directory of Open Access Journals (Sweden)

Zhu Jianguo

2009-06-01

Full Text Available Abstract Background Several animal species can reportedly act as reservoirs for Hepatitis E virus (HEV, a zoonotic pathogen. HEV and antibody to the virus have been detected in a variety of animals including rodents. Pig and rat models for HEV have been established for HEV, but a nude mouse has not yet been developed. Methods Balb/c nude mice were inoculated with swine HEV, both orally and via intravenous injection to insure infection. Negative control and experimental contact-exposed groups of mice were also included in the study. The liver, spleen, kidney, jejunum, ileum, cecum and colon of each mouse from all three groups were collected for reverse transcription nested polymerase chain reaction (RT-nPCR detection, indirect immunofluorescence observation and histopathologic examination. The sera from nude mice were tested for anti-HEV IgG by enzyme linked immunosorbent assay (ELISA. Activities of liver enzymes, including alanine aminotransferase (ALT, aspartate aminotransferase (AST and alkaline phosphatase (ALP, as well as total bilirubin (TBIL were also measured in the sera of the nude mice. Results HEV antigens and HEV RNA were detected in liver, spleen, kidney, jejunum, ileum and colon both by indirect immunofluorescence and by RT-nPCR in all of the inoculated and in one of the contact-exposed nude mice. Histopathological changes were observed in the liver and spleen of these mice. Infected mice showed increased levels of AST, ALP, and anti-HEV IgG in sera. The livers of contact-exposed mice showed obvious histopathological damage. Conclusion Nude mice could be readily infected by HEV isolated from pigs. The nude mouse may therefore be a useful animal model for studying the pathogenesis of HEV.

T-cell-dependent control of acute Giardia lamblia infections in mice.

Science.gov (United States)

Singer, S M; Nash, T E

2000-01-01

We have studied immune mechanisms responsible for control of acute Giardia lamblia and Giardia muris infections in adult mice. Association of chronic G. lamblia infection with hypogammaglobulinemia and experimental infections of mice with G. muris have led to the hypothesis that antibodies are required to control these infections. We directly tested this hypothesis by infecting B-cell-deficient mice with either G. lamblia or G. muris. Both wild-type mice and B-cell-deficient mice eliminated the vast majority of parasites between 1 and 2 weeks postinfection with G. lamblia. G. muris was also eliminated in both wild-type and B-cell-deficient mice. In contrast, T-cell-deficient and scid mice failed to control G. lamblia infections, as has been shown previously for G. muris. Treatment of wild-type or B-cell-deficient mice with antibodies to CD4 also prevented elimination of G. lamblia, confirming a role for T cells in controlling infections. By infecting mice deficient in either alphabeta- or gammadelta-T-cell receptor (TCR)-expressing T cells, we show that the alphabeta-TCR-expressing T cells are required to control parasites but that the gammadelta-TCR-expressing T cells are not. Finally, infections in mice deficient in production of gamma interferon or interleukin 4 (IL-4) and mice deficient in responding to IL-4 and IL-13 revealed that neither the Th1 nor the Th2 subset is absolutely required for protection from G. lamblia. We conclude that a T-cell-dependent mechanism is essential for controlling acute Giardia infections and that this mechanism is independent of antibody and B cells.

Human CD141+ Dendritic Cell and CD1c+ Dendritic Cell Undergo Concordant Early Genetic Programming after Activation in Humanized Mice In Vivo

Directory of Open Access Journals (Sweden)

Yoshihito Minoda

2017-10-01

Full Text Available Human immune cell subsets develop in immunodeficient mice following reconstitution with human CD34+ hematopoietic stem cells. These “humanized” mice are useful models to study human immunology and human-tropic infections, autoimmunity, and cancer. However, some human immune cell subsets are unable to fully develop or acquire full functional capacity due to a lack of cross-reactivity of many growth factors and cytokines between species. Conventional dendritic cells (cDCs in mice are categorized into cDC1, which mediate T helper (Th1 and CD8+ T cell responses, and cDC2, which mediate Th2 and Th17 responses. The likely human equivalents are CD141+ DC and CD1c+ DC subsets for mouse cDC1 and cDC2, respectively, but the extent of any interspecies differences is poorly characterized. Here, we exploit the fact that human CD141+ DC and CD1c+ DC develop in humanized mice, to further explore their equivalency in vivo. Global transcriptome analysis of CD141+ DC and CD1c+ DC isolated from humanized mice demonstrated that they closely resemble those in human blood. Activation of DC subsets in vivo, with the TLR3 ligand poly I:C, and the TLR7/8 ligand R848 revealed that a core panel of genes consistent with DC maturation status were upregulated by both subsets. R848 specifically upregulated genes associated with Th17 responses by CD1c+ DC, while poly I:C upregulated IFN-λ genes specifically by CD141+ DC. MYCL expression, known to be essential for CD8+ T cell priming by mouse DC, was specifically induced in CD141+ DC after activation. Concomitantly, CD141+ DC were superior to CD1c+ DC in their ability to prime naïve antigen-specific CD8+ T cells. Thus, CD141+ DC and CD1c+ DC share a similar activation profiles in vivo but also have induce unique signatures that support specialized roles in CD8+ T cell priming and Th17 responses, respectively. In combination, these data demonstrate that humanized mice provide an attractive and tractable model to study

Splenic CD11clowCD45RBhigh dendritic cells derived from endotoxin-tolerant mice attenuate experimental acute liver failure

Science.gov (United States)

Zhang, Sai-Nan; Yang, Nai-Bin; Ni, Shun-Lan; Dong, Jin-Zhong; Shi, Chun-Wei; Li, Shan-Shan; Zhang, Sheng-Guo; Tang, Xin-Yue; Lu, Ming-Qin

2016-01-01

Endotoxin tolerance (ET) is suggested to attenuate the severity of acute liver failure (ALF) in mice, possibly through both innate and adaptive immunity. However, the involvement of regulatory dendritic cells (DCregs) in ET has not been fully elucidated. In this study, their effect on ALF in mice was investigated. Splenic DCregs from ET-exposed mice (ET-DCregs) showed lower expression levels of CD40, CD80, and MHC-II markers and stronger inhibition of allogenic T cells and regulation of IL-10 and IL-12 secretion than splenic DCregs from normal mice (nDCregs). Moreover, the mRNA and protein levels of TNF-α and P65 in splenic ET-DCregs were significantly lower than those in the splenic nDCregs. The survival rate was significantly increased and liver injury was mitigated in mice with ALF treated with splenic ET-DCregs. In addition, A20 expression was decreased in the liver of ALF mice, but elevated after infusion of splenic nDCregs and ET-DCregs, and a much higher elevation was observed after infusing the latter cells. The functionality of splenic DCregs was altered after ET exposure, contributing to protection of the livers against D-GalN/LPS-induced ALF. PMID:27625297

Evaluation of CD4+/CD8+ status and urinary tract infections ...

African Journals Online (AJOL)

Evaluation of CD4+/CD8+ status and urinary tract infections associated with urinary schistosomiasis ... African Health Sciences ... by <50 ova /10ml of urine had a mean CD4+:CD8+ ratio of 1.57 while those with heavy infections as ... Key words: CD4+, CD8+, urinary tract infections, urinary schistosomiasis, rural Nigerians

Biochemical and Parasitological Studies on the Effect of hUCB-Selected CD34+ Progenitor/Stem Cells in Mice Infected with Schistosoma mansoni

Science.gov (United States)

Abou-Zied, Akram M.; Soliman, Rasha H.; Hefila, Shorouk M.; Imam, Samir A.

2014-01-01

Background and Objectives: Placenta and blood that remained in the umbilical cord is routinely available as a discarded tissue after deliveries and it is free of any legal, moral, ethical or religious objections, providing a high number of multipotent CD34+ progenitor and stem cells. Using ex vivo isolated CD34+ cells from human umbilical cord blood (hUCB) have emerged as promising candidates to treat various diseases, including exogenous pathogenic infections. We have expanded to build a rational approach to study the effect of CD34+ cells after damaged liver tissues by the devastating human parasitic flatworm Schistosoma mansoni. Methods and Results: Experimental studies were conducted in the Department of Zoology, Faculty of Science and Departments of Parasitology and Physiology, Faculty of Medicine, SCU, Egypt. We have studied the impact of ex vivo preparation of CD34+ cells from hUCB on S. mansoni-induced liver fibrosis de novo, and treated for shorter and longer periods in vivo. Ova count, ALT and albumin were measured at specific time interval and histopathological examination of liver was conducted to confirm the biochemical results. The data obtained were statistically analyzed by ANOVA between groups. It was found that the administration of CD34+ cells have modestly reduced liver damage; reduced the S. mansoni infection associated elevation in serum levels of ALT; significantly improved serum levels of albumin and reduced egg granuloma diameter in the livers. Conclusions: We demonstrated that CD34+ cells can markedly ameliorated liver fibrosis in vivo and may be beneficial for therapy to recover organ structure and/or function of S. mansoni-infected mice. PMID:25473447

Engagement of NKG2D on bystander memory CD8 T cells promotes increased immunopathology following Leishmania major infection.

Directory of Open Access Journals (Sweden)

Erika J Crosby

2014-02-01

Full Text Available One of the hallmarks of adaptive immunity is the development of a long-term pathogen specific memory response. While persistent memory T cells certainly impact the immune response during a secondary challenge, their role in unrelated infections is less clear. To address this issue, we utilized lymphocytic choriomeningitis virus (LCMV and Listeria monocytogenes immune mice to investigate whether bystander memory T cells influence Leishmania major infection. Despite similar parasite burdens, LCMV and Listeria immune mice exhibited a significant increase in leishmanial lesion size compared to mice infected with L. major alone. This increased lesion size was due to a severe inflammatory response, consisting not only of monocytes and neutrophils, but also significantly more CD8 T cells. Many of the CD8 T cells were LCMV specific and expressed gzmB and NKG2D, but unexpectedly expressed very little IFN-γ. Moreover, if CD8 T cells were depleted in LCMV immune mice prior to challenge with L. major, the increase in lesion size was lost. Strikingly, treating with NKG2D blocking antibodies abrogated the increased immunopathology observed in LCMV immune mice, showing that NKG2D engagement on LCMV specific memory CD8 T cells was required for the observed phenotype. These results indicate that bystander memory CD8 T cells can participate in an unrelated immune response and induce immunopathology through an NKG2D dependent mechanism without providing increased protection.

CD3+CD8+CD161high Tc17 cells are depleted in HIV-infection

DEFF Research Database (Denmark)

Gaardbo, Julie Christine; Hartling, Hans Jakob; Thorsteinsson, Kristina

2012-01-01

CD8+ Tc17 cells with pro-inflammatory properties have only recently been acknowledged, and Tc17 cells in HIV-infection are undescribed. CD3+CD8+CD161 Tc17 cells and the production of Interleukin-17 were examined in untreated and treated HIV-infected patients, HIV-HCV co-infected patients...... and healthy controls. Depletion of CD3+CD8+CD161 Tc17 cells and diminished production of Interleukin-17 in HIV-infected patients was found. The level of Tc17 cells was associated with the level of the CD4+ count in treated patients....

MicroRNA-155 knockout mice are susceptible to Mycobacterium tuberculosis infection.

Science.gov (United States)

Iwai, Hiroki; Funatogawa, Keiji; Matsumura, Kazunori; Kato-Miyazawa, Masako; Kirikae, Fumiko; Kiga, Kotaro; Sasakawa, Chihiro; Miyoshi-Akiyama, Tohru; Kirikae, Teruo

2015-05-01

MicroRNAs (miRNAs) are short, conserved, non-coding RNA molecules that repress translation, followed by the decay of miRNA-targeted mRNAs that encode molecules involved in cell differentiation, development, immunity and apoptosis. At least six miRNAs, including microRNA-155 (miR-155), were up-regulated when born marrow-derived macrophages from C57BL/6 mice were infected with Mycobacterium tuberculosis Erdman. C57BL/6 mice intravenously infected with Erdman showed up-regulation of miR-155 in livers and lungs. Following infection, miR-155-deficient C57BL/6 mice died significantly earlier and had significantly higher numbers of CFU in lungs than wild-type mice. Moreover, fewer CD4(+) T cells, but higher numbers of monocytes and neutrophils, were present in the lungs of Erdman-infected miR-155 knockout (miR-155(-/-)) than of wild-type mice. These findings indicated that miR-155 plays a critical role in immune responses to M. tuberculosis. Copyright © 2015 Elsevier Ltd. All rights reserved.

Conventional CD11chigh Dendritic Cells Are Important for T Cell Priming during the Initial Phase of Plasmodium yoelii Infection, but Are Dispensable at Later Time Points.

Science.gov (United States)

Ueffing, Kristina; Abberger, Hanna; Westendorf, Astrid M; Matuschewski, Kai; Buer, Jan; Hansen, Wiebke

2017-01-01

Dendritic cells (DCs) are highly specialized antigen-presenting cells that orchestrate adaptive immune responses to pathogens. During malaria infection pro- and anti-inflammatory T cell responses have to be tightly balanced to ensure parasite clearance without induction of severe immune pathologies. However, the precise role of CD11c high DCs in this process is still discussed controversially. Here, we demonstrate that long-term depletion of conventional CD11c high DCs in Plasmodium yoelii ( P. yoelii )-infected diphtheria toxin (DT)-treated RosaiDTR/CD11c-cre mice interferes with the activation of CD8 + and CD4 + T cells as well as CD4 + Foxp3 + regulatory T cells at early time points during infection. Moreover, systemic levels of the pro-inflammatory cytokines IFN-γ and TNF-α were decreased in P. yoelii -infected mice deficient for CD11c high DCs compared to infected RosaiDTR controls. To further elucidate the importance of CD11c high DCs during the later phase of infection, we treated RosaiDTR/CD11c-cre and control mice with DT only from day 4 of P. yoelii infection onward. Strikingly, this approach had no impact on the activation and IFN-γ production of CD4 + and CD8 + effector T cells. These results indicate that CD11c high DCs play a crucial role in eliciting effector T cell responses during the initial phase, but are dispensable during ongoing infection with P. yoelii .

Conventional CD11chigh Dendritic Cells Are Important for T Cell Priming during the Initial Phase of Plasmodium yoelii Infection, but Are Dispensable at Later Time Points

Directory of Open Access Journals (Sweden)

Kristina Ueffing

2017-10-01

Full Text Available Dendritic cells (DCs are highly specialized antigen-presenting cells that orchestrate adaptive immune responses to pathogens. During malaria infection pro- and anti-inflammatory T cell responses have to be tightly balanced to ensure parasite clearance without induction of severe immune pathologies. However, the precise role of CD11chigh DCs in this process is still discussed controversially. Here, we demonstrate that long-term depletion of conventional CD11chigh DCs in Plasmodium yoelii (P. yoelii-infected diphtheria toxin (DT-treated RosaiDTR/CD11c-cre mice interferes with the activation of CD8+ and CD4+ T cells as well as CD4+Foxp3+ regulatory T cells at early time points during infection. Moreover, systemic levels of the pro-inflammatory cytokines IFN-γ and TNF-α were decreased in P. yoelii-infected mice deficient for CD11chigh DCs compared to infected RosaiDTR controls. To further elucidate the importance of CD11chigh DCs during the later phase of infection, we treated RosaiDTR/CD11c-cre and control mice with DT only from day 4 of P. yoelii infection onward. Strikingly, this approach had no impact on the activation and IFN-γ production of CD4+ and CD8+ effector T cells. These results indicate that CD11chigh DCs play a crucial role in eliciting effector T cell responses during the initial phase, but are dispensable during ongoing infection with P. yoelii.

Reduced infectivity of waterborne viable but nonculturable Helicobacter pylori strain SS1 in mice.

Science.gov (United States)

Boehnke, Kevin F; Eaton, Kathryn A; Fontaine, Clinton; Brewster, Rebecca; Wu, Jianfeng; Eisenberg, Joseph N S; Valdivieso, Manuel; Baker, Laurence H; Xi, Chuanwu

2017-08-01

Helicobacter pylori infection has been consistently associated with lack of access to clean water and proper sanitation, but no studies have demonstrated that the transmission of viable but nonculturable (VBNC) H. pylori can occur from drinking contaminated water. In this study, we used a laboratory mouse model to test whether waterborne VBNCH. pylori could cause gastric infection. We performed five mouse experiments to assess the infectivity of VBNCH. pylori in various exposure scenarios. VBNC viability was examined using Live/Dead staining and Biolog phenotype metabolism arrays. High doses of VBNCH. pylori in water were chosen to test the "worst-case" scenario for different periods of time. One experiment also investigated the infectious capabilities of VBNC SS1 using gavage. Further, immunocompromised mice were exposed to examine infectivity among potentially vulnerable groups. After exposure, mice were euthanized and their stomachs were examined for H. pylori infection using culture and PCR methodology. VBNC cells were membrane intact and retained metabolic activity. Mice exposed to VBNCH. pylori via drinking water and gavage were not infected, despite the various exposure scenarios (immunocompromised, high doses) that might have permitted infection with VBNCH. pylori. The positive controls exposed to viable, culturable H. pylori did become infected. While other studies that have used viable, culturable SS1 via gavage or drinking water exposures to successfully infect mice, in our study, waterborne VBNC SS1 failed to colonize mice under all test conditions. Future studies could examine different H. pylori strains in similar exposure scenarios to compare the relative infectivity of the VBNC vs the viable, culturable state, which would help inform future risk assessments of H. pylori in water. © 2017 The Authors. Helicobacter Published by John Wiley & Sons Ltd.

Administration of kefir-fermented milk protects mice against Giardia intestinalis infection.

Science.gov (United States)

Franco, Mariana Correa; Golowczyc, Marina A; De Antoni, Graciela L; Pérez, Pablo F; Humen, Martín; Serradell, María de los Angeles

2013-12-01

Giardiasis, caused by the protozoan Giardia intestinalis, is one of the most common intestinal diseases worldwide and constitutes an important problem for the public health systems of various countries. Kefir is a probiotic drink obtained by fermenting milk with 'kefir grains', which consist mainly of bacteria and yeasts that coexist in a complex symbiotic association. In this work, we studied the ability of kefir to protect mice from G. intestinalis infection, and characterized the host immune response to this probiotic in the context of the intestinal infection. Six- to 8-week-old C75BL/6 mice were separated into four groups: controls, kefir mice (receiving 1 : 100 dilution of kefir in drinking water for 14 days), Giardia mice (infected orally with 4×10(7) trophozoites of G. intestinalis at day 7) and Giardia-kefir mice (kefir-treated G. intestinalis-infected mice), and killed at 2 or 7 days post-infection. Kefir administration was able to significantly reduce the intensity of Giardia infection at 7 days post-infection. An increase in the percentage of CD4(+) T cells at 2 days post-infection was observed in the Peyer's patches (PP) of mice belonging to the Giardia group compared with the control and kefir groups, while the percentage of CD4(+) T cells in PP in the Giardia-kefir group was similar to that of controls. At 2 days post-infection, a reduction in the percentage of B220-positive major histocompatibility complex class II medium cells in PP was observed in infected mice compared with the other groups. At 7 days post-infection, Giardia-infected mice showed a reduction in RcFcε-positive cells compared with the control group, suggesting a downregulation of the inflammatory response. However, the percentages of RcFcε-positive cells did not differ from controls in the kefir and Giardia-kefir groups. An increase in IgA-positive cells was observed in the lamina propria of the kefir group compared with controls at 2 days post-infection. Interestingly, the

Susceptibility to Entamoeba histolytica intestinal infection is related to reduction in natural killer T-lymphocytes in C57BL/6 mice

Directory of Open Access Journals (Sweden)

Fabrício M.S. Oliveira

2012-04-01

Full Text Available Entamoeba histolytica is a protozoan that causes amoebiasis. Recent studies demonstrated that natural killer T lymphocytes (NKT are critical for preventing the development of amoebic liver abscess. In spite of that, there are only a handful of studies in the area. Herein, we explored the role of NKT cells in E. histolytica infection using C57BL/6 wild-type and CD1-/- mice. Animals were inoculated with E. histolytica and sacrificed 48 hours later to collect caecum samples that were used for quantitative analyses of lesions, trophozoites, NK1.1+ T lymphocytes and expression of the mucus protein MUC-2 by immunohistochemistry technique. Quantitative analyses confirmed that the frequency of NK1.1+ T cells was significantly lower in samples from C57BL/6 CD1-/- mice as compared to their wild type (WT counterparts. The extension of necrotic mucosa was larger and the number of trophozoites higher in Entamoeba (Eh-infected CD1-/- mice when compared with Eh-infected WT mice. In mice from both groups, noninfected (CTRL and Eh-infected CD1-/-, there was a reduction in the thickness of the caecal mucosa and in the MUC-2-stained area in comparison with CTRL- and Eh-WT mice. Our results showed that NKT lymphocytes contribute to resistance against Entamoeba histolytica infection and to the control of inflammation in the colitis induced by infection. The presence of a normal epithelial layer containing appropriate levels of mucus had also a protective role against infection.

CD4(+) T cell-mediated control of a gamma-herpesvirus in B cell-deficient mice is mediated by IFN-gamma

DEFF Research Database (Denmark)

Christensen, Jan Pravsgaard; Cardin, R D; Branum, K C

1999-01-01

The lack of B cells and antibody does not prevent mice from dealing effectively with a pathogenic gamma-herpesvirus. Both CD4(+) and CD8(+) T cells contribute to the control of virus replication in the respiratory tract, with the depletion of either lymphocyte subset leading to increased titers...... for direct interaction with virus-infected targets expressing MHC class II glycoproteins, suggesting that the IFN-gamma produced by these lymphocytes is functioning at short range. The numbers of latently infected cells in the spleens of carrier mice are also significantly increased by the concurrent...

Delayed allogeneic skin graft rejection in CD26-deficient mice.

Science.gov (United States)

Zhao, Xiangli; Zhang, Kai; Daniel, Peter; Wisbrun, Natali; Fuchs, Hendrik; Fan, Hua

2018-03-23

Organ transplantation is an effective therapeutic tool for treating many terminal diseases. However, one of the biggest challenges of transplantation is determining how to achieve the long-term survival of the allogeneic or xenogeneic transplant by, for example, preventing transplant rejection. In the current study, CD26 gene-knockout mice were used to investigate the potential role of CD26/dipeptidyl peptidase-4 (DPPIV) in allogeneic skin graft rejection by tail-skin transplantation. Compared with wild-type (CD26 +/+ ) counterparts, CD26 -/- mice showed reduced necrosis of grafts and delayed graft rejection after skin transplantation. Concentrations of serum IgG, including its subclasses IgG1 and IgG2a, were significantly reduced in CD26 -/- mice during graft rejection. Moreover, after allogeneic skin transplantation, the secretion levels of the cytokines IFN-γ, IL-2, IL-6, IL-4, and IL-13 were significantly reduced, whereas the level of the cytokine IL-10 was increased in the serum of CD26 -/- mice compared with that in the serum of CD26 +/+ mice. Additionally, the concentration of IL-17 in serum and the percentage of cells secreting IL-17 in mouse peripheral blood lymphocytes (MPBLs) were both significantly lower, while the percentage of regulatory T cells (Tregs) was significantly higher in MPBLs of CD26 -/- mice than in those of CD26 +/+ mice. Furthermore, a lower percentage of CD8 + T cells in MPBLs and fewer infiltrated macrophages and T cells in graft tissues of CD26 -/- mice were detected during graft rejection. These results indicate that CD26 is involved in allogeneic skin graft rejection and provides another hint that CD26 deficiency leads to less rejection due to lower activation and proliferation of host immune cells.

Endogenous interleukin-12 is not required for resolution of Chlamydophila abortus (Chlamydia psittaci serotype 1) infection in mice.

Science.gov (United States)

Del Río, L; Buendía, A J; Sánchez, J; Gallego, M C; Caro, M R; Ortega, N; Seva, J; Pallarés, F J; Cuello, F; Salinas, J

2001-08-01

A Th1 immune response involving gamma interferon (IFN-gamma) production is required to eliminate Chlamydophila abortus infections. In this study, the role of interleukin-12 (IL-12) in protecting against C. abortus infection was investigated using IL-12(-/-) and wild-type (WT) C57BL/6 mice to determine the role of this Th1-promoting cytokine. IL-12(-/-) mice were able to eliminate the C. abortus infection in a primary infection. However, there was a delay in the clearance of bacteria when IL-12(-/-) mice were infected with a sublethal dose of C. abortus, the delay being associated with a lower production of IFN-gamma. The low level of IFN-gamma was essential for survival of IL-12(-/-) infected mice. Both WT and IL-12(-/-) mice developed a Th1 immune response against C. abortus infection, since they both produced IFN-gamma and immunoglobulin G2a antibody isotype. In addition, when mice were given a secondary infectious challenge with C. abortus, a protective host response which resolved the secondary infection was developed by both WT and IL-12(-/-) mice. The lack of IL-12 resulted in few infiltrating CD4(+) T cells in the liver relative to the number in WT mice, although the number of CD8(+) T cells was slightly higher. The more intense Th1 response presented by WT mice may have a pathogenic effect, as the animals showed higher morbidity after the infection. In conclusion, these results suggest that although IL-12 expedites the clearance of C. abortus infection, this cytokine is not essential for the establishment of a protective host response against the infection.

Human CD4 restores normal T cell development and function in mice deficient in murine CD4

OpenAIRE

1994-01-01

The ability of a human coreceptor to function in mice was investigated by generating human CD4 (hCD4)-expressing transgenic mice on a mouse CD4-deficient (mCD4-/-) background. From developing thymocyte to matured T lymphocyte functions, hCD4 was shown to be physiologically active. By examining the expansion and deletion of specific V beta T cell families in mutated mice with and without hCD4, it was found that hCD4 can participate in positive and negative selection. Mature hCD4 single positiv...

The Dynamics of Treg/Th17 and the Imbalance of Treg/Th17 in Clonorchis sinensis-Infected Mice

Science.gov (United States)

Hua, Hui; Li, Bo; Zhang, Bo; Yu, Qian; Li, Xiang-Yang; Liu, Ying; Pan, Wei; Liu, Xiang-Ye; Tang, Ren-Xian; Zheng, Kui-Yang

2015-01-01

Clonorchiasis, caused by the liver fluke Clonorchis sinensis, is a chronic parasitic infection regulated by T cell subsets. An imbalance of CD4+CD25+ Foxp3+regulatory T (Treg) and interleukin (IL)-17-secreting T cells (Th17) may control inflammation and play an important role in the pathogenesis of immune evasion. In the present study, we assessed the dynamics of Treg/Th17 and determined whether the Treg/Th17 ratio is altered in C. sinensis-infected mice. The results showed that the percentages of splenic Treg cells in CD4+ T cells were suppressed on day 14 post-infection (PI) but increased on day 56 PI, while Th17 cells were increased on day 56 PI compared with normal control (NC) mice. The Treg/Th17 ratio steadily increased from day 28 to day 56 PI. The hepatic levels of their specific transcription factors (Foxp3 for Treg and RORγt for Th17) were increased in C. sinensis-infected mice from day 14 to 56 PI, and significantly higher than those in NC mice. Meanwhile, serum levels of IL-2 and IL-17 were profoundly increased in C. sinensis-infected mice throughout the experiment; while the concentrations of IL-6 and transforming growth factor β1 (TGF-β1) peaked on day 14 PI, but then decreased on day 28 and 56 PI. Our results provide the first evidence of an increased Treg/Th17 ratio in C. sinensis-infected mice, suggesting that a Treg/Th17 imbalance may play a role in disease outcomes of clonorchiasis. PMID:26599407

Behavioral characterization of CD36 knockout mice with SHIRPA primary screen.

Science.gov (United States)

Zhang, Shuxiao; Wang, Wei; Li, Juan; Cheng, Ke; Zhou, Jingjing; Zhu, Dan; Yang, Deyu; Liang, Zihong; Fang, Liang; Liao, Li; Xie, Peng

2016-02-15

CD36 is a member of the class B scavenger receptor family of cell surface proteins, which plays a major role in fatty acid, glucose and lipid metabolism. Besides, CD36 functions as a microglial surface receptor for amyloid beta peptide. Regarding this, we suggest CD36 might also contribute to neuropsychiatric disease. The aim of this study was to achieve a behavioral phenotype of CD36 knockout (CD36(-/-)) mice. We characterized the behavior of CD36(-/-) mice and C57BL/6J mice by subjecting them to a series of tests, which include SHIRPA primary behavioral screen test, 1% sucrose preference test, elevated plus-maze test, open-field test and forced swimming test. The results showed that CD36(-/-) mice traversed more squares, emitted more defecation, exhibited higher tail elevation and had more aggressive behaviors than C57BL/6J mice. The CD36(-/-) mice spent more time and traveled longer distance in periphery zone in the open-field test. Meanwhile, the numbers that CD36(-/-) mice entered in the open arms of elevated plus-maze were reduced. These findings suggest that CD36(-/-) mice present an anxious phenotype and might be involved in neuropsychiatric disorders. Copyright © 2015. Published by Elsevier B.V.

Alteration of cytokine profiles in mice exposed to chronic low-dose ionizing radiation

Energy Technology Data Exchange (ETDEWEB)

Shin, Suk Chul [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., 388-1, Ssangmun-dong, Dobong-gu, Seoul 132-703 (Korea, Republic of); Lee, Kyung-Mi [Global Research Lab, BAERI Institute, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul 136-705 (Korea, Republic of); Kang, Yu Mi [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., 388-1, Ssangmun-dong, Dobong-gu, Seoul 132-703 (Korea, Republic of); Kim, Kwanghee [Global Research Lab, BAERI Institute, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul 136-705 (Korea, Republic of); Kim, Cha Soon; Yang, Kwang Hee; Jin, Young-Woo [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., 388-1, Ssangmun-dong, Dobong-gu, Seoul 132-703 (Korea, Republic of); Kim, Chong Soon [Department of Nuclear Medicine, Haeundae Paik Hospital, Inje University, Busan 612-030 (Korea, Republic of); Kim, Hee Sun, E-mail: hskimdvm@khnp.co.kr [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., 388-1, Ssangmun-dong, Dobong-gu, Seoul 132-703 (Korea, Republic of)

2010-07-09

While a high-dose of ionizing radiation is generally harmful and causes damage to living organisms, a low-dose of radiation has been shown to be beneficial in a variety of animal models. To understand the basis for the effect of low-dose radiation in vivo, we examined the cellular and immunological changes evoked in mice exposed to low-dose radiation at very low (0.7 mGy/h) and low (3.95 mGy/h) dose rate for the total dose of 0.2 and 2 Gy, respectively. Mice exposed to low-dose radiation, either at very low- or low-dose rate, demonstrated normal range of body weight and complete blood counts. Likewise, the number and percentage of peripheral lymphocyte populations, CD4{sup +} T, CD8{sup +} T, B, or NK cells, stayed unchanged following irradiation. Nonetheless, the sera from these mice exhibited elevated levels of IL-3, IL-4, leptin, MCP-1, MCP-5, MIP-1{alpha}, thrombopoietin, and VEGF along with slight reduction of IL-12p70, IL-13, IL-17, and IFN-{gamma}. This pattern of cytokine release suggests the stimulation of innate immunity facilitating myeloid differentiation and activation while suppressing pro-inflammatory responses and promoting differentiation of naive T cells into T-helper 2, not T-helper 1, types. Collectively, our data highlight the subtle changes of cytokine milieu by chronic low-dose {gamma}-radiation, which may be associated with the functional benefits observed in various experimental models.

Follicular helper T cells promote liver pathology in mice during Schistosoma japonicum infection.

Directory of Open Access Journals (Sweden)

Xiaojun Chen

2014-05-01

Full Text Available Following Schistosoma japonicum (S. japonicum infection, granulomatous responses are induced by parasite eggs trapped in host organs, particular in the liver, during the acute stage of disease. While excessive liver granulomatous responses can lead to more severe fibrosis and circulatory impairment in chronically infected host. However, the exact mechanism of hepatic granuloma formation has remained obscure. In this study, we for the first time showed that follicular helper T (Tfh cells are recruited to the liver to upregulate hepatic granuloma formation and liver injury in S. japonicum-infected mice, and identified a novel function of macrophages in Tfh cell induction. In addition, our results showed that the generation of Tfh cells driven by macrophages is dependent on cell-cell contact and the level of inducible costimulator ligand (ICOSL on macrophages which is regulated by CD40-CD40L signaling. Our findings uncovered a previously unappreciated role for Tfh cells in liver pathology caused by S. japonicum infection in mice.

CD11c-expressing cells affect Treg behavior in the meninges during CNS infection1

Science.gov (United States)

O’Brien, Carleigh A.; Overall, Christopher; Konradt, Christoph; O’Hara Hall, Aisling C.; Hayes, Nikolas W.; Wagage, Sagie; John, Beena; Christian, David A.; Hunter, Christopher A.; Harris, Tajie H.

2017-01-01

Treg cells play an important role in the CNS during multiple infections as well as autoimmune inflammation, but the behavior of this cell type in the CNS has not been explored. In mice, infection with Toxoplasma gondii leads to a Th1-polarized parasite-specific effector T cell response in the brain. Similarly, the Treg cells in the CNS during T. gondii infection are Th1-polarized, exemplified by T-bet, CXCR3, and IFN-γ expression. Unlike effector CD4+ T cells, an MHC Class II tetramer reagent specific for T. gondii did not recognize Treg cells isolated from the CNS. Likewise, TCR sequencing revealed minimal overlap in TCR sequence between effector and regulatory T cells in the CNS. Whereas effector T cells are found in the brain parenchyma where parasites are present, Treg cells were restricted to the meninges and perivascular spaces. The use of intravital imaging revealed that activated CD4+ T cells within the meninges were highly migratory, while Treg cells moved more slowly and were found in close association with CD11c+ cells. To test whether the behavior of Tregs in the meninges is influenced by interactions with CD11c+ cells, mice were treated with anti-LFA-1 antibodies to reduce the number of CD11c+ cells in this space. The anti-LFA-1 treatment led to fewer contacts between Tregs and the remaining CD11c+ cells and increased the speed of Treg cell migration. These data suggest that Treg cells are anatomically restricted within the CNS and the interaction with CD11c+ populations regulates their local behavior during T. gondii infection. PMID:28389591

The Efect of Probiotic Lactobacilli and Alginite on the Cellular Immune Response in Salmonella Infected Mice

Directory of Open Access Journals (Sweden)

Hlubeňová K.

2017-06-01

Full Text Available Alginite is organic matter rich in humic substances and commonly found in nature, but despite that, the knowledge of its biological effects is limited. In our study we focused on monitoring the effects of alginite alone, as well as its effect as a carrier of probiotic lactobacilli on the cellular immune response in SPF mice after infection with Salmonella Typhimurium. Sixty six conventional SPF female mice of the Balb/c line were divided into 4 groups: 1. infection free negative control (NK supplied neither alginite nor probiotic lactobacilli in the feed; 2. infection free alginite control (Alg supplied feed with 10 % alginite; infected control supplied alginite in the feed but no lactobacilli; 3. infectious control (Alg + Sal - animals infected with salmonella and supplied 10 % alginite in the feed but no lactobacilli;and 4. probiotic group (Lab + Alg + Sal - animals infected with salmonella and administered 10 % alginite and Lactobacillus reuteri 2/6 in the feed. On day 21 of the experiments, the mice were bled and their mesenteric lymph nodes were taken after their death. The peripheral blood of the mice was analysed for the activity of phagocytes and the percentage of selected lymphocyte subpopulations was determined in the mesenteric lymph nodes and blood. The significantly highest phagocytic activity (FA was noted in the infected group with alginite (Alg + Sal. The FA was significantly increased in groups Alg and Lab + Alg + Sal in comparison with the NK group. The highest engulfing ability of phagocytes (phagocytic index was observed in the Lab + Alg + Sal group in comparison with other groups, but also in Alg group in comparison with NK. In the Lab + Alg + Sal group, we observed a significantly higher percentage of B-lymphocytes, CD4+CD8+ and natural killer T cells (NKT, but more significant impact on the numbers of subpopulations of lymphocytes was observed in the mesenteric lymph nodes, with the significantly highest proportions of CD4

Exendin-4 improves resistance to Listeria monocytogenes infection in diabetic db/db mice

OpenAIRE

Liu, Hsien Yueh; Chung, Chih-Yao; Yang, Wen-Chin; Liang, Chih-Lung; Wang, Chi-Young; Chang, Chih-Yu; Chang, Cicero Lee-Tian

2012-01-01

The incidence of diabetes mellitus is increasing among companion animals. This disease has similar characteristics in both humans and animals. Diabetes is frequently identified as an independent risk factor for infections associated with increased mortality. In the present study, homozygous diabetic (db/db) mice were infected with Listeria (L.) monocytogenes and then treated with the anti-diabetic drug exendin-4, a glucagon-like peptide 1 analogue. In aged db/db mice, decreased CD11b+ macroph...

Absence of CD4+ T lymphocytes, CD8+ T lymphocytes, or B lymphocytes has different effects on the efficacy of posaconazole and benznidazole in treatment of experimental acute Trypanosoma cruzi infection.

Science.gov (United States)

Ferraz, Marcela L; Gazzinelli, Ricardo T; Alves, Rosana O; Urbina, Julio A; Romanha, Alvaro J

2009-01-01

We investigated the influence of CD4(+) T lymphocytes, CD8(+) T lymphocytes, and B lymphocytes on the efficacy of posaconazole (POS) and the reference drug benznidazole (BZ) during treatment of acute Trypanosoma cruzi infection in a murine model. Wild-type mice infected with T. cruzi and treated with POS or BZ presented no parasitemia, 100% survival, and 86 to 89% cure rates, defined as the percentages of animals with negative hemocultures at the end of the observation period. CD4(+)-T-lymphocyte-knockout (KO) mice infected with T. cruzi and treated with BZ or POS controlled parasitemia during treatment, although circulating parasites reappeared after drug pressure cessation, leading to only a 6% survival rate and no cure. CD8(+)-T-lymphocyte-KO mice infected with T. cruzi and treated with POS or BZ had intermediate results, displaying discrete parasitemia after the treatment was ended, 81 and 86% survival, and cure rates of 31 and 66%, respectively. B-lymphocyte-KO mice infected with T. cruzi and treated with BZ relapsed with parasitemia 1 week after the end of treatment and had a 67% survival rate and only a 22% cure rate. In contrast, the activity of POS was much less affected in these animals, with permanent suppression of parasitemia, 100% survival, and a 71% cure rate. Our results demonstrate that abrogation of different lymphocytes' activities has distinct effects on the efficacy of POS and BZ in this experimental model, probably reflecting different parasite stages preferentially targeted by the two drugs and distinct cooperation patterns with the host immune system.

CD8{sup +}CD25{sup +} T cells reduce atherosclerosis in apoE(−/−) mice

Energy Technology Data Exchange (ETDEWEB)

Zhou, Jianchang; Dimayuga, Paul C.; Zhao, Xiaoning; Yano, Juliana; Lio, Wai Man; Trinidad, Portia; Honjo, Tomoyuki; Cercek, Bojan; Shah, Prediman K.; Chyu, Kuang-Yuh, E-mail: Chyuk@cshs.org

2014-01-17

Highlights: •The role of a sub-population of CD8{sup +} T cells with suppressor functions was investigated in atherosclerosis. •CD8{sup +}CD25{sup +} T cells from adult apoE(−/−) mice had phenotype characteristics of T suppressor cells. •These CD8{sup +}CD25{sup +} T cells reduced CD4{sup +} T cell proliferation and CD8{sup +} cytotoxic activity in vitro. •Adoptive transfer of CD8{sup +}CD25{sup +} T cells significantly reduced atherosclerosis. •CD8{sup +}CD25{sup +} T cells have a suppressive function in atherosclerosis. -- Abstract: Background: It is increasingly evident that CD8{sup +} T cells are involved in atherosclerosis but the specific subtypes have yet to be defined. CD8{sup +}CD25{sup +} T cells exert suppressive effects on immune signaling and modulate experimental autoimmune disorders but their role in atherosclerosis remains to be determined. The phenotype and functional role of CD8{sup +}CD25{sup +} T cells in experimental atherosclerosis were investigated in this study. Methods and results: CD8{sup +}CD25{sup +} T cells were observed in atherosclerotic plaques of apoE(−/−) mice fed hypercholesterolemic diet. Characterization by flow cytometric analysis and functional evaluation using a CFSE-based proliferation assays revealed a suppressive phenotype and function of splenic CD8{sup +}CD25{sup +} T cells from apoE(−/−) mice. Depletion of CD8{sup +}CD25{sup +} from total CD8{sup +} T cells rendered higher cytolytic activity of the remaining CD8{sup +}CD25{sup −} T cells. Adoptive transfer of CD8{sup +}CD25{sup +} T cells into apoE(−/−) mice suppressed the proliferation of splenic CD4{sup +} T cells and significantly reduced atherosclerosis in recipient mice. Conclusions: Our study has identified an athero-protective role for CD8{sup +}CD25{sup +} T cells in experimental atherosclerosis.

TNFα and IFNγ but not perforin are critical for CD8 T cell-mediated protection against pulmonary Yersinia pestis infection.

Science.gov (United States)

Szaba, Frank M; Kummer, Lawrence W; Duso, Debra K; Koroleva, Ekaterina P; Tumanov, Alexei V; Cooper, Andrea M; Bliska, James B; Smiley, Stephen T; Lin, Jr-Shiuan

2014-05-01

Septic pneumonias resulting from bacterial infections of the lung are a leading cause of human death worldwide. Little is known about the capacity of CD8 T cell-mediated immunity to combat these infections and the types of effector functions that may be most effective. Pneumonic plague is an acutely lethal septic pneumonia caused by the Gram-negative bacterium Yersinia pestis. We recently identified a dominant and protective Y. pestis antigen, YopE69-77, recognized by CD8 T cells in C57BL/6 mice. Here, we use gene-deficient mice, Ab-mediated depletion, cell transfers, and bone marrow chimeric mice to investigate the effector functions of YopE69-77-specific CD8 T cells and their relative contributions during pulmonary Y. pestis infection. We demonstrate that YopE69-77-specific CD8 T cells exhibit perforin-dependent cytotoxicity in vivo; however, perforin is dispensable for YopE69-77-mediated protection. In contrast, YopE69-77-mediated protection is severely impaired when production of TNFα and IFNγ by CD8 T cells is simultaneously ablated. Interestingly, TNFα is absolutely required at the time of challenge infection and can be provided by either T cells or non-T cells, whereas IFNγ provided by T cells prior to challenge appears to facilitate the differentiation of optimally protective CD8 T cells. We conclude that cytokine production, not cytotoxicity, is essential for CD8 T cell-mediated control of pulmonary Y. pestis infection and we suggest that assays detecting Ag-specific TNFα production in addition to antibody titers may be useful correlates of vaccine efficacy against plague and other acutely lethal septic bacterial pneumonias.

Protective or deleterious role of scavenger receptors SR-A and CD36 on host resistance to Staphylococcus aureus depends on the site of infection.

