scholarly journals Mycobacteria-specific CD4+IFN-γ+ cell expresses naïve-surface markers and confers superior protection against tuberculosis infection compared to central and effector memory CD4+ T cell subsets

2018 ◽  
Author(s):  
Jinyun Yuan ◽  
Janice Tenant ◽  
Thomas Pacatte ◽  
Christopher Eickhoff ◽  
Azra Blazevic ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Population ◽  
Vaccine Trial ◽  
Memory Cell ◽  
T Cell Subsets ◽  
Effector Memory ◽  
Surface Markers ◽  
Activation Markers ◽  
Ifn Γ

AbstractFailure of the most recent tuberculosis (TB) vaccine trial to boost BCG mediated anti-TB immunity despite highly durable Th1-specific central (TCM) and effector (TEM) memory cell responses, highlights the importance of identifying optimal T cell targets for protective vaccines. Here we describe a novel, Mycobacterium tuberculosis (Mtb)-specific IFN-γ+CD4+ T cell population expressing surface markers characteristic of naïve T cells (TNLM), that were induced in both human (CD45RA+CCR7+CD27+CD95-) and murine (CD62L+CD44-Sca-1+CD122-) systems in response to mycobacteria. In BCG vaccinated subjects and those with latent TB infection, TNLM cells, compared to bonafide naïve CD4+ T cells were identified by absence of CD95 expression and had increased expression CCR7 and CD27, the activation markers T-bet, CD69 and PD-1 and the survival marker CD74. Increased TNLM frequencies were noted in the lung and spleen of wild type C57BL6 mice at 2 weeks after infection with Mtb, and progressively decreased at later time points, a pattern not seen in TNF-α+CD4+ T cells expressing naïve cell surface markers. Importantly, adoptive transfer of highly purified TNLM from vaccinated ESAT-61-20-specific TCR transgenic mice conferred superior protection against Mtb infection in Rag-/- mice when compared with total meory populations (central and effector memory cells). Thus, TNLM cells may represent a memory T cell population that if optimally targeted may significantly improve future TB vaccine responses.

scholarly journals Increased state of activation of CD4 positive T cells and elevated interferon γ production in pouchitis

Gut ◽  
1998 ◽  
Vol 43 (4) ◽  
pp. 499-505 ◽  
Author(s):  
A Stallmach ◽  
F Schäfer ◽  
S Hoffmann ◽  
S Weber ◽  
I Müller-Molaian ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Mononuclear Cells ◽  
Interferon Γ ◽  
Ileoanal Pouch ◽  
T Cell Subsets ◽  
Activation Markers ◽  
Ifn Γ

Background—Immunoregulatory abnormalities of T cells might be of importance in the pathogenesis of pouchitis after ileoanal pouch anastomosis (IAP).Aims—To characterise T cell subsets, their state of activation, and production of cytokines in inflamed and non-inflamed pouches in patients with ulcerative colitis (UC) and familial adenomatous polyposis (FAP). The influence of T cell activation on mucosal transformation was also studied.Patients—Mucosal biopsy specimens were taken from 42 patients with IAP (33 with UC and nine with FAP).Methods—Mononuclear cells were isolated by standard techniques and characterised by three colour flow cytometry. Interferon γ (IFN-γ) production was studied using the ELISPOT technique.Results—In patients with UC with pouchitis there was a significant increase in the CD4:CD8 ratio, expression of activation markers on CD3+ cells, and number of IFNγ producing mononuclear cells compared with patients with UC without pouchitis (CD4:CD8 ratio 1.3 (range 0.7–2.7) versus 0.6 (0.1–1.0), p=0.012). In addition, a positive correlation between increased crypt depth and the number of CD4+ cells (r=0.57) was shown.Conclusion—The observed increase in activated mucosal CD4+ T cells and IFN-γ production might lead to mucosal destruction and crypt hyperplasia as seen in pouchitis.

scholarly journals Antigen-Responsive CD4+ T Cells from C3H Mice Chronically Infected with Leishmania amazonensis Are Impaired in the Transition to an Effector Phenotype

