scholarly journals Innate IFNγ is essential for systemic Chlamydia control while CD4 T cell-dependent IFNγ production is highly redundant in the female reproductive tract

2020 ◽  
Author(s):  
Miguel A.B. Mercado ◽  
Wuying Du ◽  
Priyangi A. Malaviarachchi ◽  
Jessica I. Gann ◽  
Lin-Xi Li
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Reproductive Tract ◽  
Early Stage ◽  
Female Reproductive Tract ◽  
Cd4 T Cell ◽  
Bacterial Killing ◽  
Group I ◽  
Deficient Mice

AbstractProtective immunity to the obligate intracellular bacterium Chlamydia is thought to rely on CD4 T cell-dependent IFNγ production. Nevertheless, whether IFNγ is produced by other cellular source during Chlamydia infection and how CD4 T cell-dependent and -independent IFNγ contribute differently to host resistance has not been carefully evaluated. In this study, we dissect the requirements of IFNγ produced by innate immune cells and CD4 T cells for resolution of Chlamydia muridarum female reproductive tract (FRT) infection. After C. muridarum intravaginal inoculation, IFNγ-deficient and T cell-deficient mice exhibited opposite phenotypes for survival and bacterial shedding at the FRT mucosa, demonstrating the distinct requirements for IFNγ and CD4 T cells in host defense against Chlamydia. In Rag-deficient mice, IFNγ produced by innate lymphocytes (ILCs) accounted for early bacterial containment and prolonged survival in the absence of adaptive immunity. Although group I ILCs are potent IFNγ producers, we found that mature NK cells and ILC1 were not the sole source for innate IFNγ in response to Chlamydia. T cell adoptive transfer experiments revealed that WT and IFNγ-deficient CD4 T cells were equally capable of mediating effective bacterial killing in the FRT during the early stage of Chlamydia infection. Together, our results revealed that innate IFNγ is essential for preventing systemic Chlamydia dissemination, whereas IFNγ produced by CD4 T cells is largely dispensable at the FRT mucosa.

scholarly journals Innate IFNγ is essential for systemic Chlamydia muridarum control in mice while CD4 T cell-dependent IFNγ production is highly redundant in the female reproductive tract

2020 ◽  
Author(s):  
Miguel A.B. Mercado ◽  
Wuying Du ◽  
Priyangi A. Malaviarachchi ◽  
Jessica I. Gann ◽  
Lin-Xi Li
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Reproductive Tract ◽  
Female Reproductive Tract ◽  
Cd4 T Cell ◽  
Type I ◽  
Bacterial Killing ◽  
Chlamydia Muridarum ◽  
Deficient Mice

Protective immunity against the obligate intracellular bacterium Chlamydia has long been thought to rely on CD4 T cell-dependent IFNγ production. Nevertheless, whether IFNγ is produced by other cellular sources during Chlamydia infection and how CD4 T cell-dependent and -independent IFNγ contribute differently to host resistance has not been carefully evaluated. In this study, we dissect the requirements of IFNγ produced by innate immune cells and CD4 T cells for resolution of Chlamydia muridarum female reproductive tract (FRT) infection. After C. muridarum intravaginal infection, IFNγ-deficient and T cell-deficient mice exhibited opposite phenotypes for survival and bacterial shedding at the FRT mucosa, demonstrating the distinct requirements for IFNγ and CD4 T cells in host defense against Chlamydia. In Rag1-deficient mice, IFNγ produced by innate lymphocytes (ILCs) accounted for early bacterial control and prolonged survival in the absence of adaptive immunity. Although type I ILCs are potent IFNγ producers, we found that mature NK cells and ILC1s were not the sole source for innate IFNγ in response to Chlamydia. By conducting T cell adoptive transfer, we showed definitively that IFNγ-deficient CD4 T cells were sufficient for effective bacterial killing in the FRT during the first 21 days of infection and reduced bacterial burden more than 1,000-fold, albeit mice receiving IFNγ-deficient CD4 T cells failed to completely eradicate the bacteria from the FRT like their counterparts receiving WT CD4 T cells. Together, our results revealed that innate IFNγ is essential for preventing systemic Chlamydia dissemination, whereas IFNγ produced by CD4 T cells is largely redundant at the FRT mucosa.

scholarly journals Age-Associated Characteristics of CD4+ T-Cell Composition in Patients with Atherosclerosis

Immuno ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 277-284
Author(s):  
Anastasiia Yu. Filatova ◽  
Alexandra V. Potekhina ◽  
Tatiana I. Arefieva
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
T Cell Subsets ◽  
Cd4 T Cell ◽  
Group Iii ◽  
Cytokine Detection ◽  
Age Related ◽  
Group I ◽  
The Impact

