Medical Immunology Commons^™

The Rna Receptor Rig-I Binding Synthetic Oligodeoxynucleotide Promotes Pneumonia Survival, Yongxing Wang, Vikram V Kulkarni, Jezreel Pantaleóngarcía, Michael K Longmire, Mathilde Lethier, Stephen Cusack, Scott E Evans

Faculty, Staff and Student Publications

Pneumonia is a worldwide threat to public health, demanding novel preventative and therapeutic strategies. The lung epithelium is a critical environmental interface that functions as a physical barrier to pathogen invasion while also actively sensing and responding to pathogens. We have reported that stimulating lung epithelial cells with a combination therapeutic consisting of a diacylated lipopeptide and a synthetic CpG oligodeoxynucleotide (ODN) induces synergistic pneumonia protection against a wide range of pathogens. We report here that mice deficient in TLR9, the previously described receptor for ODN, still displayed partial ODN-induced protection. This prompted us to seek an alternate ODN receptor, …

Poly(Adp-Ribose) Polymerase-1 Regulates Pyroptosis Independent Function Of Nlrp3 Inflammasome In Neutrophil Extracellular Trap Formation, Louis J Delinois, Atul Sharma, Ashwin K Ramesh, Laurel D Boatright, Qun Li, Rong Xu, Hongbo R Luo, Bibhuti B Mishra, Jyotika Sharma

Faculty, Staff and Student Publications

Neutrophil extracellular traps (NETs) function to control infectious agents as well as to propagate inflammatory response in a variety of disease conditions. DNA damage associated with chromatin decondensation and NACHT domain-leucine-rich repeat-and pyrin domain-containing protein 3 (NLRP3) inflammasome activation have emerged as crucial events in NET formation, but the link between the two processes is unknown. In this study, we demonstrate that poly(ADP-ribose) polymerase-1 (PARP-1), a key DNA repair enzyme, regulates NET formation triggered by NLRP3 inflammasome activation in neutrophils. Activation of mouse neutrophils with canonical NLRP3 stimulants LPS and nigericin induced NET formation, which was significantly abrogated by pharmacological …

Cutting Edge: Il-21 And Tissue-Specific Signals Instruct Tbet+Cd11c+ B Cell Development Following Viral Infection, Wenzhi Song, Gina M Sanchez, Daniel P Mayer, Holly N Blackburn, Irene Chernova, Richard A Flavell, Jason S Weinstein, Joe Craft

Faculty, Staff and Student Publications

Tbet+CD11c+ B cells, also known as age-associated B cells (ABCs), are pivotal contributors to humoral immunity following infection and in autoimmunity, yet their in vivo generation is incompletely understood. We used a mouse model of systemic acute lymphocytic choriomeningitis virus infection to examine the developmental requirements of ABCs that emerged in the spleen and liver. IL-21 signaling through STAT3 was indispensable for ABC development. In contrast, IFN-γ signaling through STAT1 was required for B cell activation and proliferation. Mice that underwent splenectomy or were deficient in lymphotoxin α generated hepatic ABCs despite the lack of secondary lymphoid organ contributions, suggesting …

The Role Of Limch1 Alternative Splicing In Skeletal Muscle Function, Matthew S Penna, Rong-Chi Hu, George G Rodney, Thomas A Cooper

Faculty, Staff and Students Publications

Postnatal skeletal muscle development is a highly dynamic period associated with widespread alternative splicing changes required to adapt tissues to adult function. These splicing events have significant implications because the reversion of adult mRNA isoforms to fetal isoforms is observed in forms of muscular dystrophy. LIMCH1 is a stress fiber–associated protein that is alternatively spliced to generate uLIMCH1, a ubiquitously expressed isoform, and mLIMCH1, a skeletal muscle–specific isoform containing six additional exons simultaneously included after birth in the mouse. CRISPR/Cas9 was used to delete the six alternatively spliced exons of LIMCH1 in mice, thereby forcing the constitutive expression of the …

Magnesium Increases Numbers Of Foxp3+ Treg Cells And Reduces Arthritis Severity And Joint Damage In An Il-10-Dependent Manner Mediated By The Intestinal Microbiome, Teresina Laragione, Carolyn Harris, Nasim Azizgolshani, Christine Beeton, Gerold Bongers, Percio S Gulko

Faculty, Staff and Students Publications

BACKGROUND: Rheumatoid arthritis (RA) is a common autoimmune disease with emerging environmental and microbiome risk factors. The western diet is typically deficient in magnesium (Mg), and there is some evidence suggesting that Mg may have anti-inflammatory properties. But the actual role of Mg supplementation in arthritis or in T cell subsets has not been explored.

