Histone Deacetylase 6 (HDAC6) Influences T-Cell Activation and Survival: Implications For Cancer Immunotherapy

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1050-1050
Author(s):  
Andressa Sodre Laino ◽  
David M Woods ◽  
Fengdong Cheng ◽  
Hongwei Wang ◽  
Eduardo M. Sotomayor

Abstract The role of histone deacetylases (HDACs) as epigenetic regulators of immune function is becoming increasingly clear. Recently, the role of specific HDACs in orchestrating T-cell maturation, survival and function has begun to emerge, giving rationale to selective therapy to direct immune responses in different disease settings, including cancer. In particular, HDAC6 has recently been characterized as a negative regulator of regulatory T-cell suppressive activity (de Zoeten, Molecular and Cellular Biology, 2011). Here we report an expanded, novel role of HDAC6 in regulating T-cell survival and activation. First, the relative expression of the eleven classic HDACs was evaluated in resting and activated T-cells from mouse and human samples. It was found that the majority of HDACs decrease in expression following activation, including HDAC6. Next, in a HDAC6KO mouse model, it was found that T-cells lacking HDAC6 had skewed survival when compared to wild-type murine T-cells. This difference seems to be the result of an increased CD4+ T-cells population in the lymph nodes, with a concomitant decrease in viable CD8+ T-cells. To determine whether this population skewing was the consequence of defects in HDAC6KO mice T-cell development, wild-type murine T-cells were treated with an isotype-selective HDAC6 inhibitor. The results seen in HDAC6KO T-cells were recapitulated when wild-type T-cells were activated and treated with HDAC6 specific inhibitors, indicating a role of HDAC6 outside of thymic development in promoting CD4+ T-cell survival at the expense of CD8+ T-cells. Interestingly, it was found that activated CD4+ T-cells displayed decreased expression of the apoptosis signaling receptor FAS after HDAC6 inhibition while no differences were observed in CD8+ T-cells under the same conditions. In addition to these results implicating HDAC6 in regulating T-cell survival, expression of surface markers was altered in both CD8+ and CD4+ T-cells, including enhanced expression of the activation molecule CD69 in stimulated T-cells treated with an isotype-selective HDAC6 inhibitor. Finally, in vivo studies in tumor-bearing HDAC6KO mice revealed a significantly delayed in tumor progression. Similar results were observed in lymphoma-bearing mice treated with HDAC6 specific inhibitors. Taken together, this data shows that HDACs are dynamic in expression with regards to T-cell activation state. More specifically, we have unveiled hereto-unexplored roles of HDAC6 in regulating T-cell survival and function, pointing at this specific HDAC as an appealing target to harness T-cell immunity in hematologic malignancies. Disclosures: No relevant conflicts of interest to declare.

2021 ◽  
Vol 218 (7) ◽  
Author(s):  
Miwa Sasai ◽  
Ji Su Ma ◽  
Masaaki Okamoto ◽  
Kohei Nishino ◽  
Hikaru Nagaoka ◽  
...  

Because of their common signaling molecules, the main T cell receptor (TCR) signaling cascades in CD4+ and CD8+ T cells are considered qualitatively identical. Herein, we show that TCR signaling in CD8+ T cells is qualitatively different from that in CD4+ T cells, since CD8α ignites another cardinal signaling cascade involving phospholipase C β4 (PLCβ4). TCR-mediated responses were severely impaired in PLCβ4-deficient CD8+ T cells, whereas those in CD4+ T cells were intact. PLCβ4-deficient CD8+ T cells showed perturbed activation of peripheral TCR signaling pathways downstream of IP3 generation. Binding of PLCβ4 to the cytoplasmic tail of CD8α was important for CD8+ T cell activation. Furthermore, GNAQ interacted with PLCβ4, mediated double phosphorylation on threonine 886 and serine 890 positions of PLCβ4, and activated CD8+ T cells in a PLCβ4-dependent fashion. PLCβ4-deficient mice exhibited defective antiparasitic host defense and antitumor immune responses. Altogether, PLCβ4 differentiates TCR signaling in CD4+ and CD8+ T cells and selectively promotes CD8+ T cell–dependent adaptive immunity.