Background. We aimed to analyze the contents of the main CD4+ T-cell subsets in patients with atherosclerosis (AS) depending on age. Methods. Male patients with coronary and/or carotid AS, who are non-smokers, and who are receiving statins were divided into three age groups (I—<55 y.o. (n = 23), II—55–64 y.o. (n = 42), III—≥65 y.o. (n = 46)). Leukocyte phenotyping was performed by direct immunofluorescence and flow cytometry. For intracellular cytokine detection, blood mononuclear cells were pre-activated with phorbol 12-myristate 13-acetate and ionomycin in the presence of an intracellular vesicle transport blocker monensin. Results. The groups did not differ in traditional CVD risk factors and AS severity. The content of CD4+ T-cells was lower in group III and II than in group I. The content of CD4+CD25high Treg was lower in group III than in groups I and II. No differences in the quantities of the primed CD39+CD45RA− and CD278high Treg, CD4+INFγ+ Th1, CD4+IL17+ Th17, and CD4+IL17+INFγ+ Th1/17 were observed. There were negative correlations between the values of CD4+ T-cells, CD4+CD45RA+ T-cells, CD4+CD25high Treg, CD4+CD25highCD45RA+ Treg, and age. Conclusion. In patients with AS, the age-related depletion of naive CD4+ T-cells also extends to the regulatory compartment. This phenomenon should be considered when studying the impact of the immune cells on the progression of AS.

scholarly journals Thymus-specific serine protease contributes to the diversification of the functional endogenous CD4 T cell receptor repertoire

2010 ◽  
Vol 208 (1) ◽  
pp. 3-11 ◽  
Author(s):  
Christophe Viret ◽  
Camille Lamare ◽  
Martine Guiraud ◽  
Nicolas Fazilleau ◽  
Agathe Bour ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Serine Protease ◽  
T Cell Receptor ◽  
Cd4 T Cells ◽  
Cell Receptor ◽  
T Cell Response ◽  
Cd4 T Cell ◽  
Tcr Repertoire ◽  
Deficient Mice

Thymus-specific serine protease (TSSP) is a novel protease that may contribute to the generation of the peptide repertoire presented by MHC class II molecules in the thymus. Although TSSP deficiency has no quantitative impact on the development of CD4 T cells expressing a polyclonal T cell receptor (TCR) repertoire, the development of CD4 T cells expressing the OTII and Marilyn transgenic TCRs is impaired in TSSP-deficient mice. In this study, we assess the role of TSSP in shaping the functional endogenous polyclonal CD4 T cell repertoire by analyzing the response of TSSP-deficient mice to several protein antigens (Ags). Although TSSP-deficient mice responded normally to most of the Ags tested, they responded poorly to hen egg lysozyme (HEL). The impaired CD4 T cell response of TSSP-deficient mice to HEL correlated with significant alteration of the dominant TCR-β chain repertoire expressed by HEL-specific CD4 T cells, suggesting that TSSP is necessary for the intrathymic development of cells expressing these TCRs. Thus, TSSP contributes to the diversification of the functional endogenous CD4 T cell TCR repertoire in the thymus.

scholarly journals CD4 T Cells and Major Histocompatibility Complex Class II Expression Influence Worm Expulsion and Increased Intestinal Muscle Contraction during Trichinella spiralisInfection

1999 ◽  
Vol 67 (11) ◽  
pp. 6090-6097 ◽  
Author(s):  
Bruce A. Vallance ◽  
Francesca Galeazzi ◽  
Stephen M. Collins ◽  
Denis P. Snider
Keyword(s):  
T Cells ◽  
T Cell ◽  
Muscle Contraction ◽  
Cd4 T Cells ◽  
Cd4 T Cell ◽  
Mhc Ii ◽  
Histocompatibility Complex ◽  
Worm Expulsion ◽  
Deficient Mice