Directory of Open Access Journals (Sweden)

Charlène Blanchet

Full Text Available Staphylococcus aureus is a major human opportunistic pathogen responsible for a broad spectrum of infections ranging from benign skin infection to more severe life threatening disorders (e.g. pneumonia, sepsis, particularly in intensive care patients. Scavenger receptors (SR-A and CD36 are known to be involved in S. aureus recognition by immune cells in addition to MARCO, TLR2, NOD2 and α5β1 integrin. In the present study, we further deciphered the contribution of SR-A and CD36 scavenger receptors in the control of infection of mice by S. aureus. Using double SR-A/CD36 knockout mice (S/C-KO and S. aureus strain HG001, a clinically relevant non-mutagenized strain, we showed that the absence of these two scavenger receptors was protective in peritoneal infection. In contrast, the deletion of these two receptors was detrimental in pulmonary infection following intranasal instillation. For pulmonary infection, susceptible mice (S/C-KO had more colony-forming units (CFU in their broncho-alveolar lavages fluids, associated with increased recruitment of macrophages and neutrophils. For peritoneal infection, susceptible mice (wild-type had more CFU in their blood, but recruited less macrophages and neutrophils in the peritoneal cavity than resistant mice. Exacerbated cytokine levels were often observed in the susceptible mice in the infected compartment as well as in the plasma. The exception was the enhanced compartmentalized expression of IL-1β for the resistant mice (S/C-KO after peritoneal infection. A similar mirrored susceptibility to S. aureus infection was also observed for MARCO and TLR2. Marco and tlr2 -/- mice were more resistant to peritoneal infection but more susceptible to pulmonary infection than wild type mice. In conclusion, our results show that innate immune receptors can play distinct and opposite roles depending on the site of infection. Their presence is protective for local pulmonary infection, whereas it becomes detrimental

Effects of iridoid-anthocyanin extract of Cornus mas L. on hematological parameters, population and proliferation of lymphocytes during experimental infection of mice with Trichinella spiralis.

Science.gov (United States)

Piekarska, Jolanta; Szczypka, Marianna; Kucharska, Alicja Z; Gorczykowski, Michał

2018-05-01

The influence of iridoid-anthocyanin aqueous extract of cornelian cherry fruits (CM) on hematological parameters, lymphocyte subsets and proliferation during Trichinella spiralis infection in mice was investigated. CM (100 mg/kg) was administered orally to T. spiralis-infected mice six times within a period encompassing three days prior to the infection and three days after the infection (dai). CM increased the percentage of CD3 + , CD4 + cells and CD4 + /CD8 + ratio and decreased total count of CD8 + and CD19 + splenocytes (5 th dai). An increase in total count of CD4 + , CD3 + , CD19 + splenocytes was observed (21 st dai). CM elevated the percentage of CD4 + cells (7 th dai) and CD4 + /CD8 + ratio (21 st dai) in MLN. CM increased (14 th dai) and then reduced (21 st dai) the percentage of CD8 + MLN lymphocytes and decreased total count of MLN CD8 + cells (21 st dai) and B cells (14 th dai). An activation of lymphocyte proliferation in spleen and simultaneous decrease in MLN on 5 th dai was observed. An increase in red blood cells parameters (5 th dai) and in leukocyte count (7 th dai) was found. A rise in platelet count was noticed both on 5 th and 7 th dai. Moreover, the number of adult T. spiralis on 5 th dai in mice receiving CM extract was lower than in the control mice. These results suggested that iridoid-anthocyanin aqueous extract of CM stimulated murine immune response during T. spiralis infection. Copyright © 2018 Elsevier Inc. All rights reserved.

Effect of adiponectin deficiency on intestinal damage and hematopoietic responses of mice exposed to gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Ponemone, Venkatesh; Fayad, Raja; Gove, Melissa E.; Pini, Maria [Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL 60612 (United States); Fantuzzi, Giamila, E-mail: giamila@uic.edu [Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL 60612 (United States)

2010-08-07

Adiponectin (APN) is an adipose tissue-derived cytokine that regulates insulin sensitivity and inflammation. It is also involved in modulation of cell proliferation by binding to various growth factors. Based on its known effects in modulating cell proliferation and oxidative stress, APN may potentially be involved in regulating tissue damage and repair following irradiation. Adiponectin KO mice and their WT littermates were exposed to a single whole-body dose of 3 or 6 Gy gamma radiation. Radiation-induced alterations were studied in jejunum, blood, bone marrow and thymus at days 1 and 5 post-irradiation and compared with sham-irradiated groups. In WT mice, irradiation did not significantly alter serum APN levels while inducing a significant decrease in serum leptin. Irradiation caused a significant reduction in thymocyte cellularity, with concomitant decrease in CD4{sup +}, CD8{sup +} and CD4{sup +}CD8{sup +} T cell populations, with no significant differences between WT and APN KO mice. Irradiation resulted in a significantly higher increase in the frequency of micronucleated reticulocytes in the blood of APN KO compared with WT mice, whereas frequency of micronucleated normochromatic erythrocytes in the bone marrow at day 5 was significantly higher in WT compared with APN KO mice. Finally, irradiation induced similar alterations in villus height and crypt cell proliferation in the jejunum of WT and APN KO mice. Jejunum explants from sham-irradiated APN KO mice produced higher levels of IL-6 compared with tissue from WT animals, but the difference was no longer apparent following irradiation. Our data indicate that APN deficiency does not play a significant role in modulating radiation-induced gastrointestinal injury in mice, while it may participate in regulation of damage to the hematopoietic system.

Effect of adiponectin deficiency on intestinal damage and hematopoietic responses of mice exposed to gamma radiation

International Nuclear Information System (INIS)

Ponemone, Venkatesh; Fayad, Raja; Gove, Melissa E.; Pini, Maria; Fantuzzi, Giamila

2010-01-01

Adiponectin (APN) is an adipose tissue-derived cytokine that regulates insulin sensitivity and inflammation. It is also involved in modulation of cell proliferation by binding to various growth factors. Based on its known effects in modulating cell proliferation and oxidative stress, APN may potentially be involved in regulating tissue damage and repair following irradiation. Adiponectin KO mice and their WT littermates were exposed to a single whole-body dose of 3 or 6 Gy gamma radiation. Radiation-induced alterations were studied in jejunum, blood, bone marrow and thymus at days 1 and 5 post-irradiation and compared with sham-irradiated groups. In WT mice, irradiation did not significantly alter serum APN levels while inducing a significant decrease in serum leptin. Irradiation caused a significant reduction in thymocyte cellularity, with concomitant decrease in CD4 + , CD8 + and CD4 + CD8 + T cell populations, with no significant differences between WT and APN KO mice. Irradiation resulted in a significantly higher increase in the frequency of micronucleated reticulocytes in the blood of APN KO compared with WT mice, whereas frequency of micronucleated normochromatic erythrocytes in the bone marrow at day 5 was significantly higher in WT compared with APN KO mice. Finally, irradiation induced similar alterations in villus height and crypt cell proliferation in the jejunum of WT and APN KO mice. Jejunum explants from sham-irradiated APN KO mice produced higher levels of IL-6 compared with tissue from WT animals, but the difference was no longer apparent following irradiation. Our data indicate that APN deficiency does not play a significant role in modulating radiation-induced gastrointestinal injury in mice, while it may participate in regulation of damage to the hematopoietic system.

Functional analysis of the CC chemokine receptor 5 (CCR5) on virus-specific CD8+ T cells following coronavirus infection of the central nervous system

International Nuclear Information System (INIS)

Glass, William G.; Lane, Thomas E.

2003-01-01

Intracranial infection of C57BL/6 mice with mouse hepatitis virus (MHV) results in an acute encephalomyelitis followed by a demyelinating disease similar in pathology to the human disease multiple sclerosis (MS). T cells participate in both defense and disease progression following MHV infection. Expression of chemokine receptors on activated T cells is important in allowing these cells to traffic into and accumulate within the central nervous system (CNS) of MHV-infected mice. The present study evaluated the contributions of CCR5 to the activation and trafficking of virus-specific CD8 + T cells into the MHV-infected CNS mice. Comparable numbers of virus-specific CD8 + T cells derived from immunized CCR5 +/+ or CCR5 -/- mice were present within the CNS of MHV-infected RAG1 -/- mice following adoptive transfer, indicating that CCR5 is not required for trafficking of these cells into the CNS. RAG1 -/- recipients of CCR5 -/- -derived CD8 + T cells exhibited a modest, yet significant (P ≤ 0.05), reduction in viral burden within the brain which correlated with increased CTL activity and IFN-γ expression. Histological analysis of RAG1 -/- recipients of either CCR5 +/+ or CCR5 -/- -derived CD8 + T cells revealed only focal areas of demyelination with no significant differences in white matter destruction. These data indicate that CCR5 signaling on CD8 + T cells modulates antiviral activities but is not essential for entry into the CNS

Protein-energy malnutrition alters IgA responses to rotavirus vaccination and infection but does not impair vaccine efficacy in mice.

Science.gov (United States)

Maier, Elizabeth A; Weage, Kristina J; Guedes, Marjorie M; Denson, Lee A; McNeal, Monica M; Bernstein, David I; Moore, Sean R

2013-12-17

Conflicting evidence links malnutrition to the reduced efficacy of rotavirus vaccines in developing countries, where diarrhea and undernutrition remain leading causes of child deaths. Here, we adapted mouse models of rotavirus vaccination (rhesus rotavirus, RRV), rotavirus infection (EDIM), and protein-energy malnutrition (PEM) to test the hypothesis that undernutrition reduces rotavirus vaccine immunogenicity and efficacy. We randomized wild type Balb/C dams with 3-day-old pups to a control diet (CD) or an isocaloric, multideficient regional basic diet (RBD) that produces PEM. At 3 weeks of age, we weaned CD and RBD pups to their dams' diet and subrandomized weanlings to receive a single dose of either live oral rotavirus vaccine (RRV) or PBS. At 6 weeks of age, we orally challenged all groups with murine rotavirus (EDIM). Serum and stool specimens were collected before and after RRV and EDIM administration to measure viral shedding and antibody responses by ELISA. RBD pups and weanlings exhibited significant failure to thrive compared to age-matched CD mice (Pvaccination induced higher levels of serum anti-RV IgA responses in RBD vs. CD mice (PVaccination protected CD and RBD mice equally against EDIM infection, as measured by viral shedding. In unvaccinated RBD mice, EDIM shedding peaked 1 day earlier (Pvaccination (Pvaccination mitigated stool IgA responses to EDIM more in CD vs. RBD mice (Pvaccination and infection, undernutrition does not impair rotavirus vaccine efficacy nor exacerbate infection in this mouse model of protein-energy malnutrition. Alternative models are needed to elucidate host-pathogen factors undermining rotavirus vaccine effectiveness in high-risk global settings. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

The Dynamics of Treg/Th17 and the Imbalance of Treg/Th17 in Clonorchis sinensis-Infected Mice.

Directory of Open Access Journals (Sweden)

Chao Yan

Full Text Available Clonorchiasis, caused by the liver fluke Clonorchis sinensis, is a chronic parasitic infection regulated by T cell subsets. An imbalance of CD4+CD25+ Foxp3+regulatory T (Treg and interleukin (IL-17-secreting T cells (Th17 may control inflammation and play an important role in the pathogenesis of immune evasion. In the present study, we assessed the dynamics of Treg/Th17 and determined whether the Treg/Th17 ratio is altered in C. sinensis-infected mice. The results showed that the percentages of splenic Treg cells in CD4+ T cells were suppressed on day 14 post-infection (PI but increased on day 56 PI, while Th17 cells were increased on day 56 PI compared with normal control (NC mice. The Treg/Th17 ratio steadily increased from day 28 to day 56 PI. The hepatic levels of their specific transcription factors (Foxp3 for Treg and RORγt for Th17 were increased in C. sinensis-infected mice from day 14 to 56 PI, and significantly higher than those in NC mice. Meanwhile, serum levels of IL-2 and IL-17 were profoundly increased in C. sinensis-infected mice throughout the experiment; while the concentrations of IL-6 and transforming growth factor β1 (TGF-β1 peaked on day 14 PI, but then decreased on day 28 and 56 PI. Our results provide the first evidence of an increased Treg/Th17 ratio in C. sinensis-infected mice, suggesting that a Treg/Th17 imbalance may play a role in disease outcomes of clonorchiasis.

Human Asymptomatic Epitopes Identified from the Herpes Simplex Virus Tegument Protein VP13/14 (UL47) Preferentially Recall Polyfunctional Effector Memory CD44high CD62Llow CD8+ TEM Cells and Protect Humanized HLA-A*02:01 Transgenic Mice against Ocular Herpesvirus Infection.

Science.gov (United States)

Srivastava, Ruchi; Khan, Arif A; Garg, Sumit; Syed, Sabrina A; Furness, Julie N; Vahed, Hawa; Pham, Tiffany; Yu, Howard T; Nesburn, Anthony B; BenMohamed, Lbachir

2017-01-15

Herpes simplex virus 1 (HSV-1) infection is widespread among humans. The HSV-1 virion protein 13/14 (VP13/14), also known as UL47, is a tegument antigen targeted by CD8 + T cells from HSV-seropositive individuals. However, whether VP13/14-specific CD8 + T cells play a role in the natural protection seen in asymptomatic (ASYMP) individuals (individuals who have never had a clinical herpetic disease) has not been elucidated. Using predictive computer-assisted algorithms, we identified 10 potential HLA-A*02:01-restricted CD8 + T-cell epitopes from the 693-amino-acid sequence of the VP13/14 protein. Three out of 10 epitopes exhibited a high to moderate affinity of binding to soluble HLA-A*02:01 molecules. The phenotype and function of CD8 + T cells specific for each epitope were compared in HLA-A*02:01-positive ASYMP individuals and symptomatic (SYMP) individuals (individuals who have frequent clinical herpetic diseases) using determination of a combination of tetramer frequency and the levels of granzyme B, granzyme K, perforin, gamma interferon, tumor necrosis factor alpha, and interleukin-2 production and CD107 a/b cytotoxic degranulation. High frequencies of multifunctional CD8 + T cells directed against three epitopes, VP13/14 from amino acids 286 to 294 (VP13/14 286-294 ), VP13/14 from amino acids 504 to 512 (VP13/14 504-512 ), and VP13/14 from amino acids 544 to 552 (VP13/14 544-552 ), were detected in ASYMP individuals, while only low frequencies were detected in SYMP individuals. The three epitopes also predominantly recalled more CD45RA low CD44 high CCR7 low CD62L low CD8 + effector memory T cells (T EM cells) in ASYMP individuals than SYMP individuals. Moreover, immunization of HLA-A*02:01 transgenic mice with the three CD8 + T EM -cell epitopes from ASYMP individuals induced robust and polyfunctional HSV-specific CD8 + T EM cells associated with strong protective immunity against ocular herpesvirus infection and disease. Our findings outline the phenotypic

IFN-Gamma-Dependent and Independent Mechanisms of CD4+ Memory T Cell-Mediated Protection from Listeria Infection

Directory of Open Access Journals (Sweden)

Stephanie M. Meek

2018-02-01

Full Text Available While CD8+ memory T cells can promote long-lived protection from secondary exposure to intracellular pathogens, less is known regarding the direct protective mechanisms of CD4+ T cells. We utilized a prime/boost model in which mice are initially exposed to an acutely infecting strain of lymphocytic choriomeningitis virus (LCMV, followed by a heterologous rechallenge with Listeria monocytogenes recombinantly expressing the MHC Class II-restricted LCMV epitope, GP61–80 (Lm-gp61. We found that heterologous Lm-gp61 rechallenge resulted in robust activation of CD4+ memory T cells and that they were required for rapid bacterial clearance. We further assessed the relative roles of TNF and IFNγ in the direct anti-bacterial function of CD4+ memory T cells. We found that disruption of TNF resulted in a complete loss of protection mediated by CD4+ memory T cells, whereas disruption of IFNγ signaling to macrophages results in only a partial loss of protection. The protective effect mediated by CD4+ T cells corresponded to the rapid accumulation of pro-inflammatory macrophages in the spleen and an altered inflammatory environment in vivo. Overall, we conclude that protection mediated by CD4+ memory T cells from heterologous Listeria challenge is most directly dependent on TNF, whereas IFNγ only plays a minor role.

CNS recruitment of CD8+ T lymphocytes specific for a peripheral virus infection triggers neuropathogenesis during polymicrobial challenge.

Directory of Open Access Journals (Sweden)

Christine M Matullo

2011-12-01

Full Text Available Although viruses have been implicated in central nervous system (CNS diseases of unknown etiology, including multiple sclerosis and amyotrophic lateral sclerosis, the reproducible identification of viral triggers in such diseases has been largely unsuccessful. Here, we explore the hypothesis that viruses need not replicate in the tissue in which they cause disease; specifically, that a peripheral infection might trigger CNS pathology. To test this idea, we utilized a transgenic mouse model in which we found that immune cells responding to a peripheral infection are recruited to the CNS, where they trigger neurological damage. In this model, mice are infected with both CNS-restricted measles virus (MV and peripherally restricted lymphocytic choriomeningitis virus (LCMV. While infection with either virus alone resulted in no illness, infection with both viruses caused disease in all mice, with ∼50% dying following seizures. Co-infection resulted in a 12-fold increase in the number of CD8+ T cells in the brain as compared to MV infection alone. Tetramer analysis revealed that a substantial proportion (>35% of these infiltrating CD8+ lymphocytes were LCMV-specific, despite no detectable LCMV in CNS tissues. Mechanistically, CNS disease was due to edema, induced in a CD8-dependent but perforin-independent manner, and brain herniation, similar to that observed in mice challenged intracerebrally with LCMV. These results indicate that T cell trafficking can be influenced by other ongoing immune challenges, and that CD8+ T cell recruitment to the brain can trigger CNS disease in the apparent absence of cognate antigen. By extrapolation, human CNS diseases of unknown etiology need not be associated with infection with any particular agent; rather, a condition that compromises and activates the blood-brain barrier and adjacent brain parenchyma can render the CNS susceptible to pathogen-independent immune attack.

Respiratory syncytial virus infections enhance cigarette smoke induced COPD in mice.

Directory of Open Access Journals (Sweden)

Robert F Foronjy

Full Text Available Respiratory syncytial viral (RSV infections are a frequent cause of chronic obstructive pulmonary disease (COPD exacerbations, which are a major factor in disease progression and mortality. RSV is able to evade antiviral defenses to persist in the lungs of COPD patients. Though RSV infection has been identified in COPD, its contribution to cigarette smoke-induced airway inflammation and lung tissue destruction has not been established. Here we examine the long-term effects of cigarette smoke exposure, in combination with monthly RSV infections, on pulmonary inflammation, protease production and remodeling in mice. RSV exposures enhanced the influx of macrophages, neutrophils and lymphocytes to the airways of cigarette smoke exposed C57BL/6J mice. This infiltration of cells was most pronounced around the vasculature and bronchial airways. By itself, RSV caused significant airspace enlargement and fibrosis in mice and these effects were accentuated with concomitant smoke exposure. Combined stimulation with both smoke and RSV synergistically induced cytokine (IL-1α, IL-17, IFN-γ, KC, IL-13, CXCL9, RANTES, MIF and GM-CSF and protease (MMP-2, -8, -12, -13, -16 and cathepsins E, S, W and Z expression. In addition, RSV exposure caused marked apoptosis within the airways of infected mice, which was augmented by cigarette smoke exposure. RSV and smoke exposure also reduced protein phosphatase 2A (PP2A and protein tyrosine phosphates (PTP1B expression and activity. This is significant as these phosphatases counter smoke-induced inflammation and protease expression. Together, these findings show for the first time that recurrent RSV infection markedly enhances inflammation, apoptosis and tissue destruction in smoke-exposed mice. Indeed, these results indicate that preventing RSV transmission and infection has the potential to significantly impact on COPD severity and progression.

The impact of maternal HIV infection on cord blood lymphocyte subsets and cytokine profile in exposed non-infected newborns

Directory of Open Access Journals (Sweden)

Reis-Alves Suiellen C

2011-02-01

Full Text Available Abstract Background Children born to HIV+ mothers are exposed intra-utero to several drugs and cytokines that can modify the developing immune system, and influence the newborn's immune response to infections and vaccines. We analyzed the relation between the distribution of cord blood lymphocyte subsets and cytokine profile in term newborns of HIV+ mothers using HAART during pregnancy and compared them to normal newborns. Methods In a prospective, controlled study, 36 mother-child pairs from HIV+ mothers and 15 HIV-uninfected mothers were studied. Hematological features and cytokine profiles of mothers at 35 weeks of pregnancy were examined. Maternal and cord lymphocyte subsets as well as B-cell maturation in cord blood were analyzed by flow cytometry. The non-stimulated, as well as BCG- and PHA-stimulated production of IL2, IL4, IL7, IL10, IL12, IFN-γ and TNF-alpha in mononuclear cell cultures from mothers and infants were quantified using ELISA. Results After one year follow-up none of the exposed infants became seropositive for HIV. An increase in B lymphocytes, especially the CD19/CD5+ ones, was observed in cord blood of HIV-exposed newborns. Children of HIV+ hard drug using mothers had also an increase of immature B-cells. Cord blood mononuclear cells of HIV-exposed newborns produced less IL-4 and IL-7 and more IL-10 and IFN-γ in culture than those of uninfected mothers. Cytokine values in supernatants were similar in infants and their mothers except for IFN-γ and TNF-alpha that were higher in HIV+ mothers, especially in drug abusing ones. Cord blood CD19/CD5+ lymphocytes showed a positive correlation with cord IL-7 and IL-10. A higher maternal age and smoking was associated with a decrease of cord blood CD4+ cells. Conclusions in uninfected infants born to HIV+ women, several immunological abnormalities were found, related to the residual maternal immune changes induced by the HIV infection and those associated with antiretroviral

HIV-1 Nef mutations abrogating downregulation of CD4 affect other Nef functions and show reduced pathogenicity in transgenic mice

International Nuclear Information System (INIS)

Hanna, Zaher; Priceputu, Elena; Hu, Chunyan; Vincent, Patrick; Jolicoeur, Paul

2006-01-01

HIV-1 Nef has the ability to downmodulate CD4 cell surface expression. Several studies have shown that CD4 downregulation is required for efficient virus replication and high infectivity. However, the pathophysiological relevance of this phenomenon in vivo, independently of its role in sustaining high virus loads, remains unclear. We studied the impact of the CD4 downregulation function of Nef on its pathogenesis in vivo, in the absence of viral replication, in the CD4C/HIV transgenic (Tg) mouse model. Two independent Nef mutants (RD35/36AA and D174K), known to abrogate CD4 downregulation, were tested in Tg mice. Flow cytometry analysis showed that downregulation of murine CD4 was severely decreased or abrogated on Tg T cells expressing respectively Nef RD35/36AA and Nef D174K . Similarly, the severe depletion of double-positive CD4 + CD8 + and of single-positive CD4 + CD8 - thymocytes, usually observed with Nef Wt , was not detected in Nef RD35/36AA and Nef D174K Tg mice. However, both mutant Tg mice showed a partial depletion of peripheral CD4 + T cells. This was accompanied, as previously reported for Net Wt Tg mice, by the presence of an activated/memory-like phenotype (CD69 + , CD25 + , CD44 + , CD45RB Low , CD62 Low ) of CD4 + T cells expressing Nef RD35/36AA and to a lesser extent Nef D174K . In addition, both mutants retained the ability to block CD4 + T cell proliferation in vitro after anti-CD3 stimulation, but not to enhance apoptosis/death of CD4 + T cells. Therefore, it appears that Nef-mediated CD4 downregulation is associated with thymic defects, but segregates independently of the activated/memory-like phenotype, of the partial depletion and of the impaired in vitro proliferation of peripheral CD4 + T cells. Histopathological assessment revealed the total absence of or decrease severity and frequency of organ AIDS-like diseases (lung, heart and kidney pathologies) in respectively Nef RD35/36AA and Nef D174K Tg mice, relative to those developing in

Different thresholds of T cell activation regulate FIV infection of CD4+CD25+ and CD4+CD25- cells

International Nuclear Information System (INIS)

Joshi, Anjali; Garg, Himanshu; Tompkins, Mary B.; Tompkins, Wayne A.

2005-01-01

Cellular activation plays an important role in retroviral replication. Previously, we have shown that CD4 + CD25 + T cells by the virtue of their partially activated phenotype represent ideal candidates for a productive feline immunodeficiency virus (FIV) infection. In the present study, we extended our previous observations with regard to FIV replication in CD4 + CD25 + and CD4 + CD25 - cells under different stimulation conditions. Both CD4 + CD25 + and CD4 + CD25 - cells remain latently infected in the absence of IL-2 or concanvalinA (ConA), respectively; harboring a replication competent provirus capable of reactivation several days post-infection. While CD4 + CD25 + cells require low levels of exogenous IL-2 and virus inputs for an efficient FIV replication, CD4 + CD25 - T cells can only be productively infected in the presence of either high concentrations of IL-2 or high virus titers, even in the absence of mitogenic stimulation. Interestingly, while high virus input activates CD4 + CD25 - cells to replicate FIV, it induces apoptosis in a high percentage of CD4 + CD25 + T cells. High IL-2 concentrations but not high virus inputs lead to surface upregulation of CD25 and significant cellular proliferation in CD4 + CD25 - cells. These results suggest that CD4 + CD25 + and CD4 + CD25 - T cells have different activation requirements which can be modulated by both viral and cytokine stimuli to reach threshold activation levels in order to harbor a productive FIV infection. This holds implications in vivo for CD4 + CD25 + and CD4 + CD25 - cells to serve as potential reservoirs of a productive and latent FIV infection

Nanoparticles containing siRNA to silence CD4 and CCR5 reduce expression of these receptors and inhibit HIV-1 infection in human female reproductive tract tissue explants

Directory of Open Access Journals (Sweden)

Susan K. Eszterhas

2011-09-01

Full Text Available Human Immunodeficiency Virus-type 1 (HIV- 1 binds to CD4 and CCR5 receptors on target cells in the human female reproductive tract. We sought to determine whether reducing levels of messenger RNA (mRNA transcripts that encode these receptors in female reproductive tract cells could protect mucosal tissue explants from HIV- 1 infection. Explants prepared from the endometrium, endocervix, and ectocervix of hysterectomy tissues from HIV-1 sero-negative women were exposed to nanoparticles containing CD4- and CCR5-specific short-interfering RNA (siRNA sequences. Explants were then exposed two days later to HIV-1, and HIV-1 reverse transcripts were measured five days post-infection. Explants treated with nanoparticles containing CD4- and CCR5-specific siRNA showed reduced levels of CD4 and CCR5 transcripts, and significantly lower levels of HIV-1 reverse transcripts compared to those treated with an irrelevant siRNA. In female reproductive tract explants and in peripheral blood cell cultures, siRNA transfection induced the secretion of IFN-alpha (IFN-α, a potent antiviral cytokine. In female mice, murine-specific Cd4-siRNA nanoparticles instilled within the uterus significantly reduced murine Cd4 transcripts by day 3. Our findings demonstrate that siRNA nanoparticles reduce expression of HIV-1 infectivity receptors in human female reproductive tract tissues and also inhibit HIV-1 infection. Murine studies demonstrate that nanoparticles can penetrate the reproductive tract tissues in vivo and silence gene expression. The induction of IFN-α after siRNA transfection can potentially contribute to the antiviral effect. These findings support the therapeutic development of nanoparticles to deliver siRNA molecules to silence host cell receptors in the female reproductive tract as a novel microbicide to inhibit mucosal HIV-1 transmission.

Compromised virus control and augmented perforin-mediated immunopathology in IFN-gamma-deficient mice infected with lymphocytic choriomeningitis virus

DEFF Research Database (Denmark)

Nansen, A; Jensen, Teis; Christensen, Jan Pravsgaard

1999-01-01

To define the role of IFN-gamma in the control of acute infection with a noncytopathogenic virus, mice with targeted defects of the genes encoding IFN-gamma, perforin, or both were infected i.v. with two strains of lymphocytic choriomeningitis virus differing markedly in their capacity to spread...... in wild-type mice. Our results reveal that IFN-gamma is pivotal to T cell-mediated control of a rapidly invasive stain, whereas it is less important in the acute elimination of a slowly invasive strain. Moreover, the majority of mice infected with the rapidly invasive strain succumb to a wasting syndrome...... mediated by CD8+ effector cells. The primary effector mechanism underlying this disease is perforin-dependent lysis, but other mechanisms are also involved. Wasting disease can be prevented if naive CD8+ cells from mice transgenic for an MHC class I-restricted lymphocytic choriomeningitis virus...

The growth and development of Schistosoma mansoni in mice exposed to sublethal doses of radiation

International Nuclear Information System (INIS)

Aitken, R.; Wilson, R.A.

1989-01-01

The maturation of Schistosoma mansoni was studied in mice exposed to various sublethal doses of radiation. Although the treatment of mice with 500 rads of radiation prior to infection did not alter parasite maturation, doses in excess of 500 rads led to a reduction in worm burden. This could not be attributed to a delay in the arrival of parasites in the hepatic portal system. Worms developing in mice treated with 800 rads commenced egg-laying about 1 wk later than worms in intact mice, and the rate of egg deposition appeared to be lower in irradiated hosts. The data demonstrate that exposure of C57BL/6 mice to doses of radiation in excess of 500 rads impairs their ability to carry infections of S. mansoni. The findings do not support the hypothesis that primary worm burdens in the mouse are controlled by a host immune response

Exhaustion of CTL memory and recrudescence of viremia in lymphocytic choriomeningitis virus-infected MHC class II-deficient mice and B cell-deficient mice

DEFF Research Database (Denmark)

Thomsen, Allan Randrup; Johansen, J; Marker, O

1996-01-01

To study the contribution of CD4+ T cells and B cells to antiviral immunity and long term virus control, MHC class II-deficient and B cell-deficient mice were infected with lymphocytic choriomeningitis virus. In class II-deficient mice, which lack CD4+ T cells, the primary CTL response is virtually...... this phenomenon could reflect participation of B cells and/or Abs in long term virus control, similar experiments were performed with mice that do not have mature B cells because of a disrupted membrane exon of the mu chain gene. In these mice, the cell-mediated immune response was slightly delayed, but transient...... and that in their absence, the virus-specific CTL potential becomes exhausted. Together our results indicate that while CD8+ cells play a dominant role in acute virus control, all three major components of the immune system are required for long term virus control....

An enhanced postnatal autoimmune profile in 24 week-old C57BL/6 mice developmentally exposed to TCDD

International Nuclear Information System (INIS)

Mustafa, A.; Holladay, S.D.; Goff, M.; Witonsky, S.G.; Kerr, R.; Reilly, C.M.; Sponenberg, D.P.; Gogal, R.M.

2008-01-01

Developmental exposure of mice to the environmental contaminant and AhR agonist, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), causes persistent postnatal suppression of T cell-mediated immune responses. The extent to which prenatal TCDD may induce or exacerbate postnatal autoimmune disease remains unknown. In the present study, time-pregnant high affinity AhR C57BL/6 mice received a single oral administration of 0, 2.5, or 5 μg/kg TCDD on gestation day (gd) 12. Offspring of these mice (n = 5/gender/treatment) were evaluated at 24 weeks-of-age and showed considerable immune dysregulation that was often gender-specific. Decreased thymic weight and percentages of CD4 + CD8 + thymocytes, and increased CD4 + CD8 - thymocytes, were present in the female but not male offspring. Males but not females showed decreased CD4 - CD8 + T cells, and increased Vβ3 + and Vβ17a + T cells, in the spleen. Males but not females also showed increased percentages of bone marrow CD24 - B220 + B cell progenitors. Antibody titers to dsDNA, ssDNA and cardiolipin displayed increasing trends in both male and female mice, reaching significance for anti-dsDNA in both genders and for ssDNA in males at 5 μg/kg TCDD. Immunofluorescent staining of IgG and C3 deposition in kidney glomeruli increased in both genders of prenatal TCDD-exposed mice, suggestive of early stages of autoimmune glomerulonephritis. Collectively, these results show that exposure to TCDD during immune system development causes persistent humoral immune dysregulation as well as altered cell-mediated responses, and induces an adult profile of changes suggestive of increased risk for autoimmune disease

Exacerbation of autoimmune neuro-inflammation in mice cured from blood-stage Plasmodium berghei infection.

Directory of Open Access Journals (Sweden)

Rodolfo Thomé

Full Text Available The thymus plays an important role shaping the T cell repertoire in the periphery, partly, through the elimination of inflammatory auto-reactive cells. It has been shown that, during Plasmodium berghei infection, the thymus is rendered atrophic by the premature egress of CD4+CD8+ double-positive (DP T cells to the periphery. To investigate whether autoimmune diseases are affected after Plasmodium berghei NK65 infection, we immunized C57BL/6 mice, which was previously infected with P. berghei NK65 and treated with chloroquine (CQ, with MOG35-55 peptide and the clinical course of Experimental Autoimmune Encephalomyelitis (EAE was evaluated. Our results showed that NK65+CQ+EAE mice developed a more severe disease than control EAE mice. The same pattern of disease severity was observed in MOG35-55-immunized mice after adoptive transfer of P. berghei-elicited splenic DP-T cells. The higher frequency of IL-17+- and IFN-γ+-producing DP lymphocytes in the Central Nervous System of these mice suggests that immature lymphocytes contribute to disease worsening. To our knowledge, this is the first study to integrate the possible relationship between malaria and multiple sclerosis through the contribution of the thymus. Notwithstanding, further studies must be conducted to assert the relevance of malaria-induced thymic atrophy in the susceptibility and clinical course of other inflammatory autoimmune diseases.

Therapy of infections in mice irradiated in mixed neutron/photon fields and inflicted with wound trauma: a review of current work.

Science.gov (United States)

Ledney, G D; Madonna, G S; Elliott, T B; Moore, M M; Jackson, W E

1991-10-01

When host antimicrobial defenses are severely compromised by radiation or trauma in conjunction with radiation, death from sepsis results. To evaluate therapies for sepsis in radiation casualties, we developed models of acquired and induced bacterial infections in irradiated and irradiated-wounded mice. Animals were exposed to either a mixed radiation field of equal proportions of neutrons and gamma rays (n/gamma = 1) from a TRIGA reactor or pure gamma rays from 60[Co sources. Skin wounds (15% of total body surface area) were inflicted under methoxyflurane anesthesia 1 h after irradiation. In all mice, wounding after irradiation decreased resistance to infection. Treatments with the immunomodulator synthetic trehalose dicorynomycolate (S-TDCM) before or after mixed neutron-gamma irradiation or gamma irradiation increased survival. Therapy with S-TDCM for mice irradiated with either a mixed field or gamma rays increased resistance to Klebsiella pneumoniae-induced infections. Combined therapy with S-TDCM and ceftriaxone for K. pneumoniae infections in mice exposed to a mixed radiation field or to gamma rays was more effective than single-agent therapy. In all irradiated-wounded mice, single therapy of acquired infections with an antibiotic or S-TDCM did not increase survival. Survival of irradiated-wounded mice after topical application of gentamicin sulfate cream suggested that bacteria colonizing the wound disseminated systemically in untreated irradiated mice, resulting in death from sepsis. In lethal models of acquired infections in irradiated-wounded mice, significant increases in survival were achieved when systemic treatments with S-TDCM or gentamicin were combined with topical treatments of gentamicin cream. Therapies for sepsis in all mice exposed to a mixed field were less effective than in mice exposed to gamma rays. Nonetheless, the data show a principle by which successful therapy may be provided to individuals receiving tissue trauma in conjunction with

In Situ Microscopy Analysis Reveals Local Innate Immune Response Developed around Brucella Infected Cells in Resistant and Susceptible Mice

Science.gov (United States)

Copin, Richard; Vitry, Marie-Alice; Hanot Mambres, Delphine; Machelart, Arnaud; De Trez, Carl; Vanderwinden, Jean-Marie; Magez, Stefan; Akira, Shizuo; Ryffel, Bernhard; Carlier, Yves; Letesson, Jean-Jacques; Muraille, Eric

2012-01-01

Brucella are facultative intracellular bacteria that chronically infect humans and animals causing brucellosis. Brucella are able to invade and replicate in a broad range of cell lines in vitro, however the cells supporting bacterial growth in vivo are largely unknown. In order to identify these, we used a Brucella melitensis strain stably expressing mCherry fluorescent protein to determine the phenotype of infected cells in spleen and liver, two major sites of B. melitensis growth in mice. In both tissues, the majority of primary infected cells expressed the F4/80 myeloid marker. The peak of infection correlated with granuloma development. These structures were mainly composed of CD11b+ F4/80+ MHC-II+ cells expressing iNOS/NOS2 enzyme. A fraction of these cells also expressed CD11c marker and appeared similar to inflammatory dendritic cells (DCs). Analysis of genetically deficient mice revealed that differentiation of iNOS+ inflammatory DC, granuloma formation and control of bacterial growth were deeply affected by the absence of MyD88, IL-12p35 and IFN-γ molecules. During chronic phase of infection in susceptible mice, we identified a particular subset of DC expressing both CD11c and CD205, serving as a reservoir for the bacteria. Taken together, our results describe the cellular nature of immune effectors involved during Brucella infection and reveal a previously unappreciated role for DC subsets, both as effectors and reservoir cells, in the pathogenesis of brucellosis. PMID:22479178

Alcohol intake alters immune responses and promotes CNS viral persistence in mice.

Science.gov (United States)

Loftis, Jennifer M; Taylor, Jonathan; Raué, Hans-Peter; Slifka, Mark K; Huang, Elaine

2016-10-01

Chronic hepatitis C virus (HCV) infection leads to progressive liver disease and is associated with a variety of extrahepatic effects, including central nervous system (CNS) damage and neuropsychiatric impairments. Alcohol abuse can exacerbate these adverse effects on brain and behavior, but the molecular mechanisms are not well understood. This study investigated the role of alcohol in regulating viral persistence and CNS immunopathology in mice infected with lymphocytic choriomeningitis virus (LCMV), a model for HCV infections in humans. Female and male BALB/c mice (n=94) were exposed to alcohol (ethanol; EtOH) and water (or water only) using a two-bottle choice paradigm, followed one week later by infection with either LCMV clone 13 (causes chronic infection similar to chronic HCV), LCMV Armstrong (causes acute infection), or vehicle. Mice were monitored for 60days post-infection and continued to receive 24-h access to EtOH and water. Animals infected with LCMV clone 13 drank more EtOH, as compared to those with an acute or no viral infection. Six weeks after infection with LCMV clone 13, mice with EtOH exposure evidenced higher serum viral titers, as compared to mice without EtOH exposure. EtOH intake was also associated with reductions in virus-specific CD8(+) T cell frequencies (particularly CD11a(hi) subsets) and evidence of persistent CNS viremia in chronically infected mice. These findings support the hypothesis that EtOH use and chronic viral infection can result in combined toxic effects accelerating CNS damage and neuropsychiatric dysfunction and suggest that examining the role of EtOH in regulating viral persistence and CNS immunopathology in mice infected with LCMV can lead to a more comprehensive understanding of comorbid alcohol use disorder and chronic viral infection. Published by Elsevier B.V.

Outbred CD1 mice are as suitable as inbred C57BL/6J mice in performing social tasks.

Science.gov (United States)

Hsieh, Lawrence S; Wen, John H; Miyares, Laura; Lombroso, Paul J; Bordey, Angélique

2017-01-10

Inbred mouse strains have been used preferentially for behavioral testing over outbred counterparts, even though outbred mice reflect the genetic diversity in the human population better. Here, we compare the sociability of widely available outbred CD1 mice with the commonly used inbred C57BL/6J (C57) mice in the one-chamber social interaction test and the three-chamber sociability test. In the one-chamber task, intra-strain pairs of juvenile, non-littermate, male CD1 or C57 mice display a series of social and aggressive behaviors. While CD1 and C57 pairs spend equal amount of time socializing, CD1 pairs spend significantly more time engaged in aggressive behaviors than C57 mice. In the three-chamber task, sociability of C57 mice was less dependent on acclimation paradigms than CD1 mice. Following acclimation to all three chambers, both groups of age-matched male mice spent more time in the chamber containing a stranger mouse than in the empty chamber, suggesting that CD1 mice are sociable like C57 mice. However, the observed power suggests that it is easier to achieve statistical significance with C57 than CD1 mice. Because the stranger mouse could be considered as a novel object, we assessed for a novelty effect by adding an object. CD1 mice spend more time in the chamber with a stranger mouse than that a novel object, suggesting that their preference is social in nature. Thus, outbred CD1 mice are as appropriate as inbred C57 mice for studying social behavior using either the single or the three-chamber test using a specific acclimation paradigm. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

eCD4-Ig promotes ADCC activity of sera from HIV-1-infected patients.

Directory of Open Access Journals (Sweden)

Meredith E Davis-Gardner

2017-12-01

Full Text Available Antibody-dependent cell-mediated cytotoxity (ADCC can eliminate HIV-1 infected cells, and may help reduce the reservoir of latent virus in infected patients. Sera of HIV-1 positive individuals include a number of antibodies that recognize epitopes usually occluded on HIV-1 envelope glycoprotein (Env trimers. We have recently described eCD4-Ig, a potent and exceptionally broad inhibitor of HIV-1 entry that can be used to protect rhesus macaques from multiple high-dose challenges with simian-human immunodeficiency virus AD8 (SHIV-AD8. Here we show that eCD4-Ig bearing an IgG1 Fc domain (eCD4-IgG1 can mediate efficient ADCC activity against HIV-1 isolates with differing tropisms, and that it does so at least 10-fold more efficiently than CD4-Ig, even when more CD4-Ig molecules bound cell surface-expressed Env. An ADCC-inactive IgG2 form of eCD4-Ig (eCD4-IgG2 exposes V3-loop and CD4-induced epitopes on cell-expressed trimers, and renders HIV-1-infected cells susceptible to ADCC mediated by antibodies of these classes. Moreover, eCD4-IgG2, but not IgG2 forms of the broadly neutralizing antibodies VRC01 and 10-1074, enhances the ADCC activities of serum antibodies from patients by 100-fold, and significantly enhanced killing of two latently infected T-cell lines reactivated by vorinostat or TNFα. Thus eCD4-Ig is qualitatively different from CD4-Ig or neutralizing antibodies in its ability to mediate ADCC, and it may be uniquely useful in treating HIV-1 infection or reducing the reservoir of latently infected cells.

Pronounced susceptibility to infection by Salmonella enterica serovar Typhimurium in mice chronically exposed to lead correlates with a shift to Th2-type immune responses

International Nuclear Information System (INIS)

Fernandez-Cabezudo, Maria J.; Ali, Sumaya A.E.; Ullah, Azim; Hasan, Mohammed Y.; Kosanovic, Melita; Fahim, Mohamed A.; Adem, Abdu; Al-Ramadi, Basel K.

2007-01-01

Persistent exposure to inorganic lead (Pb) is known to adversely affect the immune system. In the present study, we assessed the effect of chronic Pb exposure on susceptibility to infection by the facultative intracellular pathogen Salmonella enterica serovar Typhimurium. Mice were exposed to 10 mM Pb-acetate in drinking water for ∼ 16 weeks, resulting in a significant level of Pb in the blood (106.2 ± 8.9 μg/dl). Pb exposure rendered mice susceptible to Salmonella infection, manifested by increased bacterial burden in target organs and heightened mortality. Flow cytometric analysis of the splenic cellular composition in normal and Pb-exposed mice revealed no gross alteration in the ratios of B and T lymphocytes or myeloid cells. Similarly, the capacity of B and T cells to upregulate the expression of activation antigens in response to mitogenic or inflammatory stimuli was not hindered by Pb exposure. Analysis of the ability of ex vivo-cultured splenocytes to secrete cytokines demonstrated a marked reduction in IFN-γ and IL-12p40 production associated with Pb exposure. In contrast, secretion of IL-4 by splenocytes of Pb-treated mice was 3- to 3.6-fold higher than in normal mice. The increased capacity to produce IL-4 correlated with a shift in the in vivo anti-Salmonella antibody response from the protective IgG2a isotype to the Th2-induced IgG1 isotype. We conclude that chronic exposure to high levels of Pb results in a state of immunodeficiency which is not due to an overt cytotoxic or immunosuppressive mechanism, but rather is largely caused by a shift in immune responsiveness to Th2-type reactions

Intestinal IgA responses to Giardia muris in mice depleted of helper T lymphocytes and in immunocompetent mice.