Author(s):  
Njabulo Ngwenyama ◽  
Annet Kirabo ◽  
Mark Aronovitz ◽  
Francisco Velázquez ◽  
Francisco Carrillo-Salinas ◽  
...  

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.


2003 ◽  
Vol 197 (7) ◽  
pp. 861-874 ◽  
Author(s):  
Ye Zheng ◽  
Monika Vig ◽  
Jesse Lyons ◽  
Luk Van Parijs ◽  
Amer A. Beg

Signaling pathways involved in regulating T cell proliferation and survival are not well understood. Here we have investigated a possible role of the nuclear factor (NF)-κB pathway in regulating mature T cell function by using CD4+ T cells from p50−/− cRel−/− mice, which exhibit virtually no inducible κB site binding activity. Studies with these mice indicate an essential role of T cell receptor (TCR)-induced NF-κB in regulating interleukin (IL)-2 expression, cell cycle entry, and survival of T cells. Our results further indicate that NF-κB regulates TCR-induced expression of antiapoptotic Bcl-2 family members. Strikingly, retroviral transduction of CD4+ T cells with the NF-κB–inducing IκB kinase β showed that NF-κB activation is not only necessary but also sufficient for T cell survival. In contrast, our results indicate a lack of involvement of NF-κB in both IL-2 and Akt-induced survival pathways. In vivo, p50−/− cRel−/− mice showed impaired superantigen-induced T cell responses as well as decreased numbers of effector/memory and regulatory CD4+ T cells. These findings provide the first demonstration of a role for NF-κB proteins in regulating T cell function in vivo and establish a critically important function of NF-κB in TCR-induced regulation of survival.


2002 ◽  
Vol 195 (7) ◽  
pp. 811-823 ◽  
Author(s):  
Dietrich Conze ◽  
Troy Krahl ◽  
Norman Kennedy ◽  
Linda Weiss ◽  
Joanne Lumsden ◽  
...  

The c-Jun NH2-terminal kinase (JNK) signaling pathway is induced by cytokines and stress stimuli and is implicated in cell death and differentiation, but the specific function of this pathway depends on the cell type. Here we examined the role of JNK1 and JNK2 in CD8+ T cells. Unlike CD4+ T cells, the absence of JNK2 causes increased interleukin (IL)-2 production and proliferation of CD8+ T cells. In contrast, JNK1-deficient CD8+ T cells are unable to undergo antigen-stimulated expansion in vitro, even in the presence of exogenous IL-2. The hypoproliferation of these cells is associated with impaired IL-2 receptor α chain (CD25) gene and cell surface expression. The reduced level of nuclear activating protein 1 (AP-1) complexes in activated JNK1-deficient CD8+ T cells can account for the impaired IL-2 receptor α chain gene expression. Thus, JNK1 and JNK2 play different roles during CD8+ T cell activation and these roles differ from those in CD4+ T cells.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3054-3054
Author(s):  
Yuji Miura ◽  
Christopher J. Thoburn ◽  
Emilie C. Bright ◽  
Elizabeth C. Matsui ◽  
William H. Matsui ◽  
...  

