scholarly journals Osteoclast-Induced Immunosuppression Occurs through Dysregulation of Immune Checkpoint Axes in Multiple Myeloma

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4382-4382
Author(s):  
Kenta Mukaihara ◽  
Mattia D'Agostino ◽  
Cristina Panaroni ◽  
Keertik Fulzele ◽  
Tomoaki Mori ◽  
...  

Osteolytic bone disease has a significant impact on both quality of life and overall survival of patients with multiple myeloma (MM). Given that bone and immune cells share the same microenvironment and interact with each other via cytokines, signaling molecules and regulatory proteins in the bone marrow (Tsukasaki M et al., Nat Rev Immunol 2019), we sought to elucidate the effect of osteoclasts (OCs) on the immune microenvironment. Specifically, T cells significantly suppress differentiation of OCs through signaling crosstalk between RANKL and IFN-γ (Takayanagi H et al., Nature 2000). However, little is known regarding the effect of OCs on the immune system. Here we investigated the effect of OCs on immune cells, especially on T cells. Dysregulation of several checkpoint molecules has been shown in MM (Kwon M et al., J Immunol 2017). We, therefore, assessed the expression of various immune checkpoint receptors, such as PD-1, TIGIT, OX40 and CD137 on T cells in co-culture with or without autologous OCs by multi-color flow cytometry. OC co-culture significantly increased co-inhibitory checkpoint (PD-1 and TIGIT) through direct contact, while decreasing co-stimulatory checkpoint (OX40 and CD137) in CD3+ T cells. Expression of the checkpoint ligand, PD-L1 was significantly increased on MM cells in the presence of both T cells and OCs compared to the presence of T cells alone. Conversely, OCs in the absence of T cells did not induce significant increase of PD-L1 on MM cells. According to previous literature, PD-L1 expression on MM cells is induced in part by IFN-γ (Liu J et al., Blood 2007). Interestingly, our data demonstrated that OCs activated IFN-γ producing T cells in co-culture conditions. Furthermore, we observed that T cell and OC-mediated upregulation of PD-L1 on MM cells was partially reversed by using IFN-γ neutralizing antibody. This implies that OCs indirectly induce PD-L1 upregulation on MM cells by enhancing IFN-γ secretion from T cells. In addition, we found that naïve CD4+ T cells have a higher propensity to differentiate into Th17 lineage in the presence of Th17 differentiation cytokines when co-cultured with OCs. Moreover, we observed an increased expansion of Th17 cells in co-culture with OCs. Those Th17 cells also showed a similar pattern of dysregulation of immune checkpoint axes. Our study demonstrates that OCs positively regulate co-inhibitory checkpoint molecules and negatively regulate co-stimulatory molecules on T cells. These findings indicate that OCs play an important role in inhibiting T cell-mediated antitumor immunity. Targeting OCs may help restore impaired immune surveillance in MM in addition to their critical role in preventing lytic bone lesions in MM. These data may support the role of antiresorptives in immune surveillance with indirect anti-tumor effects. Disclosures No relevant conflicts of interest to declare.

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 4447-4447
Author(s):  
Kenta Mukaihara ◽  
Ka Tat Siu ◽  
Cristina Panaroni ◽  
Keertik Fulzele ◽  
Rosemary Soucy ◽  
...  