Science.gov (United States)

Heyworth, M F

1989-04-01

Immunocompetent mice infected with Giardia muris generate an intestinal antibody response to this parasite and clear G. muris infection. Previous work has shown that G. muris infection is prolonged in mice that have been depleted of helper (CD4+) T lymphocytes by treatment with a monoclonal antibody (mAb) directed against the murine CD4 antigen. The aim of the present study was to compare the intestinal anti-Giardia antibody response in immunocompetent mice and in mice depleted of helper T (Th) lymphocytes by treatment with anti-CD4 mAb. Immunocompetent mice generated an IgA response to G. muris, as judged by the presence of IgA on Giardia trophozoites harvested from the intestine of these animals more than 10 days after the start of the infection. The anti-Giardia IgA response was impaired in mice depleted of Th lymphocytes, as judged by virtual absence of immunofluorescent staining of trophozoites from these animals for surface-bound IgA. Clearance of G. muris infection was impaired by treatment of mice with anti-CD4 mAb. The results suggest that Th (CD4+) lymphocytes are important for the generation of a local IgA response against G. muris trophozoites in the mouse intestine and that IgA anti-trophozoite antibody may contribute to the clearance of G. muris from the intestine of immunocompetent mice.

NLRP3 Controls the Development of Gastrointestinal CD11b+ Dendritic Cells in the Steady State and during Chronic Bacterial Infection

Directory of Open Access Journals (Sweden)

Isabelle C. Arnold

2017-12-01

Full Text Available The gastric lamina propria is largely uncharted immunological territory. Here we describe the evolution and composition of the gastric, small intestinal, and colonic lamina propria mononuclear phagocyte system during the steady state and infection with the gastric pathogen Helicobacter pylori. We show that monocytes, CX3CR1hi macrophages, and CD11b+ dendritic cells are recruited to the infected stomach in a CCR2-dependent manner. All three populations, but not BATF3-dependent CD103+ DCs, sample red fluorescent protein (RFP+ Helicobacter pylori (H. pylori. Mice reconstituted with human hematopoietic stem cells recapitulate several features of the myeloid cell-H. pylori interaction. The differentiation in and/or recruitment to gastrointestinal, lung, and lymphoid tissues of CD11b+ DCs requires NLRP3, but not apoptosis-associated speck-like protein containing a carboxy-terminal CARD (ASC or caspase-1, during steady-state and chronic infection. NLRP3−/− mice fail to generate Treg responses to H. pylori and control the infection more effectively than wild-type mice. The results demonstrate a non-canonical inflammasome-independent function of NLRP3 in DC development and immune regulation.

Exercise Improves Host Response to Influenza Viral Infection in Obese and Non-Obese Mice through Different Mechanisms

Science.gov (United States)

Warren, Kristi J.; Olson, Molly M.; Thompson, Nicholas J.; Cahill, Mackenzie L.; Wyatt, Todd A.; Yoon, Kyoungjin J.; Loiacono, Christina M.; Kohut, Marian L.

2015-01-01

Obesity has been associated with greater severity of influenza virus infection and impaired host defense. Exercise may confer health benefits even when weight loss is not achieved, but it has not been determined if regular exercise improves immune defense against influenza A virus (IAV) in the obese condition. In this study, diet-induced obese mice and lean control mice exercised for eight weeks followed by influenza viral infection. Exercise reduced disease severity in both obese and non-obese mice, but the mechanisms differed. Exercise reversed the obesity-associated delay in bronchoalveolar-lavage (BAL) cell infiltration, restored BAL cytokine and chemokine production, and increased ciliary beat frequency and IFNα-related gene expression. In non-obese mice, exercise treatment reduced lung viral load, increased Type-I-IFN-related gene expression early during infection, but reduced BAL inflammatory cytokines and chemokines. In both obese and non-obese mice, exercise increased serum anti-influenza virus specific IgG2c antibody, increased CD8+ T cell percentage in BAL, and reduced TNFα by influenza viral NP-peptide-responding CD8+ T cells. Overall, the results suggest that exercise “restores” the immune response of obese mice to a phenotype similar to non-obese mice by improving the delay in immune activation. In contrast, in non-obese mice exercise treatment results in an early reduction in lung viral load and limited inflammatory response. PMID:26110868

IFN-Gamma-Dependent and Independent Mechanisms of CD4⁺ Memory T Cell-Mediated Protection from Listeria Infection.

Science.gov (United States)

Meek, Stephanie M; Williams, Matthew A

2018-02-13

While CD8⁺ memory T cells can promote long-lived protection from secondary exposure to intracellular pathogens, less is known regarding the direct protective mechanisms of CD4⁺ T cells. We utilized a prime/boost model in which mice are initially exposed to an acutely infecting strain of lymphocytic choriomeningitis virus (LCMV), followed by a heterologous rechallenge with Listeria monocytogenes recombinantly expressing the MHC Class II-restricted LCMV epitope, GP 61-80 (Lm-gp61). We found that heterologous Lm-gp61 rechallenge resulted in robust activation of CD4⁺ memory T cells and that they were required for rapid bacterial clearance. We further assessed the relative roles of TNF and IFNγ in the direct anti-bacterial function of CD4⁺ memory T cells. We found that disruption of TNF resulted in a complete loss of protection mediated by CD4⁺ memory T cells, whereas disruption of IFNγ signaling to macrophages results in only a partial loss of protection. The protective effect mediated by CD4⁺ T cells corresponded to the rapid accumulation of pro-inflammatory macrophages in the spleen and an altered inflammatory environment in vivo. Overall, we conclude that protection mediated by CD4⁺ memory T cells from heterologous Listeria challenge is most directly dependent on TNF, whereas IFNγ only plays a minor role.

STAT3 Regulates Proliferation and Survival of CD8+ T Cells: Enhances Effector Responses to HSV-1 Infection, and Inhibits IL-10+ Regulatory CD8+ T Cells in Autoimmune Uveitis

Directory of Open Access Journals (Sweden)

Cheng-Rong Yu

2013-01-01

Full Text Available STAT3 regulates CD4+ T cell survival and differentiation. However, its effects on CD8+ T cells are not well understood. Here, we show that in comparison to WT CD8+ T cells, STAT3-deficient CD8+ T cells exhibit a preactivated memory-like phenotype, produce more IL-2, proliferate faster, and are more sensitive to activation-induced cell death (AICD. The enhanced proliferation and sensitivity to AICD correlated with downregulation of class-O forkhead transcription factors (FoxO1, FoxO3A, , , Bcl-2, OX-40, and upregulation of FasL, Bax, and Bad. We examined whether STAT3-deficient CD8+ T cells can mount effective response during herpes simplex virus (HSV-1 infection and experimental autoimmune uveitis (EAU. Compared to WT mice, HSV-1-infected STAT3-deficient mice (STAT3KO produced less IFN- and virus-specific KLRG-1+ CD8+ T cells. STAT3KO mice are also resistant to EAU and produced less IL-17-producing Tc17 cells. Resistance of STAT3KO to EAU correlated with marked expansion of IL-10-producing regulatory CD8+ T cells (CD8-Treg implicated in recovery from autoimmune encephalomyelitis. Thus, increases of IL-6-induced STAT3 activation observed during inflammation may inhibit expansion of CD8-Tregs, thereby impeding recovery from uveitis. These results suggest that STAT3 is a potential therapeutic target for upregulating CD8+ T cell-mediated responses to viruses and suggest the successful therapeutic targeting of STAT3 as treatment for uveitis, derived, in part, from promoting CD8-Treg expansion.

The role of neutrophils in the upper and lower respiratory tract during influenza virus infection of mice

Directory of Open Access Journals (Sweden)

Reading Patrick C

2008-08-01

Full Text Available Abstract Background Neutrophils have been shown to play a role in host defence against highly virulent and mouse-adapted strains of influenza virus, however it is not clear if an effective neutrophil response is an important factor moderating disease severity during infection with other virus strains. In this study, we have examined the role of neutrophils during infection of mice with influenza virus strain HKx31, a virus strain of the H3N2 subtype and of moderate virulence for mice, to determine the role of neutrophils in the early phase of infection and in clearance of influenza virus from the respiratory tract during the later phase of infection. Methods The anti-Gr-1 monoclonal antibody (mAb RB6-8C5 was used to (i identify neutrophils in the upper (nasal tissues and lower (lung respiratory tract of uninfected and influenza virus-infected mice, and (ii deplete neutrophils prior to and during influenza virus infection of mice. Results Neutrophils were rapidly recruited to the upper and lower airways following influenza virus infection. We demonstrated that use of mAb RB6-8C5 to deplete C57BL/6 (B6 mice of neutrophils is complicated by the ability of this mAb to bind directly to virus-specific CD8+ T cells. Thus, we investigated the role of neutrophils in both the early and later phases of infection using CD8+ T cell-deficient B6.TAP-/- mice. Infection of B6.TAP-/- mice with a low dose of influenza virus did not induce clinical disease in control animals, however RB6-8C5 treatment led to profound weight loss, severe clinical disease and enhanced virus replication throughout the respiratory tract. Conclusion Neutrophils play a critical role in limiting influenza virus replication during the early and later phases of infection. Furthermore, a virus strain of moderate virulence can induce severe clinical disease in the absence of an effective neutrophil response.

T-bet and Eomes Are Differentially Linked to the Exhausted Phenotype of CD8+T Cells in HIV Infection

DEFF Research Database (Denmark)

Buggert, Marcus; Tauriainen, Johanna; Yamamoto, Takuya

2014-01-01

CD8+ T cell exhaustion represents a major hallmark of chronic HIV infection. Two key transcription factors governing CD8+ T cell differentiation, T-bet and Eomesodermin (Eomes), have previously been shown in mice to differentially regulate T cell exhaustion in part through direct modulation of PD...

Cd-tolerant Suillus luteus: A fungal insurance for pines exposed to Cd

International Nuclear Information System (INIS)

Krznaric, Erik; Verbruggen, Nathalie; Wevers, Jan H.L.; Carleer, Robert; Vangronsveld, Jaco; Colpaert, Jan V.

2009-01-01

Soil metal pollution can trigger evolutionary adaptation in soil-borne organisms. An in vitro screening test showed cadmium adaptation in populations of Suillus luteus (L.: Fr.) Roussel, an ectomycorrhizal fungus of pine trees. Cadmium stress was subsequently investigated in Scots pine (Pinus sylvestris L.) seedlings inoculated with a Cd-tolerant S. luteus, isolated from a heavy metal contaminated site, and compared to plants inoculated with a Cd-sensitive isolate from a non-polluted area. A dose-response experiment with mycorrhizal pines showed better plant protection by a Cd-adapted fungus: more fungal biomass and a higher nutrient uptake at high Cd exposure. In addition, less Cd was transferred to aboveground plant parts. Because of the key role of the ectomycorrhizal symbiosis for tree fitness, the evolution of Cd tolerance in an ectomycorrhizal partner such as S. luteus can be of major importance for the establishment of pine forests on Cd-contaminated soils. - The evolutionary adaptation for higher Cd tolerance in Suillus luteus, an ectomycorrhizal fungus, is of major importance for the amelioration of Cd toxicity in pine trees exposed to high Cd concentrations.

Cd-tolerant Suillus luteus: A fungal insurance for pines exposed to Cd

Energy Technology Data Exchange (ETDEWEB)

Krznaric, Erik [Environmental Biology Group, Centre for Environmental Sciences, Hasselt University, Agoralaan, Gebouw D, 3590 Diepenbeek (Belgium); Verbruggen, Nathalie [Laboratoire de Physiologie et de Genetique Moleculaire des Plantes, Universite Libre de Bruxelles, Campus Plaine, CP242, Bd du Triomphe, 1050 Brussels (Belgium); Wevers, Jan H.L. [Environmental Biology Group, Centre for Environmental Sciences, Hasselt University, Agoralaan, Gebouw D, 3590 Diepenbeek (Belgium); Carleer, Robert [Laboratory of Applied Chemistry, Centre for Environmental Sciences, Hasselt University, Agoralaan, Gebouw D, 3590 Diepenbeek (Belgium); Vangronsveld, Jaco [Environmental Biology Group, Centre for Environmental Sciences, Hasselt University, Agoralaan, Gebouw D, 3590 Diepenbeek (Belgium); Colpaert, Jan V., E-mail: jan.colpaert@uhasselt.b [Environmental Biology Group, Centre for Environmental Sciences, Hasselt University, Agoralaan, Gebouw D, 3590 Diepenbeek (Belgium)

2009-05-15

Soil metal pollution can trigger evolutionary adaptation in soil-borne organisms. An in vitro screening test showed cadmium adaptation in populations of Suillus luteus (L.: Fr.) Roussel, an ectomycorrhizal fungus of pine trees. Cadmium stress was subsequently investigated in Scots pine (Pinus sylvestris L.) seedlings inoculated with a Cd-tolerant S. luteus, isolated from a heavy metal contaminated site, and compared to plants inoculated with a Cd-sensitive isolate from a non-polluted area. A dose-response experiment with mycorrhizal pines showed better plant protection by a Cd-adapted fungus: more fungal biomass and a higher nutrient uptake at high Cd exposure. In addition, less Cd was transferred to aboveground plant parts. Because of the key role of the ectomycorrhizal symbiosis for tree fitness, the evolution of Cd tolerance in an ectomycorrhizal partner such as S. luteus can be of major importance for the establishment of pine forests on Cd-contaminated soils. - The evolutionary adaptation for higher Cd tolerance in Suillus luteus, an ectomycorrhizal fungus, is of major importance for the amelioration of Cd toxicity in pine trees exposed to high Cd concentrations.

CD11c-Expressing Cells Affect Regulatory T Cell Behavior in the Meninges during Central Nervous System Infection.

Science.gov (United States)

O'Brien, Carleigh A; Overall, Christopher; Konradt, Christoph; O'Hara Hall, Aisling C; Hayes, Nikolas W; Wagage, Sagie; John, Beena; Christian, David A; Hunter, Christopher A; Harris, Tajie H

2017-05-15

Regulatory T cells (Tregs) play an important role in the CNS during multiple infections, as well as autoimmune inflammation, but the behavior of this cell type in the CNS has not been explored. In mice, infection with Toxoplasma gondii leads to a Th1-polarized parasite-specific effector T cell response in the brain. Similarly, Tregs in the CNS during T. gondii infection are Th1 polarized, as exemplified by their T-bet, CXCR3, and IFN-γ expression. Unlike effector CD4 + T cells, an MHC class II tetramer reagent specific for T. gondii did not recognize Tregs isolated from the CNS. Likewise, TCR sequencing revealed minimal overlap in TCR sequence between effector T cells and Tregs in the CNS. Whereas effector T cells are found in the brain parenchyma where parasites are present, Tregs were restricted to the meninges and perivascular spaces. The use of intravital imaging revealed that activated CD4 + T cells within the meninges were highly migratory, whereas Tregs moved more slowly and were found in close association with CD11c + cells. To test whether the behavior of Tregs in the meninges is influenced by interactions with CD11c + cells, mice were treated with anti-LFA-1 Abs to reduce the number of CD11c + cells in this space. The anti-LFA-1 treatment led to fewer contacts between Tregs and the remaining CD11c + cells and increased the speed of Treg migration. These data suggest that Tregs are anatomically restricted within the CNS, and their interaction with CD11c + populations regulates their local behavior during T. gondii infection. Copyright © 2017 by The American Association of Immunologists, Inc.

Porphyromonas gingivalis infection induced reproductive abnormalities in mice

Directory of Open Access Journals (Sweden)

Ke-min WEI

2016-09-01

Full Text Available Objective 　To establish a pregnant mouse model infected with Porphyromonas gingivalis (P.g, and investigate the relationship of P.g infection to prematurity and associated birth abnormalities. Methods 　Fifty two female mice were randomly divided into P.g infection group (n=26 and control group (n=26. Mice in P.g infection group were anesthetized, the pulp cavity of the first molar was opened and directly injected with W83 strain P.g, and the tooth was then filled. Six weeks after infection, the mice were mated with males and the formation of vagina plug was recorded as 0d. The P.g extracted from the granulation tissue in tooth root was cultivated. The pregnant days and the connatal body weight of infant mouse were recorded, the serum and placental tissue were collected to assess the systemic and local conditions during pregnancy. Results 　After periodontal P.g infection, the TNF-α, IL-17, IL -6 and IL -1βlevels in peripheral blood sera increased significantly. The average gestation was shorter in P.g infection group (18.25d than in control group (20.45d, P<0.01, and the connatal body weight of infant mouse was also less in the former than in the latter (P<0.01. Immunohistochemistry and PCR revealed the existence of P.g in placenta tissue. P.g infection caused premature rupture of membranes, placental abruption, degeneration and necrosis of trophoblastic and endothelial cells; significantly increased the number of neutrophils and macrophages in placenta tissues, and increased the expression of local TNF-αand COX-2 inflammatory factors at the same time. In P.g infection group, the expressions of CD-31 in endothelial cells of placenta tissues and the apoptotic factor caspase-3 decreased, and the DNA oxidative damage index 8-OHdG increased. Conclusions 　P.g infection in female mice may cause premature birth and lower connatal body weight of infant mouse, and increase the expression of serous and local inflammatory factors in the placenta

Infection and depletion of CD4+ group-1 innate lymphoid cells by HIV-1 via type-I interferon pathway.

Directory of Open Access Journals (Sweden)

Juanjuan Zhao

2018-01-01

Full Text Available Innate lymphoid cells (ILCs are severely depleted during chronic HIV-1 infection by unclear mechanisms. We report here that human ILC1s comprising of CD4+ and CD4- subpopulations were present in various human lymphoid organs but with different transcription programs and functions. Importantly, CD4+ ILC1s expressed HIV-1 co-receptors and were productively infected by HIV-1 in vitro and in vivo. Furthermore, chronic HIV-1 infection activated and depleted both CD4+ and CD4- ILC1s, and impaired their cytokine production activity. Highly active antiretroviral (HAART therapy in HIV-1 patients efficiently rescued the ILC1 numbers and reduced their activation, but failed to restore their functionality. We also found that blocking type-I interferon (IFN-I signaling during HIV-1 infection in vivo in humanized mice prevented HIV-1 induced depletion or apoptosis of ILC1 cells. Therefore, we have identified the CD4+ ILC1 cells as a new target population for HIV-1 infection, and revealed that IFN-I contributes to the depletion of ILC1s during HIV-1 infection.

Minocycline attenuates HIV-1 infection and suppresses chronic immune activation in humanized NOD/LtsZ-scidIL-2Rγnull mice

Science.gov (United States)

Singh, Maneesh; Singh, Pratibha; Vaira, Dolores; Amand, Mathieu; Rahmouni, Souad; Moutschen, Michel

2014-01-01

More than a quarter of a century of research has established chronic immune activation and dysfunctional T cells as central features of chronic HIV infection and subsequent immunodeficiency. Consequently, the search for a new immunomodulatory therapy that could reduce immune activation and improve T-cell function has been increased. However, the lack of small animal models for in vivo HIV study has hampered progress. In the current study, we have investigated a model of cord blood haematopoietic progenitor cells (CB-HPCs) -transplanted humanized NOD/LtsZ-scidIL-2Rγnull mice in which progression of HIV infection is associated with widespread chronic immune activation and inflammation. Indeed, HIV infection in humanized NSG mice caused up-regulation of several T-cell immune activation markers such as CD38, HLA-DR, CD69 and co-receptor CCR5. T-cell exhaustion markers PD-1 and CTLA-4 were found to be significantly up-regulated on T cells. Moreover, increased plasmatic levels of lipopolysaccharide, sCD14 and interleukin-10 were also observed in infected mice. Treatment with minocycline resulted in a significant decrease of expression of cellular and plasma immune activation markers, inhibition of HIV replication and improved T-cell counts in HIV-infected humanized NSG mice. The study demonstrates that minocycline could be an effective, low-cost adjunctive treatment to regulate chronic immune activation and replication of HIV. PMID:24409837

Perinatal Exposure to Insecticide Methamidophos Suppressed Production of Proinflammatory Cytokines Responding to Virus Infection in Lung Tissues in Mice

Directory of Open Access Journals (Sweden)

Wataru Watanabe

2013-01-01

Full Text Available Methamidophos, a representative organophosphate insecticide, is regulated because of its severe neurotoxicity, but it is suspected of contaminating agricultural foods in many countries due to illicit use. To reveal unknown effects of methamidophos on human health, we evaluated the developmental immunotoxicity of methamidophos using a respiratory syncytial virus (RSV infection mouse model. Pregnant mice were exposed to methamidophos (10 or 20 ppm in their drinking water from gestation day 10 to weaning on postnatal day 21. Offsprings born to these dams were intranasally infected with RSV. The levels of interleukin-6 (IL-6 and interferon-gamma in the bronchoalveolar lavage fluids after infection were significantly decreased in offspring mice exposed to methamidophos. Treatment with methamidophos did not affect the pulmonary viral titers but suppressed moderately the inflammation of lung tissues of RSV-infected offspring, histopathologically. DNA microarray analysis revealed that gene expression of the cytokines in the lungs of offspring mice exposed to 20 ppm of methamidophos was apparently suppressed compared with the control. Methamidophos did not suppress IL-6 production in RSV-infected J774.1 cell cultures. Thus, exposure of the mother to methamidophos during pregnancy and nursing was suggested to cause an irregular immune response in the lung tissues in the offspring mice.

Delayed contraction of the CD8+ T cell response toward lymphocytic choriomeningitis virus infection in mice lacking serglycin

DEFF Research Database (Denmark)

Grujic, Mirjana; Christensen, Jan P; Sørensen, Maria R

2008-01-01

(-/-)) mice with lymphocytic choriomeningitis virus (LCMV). Wt and SG(-/-) mice cleared 10(3) PFU of highly invasive LCMV with the same kinetics, and the CD8(+) T lymphocytes from wt and SG(-/-) animals did not differ in GrB, perforin, IFN-gamma, or TNF-alpha content. However, when a less invasive LCMV strain...

[Association between intracellular zinc levels and nutritional status in HIV-infected and uninfected children exposed to the virus].

Science.gov (United States)

Gómez G, Erika María; Maldonado C, María Elena; Rojas L, Mauricio; Posada J, Gladys

2015-01-01

Malnutrition, growth retardation and opportunistic infections outlast the metabolic, immune and gastrointestinal disorders produced by HIV. Zinc deficiency has been associated with deteriorating nutritional status, growth failure, and risk of infection. The aim of this study is to determine the association between zinc levels in peripheral blood mononuclear cells (PBMC) and the nutritional status of HIV-infected and uninfected children exposed to the virus. An analytical, observational, cross-sectional study was conducted on 17 infected and 17 exposed children, aged 2-10 years. Anthropometric measurements, clinical and nutritional history, 24h recall, measurement of physical activity, and zinc in PBMC by flow cytometry analysis were recorded. Height according to age, energy consumption and adequacy of energy, protein and dietary zinc were significantly higher in children exposed to the virus compared to those infected with HIV (P .05). However, the median levels of zinc in monocytes of infected patients was higher (218.6) compared to the control group (217.0). No association was found between zinc intake and levels of intracellular zinc. The deterioration of nutritional status and growth retardation in children were associated with HIV, but not with the levels of intracellular zinc. The dietary intake of this nutrient was not associated with levels of zinc in monocytes or CD4 + and CD4- lymphocytes. Copyright © 2015. Publicado por Elsevier España, S.L.U.

Behavioural changes in mice exposed to low level microwave fields

International Nuclear Information System (INIS)

Goiceanu, C.; Gradinaru, F.; Danulescu, R.; Balaceanu, G.; Sandu, D. D.; Avadanei, O. G.

2001-01-01

The aim of our study is to point out some changes in mice behaviour due possibly to exposure to low-level microwave fields. Animals spontaneous behaviour were monitored and the exploring behaviour and motor activity were assessed. Ten selected Swiss male mice were exposed to low-level microwave fields of about 1 mW/cm 2 power density for a relatively long period of time (13 weeks), comparing to their lifetime. The exposure system consists in a transverse electromagnetic (TEM) Cell. A control lot of ten Swiss male mice was used. All twenty mice were selected to be of same age and of 202 g initial body weight. Each animal was placed in his own holder. The behaviour of the animals, from both exposed and control lots, was assessed by using a battery of three behavioural tests. The test sessions were performed every two weeks. During exposure period it was recorded a progressive but moderate loss of motor activity for both exposed and controls, probably due to weight gain and aging. Concerning exploratory activity there is a significant difference between control and exposed animals. Control mice had approximately constant performances in time. On the other hand exposed mice showed a progressive decrease in time of their exploratory ability. Motor activity of exposed animals does not seem to be affected by microwave exposure, in spite of moderate loss in time of motor activity in both lots, as long as it was recorded a quite similar evolution. The difference in performances of exposed and controls concerning exploratory activity seem to emphasise an effect of long-term low-level microwave exposure. The progressive loss in time of exploratory activity of exposed mice, in contrast with controls, could be due to the interference of microwaves with central nervous activity. (authors)

CD47 Promotes Protective Innate and Adaptive Immunity in a Mouse Model of Disseminated Candidiasis

Science.gov (United States)

Navarathna, Dhammika H. M. L. P.; Stein, Erica V.; Lessey-Morillon, Elizabeth C.; Nayak, Debasis; Martin-Manso, Gema; Roberts, David D.

2015-01-01

CD47 is a widely expressed receptor that regulates immunity by engaging its counter-receptor SIRPα on phagocytes and its secreted ligand thrombospondin-1. Mice lacking CD47 can exhibit enhanced or impaired host responses to bacterial pathogens, but its role in fungal immunity has not been examined. cd47 -/- mice on a C57BL/6 background showed significantly increased morbidity and mortality following Candida albicans infection when compared with wild-type mice. Despite normal fungal colonization at earlier times, cd47 -/- mice at four days post-infection had increased colonization of brain and kidneys accompanied by stronger inflammatory reactions. Neutrophil and macrophage numbers were significantly elevated in kidneys and neutrophils in the brains of infected cd47 -/- mice. However, no defect in phagocytic activity towards C. albicans was observed in cd47 -/- bone-marrow-derived macrophages, and neutrophil and macrophage killing of C. albicans was not impaired. CD47-deficiency did not alter the early humoral immune response to C. albicans. Th1, Th2, and Th17 population of CD4+ T cells were expanded in the spleen, and gene expression profiles of spleen and kidney showed stronger pro-inflammatory signaling in infected cd47 -/- mice. The chemoattractant chemokines MIP-2α and MIP-2β were highly expressed in infected spleens of cd47 -/- mice. G-CSF, GM-CSF, and the inflammasome component NLRP3 were more highly expressed in infected cd47 -/- kidneys than in infected wild-type controls. Circulating pro- (TNF-α, IL-6) and anti-inflammatory cytokines (IL-10) were significantly elevated, but IL-17 was decreased. These data indicate that CD47 plays protective roles against disseminated candidiasis and alters pro-inflammatory and immunosuppressive pathways known to regulate innate and T cell immunity. PMID:26010544

Effects of Lycium barbarum Polysaccharides on Apoptosis, Cellular Adhesion, and Oxidative Damage in Bone Marrow Mononuclear Cells of Mice Exposed to Ionizing Radiation Injury.

Science.gov (United States)

Zhou, Jing; Pang, Hua; Li, Wenbo; Liu, Qiong; Xu, Lu; Liu, Qian; Liu, Ying

2016-01-01

Lycium barbarum has been used for more than 2500 years as a traditional herb and food in China. We investigated the effects of Lycium barbarum polysaccharides (LBP) on apoptosis, oxidative damage, and expression of adhesion molecules in bone marrow mononuclear cells (BMNC) of mice injured by ionizing radiation. Kunming mice were exposed to X-rays; then mice in the LBP groups were continuously injected with various concentrations of LBP intraperitoneally for 14 days. Mice in the control group were continuously injected with normal saline (NS) by the same route for 14 days. A normal group was set up. After 1, 7, and 14 days of treatment, mice were killed and BMNC were extracted. Cell cycle, apoptosis, and the expression of adhesion molecules CD44 and CD49d were detected by flow cytometry. The levels of malondialdehyde (MDA) and superoxide dismutase (SOD) were identified by colorimetric analyses. LBP significantly decreased the percentage of G0/G1 phase, apoptosis, MDA level, and expression of CD44 and CD49d and distinctly increased the activity of SOD. LBP showed a protective effect on BMNC against ionizing radiation-induced apoptosis and oxidative damage and altered the expression of adhesion molecule.

Ligation of TLR7 on CD19(+) CD1d(hi) B cells suppresses allergic lung inflammation via regulatory T cells.

Science.gov (United States)

Khan, Adnan R; Amu, Sylvie; Saunders, Sean P; Hams, Emily; Blackshields, Gordon; Leonard, Martin O; Weaver, Casey T; Sparwasser, Tim; Sheils, Orla; Fallon, Padraic G

2015-06-01

B cells have been described as having the capacity to regulate cellular immune responses and suppress inflammatory processes. One such regulatory B-cell population is defined as IL-10-producing CD19(+) CD1d(hi) cells. Previous work has identified an expansion of these cells in mice infected with the helminth, Schistosoma mansoni. Here, microarray analysis of CD19(+) CD1d(hi) B cells from mice infected with S. mansoni demonstrated significantly increased Tlr7 expression, while CD19(+) CD1d(hi) B cells from uninfected mice also demonstrated elevated Tlr7 expression. Using IL-10 reporter, Il10(-/-) and Tlr7(-/-) mice, we formally demonstrate that TLR7 ligation of CD19(+) CD1d(hi) B cells increases their capacity to produce IL-10. In a mouse model of allergic lung inflammation, the adoptive transfer of TLR7-elicited CD19(+) CD1d(hi) B cells reduced airway inflammation and associated airway hyperresponsiveness. Using DEREG mice to deplete FoxP3(+) T regulatory cells in allergen-sensitized mice, we show that that TLR7-elicited CD19(+) CD1d(hi) B cells suppress airway hyperresponsiveness via a T regulatory cell dependent mechanism. These studies identify that TLR7 stimulation leads to the expansion of IL-10-producing CD19(+) CD1d(hi) B cells, which can suppress allergic lung inflammation via T regulatory cells. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Incomplete effector/memory differentiation of antigen-primed CD8+ T cells in gene gun DNA-vaccinated mice

DEFF Research Database (Denmark)

Bartholdy, Christina; Stryhn, Anette; Hansen, Nils Jacob Vest

2003-01-01

DNA vaccination is an efficient way to induce CD8+ T cell memory, but it is still unclear to what extent such memory responses afford protection in vivo. To study this, we induced CD8+ memory responses directed towards defined viral epitopes, using DNA vaccines encoding immunodominant MHC class I......-restricted epitopes of lymphocytic choriomeningitis virus covalently linked to beta2-microglobulin. This vaccine construct primed for a stronger recall response than did a more conventional minigene construct. Despite this, vaccinated mice were only protected against systemic infection whereas protection against...... sites. Thus, our DNA vaccine induces a long-lived memory CD8+ T cell population that provides efficient protection against high-dose systemic infection. However, viral replication in solid non-lymphoid organs is not curtailed sufficiently fast to prevent significant virus-induced inflammation. Our...

Depletion of alveolar macrophages in CD11c diphtheria toxin receptor mice produces an inflammatory response

Science.gov (United States)

Roberts, Lydia M; Ledvina, Hannah E; Tuladhar, Shraddha; Rana, Deepa; Steele, Shaun P; Sempowski, Gregory D; Frelinger, Jeffrey A

2015-01-01

Alveolar macrophages play a critical role in initiating the immune response to inhaled pathogens and have been shown to be the first cell type infected following intranasal inoculation with several pathogens, including Francisella tularensis. In an attempt to further dissect the role of alveolar macrophages in the immune response to Francisella, we selectively depleted alveolar macrophages using CD11c.DOG mice. CD11c.DOG mice express the diphtheria toxin receptor (DTR) under control of the full CD11c promoter. Because mice do not express DTR, tissue restricted expression of the primate DTR followed by treatment with diphtheria toxin (DT) has been widely used as a tool in immunology to examine the effect of acute depletion of a specific immune subset following normal development. We successfully depleted alveolar macrophages via intranasal administration of DT. However, alveolar macrophage depletion was accompanied by many other changes to the cellular composition and cytokine/chemokine milieu in the lung that potentially impact innate and adaptive immune responses. Importantly, we observed a transient influx of neutrophils in the lung and spleen. Our experience serves as a cautionary note to other researchers using DTR mice given the complex changes that occur following DT treatment that must be taken into account when analyzing data. PMID:26029367

HTLV-1 Infection and Neuropathogenesis in the Context of Rag1-/-γc-/- (RAG1-Hu) and BLT Mice.

Science.gov (United States)

Ginwala, Rashida; Caruso, Breanna; Khan, Zafar K; Pattekar, Ajinkya; Chew, Glen M; Corley, Michael J; Loonawat, Ronak; Jacobson, Steven; Sreedhar, Sreesha; Ndhlovu, Lishomwa C; Jain, Pooja

2017-09-01

To date, the lack of a suitable small animal model has hindered our understanding of Human T-cell lymphotropic virus (HTLV)-1 chronic infection and associated neuropathogenesis defined as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The host immune response plays a critical role in the outcome of HTLV-1 infection, which could be better tested in the context of humanized (hu) mice. Thus, we employ here the Balb/c-Rag1 -/- γc -/- or Rag1 as well as Bone marrow-Liver-Thymic (BLT) mouse models for engraftment of human CD34 + hematopoietic stem cells. Flow cytometry and histological analyses confirmed reconstitution of Rag1 and BLT mice with human immune cells. Following HTLV-1 infection, proviral load (PVL) was detected in the blood of Rag-1 and BLT hu-mice as early as 2 weeks post-infection (wpi) with sustained elevation in the subsequent weeks followed by Tax expression. Additionally, infection was compared between adult and neonatal Rag1 mice with both PVL and Tax expression considerably higher in the adult Rag1 mice as compared to the neonates. Establishment of peripheral infection led to lymphocytic infiltration with concomitant Tax expression and resulting myelin disruption within the central nervous system of infected mice. In addition, up-regulation in the expression of several immune checkpoint mediators such as programmed cell death-1 (PD-1), T-cell Ig and ITIM domain (TIGIT), and T cell Ig and mucin domain-3 protein (Tim-3) were observed on CD8 + T cells in various organs including the CNS of infected hu-mice. Collectively, these studies represent the first attempt to establish HTLV-1 neuropathogenesis in the context of Rag-1 and BLT hu-mice as potential novel tools for understanding HTLV-1 neuropathogenesis and testing of novel therapies such as immune checkpoint blockade in the amelioration of chronic HTLV-1 infection.

Protein energy malnutrition decreases immunity and increases susceptibility to influenza infection in mice.

Science.gov (United States)

Taylor, Andrew K; Cao, Weiping; Vora, Keyur P; De La Cruz, Juan; Shieh, Wun-Ju; Zaki, Sherif R; Katz, Jacqueline M; Sambhara, Suryaprakash; Gangappa, Shivaprakash

2013-02-01

Protein energy malnutrition (PEM), a common cause of secondary immune deficiency in children, is associated with an increased risk of infections. Very few studies have addressed the relevance of PEM as a risk factor for influenza. We investigated the influence of PEM on susceptibility to, and immune responses following, influenza virus infection using isocaloric diets providing either adequate protein (AP; 18%) or very low protein (VLP; 2%) in a mouse model. We found that mice maintained on the VLP diet, when compared to mice fed with the AP diet, exhibited more severe disease following influenza infection based on virus persistence, trafficking of inflammatory cell types to the lung tissue, and virus-induced mortality. Furthermore, groups of mice maintained on the VLP diet showed significantly lower virus-specific antibody response and a reduction in influenza nuclear protein-specific CD8(+) T cells compared with mice fed on the AP diet. Importantly, switching diets for the group maintained on the VLP diet to the AP diet improved virus clearance, as well as protective immunity to viral challenge. Our results highlight the impact of protein energy on immunity to influenza infection and suggest that balanced protein energy replenishment may be one strategy to boost immunity against influenza viral infections.

Persistent infection with ebola virus under conditions of partial immunity.

Science.gov (United States)

Gupta, Manisha; Mahanty, Siddhartha; Greer, Patricia; Towner, Jonathan S; Shieh, Wun-Ju; Zaki, Sherif R; Ahmed, Rafi; Rollin, Pierre E

2004-01-01

Ebola hemorrhagic fever in humans is associated with high mortality; however, some infected hosts clear the virus and recover. The mechanisms by which this occurs and the correlates of protective immunity are not well defined. Using a mouse model, we determined the role of the immune system in clearance of and protection against Ebola virus. All CD8 T-cell-deficient mice succumbed to subcutaneous infection and had high viral antigen titers in tissues, whereas mice deficient in B cells or CD4 T cells cleared infection and survived, suggesting that CD8 T cells, independent of CD4 T cells and antibodies, are critical to protection against subcutaneous Ebola virus infection. B-cell-deficient mice that survived the primary subcutaneous infection (vaccinated mice) transiently depleted or not depleted of CD4 T cells also survived lethal intraperitoneal rechallenge for >/==" BORDER="0">25 days. However, all vaccinated B-cell-deficient mice depleted of CD8 T cells had high viral antigen titers in tissues following intraperitoneal rechallenge and died within 6 days, suggesting that memory CD8 T cells by themselves can protect mice from early death. Surprisingly, vaccinated B-cell-deficient mice, after initially clearing the infection, were found to have viral antigens in tissues later (day 120 to 150 post-intraperitoneal infection). Furthermore, following intraperitoneal rechallenge, vaccinated B-cell-deficient mice that were transiently depleted of CD4 T cells had high levels of viral antigen in tissues earlier (days 50 to 70) than vaccinated undepleted mice. This demonstrates that under certain immunodeficiency conditions, Ebola virus can persist and that loss of primed CD4 T cells accelerates the course of persistent infections. These data show that CD8 T cells play an important role in protection against acute disease, while both CD4 T cells and antibodies are required for long-term protection, and they provide evidence of persistent infection by Ebola virus suggesting

The Function of CD3+CD56+ NKT-Like Cells in HIV-Infected Individuals

Directory of Open Access Journals (Sweden)

Yongjun Jiang

2014-01-01

Full Text Available CD3+CD56+ NKT-like cells are one of the critical effectors in the immune response to viral infection and tumors, but the functional features of NKT-like cells in HIV infection have been rarely reported. In this study, we observed and described the state of NKT-like cell functions in primary HIV-infected individuals (PHIs, chronic HIV-infected individuals (CHIs, long-term nonprogressors (LTNPs, and HIV-negative controls (NCs. The results showed that the percentage of IFN-γ+CD3+CD56+ NKT-like cells was notably higher in LTNPs compared with CHIs, and the proportion of CD3+CD56+ NKT-like cells with dual function (IFN-γ+CD107a+ NKT-like cells in LTNPs was also much higher than in CHIs. Additionally, the percentages of IFN-γ+CD107a+ NKT-like cells negatively correlated with viral load. Taken together, our data demonstrated that good functions of CD3+CD56+ NKT-like cells in LTNPs likely occurred as a protective mechanism that slows down HIV disease progression.

The function of CD3+CD56+ NKT-like cells in HIV-infected individuals.

Science.gov (United States)

Jiang, Yongjun; Cui, Xiaojian; Cui, Chen; Zhang, Jian; Zhou, Fangyuan; Zhang, Zining; Fu, Yajing; Xu, Junjie; Chu, Zhenxing; Liu, Jing; Han, Xiaoxu; Liao, Christina; Wang, Yanan; Cao, Yaming; Shang, Hong

2014-01-01

CD3(+)CD56(+) NKT-like cells are one of the critical effectors in the immune response to viral infection and tumors, but the functional features of NKT-like cells in HIV infection have been rarely reported. In this study, we observed and described the state of NKT-like cell functions in primary HIV-infected individuals (PHIs), chronic HIV-infected individuals (CHIs), long-term nonprogressors (LTNPs), and HIV-negative controls (NCs). The results showed that the percentage of IFN-γ(+)CD3(+)CD56(+) NKT-like cells was notably higher in LTNPs compared with CHIs, and the proportion of CD3(+)CD56(+) NKT-like cells with dual function (IFN-γ(+)CD107a(+) NKT-like cells) in LTNPs was also much higher than in CHIs. Additionally, the percentages of IFN-γ(+)CD107a(+) NKT-like cells negatively correlated with viral load. Taken together, our data demonstrated that good functions of CD3(+)CD56(+) NKT-like cells in LTNPs likely occurred as a protective mechanism that slows down HIV disease progression.

Requirement for CD4 T Cell Help in Generating Functional CD8 T Cell Memory

Science.gov (United States)

Shedlock, Devon J.; Shen, Hao

2003-04-01

Although primary CD8 responses to acute infections are independent of CD4 help, it is unknown whether a similar situation applies to secondary responses. We show that depletion of CD4 cells during the recall response has minimal effect, whereas depletion during the priming phase leads to reduced responses by memory CD8 cells to reinfection. Memory CD8 cells generated in CD4+/+ mice responded normally when transferred into CD4-/- hosts, whereas memory CD8 cells generated in CD4-/- mice mounted defective recall responses in CD4+/+ adoptive hosts. These results demonstrate a previously undescribed role for CD4 help in the development of functional CD8 memory.

Increased Susceptibility of Humanized NSG Mice to Panton-Valentine Leukocidin and Staphylococcus aureus Skin Infection.

Directory of Open Access Journals (Sweden)

Ching Wen Tseng

Full Text Available Staphylococcus aureus is a leading cause of skin and soft-tissue infections worldwide. Mice are the most commonly used animals for modeling human staphylococcal infections. However a supra-physiologic S. aureus inoculum is required to establish gross murine skin pathology. Moreover, many staphylococcal factors, including Panton-Valentine leukocidin (PVL elaborated by community-associated methicillin-resistant S. aureus (CA-MRSA, exhibit selective human tropism and cannot be adequately studied in mice. To overcome these deficiencies, we investigated S. aureus infection in non-obese diabetic (NOD/severe combined immune deficiency (SCID/IL2rγnull (NSG mice engrafted with human CD34+ umbilical cord blood cells. These "humanized" NSG mice require one to two log lower inoculum to induce consistent skin lesions compared with control mice, and exhibit larger cutaneous lesions upon infection with PVL+ versus isogenic PVL- S. aureus. Neutrophils appear important for PVL pathology as adoptive transfer of human neutrophils alone to NSG mice was sufficient to induce dermonecrosis following challenge with PVL+ S. aureus but not PVL- S. aureus. PMX53, a human C5aR inhibitor, blocked PVL-induced cellular cytotoxicity in vitro and reduced the size difference of lesions induced by the PVL+ and PVL- S. aureus, but PMX53 also reduced recruitment of neutrophils and exacerbated the infection. Overall, our findings establish humanized mice as an important translational tool for the study of S. aureus infection and provide strong evidence that PVL is a human virulence factor.