METHODS: We investigated the role of a high Mg diet in two different mouse models of RA induced with the KRN serum, and collagen-induced arthritis. We also characterized the phenotypes of splenocytes, gene expression, and an extensive intestinal microbiome analyses including fecal material transplantation (FMT). …

Novel Role Of Ghrelin Receptor In Gut Dysbiosis And Experimental Colitis In Aging, Ji Yeon Noh, Chia-Shan Wu, Jennifer A A Deluca, Sridevi Devaraj, Arul Jayaraman, Robert C Alaniz, Xiao-Di Tan, Clinton D Allred, Yuxiang Sun

Faculty, Staff and Students Publications

Chronic low-grade inflammation is a hallmark of aging, which is now coined as inflamm-aging. Inflamm-aging contributes to many age-associated diseases such as obesity, type 2 diabetes, cardiovascular disease, and inflammatory bowel disease (IBD). We have shown that gut hormone ghrelin, via its receptor growth hormone secretagogue receptor (GHS-R), regulates energy metabolism and inflammation in aging. Emerging evidence suggests that gut microbiome has a critical role in intestinal immunity of the host. To determine whether microbiome is an integral driving force of GHS-R mediated immune-metabolic homeostasis in aging, we assessed the gut microbiome profiles of young and old GHS-R global knockout …

Progranulin Loss Results In Sex-Dependent Dysregulation Of The Peripheral And Central Immune System, Madelyn C Houser, Oihane Uriarte Huarte, Rebecca L Wallings, Cody E Keating, Kathryn P Macpherson, Mary K Herrick, George T Kannarkat, Sean D Kelly, Jianjun Chang, Nicholas H Varvel, Jessica E Rexach, Malú Gámez Tansey

Faculty, Staff and Student Publications

INTRODUCTION: Progranulin (PGRN) is a secreted glycoprotein, the expression of which is linked to several neurodegenerative diseases. Although its specific function is still unclear, several studies have linked it with lysosomal functions and immune system regulation. Here, we have explored the role of PGRN in peripheral and central immune system homeostasis by investigating the consequences of PGRN deficiency on adaptive and innate immune cell populations.

METHODS: First, we used gene co-expression network analysis of published data to test the hypothesis that

RESULTS: Male PGRN KO mice exhibited a lower abundance of microglial cells with higher MHC-II expression, increased CD44 expression …

Crispr/Cas9-Mediated Genome Editing Reveals 12 Testis-Enriched Genes Dispensable For Male Fertility In Mice, Yuki Oyama, Haruhiko Miyata, Keisuke Shimada, Yoshitaka Fujihara, Keizo Tokuhiro, Thomas X Garcia, Martin M Matzuk, Masahito Ikawa

Faculty, Staff and Students Publications

Gene expression analyses suggest that more than 1000-2000 genes are expressed predominantly in mouse and human testes. Although functional analyses of hundreds of these genes have been performed, there are still many testis-enriched genes whose functions remain unexplored. Analyzing gene function using knockout (KO) mice is a powerful tool to discern if the gene of interest is essential for sperm formation, function, and male fertility in vivo. In this study, we generated KO mice for 12 testis-enriched genes, 1700057G04Rik, 4921539E11Rik, 4930558C23Rik, Cby2, Ldhal6b, Rasef, Slc25a2, Slc25a41, Smim8, Smim9, Tmem210, and Tomm20l, using the clustered regularly interspaced short palindromic repeats /CRISPR-associated …