Abstract Skeletal related events impact both quality of life and overall survival of multiple myeloma (MM) patients. The underlying cause of osteolytic bone disease is an imbalance between bone-resorbing osteoclasts and bone-forming osteoblasts. Bone cells are regulated by a complex milieu of bone marrow microenvironmental components including the immune system via the effect of cytokines, signaling molecules and regulatory proteins. For example, osteoclastogenesis is tightly regulated by T cells through signaling crosstalk between RANKL and IFN-γ (Takayanagi H et al., Nature 2000). However, the effect of osteoclasts (OCs) on the immune system is less well defined. Here we investigated the effect of osteoclasts on immune cells including T cells, Th17 cells, NK cells and myeloid-derived suppressor cells (MDSCs) in MM. To gain insight into the functional impact of OCs on the immune cells, each type of immune cell was isolated from peripheral blood mononuclear cells (PBMNCs) and examined further in co-cultures with OCs. Our preliminary data showed that the frequency of NK cells and MDSCs in PBMNCs derived from myeloma patients increased when co-cultured with autologous OCs. Activation of the inhibitory immune checkpoints suppresses T cell-mediated antitumor immunity. Up-regulation of several co-inhibitory molecules has also been shown in MM (Kwon M et al., J Immunol 2017). We, therefore, assessed the expression of various immune checkpoint receptors, such as PD-1, LAG-3 and B7-H3, on T cells in co-culture with or without OCs by multi-color flow cytometry. OC co-culture significantly increased PD-1 expression in both CD4+and CD8+ T cell populations. The presence of OCs also enhanced PD-L1 protein expression on MM cells. Th17 cells, a newsubset of helper T cells, have recently been identified as immunosuppressive cells. Th17 cells are increased in myeloma; morevover they secrete IL-17 which promotes myeloma cell growth (Prabhala RH et al., Blood 2010). Interestingly, we found that naïve CD4 T cells have a higher propensity to differentiate into Th17 lineage in the presence of Th17 differentiation cytokines when co-cultured with OCs. Furthermore, we also observed an increased expansion of Th17 cells in co-culture with OCs. NK cell cytotoxic function is severely impaired in myeloma (Fauriat C et al., Leukemia. 2006). In our experiments, NK cells co-cultured in the presence of OCs demonstrated significant decrease in NK cell cytotoxicity, despite increase in NK cell numbers. Our study demonstrated that OCs suppress the cytotoxic function of T cells and NK cells and induce the expansion of immunosuppressive Th17 cells and MDSCs through direct contact. These findings indicate that OCs play an important role in tumor progression in part by enhancing immune suppression. Targeting OCs represent an attractive therapeutic option not only for controlling osteolytic bone disease but also for restoring the impaired immune surveillance in MM. Ongoing studies will focus on understanding direct-contact-mediated interactions between OCs and immune cells. Furthermore, the effect of OC inhibition using anti-resorptive drugs on the immune system will be interrrogated. Disclosures Raje: Medscape: Honoraria; Research to Practice: Honoraria; AstraZeneca: Research Funding; Takeda: Consultancy; Merck: Consultancy; Janssen: Consultancy; Celgene: Consultancy; BMS: Consultancy; Amgen Inc.: Consultancy.


2008 ◽  
Vol 76 (4) ◽  
pp. 1565-1571 ◽  
Author(s):  
Taiki Aoshi ◽  
Toshi Nagata ◽  
Mina Suzuki ◽  
Masato Uchijima ◽  
Dai Hashimoto ◽  
...  

ABSTRACT CD8+ T cells play a pivotal role in protection against Mycobacterium tuberculosis infection. We identified a novel HLA-A*0201-restricted CD8+ T-cell epitope on a dominant secreted antigen of M. tuberculosis, MPT51, in HLA-A*0201 transgenic HHD mice. HHD mice were immunized with plasmid DNA encoding MPT51 with gene gun bombardment, and gamma interferon (IFN-γ) production by the immune splenocytes was analyzed. In response to overlapping synthetic peptides covering the mature MPT51 sequence, the splenocytes were stimulated to produce IFN-γ by only one peptide, p51-70. Three-color flow cytometric analysis of intracellular IFN-γ and cell surface CD4 and CD8 staining revealed that the MPT51 p51-70 peptide contains an immunodominant CD8+ T-cell epitope. Further analysis using computer algorithms permitted identification of a bona fide T-cell epitope, p53-62. A major histocompatibility complex class I stabilization assay using T2 cells confirmed that this epitope binds to HLA-A*0201. The T cells were capable of lysing MPT51 p53-62 peptide-pulsed T2 cells. In addition, MPT51 p53-62-specific memory CD8+ T cells were found in tuberculin skin test-positive HLA-A*0201+ healthy individuals. Use of this HLA-A*0201-restricted CD8+ T-cell epitope for analysis of the role of MPT51-specific T cells in M. tuberculosis infection and for design of vaccines against tuberculosis is feasible.


2007 ◽  
Vol 204 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Keiji Hirota ◽  
Motomu Hashimoto ◽  
Hiroyuki Yoshitomi ◽  
Satoshi Tanaka ◽  
Takashi Nomura ◽  
...  