Mechanisms involved in the differential recovery of CD4 and CD8 T-lymphocytes after local irradiation in mice

International Nuclear Information System (INIS)

De Ruysscher, D; Waer, M.; Vandeputte, M.; Van der Schueren, E.

1990-01-01

The mechanisms involved in the differential recovery of CD4 (helper/inducer phenotype) and CD8 (Cytotoxic/suppressor phenotype) T-lymphocytes after fractionated local irradiation were investigated. In mice, a better recovery of CD4 cells than of CD8 cells was found, while the reverse has been described in humans. Differences in radiosensivitity between CD4 and CD8 mouse splenocytes could not be found. No sequestration of CD8 cells in irradiated tissues could be demonstrated. Irradiation of the thymus did not influence the observed immune changes. Altered thymic production of CD4 and CD8 cells could be excluded by intrathymic injection of FITC (fluorescein isothiocyanate). Hindlimb and tail irradiation did suggest that the differential recovery of CD4 and CD8 T-lymphocytes after local irradiation is determined by extrathymic factors in man and mice, and that the observed differences in immune recovery between man and mice are due to defective thymic function in the former and normal function in the latter. (author). 12 refs.; 5 figs.; 2 tabs

Dual function of CD70 in viral infection: modulator of early cytokine responses and activator of adaptive responses1

OpenAIRE

Allam, Atef; Swiecki, Melissa; Vermi, William; Ashwell, Jonathan D.; Colonna, Marco

2014-01-01

The role of the tumor necrosis factor family member CD70 in adaptive T cell responses has been intensively studied but its function in innate responses is still under investigation. Here we show that CD70 inhibits the early innate response to murine cytomegalovirus (MCMV) but is essential for the optimal generation of virus-specific CD8 T cells. CD70-/- mice reacted to MCMV infection with a robust type I interferon and proinflammatory cytokine response. This response was sufficient for initia...

Surface protein Adr2 of Rickettsia rickettsii induced protective immunity against Rocky Mountain spotted fever in C3H/HeN mice.

Science.gov (United States)

Gong, Wenping; Xiong, Xiaolu; Qi, Yong; Jiao, Jun; Duan, Changsong; Wen, Bohai

2014-04-11

Rickettsia rickettsii is the pathogen of Rocky Mountain spotted fever (RMSF), a life-threatening tick-transmitted infection. Adr2 was a surface-exposed adhesion protein of R. rickettsii and its immunoprotection against RMSF was investigated in mice. Recombinant Adr2 (rAdr2) was used to immunize C3H/HeN mice, and the rickettsial loads in organs of the mice were detected after challenge with R. rickettsii. The levels of specific antibodies of sera from the immunized mice were determined and the sera from immunized mice were applied to neutralize R. rickettsii. Proliferation and cytokine secretion of CD4(+) and CD8(+) T cells isolated from R. rickettsii-infected mice were also assayed after rAdr2 stimulation. After R. rickettsii challenge, the rickettsial loads in spleens, livers, and lungs were significantly lower and the impairment degrees of these organs in rAdr2-immunized mice were markedly slighter, compared with those in negative control mice. The ratio of specific IgG2a/IgG1 of rAdr2-immunized mice kept increasing during the immunization. After treatment with rAdr2-immunized sera, the total number of R. rickettsii organisms adhering and invading host cells was significantly lower than that treated with PBS-immunized sera. Interferon-γ secretion by CD4(+) or CD8(+) T cells and tumor necrosis factor-α secretion by CD4(+) T cells from R. rickettsii-infected mice were respectively significantly greater than those from uninfected mice after rAdr2 stimulation. Adr2 is a protective antigen of R. rickettsii. Protection offered by Adr2 is mainly dependent on antigen-specific cell-mediated immune responses, including efficient activity of CD4(+) and CD8(+) T cells to produce great amount of TNF-α and/or IFN-γ as well as rapid increase of specific IgG2a, which synergistically activate and opsonize host cells to killing intracellular rickettsiae. Copyright © 2014 Elsevier Ltd. All rights reserved.

Analysis of the T Cell Response to Zika Virus and Identification of a Novel CD8+ T Cell Epitope in Immunocompetent Mice.

Directory of Open Access Journals (Sweden)

Ryan D Pardy

2017-02-01

Full Text Available Zika virus (ZIKV is an emerging arbovirus of the Flaviviridae family. Although ZIKV infection is typically mild and self-limiting in healthy adults, infection has been associated with neurological symptoms such as Guillain-Barré syndrome, and a causal link has been established between fetal microcephaly and ZIKV infection during pregnancy. These risks, and the magnitude of the ongoing ZIKV pandemic, have created an urgent need for the development of animal models to study the immune response to ZIKV infection. Previous animal models have primarily focused on pathogenesis in immunocompromised mice. In this study, we provide a model of ZIKV infection in wild-type immunocompetent C57BL/6 mice, and have provided an analysis of the immune response to infection. We evaluated the activation of several innate immune cell types, and studied the kinetics, phenotype, and functionality of T cell responses to ZIKV infection. Our results demonstrate that ZIKV infection is mild in wild-type immunocompetent C57BL/6 mice, resulting in minimal morbidity. Our data establish that at the peak of the adaptive response, antigen-experienced CD4+ T cells polarize to a Th1 phenotype, and antigen-experienced CD8+ T cells exhibit an activated effector phenotype, producing both effector cytokines and cytolytic molecules. Furthermore, we have identified a novel ZIKV CD8+ T cell epitope in the envelope protein that is recognized by the majority of responding cells. Our model provides an important reference point that will help dissect the impact of polymorphisms in the circulating ZIKV strains on the immune response and ZIKV pathogenesis. In addition, the identification of a ZIKV epitope will allow for the design of tetramers to study epitope-specific T cell responses, and will have important implications for the design and development of ZIKV vaccine strategies.

Brugia malayi Antigen (BmA Inhibits HIV-1 Trans-Infection but Neither BmA nor ES-62 Alter HIV-1 Infectivity of DC Induced CD4+ Th-Cells.

Directory of Open Access Journals (Sweden)

Emily E I M Mouser

Full Text Available One of the hallmarks of HIV-1 disease is the association of heightened CD4+ T-cell activation with HIV-1 replication. Parasitic helminths including filarial nematodes have evolved numerous and complex mechanisms to skew, dampen and evade human immune responses suggesting that HIV-1 infection may be modulated in co-infected individuals. Here we studied the effects of two filarial nematode products, adult worm antigen from Brugia malayi (BmA and excretory-secretory product 62 (ES-62 from Acanthocheilonema viteae on HIV-1 infection in vitro. Neither BmA nor ES-62 influenced HIV-1 replication in CD4+ enriched T-cells, with either a CCR5- or CXCR4-using virus. BmA, but not ES-62, had the capacity to bind the C-type lectin dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN thereby inhibiting HIV-1 trans-infection of CD4+ enriched T-cells. As for their effect on DCs, neither BmA nor ES-62 could enhance or inhibit DC maturation as determined by CD83, CD86 and HLA-DR expression, or the production of IL-6, IL-10, IL-12 and TNF-α. As expected, due to the unaltered DC phenotype, no differences were found in CD4+ T helper (Th cell phenotypes induced by DCs treated with either BmA or ES-62. Moreover, the HIV-1 susceptibility of the Th-cell populations induced by BmA or ES-62 exposed DCs was unaffected for both CCR5- and CXCR4-using HIV-1 viruses. In conclusion, although BmA has the potential capacity to interfere with HIV-1 transmission or initial viral dissemination through preventing the virus from interacting with DCs, no differences in the Th-cell polarizing capacity of DCs exposed to BmA or ES-62 were observed. Neither antigenic source demonstrated beneficial or detrimental effects on the HIV-1 susceptibility of CD4+ Th-cells induced by exposed DCs.

TCR stimulation strength is inversely associated with establishment of functional brain-resident memory CD8 T cells during persistent viral infection.

Science.gov (United States)

Maru, Saumya; Jin, Ge; Schell, Todd D; Lukacher, Aron E

2017-04-01

Establishing functional tissue-resident memory (TRM) cells at sites of infection is a newfound objective of T cell vaccine design. To directly assess the impact of antigen stimulation strength on memory CD8 T cell formation and function during a persistent viral infection, we created a library of mouse polyomavirus (MuPyV) variants with substitutions in a subdominant CD8 T cell epitope that exhibit a broad range of efficiency in stimulating TCR transgenic CD8 T cells. By altering a subdominant epitope in a nonstructural viral protein and monitoring memory differentiation of donor monoclonal CD8 T cells in immunocompetent mice, we circumvented potentially confounding changes in viral infection levels, virus-associated inflammation, size of the immunodominant virus-specific CD8 T cell response, and shifts in TCR affinity that may accompany temporal recruitment of endogenous polyclonal cells. Using this strategy, we found that antigen stimulation strength was inversely associated with the function of memory CD8 T cells during a persistent viral infection. We further show that CD8 TRM cells recruited to the brain following systemic infection with viruses expressing epitopes with suboptimal stimulation strength respond more efficiently to challenge CNS infection with virus expressing cognate antigen. These data demonstrate that the strength of antigenic stimulation during recruitment of CD8 T cells influences the functional integrity of TRM cells in a persistent viral infection.

Jejunal brush border microvillous alterations in Giardia muris-infected mice: role of T lymphocytes and interleukin-6.

Science.gov (United States)

Scott, K G; Logan, M R; Klammer, G M; Teoh, D A; Buret, A G

2000-06-01

Intestinal colonization with the protozoan Giardia causes diffuse brush border microvillous alterations and disaccharidase deficiencies, which in turn are responsible for intestinal malabsorption and maldigestion. The role of T cells and/or cytokines in the pathogenesis of Giardia-induced microvillous injury remains unclear. The aim of this study was to assess the role of T cells and interleukin-6 (IL-6) in the brush border pathophysiology of acute murine giardiasis in vivo. Athymic nude (nu(-)/nu(-)) CD-1 mice and isogenic immunocompetent (nu(+)/nu(+)) CD-1 mice (4 weeks old) received an axenic Giardia muris trophozoite inoculum or vehicle (control) via orogastric gavage. Weight gain and food intake were assessed daily. On day 6, segments of jejunum were assessed for parasite load, brush border ultrastructure, IL-6 content, maltase and sucrase activities, villus-crypt architecture, and intraepithelial lymphocyte (IEL) infiltration. Despite similar parasitic loads on day 6, infected immunocompetent animals, but not infected nude mice, showed a diffuse loss of brush border microvillous surface area, which was correlated with a significant reduction in maltase and sucrase activities and a decrease in jejunal IL-6 concentration. In both athymic control and infected mice, jejunal brush border surface area and disaccharidases were high, but levels of tissue IL-6 were low and comparable to the concentration measured in immunocompetent infected animals. In both immunocompetent and nude mice, infection caused a small but significant increase in the numbers of IELs. These findings suggest that the enterocyte brush border injury and malfunction seen in giardiasis is, at least in part, mediated by thymus-derived T lymphocytes and that suppressed jejunal IL-6 does not necessarily accompany microvillous shortening.

Low doses of 17α-ethinyl estradiol alter the maternal brain and induce stereotypies in CD-1 mice exposed during pregnancy and lactation.

Science.gov (United States)

Catanese, Mary C; Vandenberg, Laura N

2017-10-01

Maternal care is critical for the survival, development and long-term success of offspring. Despite our current understanding of the role of endogenous estrogen in both maternal behavior and the maternal brain, the potential effects of exogenous estrogens on these endpoints remain poorly understood. Here, pregnant CD-1 mice were exposed to low doses of 17α-ethinyl estradiol (EE2), commonly used as a positive control in studies of other xenoestrogens, from day 9 of pregnancy until weaning. Using traditional maternal behavior assays, we document no significant changes in maternal behavior throughout the lactational period. However, EE2 induced increases in repetitive tail retrieval, which may indicate a stereotypy or obsessive compulsive (OCD)-like behavior. We also observed a significant reduction in tyrosine hydroxylase (TH) immunoreactivity in the ventral tegmental area (VTA), a region important for maternal motivation. These results suggest that pregnant adult females are not immune to the effects of this compound. Copyright © 2017 Elsevier Inc. All rights reserved.

Development of a Murine Model for Aerosolized Ebolavirus Infection Using a Panel of Recombinant Inbred Mice

Directory of Open Access Journals (Sweden)

Malak Kotb

2012-12-01

Full Text Available Countering aerosolized filovirus infection is a major priority of biodefense research.  Aerosol models of filovirus infection have been developed in knock-out mice, guinea pigs and non-human primates; however, filovirus infection of immunocompetent mice by the aerosol route has not been reported.  A murine model of aerosolized filovirus infection in mice should be useful for screening vaccine candidates and therapies.  In this study, various strains of wild-type and immunocompromised mice were exposed to aerosolized wild-type (WT or mouse-adapted (MA Ebola virus (EBOV.  Upon exposure to aerosolized WT-EBOV, BALB/c, C57BL/6 (B6, and DBA/2 (D2 mice were unaffected, but 100% of severe combined immunodeficiency (SCID and 90% of signal transducers and activators of transcription (Stat1 knock-out (KO mice became moribund between 7–9 days post-exposure (dpe.  Exposure to MA-EBOV caused 15% body weight loss in BALB/c, but all mice recovered.  In contrast, 10–30% lethality was observed in B6 and D2 mice exposed to aerosolized MA-EBOV, and 100% of SCID, Stat1 KO, interferon (IFN-γ KO and Perforin KO mice became moribund between 7–14 dpe. In order to identify wild-type, inbred, mouse strains in which exposure to aerosolized MA-EBOV is uniformly lethal, 60 BXD (C57BL/6 crossed with DBA/2 recombinant inbred (RI and advanced RI (ARI mouse strains were exposed to aerosolized MA-EBOV, and monitored for disease severity. A complete spectrum of disease severity was observed. All BXD strains lost weight but many recovered. However, infection was uniformly lethal within 7 to 12 days post-exposure in five BXD strains.  Aerosol exposure of these five BXD strains to 10-fold less MA-EBOV resulted in lethality ranging from 0% in two strains to 90–100% lethality in two strains.  Analysis of post-mortem tissue from BXD strains that became moribund and were euthanized at the lower dose of MA-EBOV, showed liver damage in all mice as well as lung lesions in

Effect of parsley (Petroselinum crispum, Apiaceae) juice against cadmium neurotoxicity in albino mice (Mus musculus).

Science.gov (United States)

Maodaa, Saleh N; Allam, Ahmed A; Ajarem, Jamaan; Abdel-Maksoud, Mostafa A; Al-Basher, Gadah I; Wang, Zun Yao

2016-02-04

Parsley was employed as an experimental probe to prevent the behavioral, biochemical and morphological changes in the brain tissue of the albino mice following chronic cadmium (Cd) administration. Non-anesthetized adult male mice were given parsley juice (Petroselinum crispum, Apiaceae) daily by gastric intubation at doses of 10 and 20 g/kg/day. The animals were divided into six groups: Group A, mice were exposed to saline; Groups B and C, were given low and high doses of parsley juice, respectively; Group D, mice were exposed to Cd; Groups E and F, were exposed to Cd and concomitantly given low and high doses of parsley, respectively. Cd intoxication can cause behavioral abnormalities, biochemical and histopathological disturbances in treated mice. Parsley juice has significantly improved the Cd-associated behavioral changes, reduced the elevation of lipid peroxidation and normalized the Cd effect on reduced glutathione and peroxidase activities in the brain of treated mice. Histological data have supported these foundations whereas Cd treatment has induced neuronal degeneration, chromatolysis and pyknosis in the cerebrum, cerebellum and medulla oblongata. The low dose (5 g/kg/day) of parsley exhibited beneficial effects in reducing the deleterious changes associated with Cd treatment on the behavior, neurotransmitters level, oxidative stress and brain neurons of the Cd-treated mice.

Suppression of IL-12p70 formation by IL-2 or following macrophage depletion causes T-cell autoreactivity leading to CNS demyelination in HSV-1-infected mice.

Directory of Open Access Journals (Sweden)

Dhong Hyun Lee

2017-05-01

Full Text Available We have established two mouse models of central nervous system (CNS demyelination that differ from most other available models of multiple sclerosis (MS in that they represent a mixture of viral and immune triggers. In the first model, ocular infection of different strains of mice with a recombinant HSV-1 that expresses murine IL-2 constitutively (HSV-IL-2 causes CNS demyelination. In the second model, depletion of macrophages causes CNS demyelination in mice that are ocularly infected with wild-type (WT HSV-1. In the present study, we found that the demyelination in macrophage-intact mice infected with HSV-IL-2 was blocked by depletion of FoxP3-expressing cells, while concurrent depletion of macrophages restored demyelination. In contrast, demyelination was blocked in the macrophage-depleted mice infected with wild-type HSV-1 following depletion of FoxP3-expressing cells. In macrophage-depleted HSV-IL-2-infected mice, demyelination was associated with the activity of both CD4+ and CD8+ T cells, whereas in macrophage-depleted mice infected with WT HSV-1, demyelination was associated with CD4+ T cells. Macrophage depletion or infection with HSV-IL-2 caused an imbalance of T cells and TH1 responses as well as alterations in IL-12p35 and IL-12p40 but not other members of the IL-12 family or their receptors. Demyelination was blocked by adoptive transfer of macrophages that were infected with HSV-IL-12p70 or HSV-IL-12p40 but not by HSV-IL-12p35. These results indicate that suppression of IL-12p70 formation by IL-2 or following macrophage depletion causes T-cell autoreactivity leading to CNS demyelination in HSV-1-infected mice.

Helminth Infection and Commensal Microbiota Drive Early IL-10 Production in the Skin by CD4+ T Cells That Are Functionally Suppressive.

Directory of Open Access Journals (Sweden)

David E Sanin

2015-05-01

Full Text Available The skin provides an important first line of defence and immunological barrier to invasive pathogens, but immune responses must also be regulated to maintain barrier function and ensure tolerance of skin surface commensal organisms. In schistosomiasis-endemic regions, populations can experience repeated percutaneous exposure to schistosome larvae, however little is known about how repeated exposure to pathogens affects immune regulation in the skin. Here, using a murine model of repeated infection with Schistosoma mansoni larvae, we show that the skin infection site becomes rich in regulatory IL-10, whilst in its absence, inflammation, neutrophil recruitment, and local lymphocyte proliferation is increased. Whilst CD4+ T cells are the primary cellular source of regulatory IL-10, they expressed none of the markers conventionally associated with T regulatory (Treg cells (i.e. FoxP3, Helios, Nrp1, CD223, or CD49b. Nevertheless, these IL-10+ CD4+ T cells in the skin from repeatedly infected mice are functionally suppressive as they reduced proliferation of responsive CD4+ T cells from the skin draining lymph node. Moreover, the skin of infected Rag-/- mice had impaired IL-10 production and increased neutrophil recruitment. Finally, we show that the mechanism behind IL-10 production by CD4+ T cells in the skin is due to a combination of an initial (day 1 response specific to skin commensal bacteria, and then over the following days schistosome-specific CD4+ T cell responses, which together contribute towards limiting inflammation and tissue damage following schistosome infection. We propose CD4+ T cells in the skin that do not express markers of conventional T regulatory cell populations have a significant role in immune regulation after repeated pathogen exposure and speculate that these cells may also help to maintain skin barrier function in the context of repeated percutaneous insult by other skin pathogens.

Early Life Arsenic Exposure and Acute and Long-term Responses to Influenza A Infection in Mice

OpenAIRE

Ramsey, Kathryn A.; Foong, Rachel E.; Sly, Peter D.; Larcombe, Alexander N.; Zosky, Graeme R.

2013-01-01

Background: Arsenic is a significant global environmental health problem. Exposure to arsenic in early life has been shown to increase the rate of respiratory infections during infancy, reduce childhood lung function, and increase the rates of bronchiectasis in early adulthood. Objective: We aimed to determine if early life exposure to arsenic exacerbates the response to early life influenza infection in mice. Methods: C57BL/6 mice were exposed to arsenic in utero and throughout postnatal lif...

Antigen Requirements for Efficient Priming of CD8+ T Cells by Leishmania major-Infected Dendritic Cells

Science.gov (United States)

Bertholet, Sylvie; Debrabant, Alain; Afrin, Farhat; Caler, Elisabeth; Mendez, Susana; Tabbara, Khaled S.; Belkaid, Yasmine; Sacks, David L.

2005-01-01

CD4+ and CD8+ T-cell responses have been shown to be critical for the development and maintenance of acquired resistance to infections with the protozoan parasite Leishmania major. Monitoring the development of immunodominant or clonally restricted T-cell subsets in response to infection has been difficult, however, due to the paucity of known epitopes. We have analyzed the potential of L. major transgenic parasites, expressing the model antigen ovalbumin (OVA), to be presented by antigen-presenting cells to OVA-specific OT-II CD4+ or OT-I CD8+ T cells. Truncated OVA was expressed in L. major as part of a secreted or nonsecreted chimeric protein with L. donovani 3′ nucleotidase (NT-OVA). Dendritic cells (DC) but not macrophages infected with L. major that secreted NT-OVA could prime OT-I T cells to proliferate and release gamma interferon. A diminished T-cell response was observed when DC were infected with parasites expressing nonsecreted NT-OVA or with heat-killed parasites. Inoculation of mice with transgenic parasites elicited the proliferation of adoptively transferred OT-I T cells and their recruitment to the site of infection in the skin. Together, these results demonstrate the possibility of targeting heterologous antigens to specific cellular compartments in L. major and suggest that proteins secreted or released by L. major in infected DC are a major source of peptides for the generation of parasite-specific CD8+ T cells. The ability of L. major transgenic parasites to activate OT-I CD8+ T cells in vivo will permit the analysis of parasite-driven T-cell expansion, differentiation, and recruitment at the clonal level. PMID:16177338

Spontaneous chondroma formation in CD2-Cre-driven Erk-deficient mice.

Science.gov (United States)

Shiokawa, Moe; Lu, Xiuyuan; Miyake, Yasunobu; Ishikawa, Eri; Pagès, Gilles; Pouysségur, Jacques; Ogata, Masato; Yamasaki, Sho

2017-12-18

Lineage-specific Cre Tg mice are widely used to delineate the functions of genes in a tissue-specific manner. Several T-cell-specific promoter cassettes have been developed; however, the activities of those promoters in non-T cells have not been investigated extensively. Here, we report that CD2-Cre-mediated deletion of Erk proteins by generating CD2-Cre × Erk1-/-Erk2flox/flox (Erk∆CD2-Cre) mice results in abnormal cartilage hyperplasia. Histological analysis revealed that this abnormality is caused by aberrant hyperplasia of chondrocytes. The presence of Erk-deficient T cells is not required for this chondroma formation, as it was similarly observed in the absence of T cells in a CD3ε-deficient background. In addition, adoptive transfer of bone marrow cells from Erk∆CD2-Cre mice to wild-type recipients did not cause chondroma formation, suggesting that Erk-deficient non-immune cells are responsible for this abnormality. By tracing Cre-expressed tissues using a ROSA26-STOP-RFP allele, we found that the chondroma emitted RFP fluorescence, indicating that functional Cre is expressed in hyperplastic chondrocytes in Erk∆CD2-Cre mice. Furthermore, RFP+ chondrocytes were also found in an Erk-sufficient background, albeit without aberrant growth. These results suggest that unexpected expression of CD2-driven Cre in chondrocytes generates Erk-deficient chondrocytes, resulting in hyperplastic cartilage formation. Recently, two independent reports showed that CD4-Cre-mediated Ras-Erk signaling ablation led to similar abnormal cartilage formation (Guittard, G., Gallardo, D. L., Li, W. et al. 2017. Unexpected cartilage phenotype in CD4-Cre-conditional SOS-deficient mice. Front. Immunol. 8:343; Wehenkel, M., Corr, M., Guy, C. S. et al. 2017. Extracellular signal-regulated kinase signaling in CD4-expressing cells inhibits osteochondromas. Front. Immunol. 8:482). Together with these reports, our study suggests that an unexpected link exists between T-like cell and

Auditory stimulation of opera music induced prolongation of murine cardiac allograft survival and maintained generation of regulatory CD4+CD25+ cells

Directory of Open Access Journals (Sweden)

Uchiyama Masateru

2012-03-01

Full Text Available Abstract Background Interactions between the immune response and brain functions such as olfactory, auditory, and visual sensations are likely. This study investigated the effect of sounds on alloimmune responses in a murine model of cardiac allograft transplantation. Methods Naïve CBA mice (H2k underwent transplantation of a C57BL/6 (B6, H2b heart and were exposed to one of three types of music--opera (La Traviata, classical (Mozart, and New Age (Enya--or one of six different single sound frequencies, for 7 days. Additionally, we prepared two groups of CBA recipients with tympanic membrane perforation exposed to opera for 7 days and CBA recipients exposed to opera for 7 days before transplantation (pre-treatment. An adoptive transfer study was performed to determine whether regulatory cells were generated in allograft recipients. Immunohistochemical, cell-proliferation, cytokine, and flow cytometry assessments were also performed. Results CBA recipients of a B6 cardiac graft that were exposed to opera music and Mozart had significantly prolonged allograft survival (median survival times [MSTs], 26.5 and 20 days, respectively, whereas those exposed to a single sound frequency (100, 500, 1000, 5000, 10,000, or 20,000 Hz or Enya did not (MSTs, 7.5, 8, 9, 8, 7.5, 8.5 and 11 days, respectively. Untreated, CBA mice with tympanic membrane perforations and CBA recipients exposed to opera for 7 days before transplantation (pre-treatment rejected B6 cardiac grafts acutely (MSTs, 7, 8 and 8 days, respectively. Adoptive transfer of whole splenocytes, CD4+ cells, or CD4+CD25+ cells from opera-exposed primary allograft recipients resulted in significantly prolonged allograft survival in naive secondary recipients (MSTs, 36, 68, and > 100 days, respectively. Proliferation of splenocytes, interleukin (IL-2 and interferon (IFN-γ production was suppressed in opera-exposed mice, and production of IL-4 and IL-10 from opera-exposed transplant recipients increased

Sequential activation of CD8+ T cells in the draining lymph nodes in response to pulmonary virus infection.

Science.gov (United States)

Yoon, Heesik; Legge, Kevin L; Sung, Sun-sang J; Braciale, Thomas J

2007-07-01

We have used a TCR-transgenic CD8+ T cell adoptive transfer model to examine the tempo of T cell activation and proliferation in the draining lymph nodes (DLN) in response to respiratory virus infection. The T cell response in the DLN differed for mice infected with different type A influenza strains with the onset of T cell activation/proliferation to the A/JAPAN virus infection preceding the A/PR8 response by 12-24 h. This difference in T cell activation/proliferation correlated with the tempo of accelerated respiratory DC (RDC) migration from the infected lungs to the DLN in response to influenza virus infection, with the migrant RDC responding to the A/JAPAN infection exhibiting a more rapid accumulation in the lymph nodes (i.e., peak migration for A/JAPAN at 18 h, A/PR8 at 24-36 h). Furthermore, in vivo administration of blocking anti-CD62L Ab at various time points before/after infection revealed that the virus-specific CD8+ T cells entered the DLN and activated in a sequential "conveyor belt"-like fashion. These results indicate that the tempo of CD8+ T cell activation/proliferation after viral infection is dependent on the tempo of RDC migration to the DLN and that T cell activation occurs in an ordered sequential fashion.

TCR stimulation strength is inversely associated with establishment of functional brain-resident memory CD8 T cells during persistent viral infection.

Directory of Open Access Journals (Sweden)

Saumya Maru

2017-04-01

Full Text Available Establishing functional tissue-resident memory (TRM cells at sites of infection is a newfound objective of T cell vaccine design. To directly assess the impact of antigen stimulation strength on memory CD8 T cell formation and function during a persistent viral infection, we created a library of mouse polyomavirus (MuPyV variants with substitutions in a subdominant CD8 T cell epitope that exhibit a broad range of efficiency in stimulating TCR transgenic CD8 T cells. By altering a subdominant epitope in a nonstructural viral protein and monitoring memory differentiation of donor monoclonal CD8 T cells in immunocompetent mice, we circumvented potentially confounding changes in viral infection levels, virus-associated inflammation, size of the immunodominant virus-specific CD8 T cell response, and shifts in TCR affinity that may accompany temporal recruitment of endogenous polyclonal cells. Using this strategy, we found that antigen stimulation strength was inversely associated with the function of memory CD8 T cells during a persistent viral infection. We further show that CD8 TRM cells recruited to the brain following systemic infection with viruses expressing epitopes with suboptimal stimulation strength respond more efficiently to challenge CNS infection with virus expressing cognate antigen. These data demonstrate that the strength of antigenic stimulation during recruitment of CD8 T cells influences the functional integrity of TRM cells in a persistent viral infection.

Experimental Andes virus infection in deer mice: characteristics of infection and clearance in a heterologous rodent host.

Directory of Open Access Journals (Sweden)

Jessica R Spengler

Full Text Available New World hantaviruses can cause hantavirus cardiopulmonary syndrome with high mortality in humans. Distinct virus species are hosted by specific rodent reservoirs, which also serve as the vectors. Although regional spillover has been documented, it is unknown whether rodent reservoirs are competent for infection by hantaviruses that are geographically separated, and known to have related, but distinct rodent reservoir hosts. We show that Andes virus (ANDV of South America, carried by the long tailed pygmy rice rat (Oligoryzomys longicaudatus, infects and replicates in vitro and in vivo in the deer mouse (Peromyscus maniculatus, the reservoir host of Sin Nombre virus (SNV, found in North America. In experimentally infected deer mice, viral RNA was detected in the blood, lung, heart and spleen, but virus was cleared by 56 days post inoculation (dpi. All of the inoculated deer mice mounted a humoral immune response by 14 dpi, and produced measurable amounts of neutralizing antibodies by 21 dpi. An up-regulation of Ccl3, Ccl4, Ccl5, and Tgfb, a strong CD4⁺ T-cell response, and down-regulation of Il17, Il21 and Il23 occurred during infection. Infection was transient with an absence of clinical signs or histopathological changes. This is the first evidence that ANDV asymptomatically infects, and is immunogenic in deer mice, a non-natural host species of ANDV. Comparing the immune response in this model to that of the immune response in the natural hosts upon infection with their co-adapted hantaviruses may help clarify the mechanisms governing persistent infection in the natural hosts of hantaviruses.

Circulating CD14brightCD16+ 'intermediate' monocytes exhibit enhanced parasite pattern recognition in human helminth infection.

Directory of Open Access Journals (Sweden)

Joseph D Turner

2014-04-01

Full Text Available Circulating monocyte sub-sets have recently emerged as mediators of divergent immune functions during infectious disease but their role in helminth infection has not been investigated. In this study we evaluated whether 'classical' (CD14brightCD16-, 'intermediate' (CD14brightCD16+, and 'non-classical' (CD14dimCD16+ monocyte sub-sets from peripheral blood mononuclear cells varied in both abundance and ability to bind antigenic material amongst individuals living in a region of Northern Senegal which is co-endemic for Schistosoma mansoni and S. haematobium. Monocyte recognition of excretory/secretory (E/S products released by skin-invasive cercariae, or eggs, of S. mansoni was assessed by flow cytometry and compared between S. mansoni mono-infected, S. mansoni and S. haematobium co-infected, and uninfected participants. Each of the three monocyte sub-sets in the different infection groups bound schistosome E/S material. However, 'intermediate' CD14brightCD16+ monocytes had a significantly enhanced ability to bind cercarial and egg E/S. Moreover, this elevation of ligand binding was particularly evident in co-infected participants. This is the first demonstration of modulated parasite pattern recognition in CD14brightCD16+ intermediate monocytes during helminth infection, which may have functional consequences for the ability of infected individuals to respond immunologically to infection.

Enteric parasitic infections in HIV-infected patients with low CD4 counts in Toto, Nigeria

International Nuclear Information System (INIS)

Abaver, D.T.; Nwobegahay, J.M.; Goon, D.T.; Khoza, L.B

2012-01-01

Objectives: Enteric parasites are a major cause of diarrhoea in HIV/AIDS patients with low CD4 counts. Parasitic infections in HIV-infected individuals can reduce their quality of life and life span, especially those who are severely immunosuppressed with a CD4 T-lymphocyte count 0.05). Conclusions: Low CD4 counts in HIV-infected patients can lead to enteric infections. This information strengthens the importance of monitoring CD4 counts and intestinal parasites. Routine CD4 testing will greatly improve the prognosis of HIV positive patients. (author)

CYP2E1-dependent and leptin-mediated hepatic CD57 expression on CD8 + T cells aid progression of environment-linked nonalcoholic steatohepatitis

International Nuclear Information System (INIS)

Seth, Ratanesh Kumar; Das, Suvarthi; Kumar, Ashutosh; Chanda, Anindya; Kadiiska, Maria B.; Michelotti, Gregory; Manautou, Jose; Diehl, Anna Mae; Chatterjee, Saurabh

2014-01-01

Environmental toxins induce a novel CYP2E1/leptin signaling axis in liver. This in turn activates a poorly characterized innate immune response that contributes to nonalcoholic steatohepatitis (NASH) progression. To identify the relevant subsets of T-lymphocytes in CYP2E1-dependent, environment-linked NASH, we utilized a model of diet induced obese (DIO) mice that are chronically exposed to bromodichloromethane. Mice deficient in CYP2E1, leptin (ob/ob mice), or both T and B cells (Pfp/Rag2 double knockout (KO) mice) were used to delineate the role of each of these factors in metabolic oxidative stress-induced T cell activation. Results revealed that elevated levels of lipid peroxidation, tyrosyl radical formation, mitochondrial tyrosine nitration and hepatic leptin as a consequence of metabolic oxidative stress caused increased levels of hepatic CD57, a marker of peripheral blood lymphocytes including NKT cells. CD8 + CD57 + cytotoxic T cells but not CD4 + CD57 + cells were significantly decreased in mice lacking CYP2E1 and leptin. There was a significant increase in the levels of T cell cytokines IL-2, IL-1β, and IFN-γ in bromodichloromethane exposed DIO mice but not in mice that lacked CYP2E1, leptin or T and B cells. Apoptosis as evidenced by TUNEL assay and levels of cleaved caspase-3 was significantly lower in leptin and Pfp/Rag2 KO mice and highly correlated with protection from NASH. The results described above suggest that higher levels of oxidative stress-induced leptin mediated CD8 + CD57 + T cells play an important role in the development of NASH. It also provides a novel insight of immune dysregulation and may be a key biomarker in NASH. - Highlights: • Metabolic oxidative stress caused increased levels of hepatic CD57 expression. • CD8+ CD57+ cytotoxic T cells were decreased in mice lacking CYP2E1 and leptin. • There was a significant increase in T cell cytokines in toxin-treated mice. • Apoptosis was significantly lower in leptin and Pfp

CYP2E1-dependent and leptin-mediated hepatic CD57 expression on CD8 + T cells aid progression of environment-linked nonalcoholic steatohepatitis

Energy Technology Data Exchange (ETDEWEB)

Seth, Ratanesh Kumar; Das, Suvarthi [Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208 (United States); Kumar, Ashutosh [Free Radical Metabolism Group, Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 (United States); Chanda, Anindya [Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208 (United States); Kadiiska, Maria B. [Free Radical Metabolism Group, Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 (United States); Michelotti, Gregory [Division of Gastroenterology, Duke University, Durham, NC 27707 (United States); Manautou, Jose [Dept. of Pharmaceutical Sciences, University of Connecticut, Storrs, CT 06269-3092 (United States); Diehl, Anna Mae [Division of Gastroenterology, Duke University, Durham, NC 27707 (United States); Chatterjee, Saurabh, E-mail: schatt@mailbox.sc.edu [Environmental Health and Disease Laboratory, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208 (United States)

2014-01-01

Environmental toxins induce a novel CYP2E1/leptin signaling axis in liver. This in turn activates a poorly characterized innate immune response that contributes to nonalcoholic steatohepatitis (NASH) progression. To identify the relevant subsets of T-lymphocytes in CYP2E1-dependent, environment-linked NASH, we utilized a model of diet induced obese (DIO) mice that are chronically exposed to bromodichloromethane. Mice deficient in CYP2E1, leptin (ob/ob mice), or both T and B cells (Pfp/Rag2 double knockout (KO) mice) were used to delineate the role of each of these factors in metabolic oxidative stress-induced T cell activation. Results revealed that elevated levels of lipid peroxidation, tyrosyl radical formation, mitochondrial tyrosine nitration and hepatic leptin as a consequence of metabolic oxidative stress caused increased levels of hepatic CD57, a marker of peripheral blood lymphocytes including NKT cells. CD8 + CD57 + cytotoxic T cells but not CD4 + CD57 + cells were significantly decreased in mice lacking CYP2E1 and leptin. There was a significant increase in the levels of T cell cytokines IL-2, IL-1β, and IFN-γ in bromodichloromethane exposed DIO mice but not in mice that lacked CYP2E1, leptin or T and B cells. Apoptosis as evidenced by TUNEL assay and levels of cleaved caspase-3 was significantly lower in leptin and Pfp/Rag2 KO mice and highly correlated with protection from NASH. The results described above suggest that higher levels of oxidative stress-induced leptin mediated CD8 + CD57 + T cells play an important role in the development of NASH. It also provides a novel insight of immune dysregulation and may be a key biomarker in NASH. - Highlights: • Metabolic oxidative stress caused increased levels of hepatic CD57 expression. • CD8+ CD57+ cytotoxic T cells were decreased in mice lacking CYP2E1 and leptin. • There was a significant increase in T cell cytokines in toxin-treated mice. • Apoptosis was significantly lower in leptin and Pfp

CXCR3-dependent CD4⁺ T cells are required to activate inflammatory monocytes for defense against intestinal infection.

Directory of Open Access Journals (Sweden)

Sara B Cohen

Full Text Available Chemokines and their receptors play a critical role in orchestrating immunity to microbial pathogens, including the orally acquired Th1-inducing protozoan parasite Toxoplasma gondii. Chemokine receptor CXCR3 is associated with Th1 responses, and here we use bicistronic CXCR3-eGFP knock-in reporter mice to demonstrate upregulation of this chemokine receptor on CD4⁺ and CD8⁺ T lymphocytes during Toxoplasma infection. We show a critical role for CXCR3 in resistance to the parasite in the intestinal mucosa. Absence of the receptor in Cxcr3⁻/⁻ mice resulted in selective loss of ability to control T. gondii specifically in the lamina propria compartment. CD4⁺ T cells were impaired both in their recruitment to the intestinal lamina propria and in their ability to secrete IFN-γ upon stimulation. Local recruitment of CD11b⁺Ly6C/G⁺ inflammatory monocytes, recently reported to be major anti-Toxoplasma effectors in the intestine, was not impacted by loss of CXCR3. However, inflammatory monocyte activation status, as measured by dual production of TNF-α and IL-12, was severely impaired in Cxcr3⁻/⁻ mice. Strikingly, adoptive transfer of wild-type but not Ifnγ⁻/⁻ CD4⁺ T lymphocytes into Cxcr3⁻/⁻ animals prior to infection corrected the defect in inflammatory macrophage activation, simultaneously reversing the susceptibility phenotype of the knockout animals. Our results establish a central role for CXCR3 in coordinating innate and adaptive immunity, ensuring generation of Th1 effectors and their trafficking to the frontline of infection to program microbial killing by inflammatory monocytes.

Effects of exercise and enrichment on behaviour in CD-1 mice.

Science.gov (United States)

Aujnarain, Amiirah B; Luo, Owen D; Taylor, Natalie; Lai, Jonathan K Y; Foster, Jane A

2018-04-16

A host of scholarly work has characterized the positive effects of exercise and environmental enrichment on behaviour and cognition in animal studies. The purpose of this study was to investigate the uptake and longitudinal impact of exercise and enrichment on the behavioural phenotype of male and female CD-1 mice. CD-1 mice housed in standard (STD) or exercise and enrichment (EE) conditions post-weaning were tested in the 3-chamber sociability test, open field, and elevated plus maze and exercise activity was monitored throughout the enrichment protocol. Male and female EE mice both showed reduced anxiety and activity in the open field and elevated plus maze relative to sex-matched STD mice. EE altered social behaviours in a sex-specific fashion, with only female EE mice showing increased social preference relative to female STD mice and a preference for social novelty only present in male EE mice. This sexual dimorphism was not observed to be a product of exercise uptake, as CD-1 mice of both sexes demonstrated a consistent trend of wheel rotation frequencies. These findings suggest the importance of considering variables such as sex and strain on experimental design variables in future work on environmental enrichment. Copyright © 2018 Elsevier B.V. All rights reserved.

CD28-Negative CD4+ and CD8+ T Cells in Antiretroviral Therapy–Naive HIV-Infected Adults Enrolled in Adult Clinical Trials Group Studies

Science.gov (United States)

Tassiopoulos, Katherine; Landay, Alan; Collier, Ann C.; Connick, Elizabeth; Deeks, Steven G.; Hunt, Peter; Lewis, Dorothy E.; Wilson, Cara; Bosch, Ronald

2012-01-01

Background Individuals infected with human immunodeficiency virus (HIV) have higher risk than HIV-negative individuals for diseases associated with aging. T-cell senescence, characterized by expansion of cells lacking the costimulatory molecule CD28, has been hypothesized to mediate these risks. Methods We measured the percentage of CD28−CD4+ and CD8+ T cells from HIV-infected treatment-naive adults from 5 Adult Clinical Trials Group (ACTG) antiretroviral therapy (ART) studies and the ALLRT (ACTG Longitudinal Linked Randomized Trials) cohort, and from 48 HIV-negative adults. Pretreatment and 96-week posttreatment %CD28− cells were assessed using linear regression for associations with age, sex, race/ethnicity, CD4 count, HIV RNA, ART regimen, and hepatitis C virus (HCV) infection. Results In total, 1291 chronically HIV-infected adults were studied. Pretreatment, lower CD4 count was associated with higher %CD28−CD4+ and %CD28−CD8+ cells. For CD8+ cells, younger age and HCV infection were associated with a lower %CD28−. ART reduced %CD28− levels at week 96 among virally suppressed individuals. Older age was strongly predictive of higher %CD28−CD8+. Compared to HIV-uninfected individuals, HIV-infected individuals maintained significantly higher %CD28−. Conclusions Effective ART reduced the proportion of CD28− T cells. However, levels remained abnormally high and closer to levels in older HIV-uninfected individuals. This finding may inform future research of increased rates of age-associated disease in HIV-infected adults. PMID:22448010

Editor's Highlight: Complete Attenuation of Mouse Lung Cell Proliferation and Tumorigenicity in CYP2F2 Knockout and CYP2F1 Humanized Mice Exposed to Inhaled Styrene for up to 2 Years Supports a Lack of Human Relevance.