2006 ◽  
Vol 74 (3) ◽  
pp. 1547-1554 ◽  
Author(s):  
Amanda E. Ramer ◽  
Yannick F. Vanloubbeeck ◽  
Douglas E. Jones
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Population ◽  
T Cell Response ◽  
Leishmania Amazonensis ◽  
Effector Memory ◽  
Intrinsic Defect ◽  
Antigen Stimulation ◽  
Ifn Γ

ABSTRACT C3HeB/FeJ mice challenged with Leishmania major develop a polarized Th1 response and subsequently heal, whereas Leishmania amazonensis challenge leads to chronic lesions with high parasite loads at 10 weeks postinfection. In this study, a comparison of draining lymph node cells from L. amazonensis- and L. major-infected mice at 10 weeks postinfection showed equivalent percentages of effector/memory phenotype CD44hi CD4+ T cells producing interleukin-2 (IL-2) and proliferating after antigen stimulation. However, these cells isolated from L. amazonensis-infected mice were not skewed toward either a Th1 or Th2 phenotype in vivo, as evidenced by their unbiased Th1/Th2 transcription factor mRNA profile. In vivo antigen stimulation with added IL-12 failed to enhance gamma interferon (IFN-γ) production of CD4+ T cells from L. amazonensis-infected mice. Antigen stimulation of CD4+ T cells from L. amazonensis-infected mice in vitro in the presence of IL-12 resulted in production of only 10 to 15% of the IFN-γ produced by T cells from L. major-infected mice under identical conditions. These results suggest that the CD4+ T-cell response during chronic L. amazonensis infection is limited during the transition from an early activated CD4+ T-cell population to an effector cell population and demonstrate that these T cells have an intrinsic defect beyond the presence or absence of IL-12 during antigen stimulation.

scholarly journals Rapid Generation of Multivirus-Specific T Lymphocytes for the Prevention and Treatment of Respiratory Viral Infections

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 3332-3332
Author(s):  
Spyridoula Vasileiou ◽  
Annie Turney ◽  
Manik Kuvalekar ◽  
Shivani Mukhi ◽  
Ayumi Watanabe ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Viral Antigen ◽  
T Cell Subsets ◽  
Effector Memory ◽  
Cell Transplant ◽  
Activation Markers ◽  
Hematopoietic Stem ◽  
Equity Ownership ◽  
Tract Infections