This report shows that highly self-reactive T cells produced in mice as a result of genetically altered thymic T cell selection spontaneously differentiate into interleukin (IL)-17–secreting CD4+ helper T (Th) cells (Th17 cells), which mediate an autoimmune arthritis that clinically and immunologically resembles rheumatoid arthritis (RA). The thymus-produced self-reactive T cells, which become activated in the periphery via recognition of major histocompatibility complex/self-peptide complexes, stimulate antigen-presenting cells (APCs) to secrete IL-6. APC-derived IL-6, together with T cell–derived IL-6, drives naive self-reactive T cells to differentiate into arthritogenic Th17 cells. Deficiency of either IL-17 or IL-6 completely inhibits arthritis development, whereas interferon (IFN)-γ deficiency exacerbates it. The generation, differentiation, and persistence of arthritogenic Th17 cells per se are, however, insufficient for producing overt autoimmune arthritis. Yet overt disease is precipitated by further expansion and activation of autoimmune Th17 cells, for example, via IFN-γ deficiency, homeostatic proliferation, or stimulation of innate immunity by microbial products. Thus, a genetically determined T cell self-reactivity forms a cytokine milieu that facilitates preferential differentiation of self-reactive T cells into Th17 cells. Extrinsic or intrinsic stimuli further expand these cells, thereby triggering autoimmune disease. Intervention in these events at cellular and molecular levels is useful to treat and prevent autoimmune disease, in particular RA.


2020 ◽  
Author(s):  
Ganapathy Sriram ◽  
Lauren Milling ◽  
Jung-Kuei Chen ◽  
Wuhbet Abraham ◽  
Erika D. Handly ◽  
...  

ABSTRACTInhibition of immune checkpoints has shown promising results in the treatment of certain tumor types. However, the majority of cancers do not respond to immune checkpoint inhibition (ICI) treatment, indicating the need to identify additional modalities that enhance the response to immune checkpoint blockade. In this study, we identified a tumor-tailored approach using ex-vivo DNA damaging chemotherapy-treated tumor cells as a live injured cell adjuvant. Using an optimized ex vivo system for dendritic cell-mediated T-cell IFN-γ induction in response to DNA-damaged tumor cells, we identified specific dose-dependent treatments with etoposide and mitoxantrone that markedly enhance IFN-γ production by T-cells. Unexpectedly, the immune-enhancing effects of DNA damage failed to correlate with known markers of immunogenic cell death or with the extent of apoptosis or necroptosis. Furthermore, dead tumor cells alone were not sufficient to promote DC cross-presentation and induce IFN-γ in T-cells. Instead, the enhanced immunogenicity resided in the fraction of injured cells that remained alive, and required signaling through the RIPK1, NF-kB and p38MAPK pathways. Direct in vivo translation of these findings was accomplished by intra-tumoral injection of ex vivo etoposide-treated tumor cells as an injured cell adjuvant, in combination with systemic anti-PD1/CTLA4 antibodies. This resulted in increased intra-tumoral CD103+ dendritic cells and circulating tumor antigen-specific CD8+ T-cells, leading to enhanced anti-tumor immune responses and improved survival. The effect was abrogated in BATF3-deficient mice indicating that BATF3+ DCs are required for appropriate T-cell stimulation by live but injured DNA-damaged tumor cells. Notably, injection of the free DNA-damaging drug directly into the tumor failed to elicit such an enhanced anti-tumor response as a consequence of simultaneous damage to dendritic cells and T-cells. Finally, the DNA damage induced injured cell adjuvant and systemic ICI combination, but not ICI alone, induced complete tumor regression in a subset of mice who were then able to reject tumor re-challenge, indicating induction of a long-lasting anti-tumor immunological memory by the injured cell adjuvant treatment in vivo.