Science.gov (United States)

Cruzan, George; Bus, James S; Banton, Marcy I; Sarang, Satinder S; Waites, Robbie; Layko, Debra B; Raymond, James; Dodd, Darol; Andersen, Melvin E

2017-10-01

Styrene is a mouse-specific lung carcinogen, and short-term mode of action studies have demonstrated that cytotoxicity and/or cell proliferation, and genomic changes are dependent on CYP2F2 metabolism. The current study examined histopathology, cell proliferation, and genomic changes in CD-1, C57BL/6 (WT), CYP2F2(-/-) (KO), and CYP2F2(-/-) (CYP2F1, 2B6, 2A13-transgene) (TG; humanized) mice following exposure for up to 104 weeks to 0- or 120-ppm styrene vapor. Five mice per treatment group were sacrificed at 1, 26, 52, and 78 weeks. Additional 50 mice per treatment group were followed until death or 104 weeks of exposure. Cytotoxicity was present in the terminal bronchioles of some CD-1 and WT mice exposed to styrene, but not in KO or TG mice. Hyperplasia in the terminal bronchioles was present in CD-1 and WT mice exposed to styrene, but not in KO or TG mice. Increased cell proliferation, measured by KI-67 staining, occurred in CD-1 and WT mice exposed to styrene for 1 week, but not after 26, 52, or 78 weeks, nor in KO or TG mice. Styrene increased the incidence of bronchioloalveolar adenomas and carcinomas in CD-1 mice. No increase in lung tumors was found in WT despite clear evidence of lung toxicity, or, KO or TG mice. The absence of preneoplastic lesions and tumorigenicity in KO and TG mice indicates that mouse-specific CYP2F2 metabolism is responsible for both the short-term and chronic toxicity and tumorigenicity of styrene, and activation of styrene by CYP2F2 is a rodent MOA that is neither quantitatively or qualitatively relevant to humans. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

High numbers of IL-2-producing CD8+ T cells during viral infection: correlation with stable memory development

DEFF Research Database (Denmark)

Kristensen, Nanna Ny; Christensen, Jan Pravsgaard; Thomsen, Allan Randrup

2002-01-01

that IL-2-producing cells appear slightly delayed compared with the majority of IFN-gamma producing cells, and the relative frequency of the IL-2-producing subset increases with transition into the memory phase. In contrast to acute immunizing infection, few IL-2-producing cells are generated during...... chronic LCMV infection. Furthermore, in MHC class II-deficient mice, which only transiently control LCMV infection, IL-2-producing CD8+ T cells are initially generated, but by 4 weeks after infection this subset has nearly disappeared. Eventually the capacity to produce IFN-gamma also becomes impaired...

Differential Effect of Cytomegalovirus Infection with Age on the Expression of CD57, CD300a, and CD161 on T-Cell Subpopulations

Directory of Open Access Journals (Sweden)

Fakhri Hassouneh

2017-06-01

Full Text Available Immunosenescence is a progressive deterioration of the immune system with aging. It affects both innate and adaptive immunity limiting the response to pathogens and to vaccines. As chronic cytomegalovirus (CMV infection is probably one of the major driving forces of immunosenescence, and its persistent infection results in functional and phenotypic changes to the T-cell repertoire, the aim of this study was to analyze the effect of CMV-seropositivity and aging on the expression of CD300a and CD161 inhibitory receptors, along with the expression of CD57 marker on CD4+, CD8+, CD8+CD56+ (NKT-Like and CD4−CD8− (DN T-cell subsets. Our results showed that, regardless of the T-cell subset, CD57−CD161−CD300a+ T-cells expand with age in CMV-seropositive individuals, whereas CD57−CD161+CD300a+ T-cells decrease. Similarly, CD57+CD161−CD300a+ T-cells expand with age in CMV-seropositive individuals in all subsets except in DN cells and CD57−CD161+CD300a− T-cells decrease in all T-cell subsets except in CD4+ T-cells. Besides, in young individuals, CMV latent infection associates with the expansion of CD57+CD161−CD300a+CD4+, CD57−CD161−CD300a+CD4+, CD57+CD161−CD300a+CD8+, CD57−CD161−CD300a+CD8+, CD57+CD161−CD300a+NKT-like, and CD57+CD161−CD300a+DN T-cells. Moreover, in young individuals, CD161 expression on T-cells is not affected by CMV infection. Changes of CD161 expression were only associated with age in the context of CMV latent infection. Besides, CD300a+CD57+CD161+ and CD300a−CD57+CD161+ phenotypes were not found in any of the T-cell subsets studied except in the DN subpopulation, indicating that in the majority of T-cells, CD161 and CD57 do not co-express. Thus, our results show that CMV latent infection impact on the immune system depends on the age of the individual, highlighting the importance of including CMV serology in any study regarding immunosenescence.

Dysregulation of CD4+CD25+CD127lowFOXP3+ regulatory T cells in HIV-infected pregnant women

DEFF Research Database (Denmark)

Kolte, Lilian; Gaardbo, Julie C; Karlsson, Ingrid

2010-01-01

Pregnancy represents a major challenge to immunologic tolerance. How the fetal "semiallograft" evades maternal immune attack is unknown. Pregnancy success may involve alteration of both central (thymic) and peripheral tolerance mechanisms. HIV infection is characterized by CD4(+) T-cell depletion...... prospectively during pregnancy and postpartum. A significant expansion of CD4(+)CD25(+)CD127(low)FoxP3(+) regulatory T cells indicating alteration of peripheral tolerance was seen during second trimester, but only in HIV-negative women. HIV-infected women had lower CD4 counts, lower thymic output and Th-2...

2-deoxy-D-glucose-induced metabolic stress enhances resistance to Listeria monocytogenes infection in mice

Science.gov (United States)

Miller, E. S.; Bates, R. A.; Koebel, D. A.; Fuchs, B. B.; Sonnenfeld, G.

1998-01-01

Exposure to different forms of psychological and physiological stress can elicit a host stress response, which alters normal parameters of neuroendocrine homeostasis. The present study evaluated the influence of the metabolic stressor 2-deoxy-D-glucose (2-DG; a glucose analog, which when administered to rodents, induces acute periods of metabolic stress) on the capacity of mice to resist infection with the facultative intracellular bacterial pathogen Listeria monocytogenes. Female BDF1 mice were injected with 2-DG (500 mg/kg b. wt.) once every 48 h prior to, concurrent with, or after the onset of a sublethal dose of virulent L. monocytogenes. Kinetics of bacterial growth in mice were not altered if 2-DG was applied concurrently or after the start of the infection. In contrast, mice exposed to 2-DG prior to infection demonstrated an enhanced resistance to the listeria challenge. The enhanced bacterial clearance in vivo could not be explained by 2-DG exerting a toxic effect on the listeria, based on the results of two experiments. First, 2-DG did not inhibit listeria replication in trypticase soy broth. Second, replication of L. monocytogenes was not inhibited in bone marrow-derived macrophage cultures exposed to 2-DG. Production of neopterin and lysozyme, indicators of macrophage activation, were enhanced following exposure to 2-DG, which correlated with the increased resistance to L. monocytogenes. These results support the contention that the host response to 2-DG-induced metabolic stress can influence the capacity of the immune system to resist infection by certain classes of microbial pathogens.

Adaptation and possible attenuation of Theileria parva-infected cells grown in irradiated mice

International Nuclear Information System (INIS)

Irvin, A.D.; Brown, C.G.D.; Stagg, D.A.; Kanhai, G.K.; Kimber, C.D.; Radley, D.E.

1976-01-01

Theileria parva-infected bovine lymphoid cells were taken from 8 cattle immediately after death from East Coast fever (ECF). Cells were inoculated into groups of irradiated Swiss and athymic nude mice. The irradiated mice were exposed to 800 rad doses from a 60 Co source. Cells became established in one group of Swiss mice and 2 groups of athymic mice. Development of cells in mice only occurred if cells concurrently established in culture; when establishment in culture was delayed, cells failed to develop in mice. Cells from one of the isolates in athymic mice were passaged 6 times through further mice. On inoculation of these mouse-passaged cells into cattle, the animals underwent mild reactions and subsequently resisted a lethal ECF challenge. The possibility of vaccinating cattle aginst ECF by means of mouse passaged cells merits further study. (author)

Skin-resident memory CD4+ T cells enhance protection against Leishmania major infection.

Science.gov (United States)

Glennie, Nelson D; Yeramilli, Venkata A; Beiting, Daniel P; Volk, Susan W; Weaver, Casey T; Scott, Phillip

2015-08-24

Leishmaniasis causes a significant disease burden worldwide. Although Leishmania-infected patients become refractory to reinfection after disease resolution, effective immune protection has not yet been achieved by human vaccines. Although circulating Leishmania-specific T cells are known to play a critical role in immunity, the role of memory T cells present in peripheral tissues has not been explored. Here, we identify a population of skin-resident Leishmania-specific memory CD4+ T cells. These cells produce IFN-γ and remain resident in the skin when transplanted by skin graft onto naive mice. They function to recruit circulating T cells to the skin in a CXCR3-dependent manner, resulting in better control of the parasites. Our findings are the first to demonstrate that CD4+ TRM cells form in response to a parasitic infection, and indicate that optimal protective immunity to Leishmania, and thus the success of a vaccine, may depend on generating both circulating and skin-resident memory T cells. © 2015 Glennie et al.

Dysregulation of CD4+CD25+CD127lowFOXP3+ regulatory T cells in HIV-infected pregnant women

DEFF Research Database (Denmark)

Kolte, Lilian; Gaardbo, Julie C; Karlsson, Ingrid

2010-01-01

Pregnancy represents a major challenge to immunologic tolerance. How the fetal "semiallograft" evades maternal immune attack is unknown. Pregnancy success may involve alteration of both central (thymic) and peripheral tolerance mechanisms. HIV infection is characterized by CD4(+) T-cell depletion......, chronic immune activation, and altered lymphocyte subsets. We studied immunologic consequences of pregnancy in 20 HIV-infected women receiving highly active antiretroviral therapy (HAART), and for comparison in 16 HIV-negative women. Lymphocyte subsets, thymic output, and cytokine profiles were measured...... prospectively during pregnancy and postpartum. A significant expansion of CD4(+)CD25(+)CD127(low)FoxP3(+) regulatory T cells indicating alteration of peripheral tolerance was seen during second trimester, but only in HIV-negative women. HIV-infected women had lower CD4 counts, lower thymic output and Th-2...

Kidney failure in mice lacking the tetraspanin CD151

NARCIS (Netherlands)

Sachs, Norman; Kreft, Maaike; van den Bergh Weerman, Marius A.; Beynon, Andy J.; Peters, Theo A.; Weening, Jan J.; Sonnenberg, Arnoud

2006-01-01

The tetraspanin CD151 is a cell-surface molecule known for its strong lateral interaction with the laminin-binding integrin alpha3beta1. Patients with a nonsense mutation in CD151 display end-stage kidney failure associated with regional skin blistering and sensorineural deafness, and mice lacking

Kidney failure in mice lacking the tetraspanin CD151.

NARCIS (Netherlands)

Sachs, N.; Kreft, M.; Bergh Weerman, M. van der; Beynon, A.J.; Peters, T.A.; Weening, J.J.; Sonnenberg, A.

2006-01-01

The tetraspanin CD151 is a cell-surface molecule known for its strong lateral interaction with the laminin-binding integrin alpha3beta1. Patients with a nonsense mutation in CD151 display end-stage kidney failure associated with regional skin blistering and sensorineural deafness, and mice lacking

Oropharyngeal Candidiasis in HIV Infection: Analysis of Impaired Mucosal Immune Response to Candida albicans in Mice Expressing the HIV-1 Transgene

Directory of Open Access Journals (Sweden)

Louis de Repentigny

2015-06-01

Full Text Available IL-17-producing Th17 cells are of critical importance in host defense against oropharyngeal candidiasis (OPC. Speculation about defective Th17 responses to oral C. albicans infection in the context of HIV infection prompted an investigation of innate and adaptive immune responses to Candida albicans in transgenic mice expressing the genome of HIV-1 in immune cells and displaying an AIDS-like disease. Defective IL-17 and IL-22-dependent mucosal responses to C. albicans were found to determine susceptibility to OPC in these transgenic mice. Innate phagocytes were quantitatively and functionally intact, and individually dispensable for control of OPC and to prevent systemic dissemination of Candida to deep organs. CD8+ T-cells recruited to the oral mucosa of the transgenic mice limited the proliferation of C. albicans in these conditions of CD4+ T-cell deficiency. Therefore, the immunopathogenesis of OPC in the context of HIV infection involves defective T-cell-mediated immunity, failure of crosstalk with innate mucosal immune effector mechanisms, and compensatory cell responses, which limit Candida infection to the oral mucosa and prevent systemic dissemination.

CD4(+) T cell-mediated protection against a lethal outcome of systemic infection with vesicular stomatitis virus requires CD40 ligand expression, but not IFN-gamma or IL-4

DEFF Research Database (Denmark)

Andersen, C; Jensen, T; Nansen, A

1999-01-01

experiments using B cell- and T cell-deficient recipients revealed that no protection could be obtained in the absence of B cells, whereas treatment with virus-specific immune (IgG) serum controlled viral spreading to the central nervous system (CNS), but did not necessarily accomplish virus elimination......To investigate the mechanism(s) whereby T cells protect against a lethal outcome of systemic infection with vesicular stomatitis virus, mice with targeted defects in genes central to T cell function were tested for resistance to i.v. infection with this virus. Our results show that mice lacking...... the capacity to secrete both IFN-gamma and perforin completely resisted disease. Similar results were obtained using IL-4 knockout mice, indicating that neither cell-mediated nor T(h)2-dependent effector systems were required. In contrast, mice deficient in expression of CD40 ligand were more susceptible than...

Age- and gender-dependent impairments of neurobehaviors in mice whose mothers were exposed to lipopolysaccharide during pregnancy.

Science.gov (United States)

Wang, Hua; Meng, Xiu-Hong; Ning, Huan; Zhao, Xian-Feng; Wang, Qun; Liu, Ping; Zhang, Heng; Zhang, Cheng; Chen, Gui-Hai; Xu, De-Xiang

2010-02-01

Lipopolysaccharide (LPS)-induced intrauterine infection has been associated with neurodevelopmental injury in rodents. The purpose of the present study was to analyze the dynamic changes of neurobehaviors in mice whose mothers were exposed to LPS during pregnancy. The pregnant mice were intraperitoneally (i.p.) injected with LPS (8 microg/kg) daily from gestational day (gd) 8 to gd 15. A battery of neurobehavioral tasks was performed in mice at postnatal day (PND) 70, 200, 400 and 600. Results showed that the spatial learning and memory ability, determined by radial six-arm water maze (RAWM), were obviously impaired in two hundred-day-old female mice and four hundred-day-old male mice whose mothers were exposed to LPS during pregnancy. Open field test showed that the number of squares crossed and peripheral time, a marker of anxiety and exploration activity, were markedly increased in two hundred-day-old female mice following prenatal LPS exposure. In addition, prenatal LPS exposure significantly shortened the latency to the first grid crossing in six hundred-day-old female offspring. Moreover, sensorimotor impairment in the beam walking was observed in two hundred-day-old female mice whose mothers were exposed to LPS during pregnancy. Species-typical behavior examination showed that prenatal LPS exposure markedly increased weight burrowed in seventy-day-old male offspring and six hundred-day-old female offspring. Correspondingly, prenatal LPS exposure significantly reduced weight hoarded in two hundred-day-old female offspring. Taken together, these results suggest that prenatal LPS exposure induces neurobehavioral impairments at adulthood in an age- and gender-dependent manner. 2009 Elsevier Ireland Ltd. All rights reserved.

Rapid activation of spleen dendritic cell subsets following lymphocytic choriomeningitis virus infection of mice: analysis of the involvement of type 1 IFN.

Science.gov (United States)

Montoya, Maria; Edwards, Matthew J; Reid, Delyth M; Borrow, Persephone

2005-02-15

In this study, we report the dynamic changes in activation and functions that occur in spleen dendritic cell (sDC) subsets following infection of mice with a natural murine pathogen, lymphocytic choriomeningitis virus (LCMV). Within 24 h postinfection (pi), sDCs acquired the ability to stimulate naive LCMV-specific CD8+ T cells ex vivo. Conventional (CD11chigh CD8+ and CD4+) sDC subsets rapidly up-regulated expression of costimulatory molecules and began to produce proinflammatory cytokines. Their tendency to undergo apoptosis ex vivo simultaneously increased, and in vivo the number of conventional DCs in the spleen decreased markedly, dropping approximately 2-fold by day 3 pi. Conversely, the number of plasmacytoid (CD11clowB220+) DCs in the spleen increased, so that they constituted almost 40% of sDCs by day 3 pi. Type 1 IFN production was up-regulated in plasmacytoid DCs by 24 h pi. Analysis of DC activation and maturation in mice unable to respond to type 1 IFNs implicated these cytokines in driving infection-associated phenotypic activation of conventional DCs and their enhanced tendency to undergo apoptosis, but also indicated the existence of type 1 IFN-independent pathways for the functional maturation of DCs during LCMV infection.

Multidimensional Clusters of CD4+T Cell Dysfunction Are Primarily Associated with the CD4/CD8 Ratio in Chronic HIV Infection

DEFF Research Database (Denmark)

Frederiksen, Juliet Wairimu; Buggert, Marcus; Noyan, Kajsa

2015-01-01

was compared to a multidimensional clustering tool, FLOw Clustering with K (FLOCK) in two cohorts of 47 untreated HIV-infected individuals and 21 age and sex matched healthy controls. In order to reduce the subjectivity of FLOCK, we developed an "artificial reference", using 2% of all CD4+ gated T cells from...... each of the HIV-infected individuals. Principle component analyses demonstrated that using an artificial reference lead to a better separation of the HIV-infected individuals from the healthy controls as compared to using a single HIV-infected subject as a reference or analyzing data manually. Multiple...... correlation analyses between laboratory parameters and pathological CD4+ clusters revealed that the CD4/CD8 ratio was the preeminent surrogate marker of CD4+ T cells dysfunction using all three methods. Increased frequencies of an early-differentiated CD4+ T cell cluster with high CD38, HLA-DR and PD-1...

Membrane attack complex inhibitor CD59a protects against focal cerebral ischemia in mice

Directory of Open Access Journals (Sweden)

Nietfeld Wilfried

2010-03-01

Full Text Available Abstract Background The complement system is a crucial mediator of inflammation and cell lysis after cerebral ischemia. However, there is little information about the exact contribution of the membrane attack complex (MAC and its inhibitor-protein CD59. Methods Transient focal cerebral ischemia was induced by middle cerebral artery occlusion (MCAO in young male and female CD59a knockout and wild-type mice. Two models of MCAO were applied: 60 min MCAO and 48 h reperfusion, as well as 30 min MCAO and 72 h reperfusion. CD59a knockout animals were compared to wild-type animals in terms of infarct size, edema, neurological deficit, and cell death. Results and Discussion CD59a-deficiency in male mice caused significantly increased infarct volumes and brain swelling when compared to wild-type mice at 72 h after 30 min-occlusion time, whereas no significant difference was observed after 1 h-MCAO. Moreover, CD59a-deficient mice had impaired neurological function when compared to wild-type mice after 30 min MCAO. Conclusion We conclude that CD59a protects against ischemic brain damage, but depending on the gender and the stroke model used.

EcoHIV infection of mice establishes latent viral reservoirs in T cells and active viral reservoirs in macrophages that are sufficient for induction of neurocognitive impairment.

Science.gov (United States)

Gu, Chao-Jiang; Borjabad, Alejandra; Hadas, Eran; Kelschenbach, Jennifer; Kim, Boe-Hyun; Chao, Wei; Arancio, Ottavio; Suh, Jin; Polsky, Bruce; McMillan, JoEllyn; Edagwa, Benson; Gendelman, Howard E; Potash, Mary Jane; Volsky, David J

2018-06-01

Suppression of HIV replication by antiretroviral therapy (ART) or host immunity can prevent AIDS but not other HIV-associated conditions including neurocognitive impairment (HIV-NCI). Pathogenesis in HIV-suppressed individuals has been attributed to reservoirs of latent-inducible virus in resting CD4+ T cells. Macrophages are persistently infected with HIV but their role as HIV reservoirs in vivo has not been fully explored. Here we show that infection of conventional mice with chimeric HIV, EcoHIV, reproduces physiological conditions for development of disease in people on ART including immunocompetence, stable suppression of HIV replication, persistence of integrated, replication-competent HIV in T cells and macrophages, and manifestation of learning and memory deficits in behavioral tests, termed here murine HIV-NCI. EcoHIV established latent reservoirs in CD4+ T lymphocytes in chronically-infected mice but could be induced by epigenetic modulators ex vivo and in mice. In contrast, macrophages expressed EcoHIV constitutively in mice for up to 16 months; murine leukemia virus (MLV), the donor of gp80 envelope in EcoHIV, did not infect macrophages. Both EcoHIV and MLV were found in brain tissue of infected mice but only EcoHIV induced NCI. Murine HIV-NCI was prevented by antiretroviral prophylaxis but once established neither persistent EcoHIV infection in mice nor NCI could be reversed by long-acting antiretroviral therapy. EcoHIV-infected, athymic mice were more permissive to virus replication in macrophages than were wild-type mice, suffered cognitive dysfunction, as well as increased numbers of monocytes and macrophages infiltrating the brain. Our results suggest an important role of HIV expressing macrophages in HIV neuropathogenesis in hosts with suppressed HIV replication.

CXCR3 Directs Antigen-Specific Effector CD4+ T Cell Migration to the Lung During Parainfluenza Virus Infection

DEFF Research Database (Denmark)

Kohlmeier, Jacob E; Cookenham, Tres; Miller, Shannon C

2009-01-01

effector CD4(+) T cell migration to the lungs. To assess the role of CCR5 and CXCR3 in vivo, we directly compared the migration of Ag-specific wild-type and chemokine receptor-deficient effector T cells in mixed bone marrow chimeric mice during a parainfluenza virus infection. CXCR3-deficient effector CD4......(+) T cells were 5- to 10-fold less efficient at migrating to the lung compared with wild-type cells, whereas CCR5-deficient effector T cells were not impaired in their migration to the lung. In contrast to its role in trafficking, CXCR3 had no impact on effector CD4(+) T cell proliferation, phenotype......, or function in any of the tissues examined. These findings demonstrate that CXCR3 controls virus-specific effector CD4(+) T cell migration in vivo, and suggest that blocking CXCR3-mediated recruitment may limit T cell-induced immunopathology during respiratory virus infections....

Human hepatocyte depletion in the presence of HIV-1 infection in dual reconstituted humanized mice

Science.gov (United States)

Wang, Weimin; Cheng, Yan; Makarov, Edward; Ganesan, Murali; Gebhart, Catherine L.; Gorantla, Santhi; Osna, Natalia

2018-01-01

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) infection impairs liver function, and liver diseases have become a leading cause of morbidity in infected patients. The immunopathology of liver damage caused by HIV-1 remains unclear. We used chimeric mice dually reconstituted with a human immune system and hepatocytes to address the relevance of the model to pathobiology questions related to human hepatocyte survival in the presence of systemic infection. TK-NOG males were transplanted with mismatched human hematopoietic stem/progenitor cells and hepatocytes, human albumin concentration and the presence of human immune cells in blood were monitored for hepatocytes and immune reconstitution, and mice were infected with HIV-1. HIV-1-infected animals showed a decline in human albumin concentration with a significant reduction in percentage of human hepatocytes compared to uninfected mice. The decrease in human albumin levels correlated with a decline in CD4+ cells in the liver and with an increase in HIV-1 viral load. HIV-1 infection elicited proinflammatory response in the immunological milieu of the liver in HIV-infected mice compared to uninfected animals, as determined by upregulation of IL23, CXCL10 and multiple toll-like receptor expression. The inflammatory reaction associated with HIV-1 infection in vivo could contribute to the depletion and dysfunction of hepatocytes. The dual reconstituted TK-NOG mouse model is a feasible platform to investigate hepatocyte-related HIV-1 immunopathogenesis. This article has an associated First Person interview with the first author of the paper. PMID:29361613

Human hepatocyte depletion in the presence of HIV-1 infection in dual reconstituted humanized mice

Directory of Open Access Journals (Sweden)

Raghubendra Singh Dagur

2018-02-01

Full Text Available Human immunodeficiency virus type 1 (HIV-1 infection impairs liver function, and liver diseases have become a leading cause of morbidity in infected patients. The immunopathology of liver damage caused by HIV-1 remains unclear. We used chimeric mice dually reconstituted with a human immune system and hepatocytes to address the relevance of the model to pathobiology questions related to human hepatocyte survival in the presence of systemic infection. TK-NOG males were transplanted with mismatched human hematopoietic stem/progenitor cells and hepatocytes, human albumin concentration and the presence of human immune cells in blood were monitored for hepatocytes and immune reconstitution, and mice were infected with HIV-1. HIV-1-infected animals showed a decline in human albumin concentration with a significant reduction in percentage of human hepatocytes compared to uninfected mice. The decrease in human albumin levels correlated with a decline in CD4+ cells in the liver and with an increase in HIV-1 viral load. HIV-1 infection elicited proinflammatory response in the immunological milieu of the liver in HIV-infected mice compared to uninfected animals, as determined by upregulation of IL23, CXCL10 and multiple toll-like receptor expression. The inflammatory reaction associated with HIV-1 infection in vivo could contribute to the depletion and dysfunction of hepatocytes. The dual reconstituted TK-NOG mouse model is a feasible platform to investigate hepatocyte-related HIV-1 immunopathogenesis. This article has an associated First Person interview with the first author of the paper.

Low CD4+ T-cell levels and B-cell apoptosis in vertically HIV-exposed noninfected children and adolescents.

Science.gov (United States)

Miyamoto, Maristela; Pessoa, Silvana D; Ono, Erika; Machado, Daisy M; Salomão, Reinaldo; Succi, Regina C de M; Pahwa, Savita; de Moraes-Pinto, Maria Isabel

2010-12-01

Lymphocyte subsets, activation markers and apoptosis were assessed in 20 HIV-exposed noninfected (ENI) children born to HIV-infected women who were or not exposed to antiretroviral (ARV) drugs during pregnancy and early infancy. ENI children and adolescents were aged 6-18 years and they were compared to 25 age-matched healthy non-HIV-exposed children and adolescents (Control). ENI individuals presented lower CD4(+) T cells/mm(3) than Control group (control: 1120.3 vs. ENI: 876.3; t-test, p = 0.030). ENI individuals had higher B-cell apoptosis than Control group (Control: 36.6%, ARV exposed: 82.3%, ARV nonexposed: 68.5%; Kruskal-Wallis, p ENI and in Control children and adolescents. Subtle long-term immune alterations might persist among ENI individuals, but the clinical consequences if any are unknown, and these children require continued monitoring.

Methods of Controlling Invasive Fungal Infections Using CD8+ T Cells

Directory of Open Access Journals (Sweden)

Pappanaicken R. Kumaresan

2018-01-01

Full Text Available Invasive fungal infections (IFIs cause high rates of morbidity and mortality in immunocompromised patients. Pattern-recognition receptors present on the surfaces of innate immune cells recognize fungal pathogens and activate the first line of defense against fungal infection. The second line of defense is the adaptive immune system which involves mainly CD4+ T cells, while CD8+ T cells also play a role. CD8+ T cell-based vaccines designed to prevent IFIs are currently being investigated in clinical trials, their use could play an especially important role in acquired immune deficiency syndrome patients. So far, none of the vaccines used to treat IFI have been approved by the FDA. Here, we review current and future antifungal immunotherapy strategies involving CD8+ T cells. We highlight recent advances in the use of T cells engineered using a Sleeping Beauty vector to treat IFIs. Recent clinical trials using chimeric antigen receptor (CAR T-cell therapy to treat patients with leukemia have shown very promising results. We hypothesized that CAR T cells could also be used to control IFI. Therefore, we designed a CAR that targets β-glucan, a sugar molecule found in most of the fungal cell walls, using the extracellular domain of Dectin-1, which binds to β-glucan. Mice treated with D-CAR+ T cells displayed reductions in hyphal growth of Aspergillus compared to the untreated group. Patients suffering from IFIs due to primary immunodeficiency, secondary immunodeficiency (e.g., HIV, or hematopoietic transplant patients may benefit from bioengineered CAR T cell therapy.

A role for CD4+ but not CD8+ T cells in immunity to Schistosoma mansoni induced by 20 krad-irradiated and Ro 11-3128-terminated infections

International Nuclear Information System (INIS)

Vignali, D.A.A.; Bickle, Q.D.; Taylor, M.G.; Crocker, P.; Cobbold, S.; Waldmann, H

1989-01-01

The role of CD4 + (L3/T4 + ) and CD8 + (Lyt-2 + ) T cells in immunity to Schistosoma mansoni induced by 20 krad-irradiated and Ro 11-terminated infections in mice was investigated directly by in vivo depletion of these subsets with cytotoxic rat monoclonal antibodies (mAb). Effective physical depletion was demonstrated by flow cytometric analysis and immunohistochemical staining. Functional depletion of helper activity following anti-CD4 treatment was indicated by an abrogation of concanavalin A(Con A)-induced colony-stimulating factor (CSF) release, while anti-CD8 treatment had no effect in these assays. Pre-existing S. mansoni-specific antibody levels were unaffected by anti-CD4 and anti-CD8 treatment. In vivo depletion of CD4 + T cells resulted in a dramatic reduction in immunity induced by one (up to 100%) and two (up to 70%) vaccinations with 20 krad-irradiated cercariae and also of resistance induced by Ro 11-attenuated infections (up to 100%). Depletion of CD8 + T cells had no effect on resistance induced by any of the vaccination protocols investigated. A correlation was observed between resistance and T cell-induced, macrophage-mediated killing of schistosomula in vitro, both of which were abrogated following anti-CD4 treatment but were unaffected by CD8 + T-cell depletion. The possible role of CD4 + T cells in vivo and the implications for vaccine development are discussed. (author)

Kaempferol regulates OPN–CD44 pathway to inhibit the atherogenesis of apolipoprotein E deficient mice

International Nuclear Information System (INIS)

Xiao, Hong-Bo; Lu, Xiang-Yang; Sun, Zhi-Liang; Zhang, Heng-Bo

2011-01-01

Recent studies show that osteopontin (OPN) and its receptor cluster of differentiation 44 (CD44) are two pro-inflammatory cytokines contributing to the development of atherosclerosis. The objective of this study was to explore the inhibitory effect of kaempferol, a naturally occurring flavonoid compound, on atherogenesis and the mechanisms involved. The experiments were performed in aorta and plasma from C57BL/6J control and apolipoprotein E-deficient (ApoE −/− ) mice treated or not with kaempferol (50 or 100 mg/kg, intragastrically) for 4 weeks. Kaempferol treatment decreased atherosclerotic lesion area, improved endothelium-dependent vasorelaxation, and increased the maximal relaxation value concomitantly with decrease in the half-maximum effective concentration, plasma OPN level, aortic OPN expression, and aortic CD44 expression in ApoE −/− mice. In addition, treatment with kaempferol also significantly decreased reactive oxygen species production in mice aorta. The present results suggest that kaempferol regulates OPN–CD44 pathway to inhibit the atherogenesis of ApoE −/− mice. -- Graphical abstract: Kaempferol regulates OPN–CD44 pathway to inhibit the atherogenesis of ApoE −/− mice. Highlights: ► OPN–CD44 pathway plays a critical role in the development of atherosclerosis. ► We examine lesion area, OPN and CD44 changes after kaempferol treatment. ► Kaempferol treatment decreased atherosclerotic lesion area in ApoE −/− mice. ► Kaempferol treatment decreased aortic OPN and CD44 expressions in ApoE −/− mice. ► Kaempferol regulates OPN–CD44 pathway to inhibit the atherogenesis.

Kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis of apolipoprotein E deficient mice

Energy Technology Data Exchange (ETDEWEB)

Xiao, Hong-Bo, E-mail: xhbzhb@yahoo.com [College of Veterinary Medicine, Hunan Agricultural University, Changsha 410128 (China); Lu, Xiang-Yang; Sun, Zhi-Liang [Hunan Agricultural University, Changsha 410128 (China); Zhang, Heng-Bo [Furong District Red Cross Hospital, Changsha 410126 (China)

2011-12-15

Recent studies show that osteopontin (OPN) and its receptor cluster of differentiation 44 (CD44) are two pro-inflammatory cytokines contributing to the development of atherosclerosis. The objective of this study was to explore the inhibitory effect of kaempferol, a naturally occurring flavonoid compound, on atherogenesis and the mechanisms involved. The experiments were performed in aorta and plasma from C57BL/6J control and apolipoprotein E-deficient (ApoE{sup -/-}) mice treated or not with kaempferol (50 or 100 mg/kg, intragastrically) for 4 weeks. Kaempferol treatment decreased atherosclerotic lesion area, improved endothelium-dependent vasorelaxation, and increased the maximal relaxation value concomitantly with decrease in the half-maximum effective concentration, plasma OPN level, aortic OPN expression, and aortic CD44 expression in ApoE{sup -/-} mice. In addition, treatment with kaempferol also significantly decreased reactive oxygen species production in mice aorta. The present results suggest that kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis of ApoE{sup -/-} mice. -- Graphical abstract: Kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis of ApoE{sup -/-} mice. Highlights: Black-Right-Pointing-Pointer OPN-CD44 pathway plays a critical role in the development of atherosclerosis. Black-Right-Pointing-Pointer We examine lesion area, OPN and CD44 changes after kaempferol treatment. Black-Right-Pointing-Pointer Kaempferol treatment decreased atherosclerotic lesion area in ApoE{sup -/-} mice. Black-Right-Pointing-Pointer Kaempferol treatment decreased aortic OPN and CD44 expressions in ApoE{sup -/-} mice. Black-Right-Pointing-Pointer Kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis.

CD8(+) T cells of Listeria monocytogenes-infected mice recognize both linear and spliced proteasome products

NARCIS (Netherlands)

Platteel, Anouk C M; Mishto, Michele; Textoris-Taube, Kathrin; Keller, Christin; Liepe, Juliane; Busch, Dirk H; Kloetzel, Peter M; Sijts, Alice J A M

CD8(+) T cells responding to infection recognize pathogen-derived epitopes presented by MHC class-I molecules. While most of such epitopes are generated by proteasome-mediated antigen cleavage, analysis of tumor antigen processing has revealed that epitopes may also derive from proteasome-catalyzed

Proliferation and apoptosis of lamina propria CD4+ T cells from scid mice with inflammatory bowel disease

DEFF Research Database (Denmark)

Bregenholt, S; Reimann, J; Claesson, Mogens Helweg

1998-01-01

Scid mice transplanted with low numbers of syngeneic CD4+ T cells, develop a chronic and lethal inflammatory bowel disease (IBD) within 4-6 months. We have used in vivo 5-bromo2-deoxy-uridine (BrdU) labeling to assess the proliferation of lamina propria-derived CD4+ T cells in diseased scid mice....... The hourly rate of renewal of colonic lamina propria CD4+ T cells in diseased mice was 7% compared with 1.5% in normal BALB/c control mice. Transplantation of scid mice with in vitro activated CD4+ T cells accelerated the disease onset and development in a cell dose-dependent fashion when compared with non......-activated CD4+ T cells. In pulse-chase experiments it was shown that BrdU-labeled cells disappeared rapidly from the lamina propria of diseased mice. DNA analysis revealed that this was due to the presence of nearly four times as many apoptotic CD4+ T cells in diseased than in control mice. Further analyses...

Mice deficient in CD38 develop an attenuated form of collagen type II-induced arthritis.

Science.gov (United States)

Postigo, Jorge; Iglesias, Marcos; Cerezo-Wallis, Daniela; Rosal-Vela, Antonio; García-Rodríguez, Sonia; Zubiaur, Mercedes; Sancho, Jaime; Merino, Ramón; Merino, Jesús

2012-01-01

CD38, a type II transmembrane glycoprotein expressed in many cells of the immune system, is involved in cell signaling, migration and differentiation. Studies in CD38 deficient mice (CD38 KO mice) indicate that this molecule controls inflammatory immune responses, although its involvement in these responses depends on the disease model analyzed. Here, we explored the role of CD38 in the control of autoimmune responses using chicken collagen type II (col II) immunized C57BL/6-CD38 KO mice as a model of collagen-induced arthritis (CIA). We demonstrate that CD38 KO mice develop an attenuated CIA that is accompanied by a limited joint induction of IL-1β and IL-6 expression, by the lack of induction of IFNγ expression in the joints and by a reduction in the percentages of invariant NKT (iNKT) cells in the spleen. Immunized CD38 KO mice produce high levels of circulating IgG1 and low of IgG2a anti-col II antibodies in association with reduced percentages of Th1 cells in the draining lymph nodes. Altogether, our results show that CD38 participates in the pathogenesis of CIA controlling the number of iNKT cells and promoting Th1 inflammatory responses.

Mice deficient in CD38 develop an attenuated form of collagen type II-induced arthritis.

Directory of Open Access Journals (Sweden)

Jorge Postigo

Full Text Available CD38, a type II transmembrane glycoprotein expressed in many cells of the immune system, is involved in cell signaling, migration and differentiation. Studies in CD38 deficient mice (CD38 KO mice indicate that this molecule controls inflammatory immune responses, although its involvement in these responses depends on the disease model analyzed. Here, we explored the role of CD38 in the control of autoimmune responses using chicken collagen type II (col II immunized C57BL/6-CD38 KO mice as a model of collagen-induced arthritis (CIA. We demonstrate that CD38 KO mice develop an attenuated CIA that is accompanied by a limited joint induction of IL-1β and IL-6 expression, by the lack of induction of IFNγ expression in the joints and by a reduction in the percentages of invariant NKT (iNKT cells in the spleen. Immunized CD38 KO mice produce high levels of circulating IgG1 and low of IgG2a anti-col II antibodies in association with reduced percentages of Th1 cells in the draining lymph nodes. Altogether, our results show that CD38 participates in the pathogenesis of CIA controlling the number of iNKT cells and promoting Th1 inflammatory responses.

Lactobacillus rhamnosus CRL1505 nasal administration improves recovery of T-cell mediated immunity against pneumococcal infection in malnourished mice.

Science.gov (United States)

Barbieri, N; Herrera, M; Salva, S; Villena, J; Alvarez, S

2017-05-30

Immunobiotic lactic acid bacteria have become an interesting alternative for the prevention of respiratory infections. Previously, we demonstrated that the nasal administration of Lactobacillus rhamnosus CRL1505, during repletion of malnourished mice, resulted in diminished susceptibility to the challenge with the respiratory pathogen Streptococcus pneumoniae. Considering the known alterations induced by malnutrition on T lymphocytes and the importance of this cell population on the protection against respiratory pathogens, we aimed to study the effect of L. rhamnosus CRL1505 nasal administration on the recovery of T cell-mediated defences against pneumococcal infection in malnourished mice under nutritional recovery. Malnourished mice received a balanced conventional diet (BCD) for seven days or BCD for seven days with nasal L. rhamnosus CRL1505 supplementation during last two days of the treatment. After the treatments mice were infected with S. pneumoniae. Flow cytometry studies were carried out in bone marrow, thymus, spleen and lung to study T cells, and Th 1 /Th 2 cytokine profiles were determined in broncho-alveolar lavages and serum. The administration of CRL1505 strain to malnourished mice under recovery reduced quantitative and qualitative alterations of CD4 + T cells in the bone marrow, thymus, spleen and lung induced by malnutrition. In addition, CRL1505 treatment augmented Th 2 -cytokines (interleukin 10 and 4) in respiratory and systemic compartments after pneumococcal infection. These results show that modulation of CD4 + T lymphocytes induced by L. rhamnosus CRL1505 has an important role in the beneficial effect induced by this strain on the recovery of malnourished mice. These data also indicate that nasally administered L. rhamnosus CRL1505 may represent a non-invasive alternative to modulate and improve the T cell-mediated immunity against respiratory pathogens in immunocompromised malnourished hosts.

T-bet and Eomes are differentially linked to the exhausted phenotype of CD8+ T cells in HIV infection.

Directory of Open Access Journals (Sweden)

Marcus Buggert

2014-07-01

Full Text Available CD8(+ T cell exhaustion represents a major hallmark of chronic HIV infection. Two key transcription factors governing CD8(+ T cell differentiation, T-bet and Eomesodermin (Eomes, have previously been shown in mice to differentially regulate T cell exhaustion in part through direct modulation of PD-1. Here, we examined the relationship between these transcription factors and the expression of several inhibitory receptors (PD-1, CD160, and 2B4, functional characteristics and memory differentiation of CD8(+ T cells in chronic and treated HIV infection. The expression of PD-1, CD160, and 2B4 on total CD8(+ T cells was elevated in chronically infected individuals and highly associated with a T-bet(dimEomes(hi expressional profile. Interestingly, both resting and activated HIV-specific CD8(+ T cells in chronic infection were almost exclusively T-bet(dimEomes(hi cells, while CMV-specific CD8(+ T cells displayed a balanced expression pattern of T-bet and Eomes. The T-bet(dimEomes(hi virus-specific CD8(+ T cells did not show features of terminal differentiation, but rather a transitional memory phenotype with poor polyfunctional (effector characteristics. The transitional and exhausted phenotype of HIV-specific CD8(+ T cells was longitudinally related to persistent Eomes expression after antiretroviral therapy (ART initiation. Strikingly, these characteristics remained stable up to 10 years after ART initiation. This study supports the concept that poor human viral-specific CD8(+ T cell functionality is due to an inverse expression balance between T-bet and Eomes, which is not reversed despite long-term viral control through ART. These results aid to explain the inability of HIV-specific CD8(+ T cells to control the viral replication post-ART cessation.

Chronic exposure to water pollutant trichloroethylene increased epigenetic drift in CD4(+) T cells.

Science.gov (United States)

Gilbert, Kathleen M; Blossom, Sarah J; Erickson, Stephen W; Reisfeld, Brad; Zurlinden, Todd J; Broadfoot, Brannon; West, Kirk; Bai, Shasha; Cooney, Craig A

2016-05-01

Autoimmune disease and CD4(+) T-cell alterations are induced in mice exposed to the water pollutant trichloroethylene (TCE). We examined here whether TCE altered gene-specific DNA methylation in CD4(+) T cells as a possible mechanism of immunotoxicity. Naive and effector/memory CD4(+) T cells from mice exposed to TCE (0.5 mg/ml in drinking water) for 40 weeks were examined by bisulfite next-generation DNA sequencing. A probabilistic model calculated from multiple genes showed that TCE decreased methylation control in CD4(+) T cells. Data from individual genes fitted to a quadratic regression model showed that TCE increased gene-specific methylation variance in both CD4 subsets. TCE increased epigenetic drift of specific CpG sites in CD4(+) T cells.

Thymidine Kinase-Negative Herpes Simplex Virus 1 Can Efficiently Establish Persistent Infection in Neural Tissues of Nude Mice.

Science.gov (United States)

Huang, Chih-Yu; Yao, Hui-Wen; Wang, Li-Chiu; Shen, Fang-Hsiu; Hsu, Sheng-Min; Chen, Shun-Hua

2017-02-15

Herpes simplex virus 1 (HSV-1) establishes latency in neural tissues of immunocompetent mice but persists in both peripheral and neural tissues of lymphocyte-deficient mice. Thymidine kinase (TK) is believed to be essential for HSV-1 to persist in neural tissues of immunocompromised mice, because infectious virus of a mutant with defects in both TK and UL24 is detected only in peripheral tissues, but not in neural tissues, of severe combined immunodeficiency mice (T. Valyi-Nagy, R. M. Gesser, B. Raengsakulrach, S. L. Deshmane, B. P. Randazzo, A. J. Dillner, and N. W. Fraser, Virology 199:484-490, 1994, https://doi.org/10.1006/viro.1994.1150). Here we find infiltration of CD4 and CD8 T cells in peripheral and neural tissues of mice infected with a TK-negative mutant. We therefore investigated the significance of viral TK and host T cells for HSV-1 to persist in neural tissues using three genetically engineered mutants with defects in only TK or in both TK and UL24 and two strains of nude mice. Surprisingly, all three mutants establish persistent infection in up to 100% of brain stems and 93% of trigeminal ganglia of adult nude mice at 28 days postinfection, as measured by the recovery of infectious virus. Thus, in mouse neural tissues, host T cells block persistent HSV-1 infection, and viral TK is dispensable for the virus to establish persistent infection. Furthermore, we found 30- to 200-fold more virus in neural tissues than in the eye and detected glycoprotein C, a true late viral antigen, in brainstem neurons of nude mice persistently infected with the TK-negative mutant, suggesting that adult mouse neurons can support the replication of TK-negative HSV-1. Acyclovir is used to treat herpes simplex virus 1 (HSV-1)-infected immunocompromised patients, but treatment is hindered by the emergence of drug-resistant viruses, mostly those with mutations in viral thymidine kinase (TK), which activates acyclovir. TK mutants are detected in brains of immunocompromised

CD44 deficiency enhanced Streptococcus equi ssp. zooepidemicus dissemination and inflammation response in a mouse model.