Mtor-Initiated Metabolic Switch And Degeneration In The Retinal Pigment Epithelium, Young-Mi Go, Jing Zhang, Jolyn Fernandes, Christopher Litwin, Rui Chen, Theodore G Wensel, Dean P Jones, Jiyang Cai, Yan Chen

Faculty, Staff and Students Publications

The retinal pigment epithelium (RPE) is a particularly vulnerable tissue to age-dependent degeneration. Over the life span, the RPE develops an expanded endo-lysosomal compartment to maintain the high efficiency of phagocytosis and degradation of photoreceptor outer segments (POS) necessary for photoreceptor survival. As the assembly and activation of the mechanistic target of rapamycin complex 1 (mTORC1) occur on the lysosome surface, increased lysosome mass with aging leads to higher mTORC1 activity. The functional consequences of hyperactive mTORC1 in the RPE are unclear. In the current study, we used integrated high-resolution metabolomic and genomic approaches to examine mice with RPE-specific deletion …

April:Taci Axis Is Dispensable For The Immune Response To Rabies Vaccination., Shannon L. Haley, Evgeni P. Tzvetkov, Andrew G. Lytle, Kishore R. Alugupalli, Joseph R. Plummer, James P. Mcgettigan

Department of Microbiology and Immunology Faculty Papers

There is significant need to develop a single-dose rabies vaccine to replace the current multi-dose rabies vaccine regimen and eliminate the requirement for rabies immune globulin in post-exposure settings. To accomplish this goal, rabies virus (RABV)-based vaccines must rapidly activate B cells to secrete antibodies which neutralize pathogenic RABV before it enters the CNS. Increased understanding of how B cells effectively respond to RABV-based vaccines may improve efforts to simplify post-exposure prophylaxis (PEP) regimens. Several studies have successfully employed the TNF family cytokine a proliferation-inducing ligand (APRIL) as a vaccine adjuvant. APRIL binds to the receptors TACI and B cell …

Herpes Simplex Virus And Interferon Signaling Induce Novel Autophagic Clusters In Sensory Neurons, Sarah Katzenell, David A. Leib

Dartmouth Scholarship

Herpes simplex virus 1 (HSV-1) establishes lifelong infection in the neurons of trigeminal ganglia (TG), cycling between productive infection and latency. Neuronal antiviral responses are driven by type I interferon (IFN) and are crucial to controlling HSV-1 virulence. Autophagy also plays a role in this neuronal antiviral response, but the mechanism remains obscure. In this study, HSV-1 infection of murine TG neurons triggered unusual clusters of autophagosomes, predominantly in neurons lacking detectable HSV-1 antigen. Treatment of neurons with IFN-β induced a similar response, and cluster formation by infection or IFN treatment was dependent upon an intact IFN-signaling pathway. The autophagic …

Role Of B Cell Receptor Signaling In Il-10 Production By Normal And Malignant B-1 Cells., Sara S Alhakeem, Vishal J Sindhava, Mary K Mckenna, Beth W Gachuki, John C Byrd, Natarajan Muthusamy, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

B-1 cells are considered innate immune cells, which produce the majority of natural antibodies. B-1 cell responses to B cell receptor (BCR) and Toll-like receptor ligation are tightly regulated owing to the cross-reactivity to self-antigens. CD5 has been shown to play a major role in downregulation of BCR responses in B-1 cells. Here, we provide evidence for another mechanism by which BCR response is regulated in B-1 cells. B-1 cells, as well as their malignant counterpart, B cell chronic lymphocytic leukemia (B-CLL) cells, produce interleukin-10 (IL-10) constitutively. IL-10 secretion by normal B-1 cells downregulates their proliferation responses to BCR ligation. …

Parasite Manipulation Of The Invariant Chain And The Peptide Editor H2-Dm Affects Major Histocompatibility Complex Class Ii Antigen Presentation During Toxoplasma Gondii Infection, Louis-Philippe Leroux, Manami Nishi, Sandy El-Hage, Barbara A. Fox, David I Bzik, Florence Dzierszinsk