2020 ◽  
Vol 52 (9) ◽  
pp. 1475-1485 ◽  
Author(s):  
Won Suk Lee ◽  
Hannah Yang ◽  
Hong Jae Chon ◽  
Chan Kim

Abstract Cancer immunotherapy with immune checkpoint inhibitors (ICIs) has revolutionized the treatment of advanced cancers. However, the tumor microenvironment (TME) functions as a formidable barrier that severely impairs the efficacy of ICIs. While the crosstalk between tumor vessels and immune cells determines the nature of anti-tumor immunity, it is skewed toward a destructive cycle in growing tumors. First, the disorganized tumor vessels hinder CD8+ T cell trafficking into the TME, disable effector functions, and even kill T cells. Moreover, VEGF, the key driver of angiogenesis, interferes with the maturation of dendritic cells, thereby suppressing T cell priming, and VEGF also induces TOX-mediated exhaustion of CD8+ T cells. Meanwhile, a variety of innate and adaptive immune cells contribute to the malformation of tumor vessels. Protumoral M2-like macrophages as well as TH2 and Treg cells secrete pro-angiogenic factors that accelerate uncontrolled angiogenesis and promote vascular immaturity. While CD8+ T and CD4+ TH1 cells suppress angiogenesis and induce vascular maturation by secreting IFN-γ, they are unable to infiltrate the TME due to malformed tumor vessels. These findings led to preclinical studies that demonstrated that simultaneous targeting of tumor vessels and immunity is a viable strategy to normalize aberrant vascular-immune crosstalk and potentiate cancer immunotherapy. Furthermore, this combination strategy has been evidently demonstrated through recent pivotal clinical trials, granted approval from FDA, and is now being used in patients with kidney, liver, lung, or uterine cancer. Overall, combining anti-angiogenic therapy and ICI is a valid therapeutic strategy that can enhance cancer immunity and will further expand the landscape of cancer treatment.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2102-2102 ◽  
Author(s):  
Mahesh Yadav ◽  
Cherie Green ◽  
Connie Ma ◽  
Alberto Robert ◽  
Andrew Glibicky ◽  
...  

Abstract Introduction:TIGIT (T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif [ITIM] domain) is an inhibitory immunoreceptor expressed by T and natural killer (NK) cells that is an important regulator of anti-tumor and anti-viral immunity. TIGIT shares its high-affinity ligand PVR (CD155) with the activating receptor CD226 (DNAM-1). We have recently shown that TIGIT blockade, together with PD-L1/PD-1 blockade, provides robust efficacy in syngeneic tumor and chronic viral infection models. Importantly, CD226 blockade abrogates the benefit of TIGIT blockade, suggesting additional benefit of TIGIT blockade through elaboration of CD226-mediated anti-tumor immunity, analogous to CTLA-4/CD28 regulation of T-cell immunity. Whether TIGIT and CD226 are expressed in patients with multiple myeloma (MM) and how TIGIT expression relates to PD-L1/PD-1 expression is unknown. Here we evaluate expression of TIGIT, CD226, PD-1 and PD-L1 in patients with MM to inform novel immunotherapy combinations. Methods:We performed multi-color flow cytometry (n = 25 patients), and multiplex qRT-PCR (n = 7) on bone marrow specimens from patients with MM to assess expression of TIGIT, CD226, PD-1, and PD-L1 on tumor and immune cells. Cells were stained with fluorescently conjugated monoclonal antibodies to label T cells (CD3, CD4, CD8), NK cells (CD56, CD3), plasma cells (CD38, CD45, CD319, CD56), inhibitory/activating receptors (PD-1, TIGIT, PD-L1, CD226), and an amine-reactive viability dye (7-AAD). Stained and fixed cells were analyzed by flow cytometry using BD FACSCanto™ and BD LSRFortessa™. Results:TIGIT, CD226 and PD-L1/PD-1 were detectable by flow cytometry in all patients with MM who were tested, with some overlapping and distinct expression patterns. TIGIT was commonly expressed by marrow-infiltrating CD8+ T cells (median, 65% of cells), CD4+ T cells (median, 12%) and NK cells. In contrast, CD226 was more commonly expressed by marrow-infiltrating CD4+ T cells (median, 74%) compared with CD8+ T cells (median, 38%). PD-1 was expressed by marrow-infiltrating CD8+ T cells (median 38%) and CD4+ T cells (median, 16%). TIGIT was co-expressed with PD-1 on CD8+ T cells (67%-97% TIGIT+ among PD-1+), although many PD-1-negative CD8+ T cells also expressed TIGIT (39%-78% of PD-1-negative). PD-L1 was also expressed by CD8+ (median, 23%) and CD4+ (median, 8%) T cells in addition to MM plasma cells (median, 95%), albeit with significantly lower intensity on T cells compared with plasma cells. The expression of TIGIT and PD-L1 mRNA was highly correlated (R2 = 0.80). Analysis of PVR expression will also be presented. Conclusions: TIGIT, CD226, PD-1, and PD-L1 were commonly expressed in MM bone marrow, but with different patterns. Among CD8+ T cells, the frequency of TIGIT+ T cells was almost twice that of PD-1+ T cells, whereas the majority of CD4+ T cells expressed CD226. TIGIT blockade may complement anti-PD-L1/PD-1 immunotherapy by activating distinct T-cell/NK-cell subsets with synergistic clinical benefit. These results provide new insight into the immune microenvironment of MM and rationale for targeting both the PD-L1/PD-1 interaction and TIGIT in MM. Disclosures Yadav: Genentech, Inc.: Employment. Green:Genentech, Inc.: Employment. Ma:Genentech, Inc.: Employment. Robert:Genentech, Inc.: Employment. Glibicky:Makro Technologies Inc.: Employment; Genentech, Inc.: Consultancy. Nakamura:Genentech, Inc.: Employment. Sumiyoshi:Genentech, Inc.: Employment. Meng:Genentech, Inc.: Employment, Equity Ownership. Chu:Genentech Inc.: Employment. Wu:Genentech: Employment. Byon:Genentech, Inc.: Employment. Woodard:Genentech, Inc.: Employment. Adamkewicz:Genentech, Inc.: Employment. Grogan:Genentech, Inc.: Employment. Venstrom:Roche-Genentech: Employment.