Abstract Acute upper and lower respiratory tract infections (RTIs) due to community-acquired respiratory viruses (CARVs) including respiratory syncytial virus (RSV), influenza, parainfluenza virus (PIV) and human metapneumovirus (hMPV) are a leading cause of morbidity and mortality worldwide, with individuals whose immune systems are naïve (e.g. children) or compromised being most vulnerable. In allogeneic hematopoietic stem cell transplant (HSCT) recipients, the incidence of CARV-related respiratory viral infection reaches 29%. Most patients initially present with mild symptoms of upper RTI and in 50% of cases the infection progresses to a lower RTI with severe symptoms including bronchiolitis and pneumonia and mortality rates as high as 50%. Currently there are no approved vaccines nor antiviral drugs for hMPV and PIV, while the preventative vaccine for Influenza is not indicated earlier than 6 months post-HSCT. Aerosolized ribavirin is FDA-approved for the treatment of RSV infections, but it is logistically difficult to administer and comes at a considerable cost. Thus, the lack of approved antiviral agents combined with the high cost of antiviral therapy emphasize the need for alternative treatment strategies for CARVs. Our group has previously demonstrated the safety and clinical efficacy of using adoptive T-cell transfer for the treatment of both latent [Epstein-Barr virus (EBV), cytomegalovirus (CMV), BK virus (BKV), human herpesvirus 6 (HHV6)] and lytic [adenovirus (AdV)] viruses in recipients of allo-HSCT by generation of multivirus-specific T cell (VST) lines. Given that susceptibility to CARVs is highly associated with underlying immune deficiency, we wanted to explore the potential for extending this approach to Influenza, RSV, hMPV and PIV3 infections. In order to do so, we exposed PBMCs from healthy donors to a cocktail of pepmixes (overlapping peptide libraries) spanning immunogenic antigens derived from our target viruses [Influenza - NP1 and MP1; RSV - N and F; hMPV - F, N, M2-1 and M; PIV3 - M, HN, N and F] followed by expansion in the presence of activating cytokines in a G-Rex device. Over 10-13 days we achieved an average 8.5 fold expansion [increase from 0.25x107 PBMCs/cm2 to mean 1.9±0.2x107 cells/cm2; n=12). Cells were comprised almost exclusively of CD3+ T cells (96.2±0.6%; mean±SEM), with a mixture of cytotoxic (CD8+) and helper (CD4+) T cells and a phenotype consistent with immediate effector function and long term memory, as evidenced by upregulation of the activation markers CD25, CD69, and CD28 as well as expression of central (CD45RO+/CD62L+) and effector memory markers (CD45RO+/CD62L−), with minimal PD1 or Tim3 expression. Anti-viral specificity of multi-R-VSTs was tested in an IFNγ Elispot assay using each of the individual stimulating antigens as an immunogen and all 12 lines screened proved to be reactive against all 4 of the target viruses [Influenza: mean 735±75.6 SFC/2x105, RSV: 758±69.8, hMPV: 526±100.8, PIV3: 391±93.7]. As demonstrated by intracellular cytokine staining, the immune response was mediated by both CD4+ and CD8+ T cell subsets, and the majority of IFNγ-producing cells also produced TNFα. In addition, the cells secreted GM-CSF as measured by Luminex array, with baseline levels of Th2/suppressive cytokines. Furthermore, upon antigenic stimulation our VSTs produced the effector molecule Granzyme B suggesting the cytolytic potential of these expanded cells, which was confirmed in a standard Cr51-release assay against viral pepmix-loaded autologous PHA blasts. Viral antigen-loaded targets were specifically recognized and lysed by our VSTs, while there was no evidence of activity against non-infected autologous or allogeneic targets. In conclusion, we have shown that it is feasible to rapidly generate a single preparation of polyclonal multi-respiratory (multi-R)-VSTs with specificities directed to Influenza, RSV, hMPV and PIV3 and a total of 12 encoded antigens using GMP-compliant manufacturing methodologies. The expanded cells are Th1-polarized, polyfunctional and selectively able to react to and kill viral antigen-expressing targets with no auto- or alloreactivity, attesting to both their selectivity and their safety for clinical use in HSCT recipients. We anticipate such multi-R-VSTs will provide clinical benefit in preventing or treating CARV infections in the immunocompromised. Disclosures Vera: Viracyte: Equity Ownership. Tzannou:Viracyte: Consultancy, Equity Ownership. Leen:Viracyte: Equity Ownership.

scholarly journals Interplay between IL-10, IFN-γ, IL-17A and PD-1 Expressing EBNA1-Specific CD4+ and CD8+ T Cell Responses in the Etiologic Pathway to Endemic Burkitt Lymphoma

Cancers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 5375
Author(s):  
Catherine S. Forconi ◽  
David H. Mulama ◽  
Priya Saikumar Lakshmi ◽  
Joslyn Foley ◽  
Juliana A. Otieno ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Burkitt Lymphoma ◽  
Cd4 T Cells ◽  
Cd8 T Cell ◽  
T Cell Response ◽  
T Cell Subsets ◽  
Effector Memory ◽  
Healthy Children ◽  
Ifn Γ

Children diagnosed with endemic Burkitt lymphoma (eBL) are deficient in interferon-γ (IFN-γ) responses to Epstein–Barr Nuclear Antigen1 (EBNA1), the viral protein that defines the latency I pattern in this B cell tumor. However, the contributions of immune-regulatory cytokines and phenotypes of the EBNA1-specific T cells have not been characterized for eBL. Using a bespoke flow cytometry assay we measured intracellular IFN-γ, IL-10, IL-17A expression and phenotyped CD4+ and CD8+ T cell effector memory subsets specific to EBNA1 for eBL patients compared to two groups of healthy children with divergent malaria exposures. In response to EBNA1 and a malaria antigen (PfSEA-1A), the three study groups exhibited strikingly different cytokine expression and T cell memory profiles. EBNA1-specific IFN-γ-producing CD4+ T cell response rates were lowest in eBL (40%) compared to children with high malaria (84%) and low malaria (66%) exposures (p < 0.0001 and p = 0.0004, respectively). However, eBL patients did not differ in CD8+ T cell response rates or the magnitude of IFN-γ expression. In contrast, eBL children were more likely to have EBNA1-specific CD4+ T cells expressing IL-10, and less likely to have polyfunctional IFN-γ+IL-10+ CD4+ T cells (p = 0.02). They were also more likely to have IFN-γ+IL-17A+, IFN-γ+ and IL-17A+ CD8+ T cell subsets compared to healthy children. Cytokine-producing T cell subsets were predominantly CD45RA+CCR7+ TNAIVE-LIKE cells, yet PD-1, a marker of persistent activation/exhaustion, was more highly expressed by the central memory (TCM) and effector memory (TEM) T cell subsets. In summary, our study suggests that IL-10 mediated immune regulation and depletion of IFN-γ+ EBNA1-specific CD4+ T cells are complementary mechanisms that contribute to impaired T cell cytotoxicity in eBL pathogenesis.