Abstract Graft-versus-host disease (GVHD) is a serious, life-threatening complication that occurs following allogeneic (allo) bone marrow transplantation (BMT). The use of non-specific immunosuppression or T cell depletion has reduced the incidence of GVHD but at the expense of increased rates of infection and leukemic relapse. Modulation of the major costimulatory pathway (CD28/CTLA4:B7) involved in T cell activation and regulation may lead to specific immune tolerance in the absence of global non-specific immunosuppression. The identification of mRNA splice variants encoding for soluble forms of CD28, CTLA4 and GITR suggests that costimulation of T cells is complex and is not limited to cell-cell contact. The present studies examined the hypothesis that the onset of GVHD and the re-establishment of immune tolerance correlate with the expression levels of these costimulatory molecules. mRNA transcript levels for the soluble (s) and full-length (fl; cell surface associated) variants assessed by quantitative PCR, were temporally examined in peripheral blood lymphocytes (PBLs) from patients undergoing alloBMT (n=38) or autologous (auto) BMT (n=39) with the induction of autoGVHD by cyclosporin A treatment post-transplant. Levels of s and fl CD28 mRNA transcripts in PBLs were significantly increased (>1.5 fold, P<0.05) in patients developing either allo or autoGVHD compared to patients who do not develop GVHD. s and flCTLA4 levels in patients at the onset of allo and autoGVHD were significantly decreased compared to healthy controls (n=22) (>2.3-fold, P<0.01). s and flCTLA4 expression in patients with autoGVHD was significantly decreased compared to patients without autoGVHD (>2.1-fold). sCTLA4 expression in patients with alloGVHD was significantly decreased than patients without alloGVHD. Interestingly, temporal analysis revealed that the levels for sCTLA4 paralleled the recovery from GVHD implicating an active process in the establishment of non-responsiveness. CD28, CTLA4 and GITR s and fl mRNA levels in CD4+CD25+ T regulatory (Treg) cells from allo and autoBMT patients were significantly increased (7-, 41- or 22-fold, P<0.01) compared to the CD4+CD25− subset. Additional studies attempted to identify the potential role of the sCTLA4 protein (encoded by the mRNA splice variant) on the regulation of the lymphocyte response mediated by Treg cells. Addition of the Treg cells to a mixed lymphocyte reaction suppressed the proliferative response of CD8+ T cells to alloantigens (75% suppression; >4 fold reduction of 3H-thymidine incorporation). However, pretreatment of the Treg subset with short interfering RNA (siRNA) to knockdown sCTLA4 gene (confirmed by quantitative PCR) significantly reduced the ability of these cells to suppress the response (minimal suppression was detected, 6%). In vitro siRNA studies also indicated that Treg cells with inhibited sCTLA4 expression were unable to suppress the response of IL-2-stimulated autoreactive CD8+ T cells. Taken together, the results indicate that increased expression of CTLA4 (soluble and cell-surface associated) and the “negative” signal delivered by this molecule to the T cell may regulate the development of GVHD and help to re-establish self tolerance after BMT. Defining the role of costimulation and the modulation of this pathway on immune recognition and regulation not only provides opportunities to enhance the re-establishment of tolerance but also may help to intensify anti-tumor immunotherapeutic strategies.


Blood ◽  
2006 ◽  
Vol 108 (12) ◽  
pp. 3818-3823 ◽  
Author(s):  
Luca Gattinoni ◽  
Anju Ranganathan ◽  
Deborah R. Surman ◽  
Douglas C. Palmer ◽  
Paul A. Antony ◽  
...  

AbstractCytotoxic T lymphocyte–associated antigen 4 (CTLA-4) maintains peripheral tolerance by suppressing T-cell activation and proliferation but its precise role in vivo remains unclear. We sought to elucidate the impact of CTLA-4 expression on self/tumor-reactive CD8+ T cells by using the glycoprotein (gp) 100–specific T-cell receptor (TCR) transgenic mouse, pmel-1. pmel-1 CLTA-4–/– mice developed profound, accelerated autoimmune vitiligo. This enhanced autoimmunity was associated with a small but highly activated CD8+ T-cell population and large numbers of CD4+ T cells not expressing the transgenic TCR. Adoptive transfer of pmel-1 CLTA-4–/– CD8+ T cells did not mediate superior antitumor immunity in the settings of either large established tumors or tumor challenge, suggesting that the mere absence of CTLA-4–mediated inhibition on CD8+ T cells did not directly promote enhancement of their effector functions. Removal of CD4+ T cells by crossing the pmel-1 CLTA-4–/– mouse onto a Rag-1–/– background resulted in the complete abrogation of CD8+ T-cell activation and autoimmune manifestations. The effects of CD4+ CLTA-4–/– T cells were dependent on the absence of CTLA-4 on CD8+ T cells. These results indicated that CD8+ CLTA-4–/– T-cell–mediated autoimmunity and tumor immunity required CD4+ T cells in which the function was dysregulated by the absence of CTLA-4–mediated negative costimulation.