Cancers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 4647
Author(s):  
Elisa Catafal-Tardos ◽  
Maria Virginia Baglioni ◽  
Vasileios Bekiaris

In recent years, checkpoint inhibitor (CPI) therapy has shown promising clinical responses across a broad range of cancers. However, many patients remain unresponsive and there is need for improvement. CPI therapy relies on antibody-mediated neutralization of immune inhibitory or checkpoint receptors (ICRs) that constitutively suppress leukocytes. In this regard, the clinical outcome of CPI therapy has primarily been attributed to modulating classical MHC-restricted αβ T cell responses, yet, it will inevitably target most lymphoid (and many myeloid) populations. As such, unconventional non-MHC-restricted gamma delta (γδ) T, mucosal associated invariant T (MAIT) and natural killer T (NKT) cells express ICRs at steady-state and after activation and may thus be affected by CPI therapies. To which extent, however, remains unclear. These unconventional T cells are polyfunctional innate-like lymphocytes that play a key role in tumor immune surveillance and have a plethora of protective and pathogenic immune responses. The robust anti-tumor potential of γδ T, MAIT, and NKT cells has been established in a variety of preclinical cancer models and in clinical reports. In contrast, recent studies have documented a pro-tumor effect of innate-like T cell subsets that secrete pro-inflammatory cytokines. Consequently, understanding the mechanisms that regulate such T cells and their response to CPI is critical in designing effective cancer immunotherapies that favor anti-tumor immunity. In this Review, we will discuss the current understanding regarding the role of immune checkpoint regulation in γδ T, MAIT, and NKT cells and its importance in anti-cancer immunity.


2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A249-A250
Author(s):  
Yilun Deng ◽  
Harshita Gupta ◽  
Myrna Garcia ◽  
Aravind Kancharla ◽  
Ryan Reyes ◽  
...  