Dartmouth Scholarship

Toxoplasma gondii is an obligate intracellular protozoan parasite. This apicomplexan is the causative agent of toxoplasmosis, a leading cause of central nervous system disease in AIDS. It has long been known that T. gondii interferes with major histocompatibility complex class II (MHC-II) antigen presentation to attenuate CD4(+) T cell responses and establish persisting infections. Transcriptional downregulation of MHC-II genes by T. gondii was previously established, but the precise mechanisms inhibiting MHC-II function are currently unknown. Here, we show that, in addition to transcriptional regulation of MHC-II, the parasite modulates the expression of key components of the MHC-II antigen presentation pathway, …

Role Of The Dna Sensor Sting In Protection From Lethal Infection Following Corneal And Intracerebral Challenge With Herpes Simplex Virus 1, Zachary M. Parker, Aisling A. Murphy, David. A. Leib

Dartmouth Scholarship

STING is a protein in the cytosolic DNA and cyclic dinucleotide sensor pathway that is critical for the initiation of innate responses to infection by various pathogens. Consistent with this, herpes simplex virus 1 (HSV-1) causes invariable and rapid lethality in STING-deficient (STING(-/-)) mice following intravenous (i.v.) infection. In this study, using real-time bioluminescence imaging and virological assays, as expected, we demonstrated that STING(-/-) mice support greater replication and spread in ocular tissues and the nervous system. In contrast, they did not succumb to challenge via the corneal route even with high titers of a virus that was routinely lethal …

B Lymphocytes Are Required During The Early Priming Of Cd4+ T Cells For Clearance Of Pneumocystis Infection In Mice, Michael M. Opata, Melissa L. Hollifield, Frances E. Lund, Troy D. Randall, Robert Dunn, Beth A. Garvy, David J. Feola

Microbiology, Immunology, and Molecular Genetics Faculty Publications

B cells play a critical role in the clearance of Pneumocystis. In addition to production of Pneumocystis-specific Abs, B cells are required during the priming phase for CD4⁺ T cells to expand normally and generate memory. Clearance of Pneumocystis was found to be dependent on Ag specific B cells and on the ability of B cells to secrete Pneumocystis-specific Ab, as mice with B cells defective in these functions or with a restricted BCR were unable to control Pneumocystis infection. Because Pneumocystis-specific antiserum was only able to partially protect B cell–deficient mice from infection, we …

Caspase-3 Mediates The Pathogenic Effect Of Yersinia Pestis Yopm In Liver Of C57bl/6 Mice And Contributes To Yopm's Function In Spleen, Zhan Ye, Amanda A. Gorman, Annette M. Uittenbogaard, Tanya Myers-Morales, Alan M. Kaplan, Donald A. Cohen, Susan C. Straley

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The virulence protein YopM of the plague bacterium Yersinia pestis has different dominant effects in liver and spleen. Previous studies focused on spleen, where YopM inhibits accumulation of inflammatory dendritic cells. In the present study we focused on liver, where PMN function may be directly undermined by YopM without changes in inflammatory cell numbers in the initial days of infection, and foci of inflammation are easily identified. Mice were infected with parent and ΔyopM-1 Y. pestis KIM5, and effects of YopM were assessed by immunohistochemistry and determinations of bacterial viable numbers in organs. The bacteria were found …

Intrinsic Innate Immunity Fails To Control Herpes Simplex Virus And Vesicular Stomatitis Virus Replication In Sensory Neurons And Fibroblasts, Pamela C. Rosato, David A. Leib

Dartmouth Scholarship

Herpes simplex virus 1 (HSV-1) establishes lifelong latent infections in the sensory neurons of the trigeminal ganglia (TG), wherein it retains the capacity to reactivate. The interferon (IFN)-driven antiviral response is critical for the control of HSV-1 acute replication. We therefore sought to further investigate this response in TG neurons cultured from adult mice deficient in a variety of IFN signaling components. Parallel experiments were also performed in fibroblasts isolated concurrently. We showed that HSV-1 replication was comparable in wild-type (WT) and IFN signaling-deficient neurons and fibroblasts. Unexpectedly, a similar pattern was observed for the IFN-sensitive vesicular stomatitis virus (VSV). …