scholarly journals TOX is expressed by exhausted and polyfunctional human effector memory CD8+ T cells

2020 ◽  
Vol 5 (49) ◽  
pp. eaba7918 ◽  
Author(s):  
Takuya Sekine ◽  
André Perez-Potti ◽  
Son Nguyen ◽  
Jean-Baptiste Gorin ◽  
Vincent H. Wu ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Subsets ◽  
Effector Memory ◽  
Chronic Infections ◽  
Activation Markers ◽  
Barr Virus ◽  
Gene And Protein Expression ◽  
Epigenetic Remodeling ◽  
Epstein Barr

CD8+ T cell exhaustion is a hallmark of many cancers and chronic infections. In mice, T cell factor 1 (TCF-1) maintains exhausted CD8+ T cell responses, whereas thymocyte selection-associated HMG box (TOX) is required for the epigenetic remodeling and survival of exhausted CD8+ T cells. However, it has remained unclear to what extent these transcription factors play analogous roles in humans. In this study, we mapped the expression of TOX and TCF-1 as a function of differentiation and specificity in the human CD8+ T cell landscape. Here, we demonstrate that circulating TOX+ CD8+ T cells exist in most humans, but that TOX is not exclusively associated with exhaustion. Effector memory CD8+ T cells generally expressed TOX, whereas naive and early-differentiated memory CD8+ T cells generally expressed TCF-1. Cytolytic gene and protein expression signatures were also defined by the expression of TOX. In the context of a relentless immune challenge, exhausted HIV-specific CD8+ T cells commonly expressed TOX, often in clusters with various activation markers and inhibitory receptors, and expressed less TCF-1. However, polyfunctional memory CD8+ T cells specific for cytomegalovirus (CMV) or Epstein-Barr virus (EBV) also expressed TOX, either with or without TCF-1. A similar phenotype was observed among HIV-specific CD8+ T cells from individuals who maintained exceptional immune control of viral replication. Collectively, these data demonstrate that TOX is expressed by most circulating effector memory CD8+ T cell subsets and not exclusively linked to exhaustion.

scholarly journals Recombinant Interleukin-7 Induces Proliferation of Naive Macaque CD4+ and CD8+ T Cells In Vivo

2004 ◽  
Vol 78 (18) ◽  
pp. 9740-9749 ◽  
Author(s):  
Marcin Moniuszko ◽  
Terry Fry ◽  
Wen-Po Tsai ◽  
Michel Morre ◽  
Brigitte Assouline ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Rhesus Macaques ◽  
Memory Cell ◽  
T Cell Subsets ◽  
Effector Memory ◽  
Phenotypic Change ◽  
Necrosis Factor Alpha ◽  
Interleukin 7

ABSTRACT Interleukin-7 (IL-7) regulates T-cell homeostasis, and its availability is augmented in lymphopenic hosts. Naive CD8+ T cells transferred to lymphopenic mice acquire a memory-like phenotype, raising the possibility that IL-7 is the biological mediator of this effect. Here, we provide direct evidence that IL-7 induces the acquisition of memory-cell markers not only in CD8+ T cells but also in CD4+ T-cell subsets in immune-competent Indian rhesus macaques. The increase of these memory-like populations was dependent on the dose of the cytokine, and these cells were found in the blood as well as secondary lymphoid organs. Memory-like CD4+ and CD8+ T cells acquired the ability to secrete tumor necrosis factor alpha and, to a lesser extent, gamma interferon following stimulation with a cognate antigen. The phenotypic change observed in naive T cells was promptly reversed after discontinuation of IL-7. Importantly, IL-7 induced cycling of both CD4+ and CD8+ central memory and effector memory T cells, demonstrating its contribution to the maintenance of the entire T-cell pool. Thus, IL-7 may be of benefit in the treatment of iatrogenic or virus-induced T-cell depletion.