Science.gov (United States)

Fu, Qiang; Xiao, Pingping; Chen, Yaosheng; Wei, Zigong; Liu, Xiaohong

2017-12-01

Streptococcus equi ssp. zooepidemicus (S. zooepidemicus) is responsible for peritonitis, septicemia, meningitis, arthritis and several other serious diseases in various species. Recent studies have demonstrated that CD44 is implicated in the process of host defense against pathogenic microorganisms. In the present study, the role of CD44 in the host response to S. zooepidemicus infection was investigated in a mouse model. Upon intraperitoneal infection with S. zooepidemicus, the expression of CD44 on the peritoneal exudate cells from wild-type (WT) mice was increased. CD44 deficiency accelerated mortality, which was accompanied by increased peritoneal bacterial growth and dissemination to distant body sites. CD44 knock-out (KO) mice showed enhanced early inflammatory cell recruitment into the peritoneal fluid on S. zooepidemicus infection. In line with this, the expression of proinflammatory cytokines, chemokines in peritoneal exudate cells and peritoneal macrophages of CD44 KO mice were increased compared with those of WT mice. In addition, CD44 deficiency was associated with reduced expression of A20, a negative regulator in TLR signaling. Overall, the present study suggests that CD44 plays a protective role in antibacterial defense against S. zooepidemicus in mice. Copyright © 2017. Published by Elsevier Ltd.

Demonstration of strong enterobacterial reactivity of CD4+CD25- T cells from conventional and germ-free mice which is counter-regulated by CD4+CD25+ T cells

DEFF Research Database (Denmark)

Gad, Monika; Pedersen, Anders Elm; Kristensen, Nanna N

2004-01-01

Unfractionated CD4+ T cells from the gut-associated lymphoid tissue (GALT) and peripheral lymph nodes are unresponsive when exposed to enterobacterial antigens in vitro. Under similar conditions, CD4+ T cells depleted in vivo or in vitro of CD4+CD25+ T cells proliferate extensively. The CD4+CD25- T...

Exposure to apoptotic activated CD4+ T cells induces maturation and APOBEC3G-mediated inhibition of HIV-1 infection in dendritic cells.

Directory of Open Access Journals (Sweden)

Venkatramanan Mohanram

Full Text Available Dendritic cells (DCs are activated by signaling via pathogen-specific receptors or exposure to inflammatory mediators. Here we show that co-culturing DCs with apoptotic HIV-infected activated CD4(+ T cells (ApoInf or apoptotic uninfected activated CD4(+ T cells (ApoAct induced expression of co-stimulatory molecules and cytokine release. In addition, we measured a reduced HIV infection rate in DCs after co-culture with ApoAct. A prerequisite for reduced HIV infection in DCs was activation of CD4(+ T cells before apoptosis induction. DCs exposed to ApoAct or ApoInf secreted MIP-1α, MIP-1β, MCP-1, and TNF-α; this effect was retained in the presence of exogenous HIV. The ApoAct-mediated induction of co-stimulatory CD86 molecules and reduction of HIV infection in DCs were partially abrogated after blocking TNF-α using monoclonal antibodies. APOBEC3G expression in DCs was increased in co-cultures of DCs and ApoAct but not by apoptotic resting CD4(+ T cells (ApoRest. Silencing of APOBEC3G in DC abrogated the HIV inhibitory effect mediated by ApoAct. Sequence analyses of an env region revealed significant induction of G-to-A hypermutations in the context of GG or GA dinucleotides in DNA isolated from DCs exposed to HIV and ApoAct. Thus, ApoAct-mediated DC maturation resulted in induction of APOBEC3G that was important for inhibition of HIV-infection in DCs. These findings underscore the complexity of differential DC responses evoked upon interaction with resting as compared with activated dying cells during HIV infection.

Evaluation of CD4+/CD8+ status and urinary tract infections ...

African Journals Online (AJOL)

The CD4+ and the CD8+ counts were correlated with the ova of S. haematobium in their urine samples at r = 0.0108 and r = 0.516 respectively. The bacteriuria, urinary schistosomiasis and urinary tract co - infections namely; Escherichia coli, Proteus, Pseudomonas aeroginosa, Staphylococcus epidermidis and Staph.

Morphological and histochemical study of cleft palate induced in CD-1 mice by whole body x-radiation

International Nuclear Information System (INIS)

Lewis, C.E.

1977-01-01

Palatogenesis in CD-1 mice exposed to 300 or 400 rads of x-radiation in utero was compared with palate development of unirradiated fetuses to determine whether any correlation exists between time of irradiation (days nine through twelve) and the incidence of morphological or histochemical variations in fetal palate tissues. Data accumulated indicate that although x-radiation reduces fetal weight and crown-rump length and retards palate closure, growth, ossification and SDH activity, fetuses exhibit some recovery from radiation damage

The effects of gut commensal bacteria depletion on mice exposed to acute lethal irradiation

International Nuclear Information System (INIS)

Hou Bing; Xu Zhiwei; Zhang Chenggang

2007-01-01

The prevention and management of bacterial infection are the mainstays of therapies for irradiation victims. However, worries about adverse effects arise from gut commensal flora depletion owing to the broad-spectrum antibiotics treatment. In the present study, we investigated the effects of gut bacteria depletion on the mice receiving total-body irradiation (TBI) at a single dose of 12 Gy. One group of mice was merely exposed to TBI but was free of antibiotic treatment throughout the experiment, while the other two groups of mice were additionally given broad-spectrum antibiotics, either from 2 weeks before or immediately after irradiation. The survival time of each animal in each group was recorded for analysis. Results showed that the mean survival time of mice was longest in the group without antibiotic treatment and shortest in the group treated with broad-spectrum antibiotics from 2 weeks before TBI. In conclusion, our data suggested that depletion of gut commensal bacteria with broad-spectrum antibiotics seemed deleterious for mammals receiving lethal TBI. (author)

The Role of Heterotypic DENV-specific CD8+T Lymphocytes in an Immunocompetent Mouse Model of Secondary Dengue Virus Infection.

Science.gov (United States)

Talarico, Laura B; Batalle, Juan P; Byrne, Alana B; Brahamian, Jorge M; Ferretti, Adrián; García, Ayelén G; Mauri, Aldana; Simonetto, Carla; Hijano, Diego R; Lawrence, Andrea; Acosta, Patricio L; Caballero, Mauricio T; Paredes Rojas, Yésica; Ibañez, Lorena I; Melendi, Guillermina A; Rey, Félix A; Damonte, Elsa B; Harris, Eva; Polack, Fernando P

2017-06-01

Dengue is the most prevalent arthropod-borne viral disease worldwide and is caused by the four dengue virus serotypes (DENV-1-4). Sequential heterologous DENV infections can be associated with severe disease manifestations. Here, we present an immunocompetent mouse model of secondary DENV infection using non mouse-adapted DENV strains to investigate the pathogenesis of severe dengue disease. C57BL/6 mice infected sequentially with DENV-1 (strain Puerto Rico/94) and DENV-2 (strain Tonga/74) developed low platelet counts, internal hemorrhages, and increase of liver enzymes. Cross-reactive CD8 + T lymphocytes were found to be necessary and sufficient for signs of severe disease by adoptively transferring of DENV-1-immune CD8 + T lymphocytes before DENV-2 challenge. Disease signs were associated with production of tumor necrosis factor (TNF)-α and elevated cytotoxicity displayed by heterotypic anti-DENV-1 CD8 + T lymphocytes. These findings highlight the critical role of heterotypic anti-DENV CD8 + T lymphocytes in manifestations of severe dengue disease. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

CD40 Ligand Deficient C57BL/6 Mouse Is a Potential Surrogate Model of Human X-Linked Hyper IgM (X-HIGM Syndrome for Characterizing Immune Responses against Pathogens

Directory of Open Access Journals (Sweden)

Catalina Lopez-Saucedo

2015-01-01

Full Text Available Individuals with X-HIGM syndrome fail to express functional CD40 ligand; consequently they cannot mount effective protective antibody responses against pathogenic bacteria. We evaluated, compared, and characterized the humoral immune response of wild type (WT and C57-CD40L deficient (C57-CD40L−/− mice infected with Citrobacter rodentium. Basal serum isotype levels were similar for IgM and IgG3 among mice, while total IgG and IgG2b concentrations were significantly lower in C57-CD40L−/− mice compared with WT. Essentially IgG1 and IgG2c levels were detectable only in WT mice. C57-CD40L−/− animals, orally inoculated with 2×109 CFU, presented several clinical manifestations since the second week of infection and eventually died. In contrast at this time point no clinical manifestations were observed among C57-CD40L−/− mice infected with 1×107 CFU. Infection was subclinical in WT mice inoculated with either bacterial dose. The serum samples from infected mice (1×107 CFU, collected at day 14 after infection, had similar C. rodentium-specific IgM titres. Although C57-CD40L−/− animals had lower IgG and IgG2b titres than WT mice, C57-CD40L−/− mice sera displayed complement-mediated bactericidal activity against C. rodentium. C. rodentium-infected C57-CD40L−/− mice are capable of producing antibodies that are protective. C57-CD40L−/− mouse is a useful surrogate model of X-HIGM syndrome for studying immune responses elicited against pathogens.

Diminished primary and secondary influenza virus-specific CD8(+) T-cell responses in CD4-depleted Ig(-/-) mice

DEFF Research Database (Denmark)

Riberdy, J M; Christensen, Jan Pravsgaard; Branum, K

2000-01-01

Optimal expansion of influenza virus nucleoprotein (D(b)NP(366))-specific CD8(+) T cells following respiratory challenge of naive Ig(-/-) microMT mice was found to require CD4(+) T-cell help, and this effect was also observed in primed animals. Absence of the CD4(+) population was consistently...

Differences between Mycobacterium-Host Cell Relationships in Latent Tuberculous Infection of Mice Ex Vivo and Mycobacterial Infection of Mouse Cells In Vitro

Directory of Open Access Journals (Sweden)

Elena Ufimtseva

2016-01-01

Full Text Available The search for factors that account for the reproduction and survival of mycobacteria, including vaccine strains, in host cells is the priority for studies on tuberculosis. A comparison of BCG-mycobacterial loads in granuloma cells obtained from bone marrow and spleens of mice with latent tuberculous infection and cells from mouse bone marrow and peritoneal macrophage cultures infected with the BCG vaccine in vitro has demonstrated that granuloma macrophages each normally contained a single BCG-Mycobacterium, while those acutely infected in vitro had increased mycobacterial loads and death rates. Mouse granuloma cells were observed to produce the IFNγ, IL-1α, GM-CSF, CD1d, CD25, CD31, СD35, and S100 proteins. None of these activation markers were found in mouse cell cultures infected in vitro or in intact macrophages. Lack of colocalization of lipoarabinomannan-labeled BCG-mycobacteria with the lysosomotropic LysoTracker dye in activated granuloma macrophages suggests that these macrophages were unable to destroy BCG-mycobacteria. However, activated mouse granuloma macrophages could control mycobacterial reproduction in cells both in vivo and in ex vivo culture. By contrast, a considerable increase in the number of BCG-mycobacteria was observed in mouse bone marrow and peritoneal macrophages after BCG infection in vitro, when no expression of the activation-related molecules was detected in these cells.

Bystander CD4+ T lymphocytes survive in HIV-infected human lymphoid tissue

Science.gov (United States)

Grivel, Jean-Charles; Biancotto, Angelique; Ito, Yoshinori; Lima, Rosangela G.; Margolis, Leonid B.

2003-01-01

HIV infection is associated with depletion of CD4(+) T cells. The mechanisms of this phenomenon remain to be understood. In particular, it remains controversial whether and to what extent uninfected ("bystander") CD4(+) T cells die in HIV-infected individuals. We address this question using a system of human lymphoid tissue ex vivo. Tissue blocks were inoculated with HIV-1. After productive infection was established, they were treated with the reverse transcriptase inhibitor nevirapine to protect from infection those CD4(+) T cells that had not yet been infected. These CD4(+) T cells residing in HIV-infected tissue are by definition bystanders. Our results demonstrate that after nevirapine application the number of bystander CD4(+) T cells is conserved. Thus, in the context of HIV-infected human lymphoid tissue, productive HIV infection kills infected cells but is not sufficient to cause the death of a significant number of uninfected CD4(+) T cells.

Protective Role of Cross-Reactive CD8 T Cells Against Dengue Virus Infection

Directory of Open Access Journals (Sweden)

Annie Elong Ngono

2016-11-01

Full Text Available Infection with one of the four dengue virus serotypes (DENV1-4 presumably leads to lifelong immunity against the infecting serotype but not against heterotypic reinfection, resulting in a greater risk of developing Dengue Hemorrhagic Fever/Dengue Shock Syndrome (DHF/DSS during secondary infection. Both antibodies and T cell responses have been implicated in DHF/DSS pathogenesis. According to the T cell-based hypothesis termed “original antigenic sin,” secondary DENV infection is dominated by non-protective, cross-reactive T cells that elicit an aberrant immune response. The goal of our study was to compare the roles of serotype-specific and cross-reactive T cells in protection vs. pathogenesis during DENV infection in vivo. Specifically, we utilized IFN-α/βR−/− HLA*B0702 transgenic mice in the context of peptide vaccination with relevant human CD8 T cell epitopes. IFN-α/βR−/− HLA*B0702 transgenic mice were immunized with DENV serotype 2 (DENV2-specific epitopes or variants found in any of the other three serotypes (DENV1, DENV3 or DENV4, followed by challenge with DENV. Although cross-reactive T cell responses were lower than responses elicited by serotype-specific T cells, immunization with either serotype-specific or variant peptide epitopes enhanced viral clearance, demonstrating that both serotype-specific and cross-reactive T cells can contribute to protection in vivo against DENV infection.

CD40 dependent exacerbation of immune mediated hepatitis by hepatic CD11b+ Gr-1+ myeloid derived suppressor cells in tumor bearing mice

Science.gov (United States)

Kapanadze, Tamar; Medina-Echeverz, José; Gamrekelashvili, Jaba; Weiss, Jonathan M.; Wiltrout, Robert H.; Kapoor, Veena; Hawk, Nga; Terabe, Masaki; Berzofsky, Jay A.; Manns, Michael P.; Wang, Ena; Marincola, Francesco M.; Korangy, Firouzeh; Greten, Tim F.

2015-01-01

Immunosuppressive CD11b+Gr-1+ myeloid-derived suppressor cells (MDSC) accumulate in the livers of tumor-bearing mice. We studied hepatic MDSC in two murine models of immune mediated hepatitis. Unexpectedly, treatment of tumor bearing mice with Concanavalin A or α-Galactosylceramide resulted in increased ALT and AST serum levels in comparison to tumor free mice. Adoptive transfer of hepatic MDSC into naïve mice exacerbated Concanavalin A induced liver damage. Hepatic CD11b+Gr-1+ cells revealed a polarized pro-inflammatory gene signature after Concanavalin A treatment. An interferon gamma- dependent up-regulation of CD40 on hepatic CD11b+Gr-1+ cells along with an up-regulation of CD80, CD86, and CD1d after Concanavalin A treatment was observed. Concanavalin A treatment resulted in a loss of suppressor function by tumor-induced CD11b+Gr-1+ MDSC as well as enhanced reactive oxygen species-mediated hepatotoxicity. CD40 knockdown in hepatic MDSC led to increased arginase activity upon Concanavalin A treatment and lower ALT/AST serum levels. Finally, blockade of arginase activity in Cd40−/− tumor-induced myeloid cells resulted in exacerbation of hepatitis and increased reactive oxygen species production in vivo. Our findings indicate that in a setting of acute hepatitis, tumor-induced hepatic MDSC act as pro-inflammatory immune effector cells capable of killing hepatocytes in a CD40-dependent manner. PMID:25616156

Laser Adjuvant-Assisted Peptide Vaccine Promotes Skin Mobilization of Dendritic Cells and Enhances Protective CD8+ TEM and TRM Cell Responses against Herpesvirus Infection and Disease.

Science.gov (United States)

Lopes, Patricia P; Todorov, George; Pham, Thanh T; Nesburn, Anthony B; Bahraoui, Elmostafa; BenMohamed, Lbachir

2018-04-15

There is an urgent need for chemical-free and biological-free safe adjuvants to enhance the immunogenicity of vaccines against widespread viral pathogens, such as herpes simplex virus 2 (HSV-2), that infect a large proportion of the world human population. In the present study, we investigated the safety, immunogenicity, and protective efficacy of a laser adjuvant-assisted peptide (LAP) vaccine in the B6 mouse model of genital herpes. This LAP vaccine and its laser-free peptide (LFP) vaccine analog contain the immunodominant HSV-2 glycoprotein B CD8 + T cell epitope (HSV-gB 498-505 ) covalently linked with the promiscuous glycoprotein D CD4 + T helper cell epitope (HSV-gD 49-89 ). Prior to intradermal delivery of the LAP vaccine, the lower-flank shaved skin of B6 or CD11c/eYFP transgenic mice received a topical skin treatment with 5% imiquimod cream and then was exposed for 60 s to a laser, using the FDA-approved nonablative diode. Compared to the LFP vaccine, the LAP vaccine (i) triggered mobilization of dendritic cells (DCs) in the skin, which formed small spots along the laser-treated areas, (ii) induced phenotypic and functional maturation of DCs, (iii) stimulated long-lasting HSV-specific effector memory CD8 + T cells (T EM cells) and tissue-resident CD8 + T cells (T RM cells) locally in the vaginal mucocutaneous tissues (VM), and (iv) induced protective immunity against genital herpes infection and disease. As an alternative to currently used conventional adjuvants, the chemical- and biological-free laser adjuvant offers a well-tolerated, simple-to-produce method to enhance mass vaccination for widespread viral infections. IMPORTANCE Herpes simplex viruses 1 and 2 (HSV-1 and HSV-2) infect a large proportion of the world population. There is an urgent need for chemical-free and biological-free safe adjuvants that would advance mass vaccination against the widespread herpes infections. The present study demonstrates that immunization with a laser

Gluten exacerbates IgA nephropathy in humanized mice through gliadin-CD89 interaction.

Science.gov (United States)

Papista, Christina; Lechner, Sebastian; Ben Mkaddem, Sanae; LeStang, Marie-Bénédicte; Abbad, Lilia; Bex-Coudrat, Julie; Pillebout, Evangéline; Chemouny, Jonathan M; Jablonski, Mathieu; Flamant, Martin; Daugas, Eric; Vrtovsnik, François; Yiangou, Minas; Berthelot, Laureline; Monteiro, Renato C

2015-08-01

IgA1 complexes containing deglycosylated IgA1, IgG autoantibodies, and a soluble form of the IgA receptor (sCD89), are hallmarks of IgA nephropathy (IgAN). Food antigens, notably gluten, are associated with increased mucosal response and IgAN onset, but their implication in the pathology remains unknown. Here, an IgAN mouse model expressing human IgA1 and CD89 was used to examine the role of gluten in IgAN. Mice were given a gluten-free diet for three generations to produce gluten sensitivity, and then challenged for 30 days with a gluten diet. A gluten-free diet resulted in a decrease of mesangial IgA1 deposits, transferrin 1 receptor, and transglutaminase 2 expression, as well as hematuria. Mice on a gluten-free diet lacked IgA1-sCD89 complexes in serum and kidney eluates. Disease severity depended on gluten and CD89, as shown by reappearance of IgAN features in mice on a gluten diet and by direct binding of the gluten-subcomponent gliadin to sCD89. A gluten diet exacerbated intestinal IgA1 secretion, inflammation, and villous atrophy, and increased serum IgA1 anti-gliadin antibodies, which correlated with proteinuria in mice and patients. Moreover, early treatment of humanized mice with a gluten-free diet prevented mesangial IgA1 deposits and hematuria. Thus, gliadin-CD89 interaction may aggravate IgAN development through induction of IgA1-sCD89 complex formation and a mucosal immune response. Hence, early-stage treatment with a gluten-free diet could be beneficial to prevent disease.

Impaired bone healing at tooth extraction sites in CD24-deficient mice: A pilot study.

Science.gov (United States)

Avivi-Arber, Limor; Avivi, Doran; Perez, Marilena; Arber, Nadir; Shapira, Shiran

2018-01-01

To use a micro-computed tomography (micro-CT) to quantify bone healing at maxillary first molar extraction sites, and test the hypothesis that bone healing is impaired in CD24-knockout mice as compared with wild-type C57BL/6J mice. Under ketamine-xylazine general anaesthesia, mice had either extraction of the right maxillary first molar tooth or sham operation. Mice were sacrificed 1 (n = 12/group), 2 (n = 6/group) or 4 (n = 6/group) weeks postoperatively. The right maxillae was disected. Micro-CT was used to quantify differences in bone microstructural features at extrction sites, between CD24-knockout mice and wild-type mice. CD24-Knockout mice displayed impaired bone healing at extraction sites that was manifested as decreased trabecular bone density, and decreased number and thickness of trabeculae. This pilot study suggests that CD24 plays an important role in extraction socket bone healing and may be used as a novel biomarker of bone quality and potential therapeutic target to improve bone healing and density following alveolar bone injury.

Low CD4/CD8 T-cell ratio associated with inflammatory arthropathy in human T-cell leukemia virus type I Tax transgenic mice.

Directory of Open Access Journals (Sweden)

Takeo Ohsugi

Full Text Available BACKGROUND: Human T-cell leukemia virus type I (HTLV-1 can cause an aggressive malignancy known as adult T-cell leukemia/lymphoma (ATL as well as inflammatory diseases such as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP. A transgenic mouse that expresses HTLV-1 Tax also develops T-cell leukemia/lymphoma and an inflammatory arthropathy that resembles rheumatoid arthritis. The aim of this study was to identify the primary T-cell subsets involved in the development of arthropathy in Tax transgenic mice. PRINCIPAL FINDINGS: By 24 months of age, Tax transgenic mice developed severe arthropathy with a cumulative incidence of 22.8%. The pathological findings of arthropathy in Tax transgenic mice were similar to those seen in human rheumatoid arthritis or mouse models of rheumatoid arthritis, with synovial proliferation and a positive rheumatoid factor. Before the onset of spontaneous arthropathy, young and old Tax transgenic mice were not sensitive to collagen and did not develop arthritis after immunization with type II collagen. The arthropathic Tax transgenic mice showed a significantly decreased proportion of splenic CD4(+ T cells, whereas the proportion of splenic CD8(+ T cells was increased. Regulatory T cells (CD4(+CD25(+Foxp3(+ were significantly decreased and CD8(+ T cells that expressed the chemokine receptor CCR4 (CD8(+CCR4(+ were significantly increased in arthropathic Tax transgenic mice. The expression of tax mRNA was strong in the spleen and joints of arthropathic mice, with a 40-fold increase compared with healthy transgenic mice. CONCLUSIONS: Our findings reveal that Tax transgenic mice develop rheumatoid-like arthritis with proliferating synovial cells in the joints; however, the proportion of different splenic T-cell subsets in these mice was completely different from other commonly used animal models of rheumatoid arthritis. The crucial T-cell subsets in arthropathic Tax transgenic mice appear to resemble

The Regulatory Roles of Toll-Like Receptor 4 in Secretions of Type 1/Type 2 Relative Cytokines by Splenocytes and Dendritic Cells Exposed to Clonorchis sinensis Excretory/Secretory Products.

Science.gov (United States)

Hua, Hui; Du, Ying; Ma, Rui; Zhang, Bei-Bei; Yu, Qian; Li, Bo; Xu, Jiang-Tao; Li, Xiang-Yang; Tang, Ren-Xian; Yan, Chao; Zheng, Kui-Yang

2018-02-01

The roles of TLR4 in mediation of innate immune response and in regulation of adaptive immune responses triggered by Clonorchis sinensis remain unknown. In the present study, splenocytes derived from C3H/HeN (TLR4 wild ) and C3H/Hej mice (TLR4 mut ) that were infected with 45 metacercariae of C. sinensis were harvested, then stimulated by C. sinensis excretory/secretory products (ESP) or medium (control) for 48 h, respectively. Meanwhile, bone marrow-derived dendritic cells (BMDCs) from normal C3H/HeN and C3H/Hej mice were prepared and stimulated with medium, ESP, LPS, or ESP+LPS for 24 h, respectively. The supernatants were collected, and the concentrations of type 1 and type 2 relative cytokines were determined by ELISA. The maturation of BMDCs indicated by surface markers of CD80, CD86, and MHC II was evaluated by flow cytometry. The results showed that the levels of IFN-γ, IL-6, TNF-α, and IL-10 in the splenocytes from C. sinensis-infected TLR4 mut mice were significantly lower than those from TLR4 wild mice when they were further exposed to ESP. For BMDCs, the productions of the cytokines IL-12p70 and IL-10, but not IL-4, in the BMDCs from TLR4 mutation mice were predominantly decreased compared with those from TLR4 wild mice when the BMDCs were co-stimulated by ESP combined with LPS. Flow cytometry analysis showed that ESP could significantly decrease the high levels of CD80, CD86, and MHC II which were elevated by LPS. In conclusion, these data suggest that TLR4 may play a regulatory role in type 1 immune responses during C. sinensis infection.

Investigation of Functional Activity of Cells in Granulomatous Inflammatory Lesions from Mice with Latent Tuberculous Infection in the New Ex Vivo Model

Directory of Open Access Journals (Sweden)

Elena Ufimtseva

2013-01-01

Full Text Available The new ex vivo model system measuring functional input of individual granuloma cells to formation of granulomatous inflammatory lesions in mice with latent tuberculous infection has been developed and described in the current study. Monolayer cultures of cells that migrated from individual granulomas were established in the proposed culture settings for mouse spleen and lung granulomas induced by in vivo exposure to BCG vaccine. The cellular composition of individual granulomas was analyzed. The expression of the leukocyte surface markers such as phagocytic receptors CD11b, CD11c, CD14, and CD16/CD32 and the expression of the costimulatory molecules CD80, CD83, and CD86 were tested as well as the production of proinflammatory cytokines (IFNγ and IL-1α and growth factors (GM-CSF and FGFb for cells of individual granulomas. The colocalization of the phagocytic receptors and costimulatory molecules in the surface microdomains of granuloma cells (with and without acid-fast BCG-mycobacteria has also been detected. It was found that some part of cytokine macrophage producers have carried acid-fast mycobacteria. Detected modulation in dynamics of production of pro-inflammatory cytokines, growth factors, and leukocyte surface markers by granuloma cells has indicated continued processes of activation and deactivation of granuloma inflammation cells during the latent tuberculous infection progress in mice.

Investigation of Functional Activity of Cells in Granulomatous Inflammatory Lesions from Mice with Latent Tuberculous Infection in the New Ex Vivo Model

Science.gov (United States)

2013-01-01

The new ex vivo model system measuring functional input of individual granuloma cells to formation of granulomatous inflammatory lesions in mice with latent tuberculous infection has been developed and described in the current study. Monolayer cultures of cells that migrated from individual granulomas were established in the proposed culture settings for mouse spleen and lung granulomas induced by in vivo exposure to BCG vaccine. The cellular composition of individual granulomas was analyzed. The expression of the leukocyte surface markers such as phagocytic receptors CD11b, CD11c, CD14, and CD16/CD32 and the expression of the costimulatory molecules CD80, CD83, and CD86 were tested as well as the production of proinflammatory cytokines (IFNγ and IL-1α) and growth factors (GM-CSF and FGFb) for cells of individual granulomas. The colocalization of the phagocytic receptors and costimulatory molecules in the surface microdomains of granuloma cells (with and without acid-fast BCG-mycobacteria) has also been detected. It was found that some part of cytokine macrophage producers have carried acid-fast mycobacteria. Detected modulation in dynamics of production of pro-inflammatory cytokines, growth factors, and leukocyte surface markers by granuloma cells has indicated continued processes of activation and deactivation of granuloma inflammation cells during the latent tuberculous infection progress in mice. PMID:24198843

CD4/CD8 Ratio and KT Ratio Predict Yellow Fever Vaccine Immunogenicity in HIV-Infected Patients.

Science.gov (United States)

Avelino-Silva, Vivian I; Miyaji, Karina T; Hunt, Peter W; Huang, Yong; Simoes, Marisol; Lima, Sheila B; Freire, Marcos S; Caiaffa-Filho, Helio H; Hong, Marisa A; Costa, Dayane Alves; Dias, Juliana Zanatta C; Cerqueira, Natalia B; Nishiya, Anna Shoko; Sabino, Ester Cerdeira; Sartori, Ana M; Kallas, Esper G

2016-12-01

HIV-infected individuals have deficient responses to Yellow Fever vaccine (YFV) and may be at higher risk for adverse events (AE). Chronic immune activation-characterized by low CD4/CD8 ratio or high indoleamine 2,3-dioxygenase-1 (IDO) activity-may influence vaccine response in this population. We prospectively assessed AE, viremia by the YFV virus and YF-specific neutralizing antibodies (NAb) in HIV-infected (CD4>350) and -uninfected adults through 1 year after vaccination. The effect of HIV status on initial antibody response to YFV was measured during the first 3 months following vaccination, while the effect on persistence of antibody response was measured one year following vaccination. We explored CD4/CD8 ratio, IDO activity (plasma kynurenine/tryptophan [KT] ratio) and viremia by Human Pegivirus as potential predictors of NAb response to YFV among HIV-infected participants with linear mixed models. 12 HIV-infected and 45-uninfected participants were included in the final analysis. HIV was not significantly associated with AE, YFV viremia or NAb titers through the first 3 months following vaccination. However, HIV-infected participants had 0.32 times the NAb titers observed for HIV-uninfected participants at 1 year following YFV (95% CI 0.13 to 0.83, p = 0.021), independent of sex, age and prior vaccination. In HIV-infected participants, each 10% increase in CD4/CD8 ratio predicted a mean 21% higher post-baseline YFV Nab titer (p = 0.024). Similarly, each 10% increase in KT ratio predicted a mean 21% lower post-baseline YFV Nab titer (p = 0.009). Viremia by Human Pegivirus was not significantly associated with NAb titers. HIV infection appears to decrease the durability of NAb responses to YFV, an effect that may be predicted by lower CD4/CD8 ratio or higher KT ratio.

CD4/CD8 Ratio and KT Ratio Predict Yellow Fever Vaccine Immunogenicity in HIV-Infected Patients

Science.gov (United States)

Hunt, Peter W.; Huang, Yong; Simoes, Marisol; Lima, Sheila B.; Freire, Marcos S.; Caiaffa-Filho, Helio H.; Hong, Marisa A.; Costa, Dayane Alves; Dias, Juliana Zanatta C.; Cerqueira, Natalia B.; Nishiya, Anna Shoko; Sabino, Ester Cerdeira; Sartori, Ana M.; Kallas, Esper G.

2016-01-01

Background HIV-infected individuals have deficient responses to Yellow Fever vaccine (YFV) and may be at higher risk for adverse events (AE). Chronic immune activation–characterized by low CD4/CD8 ratio or high indoleamine 2,3-dioxygenase-1 (IDO) activity—may influence vaccine response in this population. Methods We prospectively assessed AE, viremia by the YFV virus and YF-specific neutralizing antibodies (NAb) in HIV-infected (CD4>350) and -uninfected adults through 1 year after vaccination. The effect of HIV status on initial antibody response to YFV was measured during the first 3 months following vaccination, while the effect on persistence of antibody response was measured one year following vaccination. We explored CD4/CD8 ratio, IDO activity (plasma kynurenine/tryptophan [KT] ratio) and viremia by Human Pegivirus as potential predictors of NAb response to YFV among HIV-infected participants with linear mixed models. Results 12 HIV-infected and 45-uninfected participants were included in the final analysis. HIV was not significantly associated with AE, YFV viremia or NAb titers through the first 3 months following vaccination. However, HIV–infected participants had 0.32 times the NAb titers observed for HIV-uninfected participants at 1 year following YFV (95% CI 0.13 to 0.83, p = 0.021), independent of sex, age and prior vaccination. In HIV-infected participants, each 10% increase in CD4/CD8 ratio predicted a mean 21% higher post-baseline YFV Nab titer (p = 0.024). Similarly, each 10% increase in KT ratio predicted a mean 21% lower post-baseline YFV Nab titer (p = 0.009). Viremia by Human Pegivirus was not significantly associated with NAb titers. Conclusions HIV infection appears to decrease the durability of NAb responses to YFV, an effect that may be predicted by lower CD4/CD8 ratio or higher KT ratio. PMID:27941965

The Tetraspanin CD151 in Papillomavirus Infection

Directory of Open Access Journals (Sweden)

Konstanze D. Scheffer

2014-02-01

Full Text Available Human papillomaviruses (HPV are non-enveloped DNA tumor viruses that infect skin and mucosa. The most oncogenic subtype, HPV16, causes various types of cancer, including cervical, anal, and head and neck cancers. During the multistep process of infection, numerous host proteins are required for the delivery of virus genetic information into the nucleus of target cells. Over the last two decades, many host-cell proteins such as heparan sulfate proteoglycans, integrins, growth factor receptors, actin and the tetraspanin CD151 have been described to be involved in the process of infectious entry of HPV16. Tetraspanins have the ability to organize membrane microdomains and to directly influence the function of associated molecules, including binding of receptors to their ligands, receptor oligomerization and signal transduction. Here, we summarize the current knowledge on CD151, and CD151-associated partners during HPV infection and discuss the underlying mechanisms.

Chronic exposure to water pollutant trichloroethylene increased epigenetic drift in CD4+ T cells

Science.gov (United States)

Gilbert, Kathleen M; Blossom, Sarah J; Erickson, Stephen W; Reisfeld, Brad; Zurlinden, Todd J; Broadfoot, Brannon; West, Kirk; Bai, Shasha; Cooney, Craig A

2016-01-01

Aim: Autoimmune disease and CD4+ T-cell alterations are induced in mice exposed to the water pollutant trichloroethylene (TCE). We examined here whether TCE altered gene-specific DNA methylation in CD4+ T cells as a possible mechanism of immunotoxicity. Materials & methods: Naive and effector/memory CD4+ T cells from mice exposed to TCE (0.5 mg/ml in drinking water) for 40 weeks were examined by bisulfite next-generation DNA sequencing. Results: A probabilistic model calculated from multiple genes showed that TCE decreased methylation control in CD4+ T cells. Data from individual genes fitted to a quadratic regression model showed that TCE increased gene-specific methylation variance in both CD4 subsets. Conclusion: TCE increased epigenetic drift of specific CpG sites in CD4+ T cells. PMID:27092578

Neurobehavioral development of CD-1 mice after combined gestational and postnatal exposure to ozone

Energy Technology Data Exchange (ETDEWEB)

Dell` Omo, G [Section of Behavioral Pathophysiology, Lab. di Fisiopatologia di Organo e di Sistema, Istituto Superiore di Sanita, Rome (Italy); Fiore, M [Section of Behavioral Pathophysiology, Lab. di Fisiopatologia di Organo e di Sistema, Istituto Superiore di Sanita, Rome (Italy); Petruzzi, S [Section of Behavioral Pathophysiology, Lab. di Fisiopatologia di Organo e di Sistema, Istituto Superiore di Sanita, Rome (Italy); Alleva, E [Section of Behavioral Pathophysiology, Lab. di Fisiopatologia di Organo e di Sistema, Istituto Superiore di Sanita, Rome (Italy); Bignami, G [Section of Behavioral Pathophysiology, Lab. di Fisiopatologia di Organo e di Sistema, Istituto Superiore di Sanita, Rome (Italy)

1995-09-01

Outbred CD-1 mice were exposed continuously to ozone (O{sub 3}, 0.6 ppm) from 6 days prior to the formation of breeding pairs to the time of weaning of the offspring on postnatal day 22 (PND 22) or to PND 26. One half of the mice in each of eight O{sub 3} and eight control litters were subjected on PND 24 to a 20-min open-field test after IP treatment by either saline or scopolamine (2 mg/kg). The remaining mice (those exposed until PND 26) were subjected on PNDs 28-31 to a conditioned place preference (CPP) test, using a short schedule with a single IP injection on PND 29 of either d-amphetamine (3.3 mg/kg) or saline. Subsequently, the saline mice of the open-field experiment were used on PND 59 for an activity test in one of the CPP apparatus compartments after IP treatment by either d-amphetamine (same dose) or saline. In addition, the saline mice of the CPP experiment underwent a multitrial, step-through passive avoidance (PA) acquisition test on PND 59 or 60, followed 24 h later by a single-trial retention test. In the absence of effects on reproductive performance (proportion of successful pregnancies, litter size, offspring viability, and sex ratio), O{sub 3} offspring showed a long-lasting reduction in body weight without modification of sec differences. Ozone effects on neurobehavioral development were not large and quite selective, including: attenuation of the sex differences in several responses (rearing and sniffing in the open-field, activity in the final CPP test session); a change in response choices in the final CPP test, in the absence of a main effect on conditioning; a reduction of grooming in the activity test on PND 29; and impairment of PA acquisition limited to the initial period of training. (orig.)

Neurobehavioral development of CD-1 mice after combined gestational and postnatal exposure to ozone.

Science.gov (United States)

Dell'Omo, G; Fiore, M; Petruzzi, S; Alleva, E; Bignami, G

1995-01-01

Outbred CD-1 mice were exposed continuously to ozone (O3, 0.6 ppm) from 6 days prior to the formation of breeding pairs to the time of weaning of the offspring on postnatal day 22 (PND 22) or to PND 26. One half of the mice in each of eight O3 and eight control litters were subjected on PND 24 to a 20-min open-field test after IP treatment by either saline or scopolamine (2 mg/kg). The remaining mice (those exposed until PND 26) were subjected on PNDs 28-31 to a conditioned place preference (CPP) test, using a short schedule with a single IP injection on PND 29 of either d-amphetamine (3.3 mg/kg) or saline. Subsequently, the saline mice of the open-field experiment were used on PND 59 for an activity test in one of the CPP apparatus compartments after IP treatment by either d-amphetamine (same dose) or saline. In addition, the saline mice of the CPP experiment underwent a multi-trial, step-through passive avoidance (PA) acquisition test on PND 59 or 60, followed 24 h later by a single-trial retention test. In the absence of effects on reproductive performance (proportion of successful pregnancies, litter size, offspring viability, and sex ratio), O3 offspring showed a long-lasting reduction in body weight without modification of sex differences. Ozone effects on neurobehavioral development were not large and quite selective, including: attenuation of the sex differences in several responses (rearing and sniffing in the open-field, activity in the final CPP test session); a change in response choices in the final CPP test, in the absence of a main effect on conditioning; a reduction of grooming in the activity test on PND 29; and impairment of PA acquisition limited to the initial period of training.

Galectins expressed differently in genetically susceptible C57BL/6 and resistant BALB/c mice during acute ocular Toxoplasma gondii infection.

Science.gov (United States)

Chen, S-J; Zhang, Y-X; Huang, S-G; Lu, F-L

2017-07-01

Ocular toxoplasmosis (OT) caused by Toxoplasma gondii is a major cause of infectious uveitis, however little is known about its immunopathological mechanism. Susceptible C57BL/6 (B6) and resistant BALB/c mice were intravitreally infected with 500 tachyzoites of the RH strain of T. gondii. B6 mice showed more severe ocular pathology and higher parasite loads in the eyes. The levels of galectin (Gal)-9 and its receptors (Tim-3 and CD137), interferon (IFN)-γ, IL-6 and IL-10 were significantly higher in the eyes of B6 mice than those of BALB/c mice; however, the levels of IFN-α and -β were significantly decreased in the eyes and CLNs of B6 mice but significantly increased in BALB/c mice after infection. After blockage of galectin-receptor interactions by α-lactose, neither ocular immunopathology nor parasite loads were different from those of infected BALB/c mice without α-lactose treatment. Although the expressions of Gal-9/receptor were significantly increased in B6 mice and Gal-1 and -3 were upregulated in both strains of mice upon ocular T. gondii infection, blockage of galectins did not change the ocular pathogenesis of genetic resistant BALB/c mice. However, IFN-α and -β were differently expressed in B6 and BALB/c mice, suggesting that type I IFNs may play a protective role in experimental OT.

CD4 T Cell Responses in Latent and Chronic Viral Infections

Science.gov (United States)

Walton, Senta; Mandaric, Sanja; Oxenius, Annette

2013-01-01

The spectrum of tasks which is fulfilled by CD4 T cells in the setting of viral infections is large, ranging from support of CD8 T cells and humoral immunity to exertion of direct antiviral effector functions. While our knowledge about the differentiation pathways, plasticity, and memory of CD4 T cell responses upon acute infections or immunizations has significantly increased during the past years, much less is still known about CD4 T cell differentiation and their beneficial or pathological functions during persistent viral infections. In this review we summarize current knowledge about the differentiation, direct or indirect antiviral effector functions, and the regulation of virus-specific CD4 T cells in the setting of persistent latent or active chronic viral infections with a particular emphasis on herpes virus infections for the former and chronic lymphocytic choriomeningitis virus infection for the latter. PMID:23717308

Humoral and cellular immune response in mice induced by the classical swine fever virus E2 protein fused to the porcine CD154 antigen.

Science.gov (United States)

Sordo, Yusmel; Suárez, Marisela; Caraballo, Rosalina; Sardina, Talía; Brown, Emma; Duarte, Carlos; Lugo, Joanna; Gil, Lázaro; Perez, Danny; Oliva, Ayme; Vargas, Milagros; Santana, Elaine; Valdés, Rodolfo; Rodríguez, María Pilar

2018-03-01

The development of subunit vaccines against classical swine fever is a desirable goal, because it allows discrimination between vaccinated and infected animals. In this study, humoral and cellular immune response elicited in inbred BALB/c mice by immunization with a recombinant classical swine fever virus (CSFV) E2 protein fused to porcine CD154 antigen (E2CD154) was assessed. This model was used as a predictor of immune response in swine. Mice were immunized with E2CD154 emulsified in Montanide ISA50V2 or dissolved in saline on days 1 and 21. Another group received E2His antigen, without CD154, in the same adjuvant. Montanide ISA50V2 or saline served as negative controls for each experimental group. Animals immunized with 12.5 and 2.5 μg/dose of E2CD154 developed the highest titers (>1:2000) of CSFV neutralizing antibodies. Moreover, CSFV specific splenocyte gamma-interferon production, measured after seven and twenty-eight days of immunization, was significantly higher in mice immunized with 12.5 μg of E2CD154. As a conclusion, E2CD154 emulsified in Montanide ISA50 V2 was able to induce a potent humoral and an early cellular immune response in inbred BALB/c mice. Therefore, this immunogen might be an appropriate candidate to elicit immune response in swine, control CSF disease and to eliminate CSFV in swine. Copyright © 2018 International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

Anthrax lethal factor as an immune target in humans and transgenic mice and the impact of HLA polymorphism on CD4+ T cell immunity.