The Differential Interferon Responses Of Two Strains Of Stat1-Deficient Mice Do Not Alter Susceptibility To Hsv-1 And Vsv In Vivo, Sarah Katzenell, Yufei Chen, Zachary M. Parker, David A. Leib

Dartmouth Scholarship

Stat1 is a pivotal transcription factor for generation of the interferon (IFN)-dependent antiviral response. Two Stat1 knockout mouse lines have been previously generated, one deleted the N-terminal domain (ΔNTD) and one in the DNA-binding domain (ΔDBD). These widely-used strains are assumed interchangeable, and both are highly susceptible to various pathogens. In this study, primary cells derived from ΔNTD mice were shown to be significantly more responsive to IFN, and established an antiviral state with greater efficiency than cells derived from ΔDBD mice, following infection with vesicular stomatitis virus and herpes simplex virus type-1. Also, while mice from both strains succumbed …

Use Of Irf-3 And/Or Irf-7 Knockout Mice To Study Viral Pathogenesis: Lessons From A Murine Retrovirus-Induced Aids Model, Megan A. O'Connor, William R. Green

Dartmouth Scholarship

Interferon regulatory factor (IRF) regulation of the type I interferon response has not been extensively explored in murine retroviral infections. IRF-3(-/-) and select IRF-3/7(-/-) mice were resistant to LP-BM5-induced pathogenesis. However, further analyses strongly suggested that resistance could be attributed to strain 129-specific contamination of the known retrovirus resistance gene Fv1. Therefore, caution should be taken when interpreting phenotypes observed in these knockout mice, as strain 129-derived genetic polymorphisms may explain observed differences.

Flagellar Motility Is A Key Determinant Of The Magnitude Of The Inflammasome Response To Pseudomonas Aeruginosa, Yash R. Patankar, Rustin R. Lovewell, Matthew E. Poynter, Jeevan Jyot, Barbara I. Kazmierczak, Brent Berwin

Dartmouth Scholarship

We previously demonstrated that bacterial flagellar motility is a fundamental mechanism by which host phagocytes bind and ingest bacteria. Correspondingly, loss of bacterial motility, consistently observed in clinical isolates from chronic Pseudomonas aeruginosa infections, enables bacteria to evade association and ingestion of P. aeruginosa by phagocytes both in vitro and in vivo. Since bacterial interactions with the phagocyte cell surface are required for type three secretion system-dependent NLRC4 inflammasome activation by P. aeruginosa, we hypothesized that reduced bacterial association with phagocytes due to loss of bacterial motility, independent of flagellar expression, will lead to reduced inflammasome activation. Here we report …

Tryptophan Hydroxylase-1 Regulates Immune Tolerance And Inflammation, Elizabeth C. Nowak, Victor C. De Vries, Anna Wasiuk, Cory Ahonen, Kathryn A. Bennett, Isabelle Le Mercier, Dae-Gon Ha, Randolph J. Noelle

Dartmouth Scholarship

Nutrient deprivation based on the loss of essential amino acids by catabolic enzymes in the microenvironment is a critical means to control in ammatory responses and immune tolerance. Here we report the novel nding that Tph-1 (tryptophan hydroxylase-1), a synthase which catalyses the conversion of tryptophan to serotonin and exhausts tryptophan, is a potent regulator of immunity. In models of skin allograft tolerance, tumor growth, and experimental autoimmune encephalomyelitis, Tph-1 de ciency breaks allograft tolerance, induces tumor remission, and intensi es neuroin ammation, respectively. All of these effects of Tph-1 de ciency are independent of its downstream product serotonin. Because …

Functional Genomics Reveals An Essential And Specific Role For Stat1 In Protection Of The Central Nervous System Following Herpes Simplex Virus Corneal Infection, Tracy J. Pasieka, Cristian Cilloniz, Victoria S. Carter, Pamela Rosato, Michael G. Katze, David A. Leib