2019 ◽  
Vol 221 (7) ◽  
pp. 1156-1166
Author(s):  
Andrea A Z Kovacs ◽  
Naoko Kono ◽  
Chia-Hao Wang ◽  
Daidong Wang ◽  
Toni Frederick ◽  
...  

Abstract Background Global immune activation and HLA alleles are each associated with the pathogenesis of human immunodeficiency virus (HIV) and hepatitis C virus . Methods We evaluated the relationship between 44 HLA class I and 28 class II alleles and percentages of activated CD8 (CD8+CD38+DR+) and CD4 (CD4+CD38+DR+) T cells in 586 women who were naive to highly active antiretroviral therapy. We used linear generalized estimating equation regression models, adjusting for race/ethnicity, age, HIV load, and hepatitis C virus infection and controlling for multiplicity using a false discovery rate threshold of 0.10. Results Ten HLA alleles were associated with CD8 and/or CD4 T-cell activation. Lower percentages of activated CD8 and/or CD4 T cells were associated with protective alleles B*57:03 (CD8 T cells, −6.6% [P = .002]; CD4 T cells, −2.7% [P = .007]), C*18:01 (CD8 T cells, −6.6%; P < .0008) and DRB1*13:01 (CD4 T cells, −2.7%; P < .0004), and higher percentages were found with B*18:01 (CD8 T cells, 6.2%; P < .0003), a detrimental allele. Other alleles/allele groups associated with activation included C*12:03, group DQA1*01:00, DQB1*03:01, DQB1*03:02, DQB1*06:02, and DQB1*06:03. Conclusion These findings suggest that a person’s HLA type may play a role in modulating T-cell activation independent of viral load and sheds light on the relationship between HLA, T-cell activation, immune control, and HIV pathogenesis.


2007 ◽  
Vol 75 (5) ◽  
pp. 2244-2252 ◽  
Author(s):  
Patricia Ngai ◽  
Sarah McCormick ◽  
Cherrie Small ◽  
Xizhong Zhang ◽  
Anna Zganiacz ◽  
...  

ABSTRACT Gamma interferon (IFN-γ) is a key cytokine in host defense against intracellular mycobacterial infection. It has been believed that both CD4 and CD8 T cells are the primary sources of IFN-γ. However, the relative contributions of CD4 and CD8 T-cell subsets to IFN-γ production and the relationship between CD4 and CD8 T-cell activation have not been examined. By using a model of pulmonary mycobacterial infection and various immunodetection assays, we found that CD4 T cells mounted a much stronger IFN-γ response than CD8 T cells at various times after mycobacterial infection, and this pronounced IFN-γ production by CD4 T cells was attributed to both greater numbers of antigen-specific CD4 T cells and a greater IFN-γ secretion capacity of these cells. By using major histocompatibility complex class II-deficient or CD4-deficient mice, we found that the lack of CD4 T cells did not negatively affect primary or secondary CD8 T-cell IFN-γ responses. The CD8 T cells activated in the absence of CD4 T cells were capable of immune protection against secondary mycobacterial challenge. Our results suggest that, whereas both CD4 and CD8 T cells are capable of IFN-γ production, the former represent a much greater cellular source of IFN-γ. Moreover, during mycobacterial infection, CD8 T-cell IFN-γ responses and activation are independent of CD4 T-cell activation.