Expression of Immune Memory Markers CD8 α α and Interleukin−7 Receptor on CD8+ T Cell Subsets among HIV−1 Infected Patients.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1256-1256
Author(s):  
Jean Pierre Routy ◽  
Francois Mercier ◽  
Ahmed Galal ◽  
Med-Rachid Boulassel
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Activation ◽  
Cd8 T Cell ◽  
Central Memory ◽  
T Cell Subsets ◽  
Immune Memory ◽  
Effector Memory ◽  
Activation Markers ◽  
Hiv 1

Abstract Evidence from animal models suggests that the expression of CD8α α homodimer on CD8+ T-cells plays a key role in the generation of long-lived memory cells. However, very little information is available in the human clinical setting. Here, we examined immunophenotypic patterns of CD8+ T-cell subsets expressing CD8α α with other markers involved in generating and maintaining memory cells such as interleukin-7 receptor (IL-7Rα ) and circulating levels of IL-7 and IL-15, in three well-defined groups of human immunodeficiency virus-1 (HIV-1)-infected individuals including aviremic (n=15), viremic (n=31) and slow-progressor (n=15). In addition, immunophenotypic patterns were correlated with immune activation markers (CD38/HLA-DR), which are known to be an important factor in HIV-1 disease pathogenesis. Cell-surface expression of CD8α α , IL-7Rα and CD38/HLA-DR on CD8+ naïve, central memory, pre-terminal and terminal effector memory T-cells was measured by eight-color flow cytometry on freshly peripheral blood samples. IL-7 and IL-15 levels were measured by ELISA and viral loads were assessed by PCR. Group differences in the CD8+ T-cell subsets expressing each antigen tested were evaluated using the unpaired nonparametric Mann Whitney U test. Correlations were determined by Spearman’s correlation tests. Compared to slow-progressor subjects, expression of CD8α α was significantly reduced in aviremic and viremic patients and this reduction occurred mainly within naïve and central memory T-cell subsets and not in effector memory compartments. In contrast, persistent antigenemia in viremic patients appeared to lead to IL-7Rα loss mainly on central and effector memory subsets and not on naive T-cells. Compared to aviremic and viremic patients, slow-progressor subjects had lower levels of circulating IL-7, normal levels of IL-15, CD8α α and IL-7Rα , and reduced activated T-cells. Overall, expression of CD8α α was not significantly related to IL-7Rα although negative associations were evidenced within all CD8+ T-cell subsets. However, in viremic patients, naïve and central memory cell subsets expressing CD8α α were positively correlated with viral load but not with CD8+ T-cell subsets expressing immune activation markers. Together, these results provide new insights into the role of CD8α α /IL-7Rα along with immune activation markers in maintaining memory populations during HIV-1 infection. The inter-relationships between these immune memory markers require further investigations, which may help understanding the mechanisms of antiviral control.

scholarly journals Gamma Interferon Regulates Contraction of the Influenza Virus-Specific CD8 T Cell Response and Limits the Size of the Memory Population

2013 ◽  
Vol 87 (23) ◽  
pp. 12510-12522 ◽  
Author(s):  
Nayana Prabhu ◽  
Adrian W. Ho ◽  
Kenneth H. S. Wong ◽  
Paul Edward Hutchinson ◽  
Yen Leong Chua ◽  
...  
Keyword(s):  
T Cells ◽  
Influenza Virus ◽  
T Cell ◽  
Cell Population ◽  
Cd8 T Cells ◽  
Cell Response ◽  
Memory Cell ◽  
Cd8 T Cell ◽  
T Cell Response ◽  
Ifn Γ