ABSTRACT Expulsion of intestinal nematode parasites and the associated increased contraction by intestinal muscle are T cell dependent, since both are attenuated in athymic rodents. The CD4 T-cell subset has been strongly associated with worm expulsion; however, the relationship between these cells, antigen presentation, and worm expulsion is not definitive and the role of these factors in intestinal muscle hypercontractility has not been defined. We infected C57BL/6, athymic, CD4-deficient, CD8α-deficient, and major histocompatibility complex class II (MHC II)-deficient (C2d) mice with Trichinella spiralis larvae. We examined intestinal worm numbers, longitudinal muscle contraction, and MHC II expression. Numerous MHC II-positive cells were identified within the muscularis externa of infected but not uninfected C57BL/6 mice. C57BL/6 and CD8α-deficient mice developed large increases in muscle contraction, expelling the parasite by day 21. Athymic and C2d mice exhibited much smaller increases in muscle contraction and delayed parasite expulsion. CD4-deficient mice exhibited intermediate levels of muscle contraction and delayed parasite expulsion. To further examine the role of MHC II and CD4 T cells, we irradiated C2d mice and reconstituted them with C57BL/6 bone marrow alone or with C57BL/6 CD4 T cells. C57BL/6 bone marrow alone did not affect muscle function or worm expulsion in recipient C2d mice. Partial CD4 T-cell reconstitution was sufficient to restore increased muscle contraction but not worm expulsion. Thus, hematopoietic MHC II expression alone is insufficient for the development of muscle hypercontractility and worm expulsion, but the addition of even small numbers of CD4 T cells was sufficient to induce intestinal muscle pathophysiology.

scholarly journals Reduced immune-regulatory molecule expression on human colonic memory CD4 T cells in older adults

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Stephanie M. Dillon ◽  
Tezha A. Thompson ◽  
Allison J. Christians ◽  
Martin D. McCarter ◽  
Cara C. Wilson
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Older Persons ◽  
Age Groups ◽  
T Cell Immunity ◽  
Cd4 T Cell ◽  
Cell Immunity ◽  
Memory Cd4 T Cells

Abstract Background The etiology of the low-level chronic inflammatory state associated with aging is likely multifactorial, but a number of animal and human studies have implicated a functional decline of the gastrointestinal immune system as a potential driver. Gut tissue-resident memory T cells play critical roles in mediating protective immunity and in maintaining gut homeostasis, yet few studies have investigated the effect of aging on human gut T cell immunity. To determine if aging impacted CD4 T cell immunity in the human large intestine, we utilized multi-color flow cytometry to measure colonic lamina propria (LP) CD4 T cell frequencies and immune-modulatory marker expression in younger (mean ± SEM: 38 ± 1.5 yrs) and older (77 ± 1.6 yrs) adults. To determine cellular specificity, we evaluated colon LP CD8 T cell frequency and phenotype in the same donors. To probe tissue specificity, we evaluated the same panel of markers in peripheral blood (PB) CD4 T cells in a separate cohort of similarly aged persons. Results Frequencies of colonic CD4 T cells as a fraction of total LP mononuclear cells were higher in older persons whereas absolute numbers of colonic LP CD4 T cells per gram of tissue were similar in both age groups. LP CD4 T cells from older versus younger persons exhibited reduced CTLA-4, PD-1 and Ki67 expression. Levels of Bcl-2, CD57, CD25 and percentages of activated CD38+HLA-DR+ CD4 T cells were similar in both age groups. In memory PB CD4 T cells, older age was only associated with increased CD57 expression. Significant age effects for LP CD8 T cells were only observed for CTLA-4 expression, with lower levels of expression observed on cells from older adults. Conclusions Greater age was associated with reduced expression of the co-inhibitory receptors CTLA-4 and PD-1 on LP CD4 T cells. Colonic LP CD8 T cells from older persons also displayed reduced CTLA-4 expression. These age-associated profiles were not observed in older PB memory CD4 T cells. The decline in co-inhibitory receptor expression on colonic LP T cells may contribute to local and systemic inflammation via a reduced ability to limit ongoing T cell responses to enteric microbial challenge.

scholarly journals The Impact of Exercise Serum on Selected Parameters of CD4+ T Cell Metabolism

Immuno ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 119-131
Author(s):  
Jana Palmowski ◽  
Kristina Gebhardt ◽  
Thomas Reichel ◽  
Torsten Frech ◽  
Robert Ringseis ◽  
...  
Keyword(s):  
T Cells ◽  
Oxygen Consumption ◽  
T Cell ◽  
Real Time ◽  
Cd4 T Cells ◽  
Cell Metabolism ◽  
Cd4 T Cell ◽  
Autologous Serum ◽  
Cell Phenotype ◽  
The Impact