Science.gov (United States)

Ascough, Stephanie; Ingram, Rebecca J; Chu, Karen K; Reynolds, Catherine J; Musson, Julie A; Doganay, Mehmet; Metan, Gökhan; Ozkul, Yusuf; Baillie, Les; Sriskandan, Shiranee; Moore, Stephen J; Gallagher, Theresa B; Dyson, Hugh; Williamson, E Diane; Robinson, John H; Maillere, Bernard; Boyton, Rosemary J; Altmann, Daniel M

2014-05-01

Bacillus anthracis produces a binary toxin composed of protective antigen (PA) and one of two subunits, lethal factor (LF) or edema factor (EF). Most studies have concentrated on induction of toxin-specific antibodies as the correlate of protective immunity, in contrast to which understanding of cellular immunity to these toxins and its impact on infection is limited. We characterized CD4+ T cell immunity to LF in a panel of humanized HLA-DR and DQ transgenic mice and in naturally exposed patients. As the variation in antigen presentation governed by HLA polymorphism has a major impact on protective immunity to specific epitopes, we examined relative binding affinities of LF peptides to purified HLA class II molecules, identifying those regions likely to be of broad applicability to human immune studies through their ability to bind multiple alleles. Transgenics differing only in their expression of human HLA class II alleles showed a marked hierarchy of immunity to LF. Immunogenicity in HLA transgenics was primarily restricted to epitopes from domains II and IV of LF and promiscuous, dominant epitopes, common to all HLA types, were identified in domain II. The relevance of this model was further demonstrated by the fact that a number of the immunodominant epitopes identified in mice were recognized by T cells from humans previously infected with cutaneous anthrax and from vaccinated individuals. The ability of the identified epitopes to confer protective immunity was demonstrated by lethal anthrax challenge of HLA transgenic mice immunized with a peptide subunit vaccine comprising the immunodominant epitopes that we identified.

Unexpected Cartilage Phenotype in CD4-Cre-Conditional SOS-Deficient Mice.

Science.gov (United States)

Guittard, Geoffrey; Gallardo, Devorah L; Li, Wenmei; Melis, Nicolas; Lui, Julian C; Kortum, Robert L; Shakarishvili, Nicholas G; Huh, Sunmee; Baron, Jeffrey; Weigert, Roberto; Kramer, Joshua A; Samelson, Lawrence E; Sommers, Connie L

2017-01-01

RAS signaling is central to many cellular processes and SOS proteins promote RAS activation. To investigate the role of SOS proteins in T cell biology, we crossed Sos1 f/f Sos2 -/- mice to CD4-Cre transgenic mice. We previously reported an effect of these mutations on T cell signaling and T cell migration. Unexpectedly, we observed nodules on the joints of greater than 90% of these mutant mice at 5 months of age, especially on the carpal joints. As the mice aged further, some also displayed joint stiffness, hind limb paralysis, and lameness. Histological analysis indicated that the abnormal growth in joints originated from dysplastic chondrocytes. Second harmonic generation imaging of the carpal nodules revealed that nodules were encased by rich collagen fibrous networks. Nodules formed in mice also deficient in RAG2, indicating that conventional T cells, which undergo rearrangement of the T cell antigen receptor, are not required for this phenotype. CD4-Cre expression in a subset of cells, either immune lineage cells (e.g., non-conventional T cells) or non-immune lineage cells (e.g., chondrocytes) likely mediates the dramatic phenotype observed in this study. Disruptions of genes in the RAS signaling pathway are especially likely to cause this phenotype. These results also serve as a cautionary tale to those intending to use CD4-Cre transgenic mice to specifically delete genes in conventional T cells.

[Congenital cytomegalovirus infection manifesting as neonatal respiratory distress in an HIV-exposed uninfected newborn].

Science.gov (United States)

Pham, A; El Mjati, H; Nathan, N; Kieffer, F; Mitanchez, D

2017-09-01

Cytomegalovirus (CMV) is one of the most common intrauterine infections, affecting approximately 1% of all live births. There are few reports on congenital CMV infections manifesting as isolated pneumonitis. We report a case of congenital CMV with neonatal respiratory distress affecting an HIV-exposed uninfected infant. This infant required noninvasive ventilation beginning within the first 15min of life. The initial chest X-ray showed diffuse bilateral ground-glass opacifications. Bacterial infection, meconium aspiration and hyaline membrane disease were excluded. Salivary quantitative CMV PCR was positive (2,342,261IU/mL) and serum viral load for CMV was low (476IU/mL). Bronchoalveolar lavage (BAL) performed on day 12 for quantitative CMV PCR was significantly positive (1,045,942IU/mL). Intravenous ganciclovir treatment was started on day 14 (7.5mg/kg/12h) for 2 weeks and oral valganciclovir (15mg/kg/12h) was given for 4 weeks afterwards. Ventilatory support was stopped on day 18. HIV serum viral load was negative on day 30. Congenital CMV infection can present as isolated pneumonitis with persistent neonatal respiratory symptoms, emphysematous lung disease, or persistent pulmonary hypertension. If this diagnosis is suspected, and even if CMV viremia remains low, BAL with quantitative CMV PCR must be performed to ascertain the diagnosis and indicate antiviral treatment. HIV-exposed uninfected infants have higher rates of congenital CMV infection when the mother's CD4 rate isCMV transmission in HIV-exposed uninfected infants have occurred by maternal endogenous reactivation or reinfection. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

A potent adjuvant effect of a CD1d-binding NKT cell ligand in human immune system mice.

Science.gov (United States)

Li, Xiangming; Huang, Jing; Kaneko, Izumi; Zhang, Min; Iwanaga, Shiroh; Yuda, Masao; Tsuji, Moriya

2017-01-01

A CD1d-binding invariant natural killer T (iNKT)-cell stimulatory glycolipid, namely 7DW8-5, is shown to enhance the efficacy of radiation-attenuated sporozoites (RAS)-based malaria vaccine in mice. In the current study, we aim to determine whether 7DW8-5 can display a potent adjuvant effect in human immune system (HIS) mice. HIS-A2/hCD1d mice, which possess both functional human iNKT cells and CD8+ T cells, were generated by the transduction of NSG mice with adeno-associated virus serotype 9 expressing genes that encode human CD1d molecules and HLA-A*0201, followed by the engraftment of human hematopoietic stem cells. The magnitudes of human iNKT-cell response against 7DW8-5 and HLA-A*0201-restricted human CD8+ T-cell response against a human malaria antigen in HIS-A2/hCD1d mice were determined by using human CD1d tetramer and human HLA-A*0201 tetramer, respectively. We found that 7DW8-5 stimulates human iNKT cells in HIS-A2/hCD1d mice, as well as those derived from HIS-A2/hCD1d mice in vitro. We also found that 7DW8-5 significantly increases the level of a human malarial antigen-specific HLA-A*0201-restricted human CD8+ T-cell response in HIS-A2/hCD1d mice. Our study indicates that 7DW8-5 can display a potent adjuvant effect on RAS vaccine-induced anti-malarial immunity by augmenting malaria-specific human CD8+ T-cell response.

Dental Infection of Porphyromonas gingivalis Induces Preterm Birth in Mice.

Directory of Open Access Journals (Sweden)

Min Ao

damage was indicated in P.g. infected mice by decreased CD-31 in endothelial cells, increased expression of 8OHdG, an indicator of oxidative DNA damage, and cleaved caspase-3, a marker of apoptosis. In vitro, P.g. lipopolysaccharide significantly increased expression of COX-2, IL-8 and TNF-α, in HTR-8 trophoblasts in an NF-κB-dependent fashion.Our novel mouse model supports previous epidemiological studies signifying dental infection as predisposing factor for PTB/LBW. We demonstrate PTB and LBW in infected mice, translocation of P.g to placental tissues, increased circulating and local pro-inflammatory markers, and the capability of P.g. LPS to directly induce cytokine production in trophoblasts, in vitro. These findings further underscore the importance of local and systemic infections and inflammation during pregnancy and suggest that prevention and/or elimination of dental infections such as marginal or periapical periodontitis before pregnancy may have a beneficial effect on PTB/LBW.

BTLA interaction with HVEM expressed on CD8(+ T cells promotes survival and memory generation in response to a bacterial infection.

Directory of Open Access Journals (Sweden)

Marcos W Steinberg

Full Text Available The B and T lymphocyte attenuator (BTLA is an Ig super family member that binds to the herpes virus entry mediator (HVEM, a TNF receptor super family (TNFRSF member. Engagement of BTLA by HVEM triggers inhibitory signals, although recent evidence indicates that BTLA also may act as an activating ligand for HVEM. In this study, we reveal a novel role for the BTLA-HVEM pathway in promoting the survival of activated CD8(+ T cells in the response to an oral microbial infection. Our data show that both BTLA- and HVEM-deficient mice infected with Listeria monocytogenes had significantly reduced numbers of primary effector and memory CD8(+ T cells, despite normal proliferation and expansion compared to controls. In addition, blockade of the BTLA-HVEM interaction early in the response led to significantly reduced numbers of antigen-specific CD8(+ T cells. HVEM expression on the CD8(+ T cells as well as BTLA expression on a cell type other than CD8(+ T lymphocytes, was required. Collectively, our data demonstrate that the function of the BTLA-HVEM pathway is not limited to inhibitory signaling in T lymphocytes, and instead, that BTLA can provide crucial, HVEM-dependent signals that promote survival of antigen activated CD8(+ T cell during bacterial infection.

BTLA interaction with HVEM expressed on CD8(+) T cells promotes survival and memory generation in response to a bacterial infection.

Science.gov (United States)

Steinberg, Marcos W; Huang, Yujun; Wang-Zhu, Yiran; Ware, Carl F; Cheroutre, Hilde; Kronenberg, Mitchell

2013-01-01

The B and T lymphocyte attenuator (BTLA) is an Ig super family member that binds to the herpes virus entry mediator (HVEM), a TNF receptor super family (TNFRSF) member. Engagement of BTLA by HVEM triggers inhibitory signals, although recent evidence indicates that BTLA also may act as an activating ligand for HVEM. In this study, we reveal a novel role for the BTLA-HVEM pathway in promoting the survival of activated CD8(+) T cells in the response to an oral microbial infection. Our data show that both BTLA- and HVEM-deficient mice infected with Listeria monocytogenes had significantly reduced numbers of primary effector and memory CD8(+) T cells, despite normal proliferation and expansion compared to controls. In addition, blockade of the BTLA-HVEM interaction early in the response led to significantly reduced numbers of antigen-specific CD8(+) T cells. HVEM expression on the CD8(+) T cells as well as BTLA expression on a cell type other than CD8(+) T lymphocytes, was required. Collectively, our data demonstrate that the function of the BTLA-HVEM pathway is not limited to inhibitory signaling in T lymphocytes, and instead, that BTLA can provide crucial, HVEM-dependent signals that promote survival of antigen activated CD8(+) T cell during bacterial infection.

Exposing to cadmium stress cause profound toxic effect on microbiota of the mice intestinal tract.

Directory of Open Access Journals (Sweden)

Yehao Liu

Full Text Available Cadmium (Cd, one of the heavy metals, is an important environmental pollutant and a potent toxicant to organism. It poses a severe threat to the growth of the organism, and also has been recognized as a human carcinogen. However, the toxicity of cadmium and its influences on microbiota in mammal's intestine are still unclear. In our experiment, the changes of intestinal microbiota in two groups of mice were investigated, which were supplied with 20 and 100 mg kg(-1 cadmium chloride respectively for 3 weeks. The control group was treated with water free from cadmium chloride only. This study demonstrated that Cd accumulated in some tissues of mice after Cd administration and the gut barrier was impaired. Cd exposure also significantly elevated the colonic level of TNF-α. On the other hand, Cd-treatment could slow down the growth of gut microbiota and reduced the abundance of total intestinal bacteria of the mice. Among them, the growth of Bacteroidetes was significantly suppressed while Firmicutes growth was not. The probiotics including Lactobacillus and Bifidobacterium were notably inhibited. We also observed that the copies of key genes involved in the metabolism of carbohydrates to short-chain fatty acids (SCFAs were lower in Cd-treated groups than control. As a result, the levels of short-chain fatty acids in colonic decreased significantly. In summary, this study provides valuable insight into the effects of Cd intake on mice gut microbiota.

CD95 (FAS) and CD178 (FASL) induce the apoptosis of CD4+ and CD8+ cells isolated from the peripheral blood and spleen of dogs naturally infected with Leishmania spp.

Science.gov (United States)

Silva, Kathlenn Liezbeth Oliveira; Melo, Larissa Martins; Perosso, Juliana; Oliveira, Bruna Brito; Santos, Paulo Sérgio Patto Dos; Eugênio, Flávia de Rezende; Lima, Valéria Marçal Felix de

2013-11-08

Infected dogs are urban reservoirs of Leishmania chagasi, which is a causative agent of visceral leishmaniasis (VL). Dogs exhibit immune suppression during the course of this disease, and lymphocyte apoptosis is involved in this process. To investigate apoptosis and the expression levels of FAS-FAS-associated death domain protein (CD95 or APO-1), FASL-FAS ligand protein (CD178), and TRAIL-TNF-related apoptosis-inducing ligand (CD253) receptors in peripheral blood mononuclear cells and spleen leukocytes from 38 symptomatic dogs with moderate VL and 25 healthy dogs were evaluated by flow cytometry. The apoptosis rate of blood and splenic CD4+ and CD8+ cells was higher in infected dogs than in healthy dogs. The expression levels of FAS and FASL in blood and splenic CD4+ cells were lower in infected dogs than in healthy dogs. FAS expression in CD8+ cells was higher in infected dogs than in healthy dogs; in contrast, FASL expression was lower in infected dogs. The expression of the TRAIL receptor increased only in splenic CD8+ cells from infected dogs. The FAS and FAS-L blocking antibodies confirmed the importance of these receptors in apoptosis. Our results enhance the current understanding of the immune response in dogs infected with L. chagasi, facilitating the future development of therapeutic interventions to reduce lymphocyte depletion. Copyright © 2013 Elsevier B.V. All rights reserved.

Oral Antibiotic Treatment of Mice Exacerbates the Disease Severity of Multiple Flavivirus Infections

Directory of Open Access Journals (Sweden)

Larissa B. Thackray

2018-03-01

Full Text Available Summary: Although the outcome of flavivirus infection can vary from asymptomatic to lethal, environmental factors modulating disease severity are poorly defined. Here, we observed increased susceptibility of mice to severe West Nile (WNV, Dengue, and Zika virus infections after treatment with oral antibiotics (Abx that depleted the gut microbiota. Abx treatment impaired the development of optimal T cell responses, with decreased levels of WNV-specific CD8+ T cells associated with increased infection and immunopathology. Abx treatments that resulted in enhanced WNV susceptibility generated changes in the overall structure of the gut bacterial community and in the abundance of specific bacterial taxa. As little as 3 days of treatment with ampicillin was sufficient to alter host immunity and WNV outcome. Our results identify oral Abx therapy as a potential environmental determinant of systemic viral disease, and they raise the possibility that perturbation of the gut microbiota may have deleterious consequences for subsequent flavivirus infections. : Thackray et al. observed increased susceptibility to West Nile, Zika, and Dengue virus infections following oral antibiotic treatment in mice. Antibiotics altered the bacterial abundance and community structure and the development of optimal T cell immunity. These data suggest that antibiotics may have deleterious consequences for subsequent flavivirus infections. Keywords: West Nile virus, Dengue virus, Zika virus, flavivirus, oral antibiotics, gut microbiota, risk factors, pathogenesis determinants, immunity

T lymphocytes among HIV-infected and -uninfected infants: CD4/CD8 ratio as a potential tool in diagnosis of infection in infants under the age of 2 years

Directory of Open Access Journals (Sweden)

Bikoue Arsene

2005-02-01

Full Text Available Abstract Background Serologic tests for HIV infection in infants less than 18 months do not differentiate exposure and infection since maternally acquired IgG antibodies may be detected in infants. Thus, the gold standard for diagnosis of HIV-1 infection in infants under the age of 2 years is DNA or reverse transcriptase polymerase chain reaction. There is an urgent need to evaluate alternative and cost effective laboratory methods for early diagnosis of infant HIV-1 infection as well as identifying infected infants who may benefit from cotrimoxazole prophylaxis and/or initiation of highly active antiretroviral therapy. Methods Whole blood was collected in EDTA from 137 infants aged 0 to 18 months. DNA polymerase chain reaction was used as the reference standard for diagnosis of HIV-1 infection. T-cell subset profiles were determined by flow cytometry. Results Seventy-six infants were DNA PCR positive while 61 were negative. The median CD4 counts of PCR negative infants were significantly higher than those of the PCR positive infants, p . The median CD4/CD8 ratio and the %CD4 of the PCR positive infants were both significantly lower than those of the negative infants, p . The CD4/CD8 ratio had a >98% sensitivity for diagnosis of HIV-1 infection and a specificity of >98%. Conclusion The CD4/CD8 ratio appears useful in identifying HIV-infected infants. The development of lower cost and more robust flow cytometric methods that provide both CD4/CD8 ratio and %CD4 may be cost-effective for HIV-1 diagnosis and identification of infants for cotrimoxazole prophylaxis and/or highly active antiretroviral therapy.

Distorted leukocyte migration, angiogenesis, wound repair and metastasis in Tspan8 and Tspan8/CD151 double knockout mice indicate complementary activities of Tspan8 and CD51.

Science.gov (United States)

Zhao, Kun; Erb, Ulrike; Hackert, Thilo; Zöller, Margot; Yue, Shijing

2018-02-01

The tetraspanin Tspan8 supports via associated integrins and proteases tumor progression and angiogenesis. To shed light on its activities in non-transformed cells, we generated a Tspan8 knockout (ko) mouse, comparing leukocyte migration, angiogenesis, wound healing and tumor growth with wild type, CD151ko and Tspan8/CD151ko (dbko) mice. CD151ko mice were included as CD151 activities resemble that of Tspan8, and dbko mice to exclude mutual substitution. Tspan8ko and dbko mice show no pathological phenotype. However, delayed type hypersensitivity reactions are mitigated in Tspan8ko mice, angiogenesis is severely impaired in Tspan8ko, CD151ko and dbko mice, with Tspan8 mostly affecting lymphangiogenesis. Distinct contributions of CD151 and Tspan8 to skin wound healing rely on preferentially CD151 anchoring basal keratinocytes and Tspan8 promoting motility. Proliferation of wounded skin keratinocytes is not affected. Metastasis formation of a melanoma and a Tspan8-expressing pancreatic cancer line was impaired in Tspan8ko and dbko mice, pointing towards a contribution of host Tspan8 to tumor progression. In line with the importance of tetraspanins in exosome-mediated intercellular communication, defects became mitigated by Tspan8/CD151-competent serum exosomes, which offers a most promising therapeutic option for chronic wounds and arteriosclerosis. Copyright © 2017 Elsevier B.V. All rights reserved.

CD59 Underlines the Antiatherosclerotic Effects of C-Phycocyanin on Mice

Directory of Open Access Journals (Sweden)

Bing Li

2013-01-01

Full Text Available The effects of C-phycocyanin (C-PC on atherosclerosis and the regulatory effects of CD59 gene on anti-atherosclerotic roles of C-PC were investigated. Apolipoprotein E knockout (ApoE(−/− mice were randomly divided into four groups: control group, C-PC treatment group, CD59 transfection group and C-PC+CD59 synergy group. The mice were fed with high-fat-diet and treated with drug intervention at the same time. Results showed the atherosclerotic mouse model was successfully established. CD59 was over-expressed in blood and tissue cells. Single CD59 or C-PC could reduce blood lipid levels and promote the expression of anti-apoptotic Bcl-2 but inhibit pro-apoptotic Fas proteins in endothelial cells. The expression levels of cell cycle protein D1 (Cyclin D1 and mRNA levels of cyclin dependent protein kinase 4 (CDK4 in smooth muscle cells were restrained by CD59 and C-PC. CD59 or C-PC alone could inhibit the formation of atherosclerotic plaque by suppressing MMP-2 protein expression. In addition, C-PC could promote CD59 expression. So both CD59 and C-PC could inhibit the progress of atherosclerosis, and the anti-atherosclerotic effects of C-PC might be fulfilled by promoting CD59 expression, preventing smooth muscle cell proliferation and the apoptosis of endothelial cells, reducing blood fat levels, and at last inhibiting the development of atherosclerosis.

Investigating the effects of nanoparticles on reproduction and development in Drosophila melanogaster and CD-1 mice

Science.gov (United States)

Philbrook, Nicola Anne

Manufactured nanoparticles (NPs) are a class of small (≤ 100 nm) materials that are being used for a variety of purposes, including industrial lubricants, food additives, antibacterial agents, as well as delivery systems for drug and gene therapies. Their unique characteristics due to their small size as well as their parent materials allow them to be exploited in convenience applications; however, some of these properties also allow them to interact with and invade biological systems. Few studies have been performed to determine the potential harm that NPs can inflict on reproductive and developmental processes in organisms. In this study, Drosophila melanogaster and CD-1 mice were orally exposed to varying doses of titanium dioxide (TiO 2) NPs, silver (Ag) NPs, or hydroxyl-functionalized carbon nanotubes (fCNTs) and Drosophila were also exposed to microparticles (MPs) as a control for particle size. The subsequent effect of these materials on reproduction and development were evaluated. Strikingly, each type of NP studied negatively affected either reproduction or development in one or both of the two model systems. TiO2 NPs significantly negative effected both CD-1 mouse development (100 mg/kg or 1000 mg/kg) as well as Drosophila female fecundity (0.005%-0.5% w/v). Ag NPs significantly reduced mouse fetus viability after prenatal exposure to10 mg/kg. Ag NPs also significantly decreased the developmental success of Drosophila when they were directly exposed to these NPs (0.05% - 0.5% w/v) compared to both the vehicle and MP controls. fCNTs significantly increased the presence of morphological defects, resorptions and skeletal abnormalities in CD-1 mice, but had little effect on Drosophila. We speculate that the differences seen in the effects of NP types may be partially due to differences in reproductive physiology as well as each organism's ability to internalize these NPs. Whereas the differing response of each organism to a NP type was likely due in part to

Preferential infection and depletion of Mycobacterium tuberculosis-specific CD4 T cells after HIV-1 infection

NARCIS (Netherlands)

Geldmacher, Christof; Ngwenyama, Njabulo; Schuetz, Alexandra; Petrovas, Constantinos; Reither, Klaus; Heeregrave, Edwin J.; Casazza, Joseph P.; Ambrozak, David R.; Louder, Mark; Ampofo, William; Pollakis, Georgios; Hill, Brenna; Sanga, Erica; Saathoff, Elmar; Maboko, Leonard; Roederer, Mario; Paxton, William A.; Hoelscher, Michael; Koup, Richard A.

2010-01-01

HIV-1 infection results in the progressive loss of CD4 T cells. In this study, we address how different pathogen-specific CD4 T cells are affected by HIV infection and the cellular parameters involved. We found striking differences in the depletion rates between CD4 T cells to two common

Exogenous and endogenous hyaluronic acid reduces HIV infection of CD4+ T cells

Science.gov (United States)

Li, Peilin; Fujimoto, Katsuya; Bourguingnon, Lilly; Yukl, Steven; Deeks, Steven; Wong, Joseph K

2014-01-01

Preventing mucosal transmission of HIV is critical to halting the HIV epidemic. Novel approaches to preventing mucosal transmission are needed. Hyaluronic acid (HA) is a major extracellular component of mucosa and the primary ligand for the cell surface receptor CD44. CD44 enhances HIV infection of CD4+ T cells, but the role of HA in this process is not clear. To study this, virions were generated with CD44 (HIVCD44) or without CD44 (HIVmock). Exogenous HA reduced HIV infection of unstimulated CD4+ T cells in a CD44-dependent manner. Conversely, hyaluronidase-mediated reduction of endogenous HA on the cell surface enhanced HIV binding to and infection of unstimulated CD4+ T cells. Exogenous HA treatment reduced activation of protein kinase C alpha via CD44 on CD4+ T cells during infection with HIVCD44. These results reveal new roles for HA during the interaction of HIV with CD4+ T cells that may be relevant to mucosal HIV transmission and could be exploitable as a future strategy to prevent HIV infection. PMID:24957217

[Sulfatide-loaded CD1d tetramer to detect typeII NKT cells in mice].

Science.gov (United States)

Zhang, Gu-qin; Nie, Han-xiang; Yang, Jiong; Yu, Hong-ying

2012-07-01

To create a method of detecting typeII natural killer T (NKT) cells of mice. Biotinylated mouse CD1d monomers were mixed with sulfatide at a molar ratio of 1:3 (protein:lipid) and incubated at room temperature overnight, and then 80 μg of streptavidin-PE was added into 200 μg of the CD1d-sulfatide mixture and incubated at room temperature for 4 h to get sulfatide/CD1d tetramer. Flow cytometry was used to detect the percentage of typeII NKT cells in mononuclear cells (MNCs) of lung and spleen of normal mice, as well as the percentage of typeII NKT cells in spleen MNCs of mice after stimulated with sulfatide. In normal mice, the percentage of typeII NKT cells accounted for (0.875±0.096)% and (1.175±0.263)% in MNCs of spleen and lung; the percentage in spleen MNCs after activated with sulfatide was (2.75±0.603)%, which significantly increased as compared with that in normal mice (PNKT cells in mice.

Inhibition of MHC class I is a virulence factor in herpes simplex virus infection of mice.

Directory of Open Access Journals (Sweden)

Mark T Orr

2005-09-01

Full Text Available Herpes simplex virus (HSV has a number of genes devoted to immune evasion. One such gene, ICP47, binds to the transporter associated with antigen presentation (TAP 1/2 thereby preventing transport of viral peptides into the endoplasmic reticulum, loading of peptides onto nascent major histocompatibility complex (MHC class I molecules, and presentation of peptides to CD8 T cells. However, ICP47 binds poorly to murine TAP1/2 and so inhibits antigen presentation by MHC class I in mice much less efficiently than in humans, limiting the utility of murine models to address the importance of MHC class I inhibition in HSV immunopathogenesis. To address this limitation, we generated recombinant HSVs that efficiently inhibit antigen presentation by murine MHC class I. These recombinant viruses prevented cytotoxic T lymphocyte killing of infected cells in vitro, replicated to higher titers in the central nervous system, and induced paralysis more frequently than control HSV. This increase in virulence was due to inhibition of antigen presentation to CD8 T cells, since these differences were not evident in MHC class I-deficient mice or in mice in which CD8 T cells were depleted. Inhibition of MHC class I by the recombinant viruses did not impair the induction of the HSV-specific CD8 T-cell response, indicating that cross-presentation is the principal mechanism by which HSV-specific CD8 T cells are induced. This inhibition in turn facilitates greater viral entry, replication, and/or survival in the central nervous system, leading to an increased incidence of paralysis.

Evolving role of 2B4/CD244 in T and NK cell responses during virus infection

Directory of Open Access Journals (Sweden)

Stephen Noel Waggoner

2012-12-01

Full Text Available The signaling lymphocyte activation molecule (SLAM family receptor, 2B4/CD244, was first implicated in anti-viral immunity by the discovery that mutations of the SLAM-associated protein, SAP/SH2D1A, impaired 2B4-dependent stimulation of T and natural killer (NK cell anti-viral functions in X-linked lymphoproliferative (XLP syndrome patients with uncontrolled Epstein-Barr virus (EBV infections. Engagement of 2B4 has been variably shown to either activate or inhibit lymphocytes which express this receptor. While SAP expression is required for stimulatory functions of 2B4 on lymphocytes, it remains unclear whether inhibitory signals derived from 2B4 can predominate even in the presence of SAP. Regardless, mounting evidence suggests that 2B4 expression by NK and CD8 T cells is altered by virus infection in mice as well as in humans, and 2B4-mediated signaling may be an important determinant of effective immune control of chronic virus infections. In this review, recent findings regarding the expression and function of 2B4 as well as SAP on T and NK cells during virus infection is discussed, with a focus on the role of 2B4-CD48 interactions in crosstalk between innate and adaptive immunity.

Fas activity mediates airway inflammation during mouse adenovirus type 1 respiratory infection.

Science.gov (United States)

Adkins, Laura J; Molloy, Caitlyn T; Weinberg, Jason B

2018-06-13

CD8 T cells play a key role in clearance of mouse adenovirus type 1 (MAV-1) from the lung and contribute to virus-induced airway inflammation. We tested the hypothesis that interactions between Fas ligand (FasL) and Fas mediate the antiviral and proinflammatory effects of CD8 T cells. FasL and Fas expression were increased in the lungs of C57BL/6 (B6) mice during MAV-1 respiratory infection. Viral replication and weight loss were similar in B6 and Fas-deficient (lpr) mice. Histological evidence of pulmonary inflammation was similar in B6 and lpr mice, but lung mRNA levels and airway proinflammatory cytokine concentrations were lower in MAV-1-infected lpr mice compared to infected B6 mice. Virus-induced apoptosis in lungs was not affected by Fas deficiency. Our results suggest that the proinflammatory effects of CD8 T cells during MAV-1 infection are mediated in part by Fas activation and are distinct from CD8 T cell antiviral functions. Copyright © 2018 Elsevier Inc. All rights reserved.

Differential cellular responses in healthy mice and in mice with established airway inflammation when exposed to hematite nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Gustafsson, Åsa, E-mail: asa.gustafsson@foi.se [Swedish Defence Research Agency, Division of CBRN Defence and Security, Umeå (Sweden); Dept of Public Health and Clinical Medicine, Umeå University (Sweden); Bergström, Ulrika [Swedish Defence Research Agency, Division of CBRN Defence and Security, Umeå (Sweden); Dept of Organismal Biology, Uppsala University, SE-751 Uppsala (Sweden); Ågren, Lina [Swedish Defence Research Agency, Division of CBRN Defence and Security, Umeå (Sweden); Österlund, Lars [Dept of Engineering Sciences, The Ångström Laboratory, Uppsala University, SE-751 Uppsala (Sweden); Sandström, Thomas [Dept of Public Health and Clinical Medicine, Umeå University (Sweden); Bucht, Anders [Swedish Defence Research Agency, Division of CBRN Defence and Security, Umeå (Sweden); Dept of Public Health and Clinical Medicine, Umeå University (Sweden)

2015-10-01

The aim of this study was to investigate the inflammatory and immunological responses in airways and lung-draining lymph nodes (LDLNs), following lung exposure to iron oxide (hematite) nanoparticles (NPs). The responses to the hematite NPs were evaluated in both healthy non-sensitized mice, and in sensitized mice with an established allergic airway disease. The mice were exposed intratracheally to either hematite NPs or to vehicle (PBS) and the cellular responses were evaluated on days 1, 2, and 7, post-exposure. Exposure to hematite NPs increased the numbers of neutrophils, eosinophils, and lymphocytes in the airways of non-sensitized mice on days 1 and 2 post-exposure; at these time points the number of lymphocytes was also elevated in the LDLNs. In contrast, exposing sensitized mice to hematite NPs induced a rapid and unspecific cellular reduction in the alveolar space on day 1 post-exposure; a similar decrease of lymphocytes was also observed in the LDLN. The results indicate that cells in the airways and in the LDLN of individuals with established airway inflammation undergo cell death when exposed to hematite NPs. A possible explanation for this toxic response is the extensive generation of reactive oxygen species (ROS) in the pro-oxidative environment of inflamed airways. This study demonstrates how sensitized and non-sensitized mice respond differently to hematite NP exposure, and it highlights the importance of including individuals with respiratory disorders when evaluating health effects of inhaled nanomaterials. - Highlights: • Hematite NPs induce differential responses in airways of healthy and allergic mice. • Hematite induced an airway inflammation in healthy mice. • Hematite induced cellular reduction in the alveolus and lymph nodes of allergic mice. • Cell death is possible due to extensive pro-oxidative environment in allergic mice. • It is important to include sensitive individuals when valuing health effects of NPs.

9 CFR 73.8 - Cattle infected or exposed during transit.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Cattle infected or exposed during... SCABIES IN CATTLE § 73.8 Cattle infected or exposed during transit. (a) Healthy cattle from unquarantined State exposed en route. Should healthy cattle in transit from a State not quarantined by the Secretary...

The CD8 T Cell Response to Respiratory Virus Infections.

Science.gov (United States)

Schmidt, Megan E; Varga, Steven M

2018-01-01

Humans are highly susceptible to infection with respiratory viruses including respiratory syncytial virus (RSV), influenza virus, human metapneumovirus, rhinovirus, coronavirus, and parainfluenza virus. While some viruses simply cause symptoms of the common cold, many respiratory viruses induce severe bronchiolitis, pneumonia, and even death following infection. Despite the immense clinical burden, the majority of the most common pulmonary viruses lack long-lasting efficacious vaccines. Nearly all current vaccination strategies are designed to elicit broadly neutralizing antibodies, which prevent severe disease following a subsequent infection. However, the mucosal antibody response to many respiratory viruses is not long-lasting and declines with age. CD8 T cells are critical for mediating clearance following many acute viral infections in the lung. In addition, memory CD8 T cells are capable of providing protection against secondary infections. Therefore, the combined induction of virus-specific CD8 T cells and antibodies may provide optimal protective immunity. Herein, we review the current literature on CD8 T cell responses induced by respiratory virus infections. Additionally, we explore how this knowledge could be utilized in the development of future vaccines against respiratory viruses, with a special emphasis on RSV vaccination.

Neutrophil trails guide influenza-specific CD8+ T cells in the airways

Science.gov (United States)

Lim, Kihong; Hyun, Young-Min; Lambert-Emo, Kris; Capece, Tara; Bae, Seyeon; Miller, Richard; Topham, David J.; Kim, Minsoo

2016-01-01

During viral infections, chemokines guide activated effector T cells to infection sites. However, the cells responsible for producing these chemokines and how such chemokines recruit T cells is unknown. Here, we show that the early recruitment of neutrophils into influenza-infected trachea is essential for CD8+ T cell-mediated immune protection in mice. We observed that migrating neutrophils leave behind long-lasting trails that are enriched in the chemokine CXCL12. Experiments with granulocyte-specific CXCL12 conditional knock-out mice and a CXCR4 antagonist revealed that CXCL12 derived from neutrophil trails is critical for virus-specific CD8+ T cell recruitment and effector functions. Collectively, these results suggest neutrophils deposit long-lasting, chemokine-containing trails, which may provide both chemotactic and haptotactic cues for efficient CD8+ T cell migration and localization in influenza-infected tissues. PMID:26339033

Interferon Regulator Factor 8 (IRF8 Limits Ocular Pathology during HSV-1 Infection by Restraining the Activation and Expansion of CD8+ T Cells.

Directory of Open Access Journals (Sweden)

Lin Sun

Full Text Available Interferon Regulatory Factor-8 (IRF8 is constitutively expressed in monocytes and B cell lineages and plays important roles in immunity to pathogens and cancer. Although IRF8 expression is induced in activated T cells, the functional relevance of IRF8 in T cell-mediated immunity is not well understood. In this study, we used mice with targeted deletion of Irf8 in T-cells (IRF8KO to investigate the role of IRF8 in T cell-mediated responses during herpes simplex virus 1 (HSV-1 infection of the eye. In contrast to wild type mice, HSV-1-infected IRF8KO mice mounted a more robust anti-HSV-1 immune response, which included marked expansion of HSV-1-specific CD8+ T cells, increased infiltration of inflammatory cells into the cornea and trigeminal ganglia (TG and enhanced elimination of virus within the trigeminal ganglion. However, the consequence of the enhanced immunological response was the development of ocular inflammation, limbitis, and neutrophilic infiltration into the cornea of HSV-1-infected IRF8KO mice. Surprisingly, we observed a marked increase in virus-specific memory precursor effector cells (MPEC in IRF8KO mice, suggesting that IRF8 might play a role in regulating the differentiation of effector CD8+ T cells to the memory phenotype. Together, our data suggest that IRF8 might play a role in restraining excess lymphocyte proliferation. Thus, modulating IRF8 levels in T cells can be exploited therapeutically to prevent immune-mediated ocular pathology during autoimmune and infectious diseases of the eye.

Enhanced urinary bladder and liver carcinogenesis in male CD1 mice exposed to transplacental inorganic arsenic and postnatal diethylstilbestrol or tamoxifen

International Nuclear Information System (INIS)

Waalkes, Michael P.; Liu Jie; Ward, Jerrold M.; Diwan, Bhalchandra A.

2006-01-01

Pregnant CD1 mice received 85 ppm arsenite in the drinking water from gestation day 8 to 18, groups (n = 35) of male offspring were subsequently injected on postpartum days 1 through 5 with diethylstilbestrol (DES; 2 μg/pup/day) or tamoxifen (TAM; 10 μg/pup/day), and tumor formation was assessed over 90 weeks. Arsenic alone increased hepatocellular carcinoma (14%), adenoma (23%) and total tumors (31%) compared to control (0, 2 and 2%, respectively). Arsenic alone also increased lung adenocarcinoma, adrenal cortical adenoma and renal cystic tubular hyperplasia compared to control. Compared to arsenic alone, arsenic plus DES increased liver tumor incidence in mice at risk 2.2-fold and increased liver tumor multiplicity (tumors/liver) 1.8-fold. The treatments alone did not impact urinary bladder carcinogenesis, but arsenic plus TAM significantly increased formation of urinary bladder transitional cell tumors (papilloma and carcinoma; 13%) compared to control (0%). Urinary bladder proliferative lesions (combined tumors and hyperplasia) were also increased by arsenic plus TAM (40%) or arsenic plus DES (43%) compared to control (0%) or the treatments alone. Urinary bladder proliferative lesions occurred in the absence of any evidence of uroepithelial cytotoxic lesions. Urinary bladder lesions and hepatocellular carcinoma induced by arsenic plus TAM and/or DES overexpressed estrogen receptor-α, indicating that aberrant estrogen signaling may have been a factor in the enhanced carcinogenic response. Thus, in male CD1 mice, gestational arsenic exposure alone induced liver adenoma and carcinoma, lung adenocarcinoma, adrenal adenoma and renal cystic hyperplasia. Furthermore, DES enhanced transplacental arsenic-induced hepatocarcinogenesis. In utero arsenic also initiated urinary bladder tumor formation when followed by postnatal TAM and uroepithelial proliferative lesions when followed by TAM or DES

FIV establishes a latent infection in feline peripheral blood CD4+ T lymphocytes in vivo during the asymptomatic phase of infection

Directory of Open Access Journals (Sweden)

Murphy Brian

2012-02-01

Full Text Available Abstract Background Feline immunodeficiency virus (FIV is a lentivirus of cats that establishes a lifelong persistent infection with immunologic impairment. Results In an approximately 2 year-long experimental infection study, cats infected with a biological isolate of FIV clade C demonstrated undetectable plasma viral loads from 10 months post-infection onward. Viral DNA was detected in CD4+CD25+ and CD4+CD25- T cells isolated from infected cats whereas viral RNA was not detected at multiple time points during the early chronic phase of infection. Viral transcription could be reactivated in latently infected CD4+ T cells ex vivo as demonstrated by detectable FIV gag RNA and 2-long terminal repeat (LTR circle junctions. Viral LTR and gag sequences amplified from peripheral blood mononuclear cells during early and chronic stages of infection demonstrated minimal to no viral sequence variation. Conclusions Collectively, these findings are consistent with FIV latency in peripheral blood CD4+ T cells isolated from chronically infected cats. The ability to isolate latently FIV-infected CD4+ T lymphocytes from FIV-infected cats provides a platform for the study of in vivo mechanisms of lentiviral latency.

Semen CD4+ T Cells and Macrophages Are Productively Infected at All Stages of SIV infection in Macaques

Science.gov (United States)

Bernard-Stoecklin, Sibylle; Gommet, Céline; Corneau, Aurélien B.; Guenounou, Sabrina; Torres, Claire; Dejucq-Rainsford, Nathalie; Cosma, Antonio; Dereuddre-Bosquet, Nathalie; Le Grand, Roger

2013-01-01

The mucosal events of HIV transmission have been extensively studied, but the role of infected cells present in the genital and rectal secretions, and in the semen, in particular, remains a matter of debate. As a prerequisite to a thorough in vivo investigation of the early transmission events through infected cells, we characterized in detail by multi-parameter flow cytometry the changes in macaque seminal leukocytes during SIVmac251 infection, focusing on T cells, macrophages and dendritic cells. Using immunocytofluorescence targeting SIV proteins and real-time quantitative PCR targeting SIV DNA, we investigated the nature of the infected cells on sorted semen leukocytes from macaques at different stages of infection. Finally, we cocultured semen CD4+ T cells and macrophages with a cell line permissive to SIV infection to assess their infectivity in vitro. We found that primary infection induced strong local inflammation, which was associated with an increase in the number of leukocytes in semen, both factors having the potential to favor cell-associated virus transmission. Semen CD4+ T cells and macrophages were productively infected at all stages of infection and were infectious in vitro. Lymphocytes had a mucosal phenotype and expressed activation (CD69 & HLA-DR) and migration (CCR5, CXCR4, LFA-1) markers. CD69 expression was increased in semen T cells by SIV infection, at all stages of infection. Macrophages predominated at all stages and expressed CD4, CCR5, MAC-1 and LFA-1. Altogether, we demonstrated that semen contains the two major SIV-target cells (CD4+ T cells and macrophages). Both cell types can be productively infected at all stages of SIV infection and are endowed with markers that may facilitate transmission of infection during sexual exposure. PMID:24348253

Over-expression of Stat5b confers protection against diabetes in the non-obese diabetic (NOD) mice via up-regulation of CD4+CD25+ regulatory T cells

International Nuclear Information System (INIS)

Jin, Yulan; Purohit, Sharad; Chen, Xueqin; Yi, Bing; She, Jin-Xiong

2012-01-01

Highlights: ► This is the first study to provide direct evidence of the role of Stat5b in NOD mice. ► Over-expression of wild type Stat5b transgene protects NOD mice against diabetes. ► This protection may be mediated by the up-regulation of CD4 + CD25 + Tregs. -- Abstract: The signal transducers and activators of transcription (STAT) family of proteins play a critical role in cytokine signaling required for fine tuning of immune regulation. Previous reports showed that a mutation (L327M) in the Stat5b protein leads to aberrant cytokine signaling in the NOD mice. To further elaborate the role of Stat5b in diabetes, we established a NOD transgenic mouse that over-expresses the wild type Stat5b gene. The incidences of spontaneous diabetes as well as cyclophosphamide-induced diabetes were significantly reduced and delayed in the Stat5b transgenic NOD mice compared to their littermate controls. The total cell numbers of CD4 + T cells and especially CD8 + T cells in the spleen and pancreatic lymph node were increased in the Stat5b transgenic NOD mice. Consistent with these findings, CD4 + and CD8 + T cells from the Stat5b transgenic NOD mice showed a higher proliferation capacity and up-regulation of multiple cytokines including IL-2, IFN-γ, TNF-α and IL-10 as well as anti-apoptotic gene Bcl-xl. Furthermore, the number and proportion of CD4 + CD25 + regulatory T cells were significantly increased in transgenic mice although in vitro suppression ability of the regulatory T-cells was not affected by the transgene. Our results suggest that Stat5b confers protection against diabetes in the NOD mice by regulating the numbers and function of multiple immune cell types, especially by up-regulating CD4 + CD25 + regulatory T cells.