The factors that regulate the contraction of the CD8 T cell response and the magnitude of the memory cell population against localized mucosal infections such as influenza are important for generation of efficient vaccines but are currently undefined. In this study, we used a mouse model of influenza to demonstrate that the absence of gamma interferon (IFN-γ) or IFN-γ receptor 1 (IFN-γR1) leads to aberrant contraction of antigen-specific CD8 T cell responses. The increased accumulation of the effector CD8 T cell population was independent of viral load. Reduced contraction was associated with an increased fraction of CD8 T cells expressing the interleukin-7 receptor (IL-7R) at the peak of the response, resulting in enhanced numbers of memory/memory precursor cells in IFN-γ−/−and IFN-γR−/−compared to wild-type (WT) mice. Blockade of IL-7 within the lungs of IFN-γ−/−mice restored the contraction of influenza virus-specific CD8 T cells, indicating that IL-7R is important for survival and is not simply a consequence of the lack of IFN-γ signaling. Finally, enhanced CD8 T cell recall responses and accelerated viral clearance were observed in the IFN-γ−/−and IFN-γR−/−mice after rechallenge with a heterologous strain of influenza virus, confirming that higher frequencies of memory precursors are formed in the absence of IFN-γ signaling. In summary, we have identified IFN-γ as an important regulator of localized viral immunity that promotes the contraction of antigen-specific CD8 T cells and inhibits memory precursor formation, thereby limiting the size of the memory cell population after an influenza virus infection.

Identification of Tigit on Intra-Tumor T Cells As a New Target for Immune Checkpoint Blockade in Follicular Lymphoma

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 917-917 ◽  
Author(s):  
Sarah Gothberg ◽  
Kanutte Huse ◽  
Arne Kolstad ◽  
Ole Christian Lingjærde ◽  
Bjørn Østenstad ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Research Funding ◽  
Checkpoint Blockade ◽  
T Cell Subsets ◽  
Effector Memory ◽  
Cytokine Signaling ◽  
Ifn Γ ◽  
Checkpoint Receptors