CD4+ T cells are sensitive to peripheral changes of cytokine levels and metabolic substrates such as glucose and lactate. This study aimed to analyze whether factors released after exercise alter parameters of human T cell metabolism, specifically glycolysis and oxidative phosphorylation. We used primary human CD4+ T cells activated in the presence of autologous serum, which was collected before (CO) and after a 30-min exercise intervention (EX). In the course of activation, cells and supernatants were analyzed for cell viability and diameter, real-time oxygen consumption by using PreSens Technology, mRNA expression of glycolytic enzymes and complexes of the electron transport chain by real-time PCR, glucose, and lactate levels in supernatants, and in vitro differentiation by flow cytometry. EX did not alter T cell phenotype, viability, or on-blast formation. Similarly, no difference between CO and EX were found for CD4+ T cell activation and cellular oxygen consumption. In contrast, higher levels of glucose were found after 48 h activation in EX conditions. T cells activated in autologous exercise serum expressed lower HK1 mRNA and higher IFN-γ receptor 1. We suggest that the exercise protocol used was not sufficient to destabilize the immune metabolism of T cells. Therefore, more intense and prolonged exercise should be used in future studies.

scholarly journals Infection of HLA-DR1 Transgenic Mice with a Human Isolate of Influenza A Virus (H1N1) Primes a Diverse CD4 T-Cell Repertoire That Includes CD4 T Cells with Heterosubtypic Cross-Reactivity to Avian (H5N1) Influenza Virus

2009 ◽  
Vol 83 (13) ◽  
pp. 6566-6577 ◽  
Author(s):  
Katherine A. Richards ◽  
Francisco A. Chaves ◽  
Andrea J. Sant
Keyword(s):  
T Cells ◽  
Influenza Virus ◽  
T Cell ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Cd4 T Cells ◽  
Cross Reactivity ◽  
Cd4 T Cell ◽  
Ns1 Protein ◽  
Infected Cells

ABSTRACT The specificity of the CD4 T-cell immune response to influenza virus is influenced by the genetic complexity of the virus and periodic encounters with variant subtypes and strains. In order to understand what controls CD4 T-cell reactivity to influenza virus proteins and how the influenza virus-specific memory compartment is shaped over time, it is first necessary to understand the diversity of the primary CD4 T-cell response. In the study reported here, we have used an unbiased approach to evaluate the peptide specificity of CD4 T cells elicited after live influenza virus infection. We have focused on four viral proteins that have distinct intracellular distributions in infected cells, hemagglutinin (HA), neuraminidase (NA), nucleoprotein, and the NS1 protein, which is expressed in infected cells but excluded from virion particles. Our studies revealed an extensive diversity of influenza virus-specific CD4 T cells that includes T cells for each viral protein and for the unexpected immunogenicity of the NS1 protein. Due to the recent concern about pandemic avian influenza virus and because CD4 T cells specific for HA and NA may be particularly useful for promoting the production of neutralizing antibody to influenza virus, we have also evaluated the ability of HA- and NA-specific CD4 T cells elicited by a circulating H1N1 strain to cross-react with related sequences found in an avian H5N1 virus and find substantial cross-reactivity, suggesting that seasonal vaccines may help promote protection against avian influenza virus.

scholarly journals Isolevuglandin-Modified Cardiac Proteins Drive CD4+ T Cell Activation in the Heart and Promote Cardiac Dysfunction

Circulation ◽  
2021 ◽  
Author(s):  
Njabulo Ngwenyama ◽  
Annet Kirabo ◽  
Mark Aronovitz ◽  
Francisco Velázquez ◽  
Francisco Carrillo-Salinas ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Antigen Presentation ◽  
T Cell Activation ◽  
Cardiac Dysfunction ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
Cd4 T Cell ◽  
Myocardial Oxidative Stress