CCR2+ and CCR5+ CD8+ T cells increase during viral infection and migrate to sites of infection

DEFF Research Database (Denmark)

Nansen, A; Marker, O; Bartholdy, C

2000-01-01

Chemokines and their receptors play a critical role in the selective recruitment of various leukocyte subsets. In this study, we correlated the expression of multiple chemokine and CC chemokine receptor (CCR) genes during the course of intracerebral (i.c.) infection with lymphocytic choriomeningi......Chemokines and their receptors play a critical role in the selective recruitment of various leukocyte subsets. In this study, we correlated the expression of multiple chemokine and CC chemokine receptor (CCR) genes during the course of intracerebral (i.c.) infection with lymphocytic...... a rapidly lethal, T cell-independent encephalitis, and infection resulted in a dramatic early up-regulation of chemokine gene expression. Similar marked up-regulation of chemokine expression was not seen until late after LCMV infection and required the presence of activated T cells. Cerebral CCR gene...... expression was dominated by CCR1, CCR2 and CCR5. However, despite a stronger initial chemokine signal in VSV-infected mice, only LCMV-induced T cell-dependent inflammation was found to be associated with substantially increased expression of CCR genes. Virus-activated CD8+ T cells were found to express CCR2...

Mass Cytometry Analysis Reveals the Landscape and Dynamics of CD32a+ CD4+ T Cells From Early HIV Infection to Effective cART.

Science.gov (United States)

Coindre, Sixtine; Tchitchek, Nicolas; Alaoui, Lamine; Vaslin, Bruno; Bourgeois, Christine; Goujard, Cecile; Avettand-Fenoel, Veronique; Lecuroux, Camille; Bruhns, Pierre; Le Grand, Roger; Beignon, Anne-Sophie; Lambotte, Olivier; Favier, Benoit

2018-01-01

CD32a has been proposed as a specific marker of latently HIV-infected CD4 + T cells. However, CD32a was recently found to be expressed on CD4 + T cells of healthy donors, leading to controversy on the relevance of this marker in HIV persistence. Here, we used mass cytometry to characterize the landscape and variation in the abundance of CD32a + CD4 + T cells during HIV infection. To this end, we analyzed CD32a + CD4 + T cells in primary HIV infection before and after effective combination antiretroviral therapy (cART) and in healthy donors. We found that CD32a + CD4 + T cells include heterogeneous subsets that are differentially affected by HIV infection. Our analysis revealed that naive ( N ), central memory ( CM ), and effector/memory ( Eff/Mem ) CD32a + CD4 + T-cell clusters that co-express LILRA2- and CD64-activating receptors were more abundant in primary HIV infection and cART stages. Conversely, LILRA2 - CD32a + CD4 + T-cell clusters of either the T N , T CM , or T Eff/Mem phenotype were more abundant in healthy individuals. Finally, an activated CD32a + CD4 + T Eff/Mem cell cluster co-expressing LILRA2, CD57, and NKG2C was more abundant in all HIV stages, particularly during primary HIV infection. Overall, our data show that multiple abundance modifications of CD32a + CD4 + T-cell subsets occur in the early phase of HIV infection, and some of which are conserved after effective cART. Our study brings a better comprehension of the relationship between CD32a expression and CD4 + T cells during HIV infection.

Mass Cytometry Analysis Reveals the Landscape and Dynamics of CD32a+ CD4+ T Cells From Early HIV Infection to Effective cART

Directory of Open Access Journals (Sweden)

Sixtine Coindre

2018-06-01

Full Text Available CD32a has been proposed as a specific marker of latently HIV-infected CD4+ T cells. However, CD32a was recently found to be expressed on CD4+ T cells of healthy donors, leading to controversy on the relevance of this marker in HIV persistence. Here, we used mass cytometry to characterize the landscape and variation in the abundance of CD32a+ CD4+ T cells during HIV infection. To this end, we analyzed CD32a+ CD4+ T cells in primary HIV infection before and after effective combination antiretroviral therapy (cART and in healthy donors. We found that CD32a+ CD4+ T cells include heterogeneous subsets that are differentially affected by HIV infection. Our analysis revealed that naive (N, central memory (CM, and effector/memory (Eff/Mem CD32a+ CD4+ T-cell clusters that co-express LILRA2- and CD64-activating receptors were more abundant in primary HIV infection and cART stages. Conversely, LILRA2− CD32a+ CD4+ T-cell clusters of either the TN, TCM, or TEff/Mem phenotype were more abundant in healthy individuals. Finally, an activated CD32a+ CD4+ TEff/Mem cell cluster co-expressing LILRA2, CD57, and NKG2C was more abundant in all HIV stages, particularly during primary HIV infection. Overall, our data show that multiple abundance modifications of CD32a+ CD4+ T-cell subsets occur in the early phase of HIV infection, and some of which are conserved after effective cART. Our study brings a better comprehension of the relationship between CD32a expression and CD4+ T cells during HIV infection.

Mutagenicity of nicotine in Schistosoma mansoni - infected mice ...

African Journals Online (AJOL)

Analysis of meiotic chromosomes showed significant elevation in the Schistosoma-infected mice. Administration of nicotine to infected mice substantially increased the percentages of micronucleated cells and total CAs. The percentage of chromosomal abnormalities in spermatocyte metaphase-I cells increased significantly ...

Pulmonary hypertension and vascular remodeling in mice exposed to crystalline silica.

Science.gov (United States)

Zelko, Igor N; Zhu, Jianxin; Ritzenthaler, Jeffrey D; Roman, Jesse

2016-11-28

Occupational and environmental exposure to crystalline silica may lead to the development of silicosis, which is characterized by inflammation and progressive fibrosis. A substantial number of patients diagnosed with silicosis develop pulmonary hypertension. Pulmonary hypertension associated with silicosis and with related restrictive lung diseases significantly reduces survival in affected subjects. An animal model of silicosis has been described previously however, the magnitude of vascular remodeling and hemodynamic effects of inhaled silica are largely unknown. Considering the importance of such information, this study investigated whether mice exposed to silica develop pulmonary hypertension and vascular remodeling. C57BL6 mice were intratracheally injected with either saline or crystalline silica at doses 0.2 g/kg, 0.3 g/kg and 0.4 g/kg and then studied at day 28 post-exposure. Pulmonary hypertension was characterized by changes in right ventricular systolic pressure and lung histopathology. Mice exposed to saline showed normal lung histology and hemodynamic parameters while mice exposed to silica showed increased right ventricular systolic pressure and marked lung pathology characterized by a granulomatous inflammatory reaction and increased collagen deposition. Silica-exposed mice also showed signs of vascular remodeling with pulmonary artery muscularization, vascular occlusion, and medial thickening. The expression of pro-inflammatory genes such as TNF-α and MCP-1 was significantly upregulated as well as the expression of the pro-remodeling genes collagen type I, fibronectin and the metalloproteinases MMP-2 and TIMP-1. On the other hand, the expression of several vasculature specific genes involved in the regulation of endothelial function was significantly attenuated. We characterized a new animal model of pulmonary hypertension secondary to pulmonary fibrosis induced by crystalline silica. Our data suggest that silica promotes the damage of the

The developmental neurobehavioral effects of fenugreek seeds on prenatally exposed mice.

Science.gov (United States)

Khalki, Loubna; Bennis, Mohamed; Sokar, Zahra; Ba-M'hamed, Saâdia

2012-01-31

Fenugreek (Trigonella foenum graecum (L.)), is a medicinal plant whose seeds and leaves are widely used in Moroccan traditional medicine. Consumption of fenugreek seeds during pregnancy has been associated with a range of congenital malformations, including hydrocephalus, anencephaly and spina bifida. In previous work we have shown that exposure of pregnant mice to aqueous extract of fenugreek seeds (AEFS) leads to reduced litter size, intrauterine growth retardation, and malformations. However, there have been no studies to date of its longer-term neurobehavioral effects. We investigated these effects in prenatally exposed mice. Pregnant females were exposed to 0, 500 or 1000 mg/kg/day AEFS, by gavage, for the whole period of gestation. Pups body weight was measured at 1, 7, 14, 21 and 28 day of age. Behavior of progeny was evaluated three weeks after birth using the open field, the rotarod test and the continuous alternation task by the T-maze. At 28 postnatal day age, brain of progeny was removed and cut for histological evaluation. The progeny of exposed mice displayed reduced body weight at birth (1000 mg/kg group: 27%; 500 mg/kg group: 32%) and reduced brain weight (10% in both treated groups). Both males and females mice prenatally exposed to AEFS displayed a significant decrease in the locomotor activity, in the boli deposits during the open field test and in motor coordination. These results seem to show that exposure to AEFS induces a depressive effect in the offspring. Assessment on a continuous alternation T-maze test showed a significant reduction in successful spontaneous alternations in males and females but only in the 1000 mg/kg group. These results suggest that prenatal exposure of mice to high dose of fenugreek seeds causes growth retardation and altered neurobehavioral performance in the post-weaning period in both male and female. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Increased CD56(bright) NK cells in HIV-HCV co-infection and HCV mono-infection are associated with distinctive alterations of their phenotype.

Science.gov (United States)

Bhardwaj, Suvercha; Ahmad, Fareed; Wedemeyer, Heiner; Cornberg, Marcus; Schulze Zur Wiesch, Julian; van Lunzen, Jan; Sarin, Shiv K; Schmidt, Reinhold E; Meyer-Olson, Dirk

2016-04-18

HIV-HCV co-infection is associated with accelerated progression to hepatic fibrosis, cirrhosis and hepatocellular carcinoma than HCV mono-infection. The contribution of innate immunity during HIV-HCV co-infection has been a relatively under-investigated area. Natural killer (NK) cells are pivotal sentinels of innate immunity against viruses and tumour cells. In this study we evaluated the effect of HIV-HCV co-infection on peripheral blood NK cell subsets with emphasis on the phenotype of CD56(bright) NK cells. Sixty patients were included in the study; HIV mono-infected (n = 12), HCV mono-infected (n = 15), HCV-HIV co-infected (n = 21) and healthy controls (n = 16). PBMCs were isolated and immunophenotyping of NK cells was performed by flowcytometry. We observed an expansion of CD56(bright) NK cell subset in HIV-HCV co-infection as compared to healthy controls and HIV mono-infected group. All the infected groups had an upregulated expression of the activating receptor NKG2D on CD56(bright) NK cells in comparison to healthy controls while not differing amongst themselves. The expression of NKp46 in HIV-HCV co-infected group was significantly upregulated as compared to both HIV as well as HCV mono-infections while NKp30 expression in the HIV-HCV co-infected group significantly differed as compared to HIV mono-infection. The CD56(bright) NK cell subset was activated in HIV-HCV co-infection as assessed by the expression of CD69 as compared to healthy controls but was significantly downregulated in comparison to HIV mono-infection. CD95 expression on CD56(bright) NK cells followed the same pattern where there was an increased expression of CD95 in HIV mono-infection and HIV-HCV co-infection as compared to healthy controls. In contrast to CD69 expression, CD95 expression in HCV mono-infection was decreased when compared to HIV mono-infection and HIV-HCV co-infection. Finally, expression of CXCR3 on CD56(bright) NK cells was increased in HIV-HCV co-infection in comparison

CD4+ T Cells Mediate Aspergillosis Vaccine Protection.

Science.gov (United States)

Diaz-Arevalo, Diana; Kalkum, Markus

2017-01-01

Adaptive effector CD4 + T cells play essential roles in the defense against fungal infections, especially against invasive aspergillosis (IA). Such protective CD4 + T cells can be generated through immunization with specialized antifungal vaccines, as has been demonstrated for pulmonary Aspergillus fumigatus infections in mouse experiments. Adaptive transfer of fungal antigen-specific CD4 + T cells conferred protection onto non-immunized naive mice, an experimental approach that could potentially become a future treatment option for immunosuppressed IA patients, focusing on the ultimate goal to improve their otherwise dim chances for survival. Here, we describe the different techniques to analyze CD4 + T cell immune responses after immunization with a recombinant fungal protein. We present three major methods that are used to analyze the role of CD4 + T cells in protection against A. fumigatus challenge. They include (1) transplantation of CD4 + T cells from vaccinated mice into immunosuppressed naive mice, observing increasing protection of the cell recipients, (2) depletion of CD4 + T cells from vaccinated mice, which abolishes vaccine protection, and (3) T cell proliferation studies following stimulation with overlapping synthetic peptides or an intact protein vaccine. The latter can be used to validate immunization status and to identify protective T cell epitopes in vaccine antigens. In the methods detailed here, we used versions of the well-studied Asp f3 protein expressed in a bacterial host, either as the intact full length protein or its N-terminally truncated version, comprised of residues 15-168. However, these methods are generally applicable and can well be adapted to study other protein-based subunit vaccines.

Air pollution is associated with the development of atherosclerosis via the cooperation of CD36 and NLRP3 inflammasome in ApoE-/- mice.

Science.gov (United States)

Du, Xihao; Jiang, Shuo; Zeng, Xuejiao; Zhang, Jia; Pan, Kun; Zhou, Ji; Xie, Yuquan; Kan, Haidong; Song, Weimin; Sun, Qinghua; Zhao, Jinzhuo

2018-06-15

Previous studies have indicated that the main air pollutant fine particulate matter (≤2.5 μm; PM 2.5 ) exposure is associated with the development of atherosclerosis. Although the mechanism is not fully illustrated, the inflammatory responses play an important role. The present study aimed to explore whether PM 2.5 -exacerbated atherosclerosis was mediated by the cooperation of cluster of differentiation 36 (CD36) and nucleotide-binding oligomerization domain-like receptor protein (NLRP3) inflammasome in apolipoprotein E -/- (ApoE -/- ) mice. Thirty-two ApoE -/- mice were randomly divided into two groups. One group was fed with high fat chow (HFC) for 10 weeks to establish atherosclerotic model, and the other was fed with normal chow (NC). From week 11, the mice were exposed to concentrated PM 2.5 (PM) or filtered air (FA) using Shanghai Meteorological and Environmental Animal Exposure System for 16 weeks. In both NC and HFC groups, PM 2.5 exposure induced the formation of atherosclerosis plaque. Similarly, PM mice appeared higher lipid content in the aortic root than that in the FA mice. Compared with the FA mice, PM mice appeared a decrease in high density lipoprotein-cholesterol (HDL-C) and apolipoprotein A1 along with an increase in apolipoprotein B, low density lipoprotein-cholesterol (LDL-C) and oxidized low-density lipoprotein (ox-LDL). Moreover, PM 2.5 exposure induced increase of CD36 in serum and aorta. In both NC and HFC groups, NLRP3 inflammasome activation-related indicators were activated or increased in the aorta of the PM mice when compared with the FA mice. The cooperation of CD36 and NLRP3 inflammasome activation may be the potential mechanisms linkixposed to concentrated PM 2.5 (PM) or filtered air (FA) using Shanghai Meteorological and Environmental Animal Exposure System for 16 weeks. In both NC and HFC groups, PM 2.5 exposure induced the formation of atherosclerosis plaque. Similarly, PM mice appeared higher lipid content in the aortic

PDZ domain-binding motif of Tax sustains T-cell proliferation in HTLV-1-infected humanized mice

Science.gov (United States)

Artesi, Maria; Jalinot, Pierre

2018-01-01

Human T-cell leukemia virus type 1 (HTLV-1) is the etiological agent of adult T-cell leukemia/lymphoma (ATLL), an aggressive malignant proliferation of activated CD4+ T lymphocytes. The viral Tax oncoprotein is critically involved in both HTLV-1-replication and T-cell proliferation, a prerequisite to the development of ATLL. In this study, we investigated the in vivo contribution of the Tax PDZ domain-binding motif (PBM) to the lymphoproliferative process. To that aim, we examined T-cell proliferation in humanized mice (hu-mice) carrying a human hemato-lymphoid system infected with either a wild type (WT) or a Tax PBM-deleted (ΔPBM) provirus. We observed that the frequency of CD4+ activated T-cells in the peripheral blood and in the spleen was significantly higher in WT than in ΔPBM hu-mice. Likewise, human T-cells collected from WT hu-mice and cultivated in vitro in presence of interleukin-2 were proliferating at a higher level than those from ΔPBM animals. We next examined the association of Tax with the Scribble PDZ protein, a prominent regulator of T-cell polarity, in human T-cells analyzed either after ex vivo isolation or after in vitro culture. We confirmed the interaction of Tax with Scribble only in T-cells from the WT hu-mice. This association correlated with the presence of both proteins in aggregates at the leading edge of the cells and with the formation of long actin filopods. Finally, data from a comparative genome-wide transcriptomic analysis suggested that the PBM-PDZ association is implicated in the expression of genes regulating proliferation, apoptosis and cytoskeletal organization. Collectively, our findings suggest that the Tax PBM is an auxiliary motif that contributes to the sustained growth of HTLV-1 infected T-cells in vivo and in vitro and is essential to T-cell immortalization. PMID:29566098

PDZ domain-binding motif of Tax sustains T-cell proliferation in HTLV-1-infected humanized mice.

Science.gov (United States)

Pérès, Eléonore; Blin, Juliana; Ricci, Emiliano P; Artesi, Maria; Hahaut, Vincent; Van den Broeke, Anne; Corbin, Antoine; Gazzolo, Louis; Ratner, Lee; Jalinot, Pierre; Duc Dodon, Madeleine

2018-03-01

Human T-cell leukemia virus type 1 (HTLV-1) is the etiological agent of adult T-cell leukemia/lymphoma (ATLL), an aggressive malignant proliferation of activated CD4+ T lymphocytes. The viral Tax oncoprotein is critically involved in both HTLV-1-replication and T-cell proliferation, a prerequisite to the development of ATLL. In this study, we investigated the in vivo contribution of the Tax PDZ domain-binding motif (PBM) to the lymphoproliferative process. To that aim, we examined T-cell proliferation in humanized mice (hu-mice) carrying a human hemato-lymphoid system infected with either a wild type (WT) or a Tax PBM-deleted (ΔPBM) provirus. We observed that the frequency of CD4+ activated T-cells in the peripheral blood and in the spleen was significantly higher in WT than in ΔPBM hu-mice. Likewise, human T-cells collected from WT hu-mice and cultivated in vitro in presence of interleukin-2 were proliferating at a higher level than those from ΔPBM animals. We next examined the association of Tax with the Scribble PDZ protein, a prominent regulator of T-cell polarity, in human T-cells analyzed either after ex vivo isolation or after in vitro culture. We confirmed the interaction of Tax with Scribble only in T-cells from the WT hu-mice. This association correlated with the presence of both proteins in aggregates at the leading edge of the cells and with the formation of long actin filopods. Finally, data from a comparative genome-wide transcriptomic analysis suggested that the PBM-PDZ association is implicated in the expression of genes regulating proliferation, apoptosis and cytoskeletal organization. Collectively, our findings suggest that the Tax PBM is an auxiliary motif that contributes to the sustained growth of HTLV-1 infected T-cells in vivo and in vitro and is essential to T-cell immortalization.

Genetic Analysis of Mice Skin Exposed by Hyper-Gravity

Science.gov (United States)

Takahashi, Rika; Terada, Masahiro; Seki, Masaya; Higashibata, Akira; Majima, Hideyuki J.; Ohira, Yoshinobu; Mukai, Chiaki; Ishioka, Noriaki

2013-02-01

In the space environment, physiological alterations, such as low bone density, muscle weakness and decreased immunity, are caused by microgravity and cosmic radiation. On the other hand, it is known that the leg muscles are hypertrophy by 2G-gravity. An understanding of the effects on human body from microgravity to hyper-gravity is very important. Recently, the Japan Aerospace Exploration Agency (JAXA) has started a project to detect the changes on gene expression and mineral metabolism caused by microgravity by analyzing the hair of astronauts who stay in the international Space Station (ISS) for a long time. From these results of human hair’s research, the genetic effects of human hair roots by microgravity will become clear. However, it is unclear how the gene expression of hair roots was effected by hypergravity. Therefore, in this experiment, we analyzed the effect on mice skin contained hair roots by comparing microgravity or hypergravity exposed mice. The purpose of this experiment is to evaluate the genetic effects on mice skin by microgravity or 2G-gravity. The samples were taken from mice exposed to space flight (FL) or hypergravity environment (2G) for 3-months, respectively. The extracted and amplified RNA from these mice skin was used to DNA microarray analysis. in this experiment, we analyzed the effect of gravity by using mice skin contained hair roots, which exposed space (FL) and hyper-gravity (2G) for 3 months and each control. By DNA microarray analysis, we found the common 98 genes changed in both FL and 2G. Among these 98 genes, the functions and pathways were identified by Gene Ontology (GO) analysis and Ingenuity Pathways Analysis (IPA) software. Next, we focused the one of the identified pathways and compared the effects on each molecules in this pathways by the different environments, such as FL and 2G. As the results, we could detect some interesting molecules, which might be depended on the gravity levels. In addition, to investigate

Curcumin Protects against Cadmium-Induced Vascular Dysfunction, Hypertension and Tissue Cadmium Accumulation in Mice

Directory of Open Access Journals (Sweden)

Upa Kukongviriyapan

2014-03-01

Full Text Available Curcumin from turmeric is commonly used worldwide as a spice and has been demonstrated to possess various biological activities. This study investigated the protective effect of curcumin on a mouse model of cadmium (Cd—induced hypertension, vascular dysfunction and oxidative stress. Male ICR mice were exposed to Cd (100 mg/L in drinking water for eight weeks. Curcumin (50 or 100 mg/kg was intragastrically administered in mice every other day concurrently with Cd. Cd induced hypertension and impaired vascular responses to phenylephrine, acetylcholine and sodium nitroprusside. Curcumin reduced the toxic effects of Cd and protected vascular dysfunction by increasing vascular responsiveness and normalizing the blood pressure levels. The vascular protective effect of curcumin in Cd exposed mice is associated with up-regulation of endothelial nitric oxide synthase (eNOS protein, restoration of glutathione redox ratio and alleviation of oxidative stress as indicated by decreasing superoxide production in the aortic tissues and reducing plasma malondialdehyde, plasma protein carbonyls, and urinary nitrate/nitrite levels. Curcumin also decreased Cd accumulation in the blood and various organs of Cd-intoxicated mice. These findings suggest that curcumin, due to its antioxidant and chelating properties, is a promising protective agent against hypertension and vascular dysfunction induced by Cd.

Brain biochemistry of infant mice and rats exposed to lead

Energy Technology Data Exchange (ETDEWEB)

Berber, G.B.; Maes, J.; Gilliavod, N.; Casale, G.

1978-05-01

Brains of rats and mice exposed to lead from birth receive biochemical examinations. Mice are given drinking water with lead and are studied until they are 17 days old. Rats ae given lead in the diet and followed for more than a year. In mice a retardation in body growth and development in brain DNA is found. In rats, cathepsin is enhanced at almost all times. An important role of proteolytic processes and biogenic animes is suggested in lead encephalopathy. (33 references, 7 tables)

Virus-neutralizing antibody response of mice to consecutive infection with human and avian influenza A viruses.

Science.gov (United States)

Janulíková, J; Stropkovská, A; Bobišová, Z; Košík, I; Mucha, V; Kostolanský, F; Varečková, E

2015-06-01

In this work we simulated in a mouse model a naturally occurring situation of humans, who overcame an infection with epidemic strains of influenza A, and were subsequently exposed to avian influenza A viruses (IAV). The antibody response to avian IAV in mice previously infected with human IAV was analyzed. We used two avian IAV (A/Duck/Czechoslovakia/1956 (H4N6) and the attenuated virus rA/Viet Nam/1203-2004 (H5N1)) as well as two human IAV isolates (virus A/Mississippi/1/1985 (H3N2) of medium virulence and A/Puerto Rico/8/1934 (H1N1) of high virulence). Two repeated doses of IAV of H4 or of H5 virus elicited virus-specific neutralizing antibodies in mice. Exposure of animals previously infected with human IAV (of H3 or H1 subtype) to IAV of H4 subtype led to the production of antibodies neutralizing H4 virus in a level comparable with the level of antibodies against the human IAV used for primary infection. In contrast, no measurable levels of virus-neutralizing (VN) antibodies specific to H5 virus were detected in mice infected with H5 virus following a previous infection with human IAV. In both cases the secondary infection with avian IAV led to a significant increase of the titer of VN antibodies specific to the corresponding human virus used for primary infection. Moreover, cross-reactive HA2-specific antibodies were also induced by sequential infection. By virtue of these results we suggest that the differences in the ability of avian IAV to induce specific antibodies inhibiting virus replication after previous infection of mice with human viruses can have an impact on the interspecies transmission and spread of avian IAV in the human population.

CD4 T cell-mediated protection from lethal influenza: perforin and antibody-mediated mechanisms give a one-two punch.

Science.gov (United States)

Brown, Deborah M; Dilzer, Allison M; Meents, Dana L; Swain, Susan L

2006-09-01

The mechanisms whereby CD4 T cells contribute to the protective response against lethal influenza infection remain poorly characterized. To define the role of CD4 cells in protection against a highly pathogenic strain of influenza, virus-specific TCR transgenic CD4 effectors were generated in vitro and transferred into mice given lethal influenza infection. Primed CD4 effectors conferred protection against lethal infection over a broad range of viral dose. The protection mediated by CD4 effectors did not require IFN-gamma or host T cells, but did result in increased anti-influenza Ab titers compared with untreated controls. Further studies indicated that CD4-mediated protection at high doses of influenza required B cells, and that passive transfer of anti-influenza immune serum was therapeutic in B cell-deficient mice, but only when CD4 effectors were present. Primed CD4 cells also acquired perforin (Pfn)-mediated cytolytic activity during effector generation, suggesting a second mechanism used by CD4 cells to confer protection. Pfn-deficient CD4 effectors were less able to promote survival in intact BALB/c mice and were unable to provide protection in B cell-deficient mice, indicating that Ab-independent protection by CD4 effectors requires Pfn. Therefore, CD4 effectors mediate protection to lethal influenza through at least two mechanisms: Pfn-mediated cytotoxicity early in the response promoted survival independently of Ab production, whereas CD4-driven B cell responses resulted in high titer Abs that neutralized remaining virus.

CD80 and CD86 Costimulatory Molecules Differentially Regulate OT-II CD4+ T Lymphocyte Proliferation and Cytokine Response in Cocultures with Antigen-Presenting Cells Derived from Pregnant and Pseudopregnant Mice

Directory of Open Access Journals (Sweden)

Tomasz Maj

2014-01-01

Full Text Available Immune phenomena during the preimplantation period of pregnancy are poorly understood. The aim of our study was to assess the capacity for antigen presentation of splenic antigen-presenting cells (APCs derived from pregnant and pseudopregnant mice in in vitro conditions. Therefore, sorted CD11c+ dendritic cells and macrophages F4/80+ and CD11b+ presenting ovalbumin (OVA were cocultured with CD4+ T cells derived from OT-II mice’s (C57BL6/J-Tg(TcraTcrb1100Mjb/J spleen. After 132 hours of cell culture, proliferation of lymphocytes (ELISA-BrdU, activation of these cells (flow cytometry, cytokine profile (ELISA, and influence of costimulatory molecules blocking on these parameters were measured. We did not detect any differences in regulation of Th1/Th2 cytokine balance. CD86 seems to be the main costimulatory molecule involved in the proliferation response but CD80 is the main costimulatory molecule influencing cytokine secretion in pregnant mice. In conclusion, this study showed that CD80 and CD86 costimulatory molecules regulate OT-II CD4+ T lymphocyte proliferation and cytokine response in cocultures with antigen-presenting cells derived from pregnant and pseudopregnant mice. The implications of these changes still remain unclear.

IL10-Deficiency in CD4+ T Cells Exacerbates the IFNγ and IL17 Response During Bacteria Induced Colitis

Directory of Open Access Journals (Sweden)

Virginia Seiffart

2015-07-01

Full Text Available Background/Aims: IL10 is a key inhibitor of effector T cell activation and a mediator of intestinal homeostasis. In addition, IL10 has emerged as a key immunoregulator during infection with various pathogens, ameliorating the excessive T-cell responses that are responsible for much of the immunopathology associated with the infection. Because IL10 plays an important role in both intestinal homeostasis and infection, we studied the function of IL10 in infection-associated intestinal inflammation. Methods: Wildtype mice and mice deficient in CD4+ T cell-derived or regulatory T cells-derived IL10 were infected with the enteric pathogen Citrobacter (C. rodentium and analyzed for the specific immune response and pathogloy in the colon. Results: We found that IL10 expression is upregulated in colonic tissue after infection with C. rodentium, especially in CD4+ T cells, macrophages and dendritic cells. Whereas the deletion of IL10 in regulatory T cells had no effect on C. rodentium induced colitis, infection of mice deficient in CD4+ T cell-derived IL10 exhibited faster clearance of the bacterial burden but worse colitis, crypt hyperplasia, and pathology than did WT mice. In addition, the depletion of CD4+ T cell-derived IL10 in infected animals was accompanied by an accelerated IFNγ and IL17 response in the colon. Conclusion: Thus, we conclude that CD4+ T cell-derived IL10 is strongly involved in the control of C. rodentium-induced colitis. Interference with this network could have implications for the treatment of infection-associated intestinal inflammation.

Local immune response to primary infection and re-infection by Clonorchis sinensis in FVB mice.

Science.gov (United States)

Kim, Eun-Min; Yu, Hak Sun; Jin, Yan; Choi, Min-Ho; Bae, Young Mee; Hong, Sung-Tae

2017-08-01

Although Clonorchis sinensis lives in the bile duct, few studies have investigated the local immune response in the liver and bile duct. To investigate the local immune response to C. sinensis, we investigated the activation and recruitment of various immune cells and cytokine levels in the liver and bile duct lymph nodes (BLN) in FVB mice after primary infection and re-infection. Male 4-week-old FVB mice were divided into 6 experimental groups: uninfected controls, primary infection lasting 1week (PI 1w), primary infection lasting 4weeks (PI 4w), praziquantel treatment after PI 4w (Tx), re-infection lasting 1week after Tx (RI 1w), and re-infection lasting 4weeks after Tx (RI 4w). Recovery rates were 80.0% and 73.0% in PI 1w and PI 4w mice, respectively, but significantly decreased during re-infection to 26.6% in RI 1w and 13.3% in RI 4w. This result suggested that the mice were resistant to re-infection. In the liver, Kupffer cells were augmented 70-fold in PI 1w mice (Psinensis-specific IgG1 and IgG2a strongly increased in RI 1w mice. Secretion of C. sinensis-specific IgE reached a plateau at 4weeks after primary infection, and remained elevated in all infected groups. In conclusion, during infection with C. sinensis, Kupffer cells likely act as antigen-presenting cells, stimulating the Th2 cytokine production system. Copyright © 2016. Published by Elsevier B.V.

T cells exacerbate Lyme borreliosis in TLR2-deficient mice

Directory of Open Access Journals (Sweden)

Carrie E. Lasky

2016-11-01

Full Text Available Infection of humans with the spirochete, Borrelia burgdorferi, causes Lyme borreliosis and can lead to clinical manifestations such as, arthritis, carditis and neurological conditions. Experimental infection of mice recapitulates many of these symptoms and serves as a model system for the investigation of disease pathogenesis and immunity. Innate immunity is known to drive the development of Lyme arthritis and carditis, but the mechanisms driving this response remain unclear. Innate immune cells recognize B. burgdorferi surface lipoproteins primarily via Toll-like receptor (TLR2; however, previous work has demonstrated TLR2-/- mice had exacerbated disease and increased bacterial burden. We demonstrate increased CD4 and CD8 T cell infiltrates in B. burgdorferi-infected joints and hearts of C3H TLR2-/- mice. In vivo depletion of either CD4 or CD8 T cells reduced Borrelia-induced joint swelling and lowered tissue spirochete burden, while depletion of CD8 T cells alone reduced disease severity scores. Exacerbation of Lyme arthritis correlated with increased production of CXCL9 by synoviocytes and this was reduced with CD8 T cell depletion. These results demonstrate T cells can exacerbate Lyme disease pathogenesis and prolong disease resolution possibly through dysregulation of inflammatory responses and inhibition of bacterial clearance.

Lactobacillus paracasei feeding improves the control of secondary experimental meningococcal infection in flu-infected mice.

Science.gov (United States)

Belkacem, Nouria; Bourdet-Sicard, Raphaëlle; Taha, Muhamed-Kkeir

2018-04-10

The use of probiotics to improve anti-microbial defence, such as for influenza infections, is increasingly recommended. However, no data are available on the effect of probiotics on flu-associated secondary bacterial infections. There is strong evidence of a spatiotemporal association between influenza virus infection and invasive Neisseria meningitidis. We thus investigated the effect of feeding mice Lactobacillus paracasei CNCM I-1518 in a mouse model of sequential influenza-meningococcal infection. We intranasally infected BALB/c mice with a strain of influenza A virus (IAV) H3N2 that was first adapted to mice. Seven days later, a secondary bacterial infection was induced by intranasal administration of bioluminescent N. meningitidis. During the experiment, mice orally received either L. paracasei CNCM I-1518 or PBS as a control. The effect of L. paracasei administration on secondary bacterial infection by N. meningitidis was evaluated. Oral consumption of L. paracasei CNCM I-1518 reduced the weight loss of infected mice and lowered the bioluminescent signal of infecting meningococci. This improvement was associated with higher recruitment of inflammatory myeloid cells, such as interstitial monocytes and dendritic cells, to the lungs. Our data highlight the role of the gut-lung axis. L. paracasei CNCM I-1518 may boost the defence against IAV infection and secondary bacterial infection, which should be further studied and validated in clinical trials.

Vitamin B5 Reduces Bacterial Growth via Regulating Innate Immunity and Adaptive Immunity in Mice Infected with Mycobacterium tuberculosis

Directory of Open Access Journals (Sweden)

Wenting He

2018-02-01

Full Text Available The mechanisms by which vitamins regulate immunity and their effect as an adjuvant treatment for tuberculosis have gradually become very important research topics. Studies have found that vitamin B5 (VB5 can promote epithelial cells to express inflammatory cytokines. We aimed to examine the proinflammatory and antibacterial effect of VB5 in macrophages infected with Mycobacterium tuberculosis (MTB strain H37Rv and the therapeutic potential of VB5 in vivo with tuberculosis. We investigated the activation of inflammatory signal molecules (NF-κB, AKT, JNK, ERK, and p38, the expression of two primary inflammatory cytokines (tumor necrosis factor and interleukin-6 and the bacterial burdens in H37Rv-infected macrophages stimulated with VB5 to explore the effect of VB5 on the inflammatory and antibacterial responses of macrophages. We further treated the H37Rv-infected mice with VB5 to explore VB5’s promotion of the clearance of H37Rv in the lungs and the effect of VB5 on regulating the percentage of inflammatory cells. Our data showed that VB5 enhanced the phagocytosis and inflammatory response in macrophages infected with H37Rv. Oral administration of VB5 decreased the number of colony-forming units of H37Rv in lungs of mice at 1, 2, and 4 weeks after infection. In addition, VB5 regulated the percentage of macrophages and promoted CD4+ T cells to express interferon-γ and interleukin-17; however, it had no effect on the percentage of polymorphonuclear neutrophils, CD4+ and CD8+ T cells. In conclusion, VB5 significantly inhibits the growth of MTB by regulating innate immunity and adaptive immunity.

Inhibitory effects of Trypanosoma cruzi sialoglycoproteins on CD4+ T cells are associated with increased susceptibility to infection.

Directory of Open Access Journals (Sweden)

Marise Pinheiro Nunes

Full Text Available BACKGROUND: The Trypanosoma cruzi infection is associated with severe T cell unresponsiveness to antigens and mitogens characterized by decreased IL-2 synthesis. Trypanosoma cruzi mucin (Tc Muc has been implicated in this phenomenom. These molecules contain a unique type of glycosylation consisting of several sialylated O-glycans linked to the protein backbone via N-acetylglucosamine residues. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we evaluated the ability of Tc Muc to modulate the activation of CD4(+ T cells. Our data show that cross-linking of CD3 on naïve CD4(+ T cells in the presence of Tc Muc resulted in the inhibition of both cytokine secretion and proliferation. We further show that the sialylated O-Linked Glycan residues from tc mucin potentiate the suppression of T cell response by inducing G1-phase cell cycle arrest associated with upregulation of mitogen inhibitor p27(kip1. These inhibitory effects cannot be reversed by the addition of exogenous IL-2, rendering CD4(+ T cells anergic when activated by TCR triggering. Additionally, in vivo administration of Tc Muc during T. cruzi infection enhanced parasitemia and aggravated heart damage. Analysis of recall responses during infection showed lower frequencies of IFN-γ producing CD4(+ T cells in the spleen of Tc Muc treated mice, compared to untreated controls. CONCLUSIONS/SIGNIFICANCE: Our results indicate that Tc Muc mediates inhibitory efects on CD4(+ T expansion and cytokine production, by blocking cell cycle progression in the G1 phase. We propose that the sialyl motif of Tc Muc is able to interact with sialic acid-binding Ig-like lectins (Siglecs on CD4(+ T cells, which may allow the parasite to modulate the immune system.

Sarcocystis neurona infection in gamma interferon gene knockout (KO) mice: comparative infectivity of sporocysts in two strains of KO mice, effect of trypsin digestion on merozoite viability, and infectivity of bradyzoites to KO mice and cell culture.

Science.gov (United States)

Dubey, J P; Sundar, N; Kwok, O C H; Saville, W J A

2013-09-01

The protozoan Sarcocystis neurona is the primary cause of Equine Protozoal Myeloencephalitis (EPM). EPM or EPM-like illness has been reported in horses, sea otters, and several other mammals. The gamma interferon gene knockout (KO) mouse is often used as a model to study biology and discovery of new therapies against S. neurona because it is difficult to induce clinical EPM in other hosts, including horses. In the present study, infectivity of three life cycle stages (merozoites, bradyzoites, sporozoites) to KO mice and cell culture was studied. Two strains of KO mice (C57-black, and BALB/c-derived, referred here as black or white) were inoculated orally graded doses of S. neurona sporocysts; 12 sporocysts were infective to both strains of mice and all infected mice died or became ill within 70 days post-inoculation. Although there was no difference in infectivity of sporocysts to the two strains of KO mice, the disease was more severe in black mice. S. neurona bradyzoites were not infectious to KO mice and cell culture. S. neurona merozoites survived 120 min incubation in 0.25% trypsin, indicating that trypsin digestion can be used to recover S. neurona from tissues of acutely infected animals. Published by Elsevier B.V.

TRPV1 Antagonism by Capsazepine Modulates Innate Immune Response in Mice Infected with Plasmodium berghei ANKA

Directory of Open Access Journals (Sweden)

Elizabeth S. Fernandes

2014-01-01

Full Text Available Thousands of people suffer from severe malaria every year. The innate immune response plays a determinant role in host’s defence to malaria. Transient receptor potential vanilloid 1 (TRPV1 modulates macrophage-mediated responses in sepsis, but its role in other pathogenic diseases has never been addressed. We investigated the effects of capsazepine, a TRPV1 antagonist, in malaria. C57BL/6 mice received 105 red blood cells infected with Plasmodium berghei ANKA intraperitoneally. Noninfected mice were used as controls. Capsazepine or vehicle was given intraperitoneally for 6 days. Mice were culled on day 7 after infection and blood and spleen cell phenotype and activation were evaluated. Capsazepine decreased circulating but not spleen F4/80+Ly6G+ cell numbers as well as activation of both F4/80+and F4/80+Ly6G+ cells in infected animals. In addition, capsazepine increased circulating but not spleen GR1+ and natural killer (NK population, without interfering with natural killer T (NKT cell numbers and blood NK and NKT activation. However, capsazepine diminished CD69 expression in spleen NKT but not NK cells. Infection increased lipid peroxidation and the release of TNFα and IFNγ, although capsazepine-treated group exhibited lower levels of lipid peroxidation and TNFα. Capsazepine treatment did not affect parasitaemia. Overall, TRPV1 antagonism modulates the innate immune response to malaria.

Comparison of radiosensitivity of immune cells in three kinds of mice

International Nuclear Information System (INIS)

Wu Hongying; Wang Yueying; Zhang Heng; Li Denguan; Du Liqing; Wang Xiaochun; Lu Lu; Chang Jianhui; Zhang Junling; Zhai Zhibin; Men Aimin

2010-01-01

Objective: To compare the radiosensitivity of thymus (Th), spleen (Sp) cells between IRM-2, ICR and 615 mouse and explore the immunological and radiation resistance mechanisms of IRM-2 mice. Methods: The peripheral blood cytotype was determined by flow cytometry. By PA Law (FITC-Annexin V and PI labeling), the apoptosis of Th and Sp cells was detected after irradiation. Results: CD4/CD8 ratio of IRM-2 mice was lower than that of ICR and 615 mice; CD25/CD4 ratio was higher than 615 mice (P<0.05), lower than ICR mice;apoptosis rate of Sp cells exposed to 0, 1, 4 Gy γ-ray was lower than ICR and 615 mice, the difference was of statistical significance (P<0.05); apoptosis rate of Th cell was lower than ICR and 615 mice, especially 615 mice in 4Gy irradiated group (P<0.01). Conclusion: The apoptosis rate of IRM-2 was lower than that of ICR and 615 mice after irradiation. Th and Sp cells of IRM-2 mice were not sensitive to radiation. (authors)

The contribution of Chlamydia-specific CD8⁺ T cells to upper genital tract pathology.

Science.gov (United States)

Vlcek, Kelly R; Li, Weidang; Manam, Srikanth; Zanotti, Brian; Nicholson, Bruce J; Ramsey, Kyle H; Murthy, Ashlesh K

2016-02-01

Genital chlamydial infections lead to severe upper reproductive tract pathology in a subset of untreated women. We demonstrated previously that tumor necrosis factor (TNF)-α-producing CD8(+) T cells contribute significantly to chlamydial upper genital tract pathology in female mice. In addition, we observed that minimal chlamydial oviduct pathology develops in OT-1 transgenic (OT-1) mice, wherein the CD8(+) T-cell repertoire is restricted to recognition of the ovalbumin peptide Ova(257-264), suggesting that non-Chlamydia-specific CD8(+) T cells may not be responsible for chlamydial pathogenesis. In the current study, we evaluated whether antigen-specific CD8(+) T cells mediate chlamydial pathology. Groups of wild-type (WT) C57BL/6J, OT-1 mice, and OT-1 mice replete with WT CD8(+) T cells (1 × 10(6) cells per mouse intravenously) were infected intravaginally with C. muridarum (5 × 10(4) IFU/mouse). Serum total anti-Chlamydia antibody and total splenic anti-Chlamydia interferon (IFN)-γ and TNF-α responses were comparable among the three groups of animals. However, Chlamydia-specific IFN-γ and TNF-α production from purified splenic CD8(+) T cells of OT-1 mice was minimal, whereas responses in OT-1 mice replete with WT CD8(+) T cells were comparable to those in WT animals. Vaginal chlamydial clearance was comparable between the three groups of mice. Importantly, the incidence and severity of oviduct and uterine horn pathology was significantly reduced in OT-1 mice but reverted to WT levels in OT-1 mice replete with WT CD8(+) T cells. Collectively, these results demonstrate that Chlamydia-specific CD8(+) T cells contribute significantly to upper genital tract pathology.

Influence of conditioned psychological stress on immunological recovery in mice exposed to low-dose x irradiation