Abstract Background: Follicular lymphoma (FL) is the most common subtype of indolent non Hodgkin's lymphoma (NHL). Median survival is long (>10 years), but current chemo-immunotherapy regimens used for FL are usually not curative. While T cells in the FL tumor microenvironment are considered dysfunctional and associated with disease progression, a better understanding of T-cell signaling may reveal how to productively engage tumor-infiltrating T cells to kill lymphoma B cells. Our previous study showed that expression of the immune checkpoint receptor PD-1 was directly correlated with reduced cytokine signaling in FL T cells (Myklebust et al., Blood 2013). Antibody immunotherapy targeting the PD-1/PD-L1 pathway has shown significant activity in solid tumors, but these benefits have not been as profound in NHLs, including FL. Co-blockade of checkpoint inhibitors may therefore be necessary to generate optimal anti-tumor responses in FL. The hypothesis underlying this study was that characterizing signaling responses in FL tumor-infiltrating T cells will identify new targets for combination of checkpoint blockade. Methods: Surface expression of 9 checkpoint receptors governing T cell function was measured in subsets of CD4 and CD8 T cells from FL lymph node tumors (n = 14) and from healthy donor tonsils (n= 11) and peripheral blood samples (n = 7) using fluorescence flow cytometry. Patterns of checkpoint receptor expression were compared with 1) intracellular phospho-protein signaling response and 2) cytokine production for subsets of T cells infiltrating FL tumors and the corresponding T-cell populations in healthy tonsils. Phospho-specific flow cytometry measured phosphorylation of STATs and T cell receptor (TCR) signaling effectors within minutes following stimulation by IL-4, IL-7, IL-21, or α-CD3+α-CD28 (TCR stimulation) antibodies. Results: CD4 and CD8 T cells infiltrating FL tumors were gated into subsets defined by PD-1 and ICOS protein expression, and compared to cognate T cell subsets in healthy tonsils. FL and tonsil T cells closely matched in their signaling responses to IL-4, IL-7, and IL-21 stimulation, with PD-1 expressing cells (CD4+PD-1hiICOS+ (TFH) and CD8+PD-1int T cells) exhibiting modest phospho-protein signaling responses compared to T cells not expressing PD-1. Furthermore, TCR membrane proximal signaling events (p-CD3ζ, p-SLP76) following TCR stimulation were comparable in FL and tonsil T cells. This contrasted reduced phospho-ERK signaling in all CD4 and CD8 T cell subsets infiltrating FL tumors which distinguished them from tonsillar T cells. IFN-γ production also differed between FL and tonsils, as CD8 T cells infiltrating FL tumors produced less IFN-γ. Reduced IFN-γ production was independent of PD-1 expression, suggesting suppressed function in these T cells which could be due to inhibitory receptors other than PD-1. Of the 9 checkpoint receptors measured, PD-1 and T cell Ig and ITIM domain (TIGIT) were expressed at the highest frequency. In FL, TIGIT was expressed in 58% and 80% of CD8 effector and effector memory cells, respectively, as compared to 43% and 68% of the cognate healthy tonsillar subsets. TIGIT was also frequently expressed in CD4 FL T cells, as 52% and 79% of effector and effector memory cells expressed TIGIT, respectively, as compared to 16% and 59% of the corresponding subsets from healthy tonsils. viSNE analysis demonstrated that TIGIT and PD-1 were frequently co-expressed in FL T cells, and a large fraction of PD-1int T cells had high expression of TIGIT (Figure 1). These results provide a rationale for co-blockade of PD-1 and TIGIT in FL and for investigation of how co-blockade impacts T cell functions. Conclusions: These results reveal specific suppression of cytokine signaling in CD8 effector T cells infiltrating FL tumors and identify TIGIT and PD-1 as strong candidates for co-checkpoint blockade in FL. A deeper understanding of the interplay between checkpoint receptors and key T cell cytokine signaling events in FL will further assist in engineering immuno-therapeutic regiments that improve FL patient clinical outcomes. Disclosures Kolstad: Nordic Nanovector: Other: Membership of Scientific Advisory Board. Levy:Kite Pharma: Consultancy; Five Prime Therapeutics: Consultancy; Innate Pharma: Consultancy; Beigene: Consultancy; Corvus: Consultancy; Dynavax: Research Funding; Pharmacyclics: Research Funding. Irish:Incyte: Research Funding; Janssen: Research Funding; Cytobank, Inc.: Equity Ownership, Membership on an entity's Board of Directors or advisory committees.

scholarly journals Interferon regulatory factor 4 controls effector functions of CD8+ memory T cells

2021 ◽  
Vol 118 (16) ◽  
pp. e2014553118
Author(s):  
Aenne Harberts ◽  
Constantin Schmidt ◽  
Joanna Schmid ◽  
Daniel Reimers ◽  
Friedrich Koch-Nolte ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Population ◽  
T Cell Activation ◽  
Cell Activation ◽  
Memory T Cells ◽  
Memory Cell ◽  
Effector Memory ◽  
Effector Cells ◽  
Effector Functions

The transcription factor IRF4 is required for CD8+ T cell activation, proliferation, and differentiation to effector cells and thus is essential for robust CD8+ T cell responses. The function of IRF4 in memory CD8+ T cells yet needs to be explored. To investigate the role of IRF4 for maintaining differentiation state and survival of CD8+ memory T cells, we used a mouse model with tamoxifen-inducible Irf4 knockout to preclude effects due to inefficient memory cell differentiation in absence of IRF4. We infected mice with ovalbumin-recombinant listeria and induced Irf4 knockout after clearance of the pathogen. Loss of IRF4 resulted in phenotypical changes of CD8+ memory T cells but did not cause a reduction of the total memory T cell population. However, upon reencounter of the pathogen, CD8+ memory T cells showed impaired expansion and acquisition of effector functions. When compared to CD8+ effector memory T cells, CD8+ tissue-resident memory T cells (TRM cells) expressed higher IRF4 levels. Mice with constitutive Irf4 knockout had diminished CD8+ TRM-cell populations, and tamoxifen-induced Irf4 deletion caused a reduction of this cell population. In conclusion, our results demonstrate that IRF4 is required for effective reactivation but not for general survival of CD8+ memory T cells. Formation and maintenance of CD8+ TRM cells, in contrast, appear to depend on IRF4.

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