2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A672-A672
Author(s):  
Sruthi Ravindranathan ◽  
Tenzin Passang Fnu ◽  
Edmund Waller

BackgroundOnly a fraction of cancer patients responds to current antibody-based immune checkpoint inhibitors.1 Our lab has identified vasoactive intestinal peptide-receptor (VIP-R) signaling as a targetable immune checkpoint pathway in cancer. VIP is a small neuropeptide with known immunosuppressive effects on T cells, in particular, CD4+ T cells.2–5 However, little is known about VIP-R signaling in CD8+ T cells. To define mechanisms by which VIP limits T cell activation and function, we studied the regulation of VIP and VIP receptors (VIP-R) in T cells following their activation in vitro and in mouse models of cancer.MethodsT cells from healthy human donors and murine splenocytes were activated using anti-CD3 coated plates. Western blots measured intracellular pre-pro-VIP, along with its cognate receptors; VPAC1 and VPAC2. Purified cultures of CD4+ and CD8+ T cells were used to interrogate the protein expression on specific T cell subsets. Activation and chemokine receptor expression was assessed by flow cytometry to evaluate T cell response to VIP-R antagonists in vitro and in tumor-bearing mice engrafted with pancreatic cancer cell lines.ResultsBoth murine and human T cells upregulate pre-pro-VIP following TCR stimulation with similar kinetics of VIP receptors between species. VIP expression is upregulated in vivo following treatment of tumor-bearing mice with anti-PD1 MoAb. VIP expression is temporally correlated with the upregulation of other co-inhibitory molecules. VPAC1 expression modestly increased in activated T cells while VPAC2 expression decreased. A non-canonical high molecular weight (HMW) form of VPAC2-related protein robustly and transiently increase in activated T cells. Expression of HMW form of VPAC2 is only detected in activated CD4+ T cells. Of note, activated CD4+ but not CD8+ T cells upregulate pre-pro-VIP. Pharmacological inhibition of VIP-R signaling significantly increased CD69+, OX40+, Lag3+, and PD1+ expression in CD4+ subsets compared to activated T cells without VIP-R antagonists (p < 0.05). In contrast, CD8+ T cells upregulate VPAC1 but not VPAC2 receptor following activation. VIP-R antagonist treatment of activated CD8+ T cells significantly decreased CXCR4+ expression (p < 0.05). CXCR3 and CXCR5 expression were not affected by VIP-R antagonist treatment.ConclusionsVIP-R signaling is a novel immune autocrine and paracrine checkpoint pathway in activated CD4+ T cells. Activated CD4+ and CD8+ T cells demonstrate different kinetics of VPAC1 and VPAC2 expression, suggesting different immune-regulatory responses to VIP-R antagonists. Understanding VIP-R signaling induced during T cell activation can lead to specific drugs that target VIP-R pathways to enhance cancer immunotherapy.AcknowledgementsWe thank healthy volunteers for blood samples. The authors also thank the shared resources at Emory University, namely, Emory Flow Cytometry Core (EFCC) and Integrated Cellular Imaging Core (ICI) and Yerkes Nonhuman Primate Genomics Core that provided services or instruments at subsidized cost to conduct some of the reported experiments. This work was supported in part by Katz Foundation funding, Georgia Research Alliance, and Emory School of Medicine Dean's Imagine, Innovate and Impact (I3) venture award to Edmund K. Waller.ReferencesDarvin P, Toor SM, Sasidharan Nair V, Elkord E. Immune checkpoint inhibitors: recent progress and potential biomarkers. Experimental and Molecular Medicine 2018.Wang HY, Jiang XM, Ganea D. The Neuropeptides VIP and PACAP Inhibit IL-2 Transcription by Decreasing c-Jun and Increasing JunB Expression in T Cells. J Neuroimmunol 2000;104(1):68–78.Delgado M. Vasoactive intestinal peptide generates CD4+CD25+ regulatory T Cells in Vivo. J Leukoc Biol 2005.Anderson P, Gonzalez-Rey E. Vasoactive intestinal peptide induces cell cycle arrest and regulatory functions in human T cells at multiple levels. Mol Cell Biol 2010.Delgado M, Ganea D. Vasoactive intestinal peptide: a neuropeptide with pleiotropic immune functions. Amino Acids. NIH Public Access July 2013, 25–39.Ethics ApprovalDe-identified blood samples from consented healthy volunteers (IRB 00046063) were obtained with approval from Institutional Review Boards.


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