Dartmouth Scholarship

Innate immune deficiencies result in a spectrum of severe clinical outcomes following infection. In particular, there is a strong association between loss of the signal transducer and activator of transcription (Stat) pathway, breach of the blood-brain barrier (BBB), and virus-induced neuropathology. The gene signatures that characterize resistance, disease, and mortality in the virus-infected nervous system have not been defined. Herpes simplex virus type 1 (HSV-1) is commonly associated with encephalitis in humans, and humans and mice lacking Stat1 display increased susceptibility to HSV central nervous system (CNS) infections. In this study, two HSV-1 strains were used, KOS (wild type [WT]), …

A Retinoic Acid–Dependent Checkpoint In The Development Of Cd4+ T Cell–Mediated Immunity, Karina Pino-Lagos, Yanxia Guo, Chrysothemis Brown, Matthew P. Alexander, Raúl Elgueta, Kathryn A. Bennett, Victor De Vries, Elizabeth Nowak, Rune Blomhoff, Shanthini Sockanathan, Roshantha A. Chandraratna, Ethan Dmitrovsky, Randolph J. Noelle

Dartmouth Scholarship

It is known that vitamin A and its metabolite, retinoic acid (RA), are essential for host defense. However, the mechanisms for how RA controls inflammation are incompletely understood. The findings presented in this study show that RA signaling occurs concurrent with the development of inflammation. In models of vaccination and allogeneic graft rejection, whole body imaging reveals that RA signaling is temporally and spatially restricted to the site of inflammation. Conditional ablation of RA signaling in T cells significantly interferes with CD4⁺ T cell effector function, migration, and polarity. These findings provide a new perspective of the role of …

Cd4+ T Cell Regulation Of Cd25 Expression Controls Development Of Short-Lived Effector Cd8+ T Cells In Primary And Secondary Responses, Joshua J. Obar, Michael J. Molloy, Evan R. Jellison, Thomas A. Stoklasek, Weijun Zhang, Edward J. Usherwood, Leo Lefrançois

Dartmouth Scholarship

Both CD4(+) T cell help and IL-2 have been postulated to "program" activated CD8(+) T cells for memory cell development. However, the linkage between these two signals has not been well elucidated. Here we have studied effector and memory CD8(+) T cell differentiation following infection with three pathogens (Listeria monocytogenes, vesicular stomatitis virus, and vaccinia virus) in the absence of both CD4(+) T cells and IL-2 signaling. We found that expression of CD25 on antigen-specific CD8(+) T cells peaked 3-4 days after initial priming and was dependent on CD4(+) T cell help, likely through a CD28:CD80/86 mediated pathway. CD4(+) T …

Il-4(-/-) Mice With Lethal Mesocestoides Corti Infections--Reduced Th2 Cytokines And Alternatively Activated Macrophages., A. E. O'Connell, L. A. Kerepesi, G. L. Vandergrift, D. R. Herbert, T J. Van Winkle, D. C. Hooper, E J. Pearce, D. Abraham

Department of Microbiology and Immunology Faculty Papers

Protection against Mesocestoides corti, a cestode that invades vital organs, is dependent on the production of IL-4, as IL-4(-/-) mice were found to have higher parasite burdens when compared with wild-type mice. The goal of this study was to investigate the role of IL-4 in immunity to M. corti, focusing on the immunological profile and on potential mediators of pathology. IL-4(-/-) mice infected with M. corti showed 100% mortality by 32 days, whereas wild-type mice survived for approximately 1 year. Parasite burdens were significantly increased in the liver, peritoneal, and thoracic cavities of IL-4(-/-) mice, associated with impaired recruitment of …

Uncoupling Scavenger Receptor A-Mediated Phagocytosis Of Bacteria From Endotoxic Shock Resistance, Eyal Amiel, Julie L. Acker, Ryan M. Collins, Brent Berwin

Dartmouth Scholarship

Unresolved infection by gram-negative bacteria can result in the potentially lethal condition known as endotoxic shock, whereby uncontrolled inflammation can lead to multiple organ failure and death of the infected host. Previous results have demonstrated that animals deficient in class A scavenger receptor (SRA), a trafficking receptor for bacteria and bacterium-derived molecules, are more susceptible to endotoxic shock. This has been proposed to be a result of impaired SRA-dependent phagocytic clearance of bacteria resulting in stronger proinflammatory stimuli. In this report, we test the hypothesis that there is an obligate reciprocal relationship between SRA-mediated phagocytosis of bacteria and susceptibility to …