Background: Despite the well-established association between T cell-mediated inflammation and non-ischemic heart failure (HF), the specific mechanisms triggering T cell activation during the progression of HF and the antigens involved are poorly understood. We hypothesized that myocardial oxidative stress induces the formation of isolevuglandin (IsoLG)-modified proteins that function as cardiac neoantigens to elicit CD4+ T cell receptor (TCR) activation and promote HF. Methods: We used transverse aortic constriction (TAC) in mice to trigger myocardial oxidative stress and T cell infiltration. We profiled the TCR repertoire by mRNA sequencing of intramyocardial activated CD4+ T cells in Nur77 GFP reporter mice, which transiently express GFP upon TCR engagement. We assessed the role of antigen presentation and TCR specificity in the development of cardiac dysfunction using antigen presentation-deficient MhcII -/- mice, and TCR transgenic OTII mice that lack specificity for endogenous antigens. We detected IsoLG-protein adducts in failing human hearts. We also evaluated the role of reactive oxygen species (ROS) and IsoLGs in eliciting T cell immune responses in vivo by treating mice with the antioxidant TEMPOL, and the IsoLG scavenger 2-hydroxybenzylamine (2-HOBA) during TAC, and ex-vivo in mechanistic studies of CD4+ T cell proliferation in response to IsoLG-modified cardiac proteins. Results: We discovered that TCR antigen recognition increases in the left ventricle (LV) as cardiac dysfunction progresses, and identified a limited repertoire of activated CD4+ T cell clonotypes in the LV. Antigen presentation of endogenous antigens was required to develop cardiac dysfunction since MhcII -/- mice reconstituted with CD4+ T cells, and OTII mice immunized with their cognate antigen were protected from TAC-induced cardiac dysfunction despite the presence of LV-infiltrated CD4+ T cells. Scavenging IsoLGs with 2-HOBA reduced TCR activation and prevented cardiac dysfunction. Mechanistically, cardiac pressure overload resulted in ROS dependent dendritic cell accumulation of IsoLG-protein adducts which induced robust CD4+ T cell proliferation. Conclusions: Collectively, our study demonstrates an important role of ROS-induced formation of IsoLG-modified cardiac neoantigens that lead to TCR-dependent CD4+ T cell activation within the heart.

scholarly journals 739 Intratumor childhood vaccine-specific CD4+ T cell recall helps antitumor CD8 T cells

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A770-A770
Author(s):  
Michael Brown ◽  
Zachary McKay ◽  
Yuanfan Yang ◽  
Darell Bigner ◽  
Smita Nair ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Viral Replication ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Cd4 T Cell ◽  
Antitumor Efficacy ◽  
Polio Vaccine ◽  
Recall Antigen ◽  
Childhood Vaccine

BackgroundPVSRIPO, a recombinant poliovirus derived from the live-attenuated Sabin oral polio vaccine strain, is being tested in multi-institutional phase II clinical trials for recurrent glioblastoma (NCT04479241) and unresectable, PD-1 refractory melanoma (NCT04577807) in combination with PD1 blockade. PVSRIPO capsid is identical to the Sabin vaccine strain and >99% identical to the inactivated Polio vaccine (IPOL, Salk), against which public health mandated childhood vaccination is near universal. In non-vaccinated mice, PVSRIPO mediates antitumor efficacy in a replication-dependent manner via engaging innate inflammation and antitumor T cells. Accordingly, it is anticipated that pre-existing immunity to PVSRIPO impedes antitumor therapy. However, recent evidence indicates that immunological 'recall', or reactivation of memory T cells, may mediate anti-tumor effects.MethodsThe impact of prior polio vs control (KLH) vaccination on intratumor viral replication, tumor inflammation, and overall tumor growth after intratumor PVSRIPO therapy was assessed in murine tumor models. The role of polio capsid and tetanus recall antigens in mediating intratumor inflammation and antitumor efficacy was similarly studied in mice non-permissive to PVSRIPO infection. To mechanistically define antitumor effects of polio recall, B cell and CD8 T cell knockout mice were used, in addition to adoptive transfer of CD4+ T cells from vaccinated mice. Intratumor polio or tetanus recall antigen therapy was performed after OT-I transfer (OVA-specific T cells) in the B16-OVA melanoma model to gauge antitumor T cell activity. Lastly, the inflammatory effects of polio and tetanus antigens was tested in human peripheral blood mononuclear cells (PBMCs).ResultsDespite curtailing intratumor viral replication, prior polio vaccination in mice potentiated subsequent antitumor efficacy of PVSRIPO. Intratumor recall responses induced by polio and tetanus antigens also delayed tumor growth. Recall antigen therapy was associated with marked intratumor influx of eosinophils, conventional CD4+ T cells, and increased expression of IFN-g, TNF, and Granzyme B in tumor infiltrating T cells. The antitumor efficacy of polio recall antigen was mediated by CD4+ T cells, partially depended upon CD8+ T cells, and was impaired by B cells. Both polio and tetanus recall antigen therapy bolstered the antitumor function of tumor-specific OT-I CD8+ T cells. Polio and tetanus antigens induced CXCL10 and type I/II/III IFNs in PBMCs in vitro.ConclusionsChildhood vaccine-specific CD4+ T cells hold cancer immunotherapy potential. In the context of PVSRIPO therapy, antitumor and inflammatory effects of polio vaccine-specific CD4+ T cell recall supersedes inhibitory effects of attenuated intratumor viral replication, and represents a novel mechanism of action.Ethics ApprovalThe animal work described in this study was approved by the Duke University IACUC.

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