Il-9 As A Mediator Of Th17-Driven Inflammatory Disease, Elizabeth C. Nowak, Casey T. Weaver, Henrietta Turner, Sakhina Begum-Haque, Burkhard Becher, Bettina Schreiner, Anthony J. Coyle, Lloyd H. Kasper, Randolph J. Noelle

Dartmouth Scholarship

We report that like other T cells cultured in the presence of transforming growth factor (TGF) beta, Th17 cells also produce interleukin (IL) 9. Th17 cells generated in vitro with IL-6 and TGF-beta as well as purified ex vivo Th17 cells both produced IL-9. To determine if IL-9 has functional consequences in Th17-mediated inflammatory disease, we evaluated the role of IL-9 in the development and progression of experimental autoimmune encephalomyelitis, a mouse model of multiple sclerosis. The data show that IL-9 neutralization and IL-9 receptor deficiency attenuates disease, and this correlates with decreases in Th17 cells and IL-6-producing macrophages in …

Cd5 Plays An Inhibitory Role In The Suppressive Function Of Murine Cd4(+) Cd25(+) T(Reg) Cells., Trivikram Dasu, Joseph E Qualls, Halide Tuna, Chander Raman, Donald A Cohen, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

A subset of CD4(+) T cells, the CD4(+) CD25(+) regulatory T (T(reg)) cells in the lymphoid organs and peripheral blood are known to possess suppressive function. Previous in vitro and in vivo studies have indicated that T cell receptor (TCR) signal is required for development of such 'natural regulatory (T(reg)) cells' and for activation of the effector function of CD4(+) CD25(+) regulatory T cells. CD5 is a cell surface molecule present on all T cells and a subtype of B lymphocytes, the B-1 cells, primarily localized to coelomic cavities, Peyer's patches, tonsils and spleen. CD5 acts as a negative regulator …

A Novel Inhibitory Mechanism Of Mitochondrion-Dependent Apoptosis By A Herpesviral Protein, Pinghui Feng, Chengyu Liang, Young C. Shin, Xiaofei E, Weijun Zhang, Robyn Gravel, Ting-Ting Wu, Ren Sun, Edward Usherwood, Jae U. Jung

Dartmouth Scholarship

Upon viral infection, cells undergo apoptosis as a defense against viral replication. Viruses, in turn, have evolved elaborate mechanisms to subvert apoptotic processes. Here, we report that a novel viral mitochondrial anti-apoptotic protein (vMAP) of murine gamma-herpesvirus 68 (gammaHV-68) interacts with Bcl-2 and voltage-dependent anion channel 1 (VDAC1) in a genetically separable manner. The N-terminal region of vMAP interacted with Bcl-2, and this interaction markedly increased not only Bcl-2 recruitment to mitochondria but also its avidity for BH3-only pro-apoptotic proteins, thereby suppressing Bax mitochondrial translocation and activation. In addition, the central and C-terminal hydrophobic regions of vMAP interacted with VDAC1. …

Lack Of Il-15 Results In The Suboptimal Priming Of Cd4+ T Cell Response Against An Intracellular Parasite, Crescent L. Combe, Magali M. Moretto, Joseph D. Schwartzman, Jason P. Gigley, David J. Bzik, Imtiaz A. Khan

Dartmouth Scholarship

IFN-gamma-producing CD4+ T cells, although important for protection against acute Toxoplasma gondii infection, can cause gut pathology, which may prove to be detrimental for host survival. Here we show that mice lacking IL-15 gene develop a down-regulated IFN-gamma-producing CD4+ T cell response against the parasite, which leads to a reduction in gut necrosis and increased level of survival against infection. Moreover, transfer of immune CD4+ T cells from WT to IL-15-/- mice reversed inhibition of gut pathology and caused mortality equivalent to levels of parental WT mice. Down-regulated CD4+ T cell response in the absence of IL-15, manifested as reduced …