BackgroundAging is the biggest risk factor for cancer, yet there are limited pre-clinical/clinical data regarding aging effects on immune checkpoint (IC) inhibition (ICI) outcomes. αPD-1 can potentially block PD-L1 and PD-L2 while αPD-L1 can block PD-1 and CD80. Melanoma response to αPD-1/αPD-L1 correlates with CD8+TCF-1+ T cell stem cell (TCSC) generation.1 Lack of host IL-17 can lead to increased IFN-γ production.2 3MethodsWe tested αPD-1 (200 μg/mouse), αPD-L1 (100 μg/mouse) or αPD-L2 (200 μg/mouse) in aged (18–33 months) and young (3–8 months) mice challenged orthotopically with B16 (WT or PD-L1ko) or TPN61R melanoma (NRAS mutation melanoma model)4 (αPD-L2 only) (SQ). Tumors were analyzed by flow. We tested αPD-L2 (20 μg/ml) effects by co-culturing young or aged T cells ± young or aged myeloid cells.ResultsWe reported that αPD-1 treats young and aged with B16 whereas αPD-L1 treats young not aged.5 αPD-L2 treated B16 and TPN61R melanoma in aged but, remarkably, not young, the first single agent anti-cancer immunotherapy exhibiting this property (figure 1). B16 tumors from aged had differential IC content (PD-1, PD-L1, CD80, PD-L2) versus tumors from young (e.g., more PD-L2+ tumor and stroma cells in aged mice; figure 2). Efficacy in young (αPD-1, αPD-L1) and aged (αPD-L2) correlated with increased tumor TCSC content (figure 3). αPD-L2 efficacy against B16 in aged mice required host IFN-γ and IL-17 (figure 4). αPD-1 efficacy against B16 in aged appeared to be host and tumor PD-L1 independent (figure 5). PD-L1KO B16 response to αPD-1 in aged also correlated with increased tumor TCSC content. Myeloid cell PD-L2 signaling inhibited aged but not young CD8+ T cell IL-2 production in vitro (figure 6).Abstract 234 Figure 1Abstract 234 Figure 2Abstract 234 Figure 3Abstract 234 Figure 4Abstract 234 Figure 5Abstract 234 Figure 6ConclusionsTreatment differences in aged versus young could depend on IC, TCSC and/or host cytokine differences (IL-17/IFN-γ). αPD-1 efficacy in aged PD-L1KO mice challenged with PD-L1KO B16 suggests that PD-L2 block is sufficient for αPD-1 efficacy in aged. PD-L2 expression differences in the tumor microenvironment could also contribute to treatment efficacy differences. PD-L2 inhibitory signaling on aged but not young CD8+ T cells is a likely mechanism for αPD-L2 efficacy in aged but not young. We are now testing the role of IL-17 in αPD-L2 efficacy as it could be upstream of IFN-γ effects, and TCSC effects in aged versus young. Our work can improve cancer immunotherapy in aged hosts and provides insights into treatment failure, including in young hosts.AcknowledgementsSouth Texas MSTP training grant (NIH T32GM113896), TL1TR002647, NIH T32AI138944, R01 CA231325, Waxman Grant, UL1 TR001120ReferencesMiller BC, Sen DR, Al Abosy R, Bi K, Virkud YV, LaFleur MW, Yates KB, Lako A, Felt K, Naik GS, et al. Subsets of exhausted CD8(+) T cells differentially mediate tumor control and respond to checkpoint blockade. Nat Immunol 2019;20(3):326–336.Moroda M, Takamoto M, Iwakura Y, Nakayama J, Aosai F. Interleukin-17A-deficient mice are highly susceptible to toxoplasma gondii infection due to excessively induced T. gondii HSP70 and interferon gamma production. Infection and immunity 2017;85(12):e00399–00317.Yi T, Zhao D, Lin C-L, Zhang C, Chen Y, Todorov I, LeBon T, Kandeel F, Forman S, Zeng D. Absence of donor Th17 leads to augmented Th1 differentiation and exacerbated acute graft-versus-host disease. Blood, The Journal of the American Society of Hematology 2008;112(5):2101–2110.Burd CE, Liu W, Huynh MV, Waqas MA, Gillahan JE, Clark KS, Fu K, Martin BL, Jeck WR, Souroullas GP. Mutation-specific RAS oncogenicity explains NRAS codon 61 selection in melanoma. Cancer discovery 2014;4(12):1418–1429.Padron A, Hurez V, Gupta HB, Clark CA, Pandeswara SL, Yuan B, Svatek RS, Turk MJ, Drerup JM, Li R, et al. Age effects of distinct immune checkpoint blockade treatments in a mouse melanoma model. Exp Gerontol 2018;105:146–154.Ethics ApprovalAll animal studies are approved by UTHSA IACUC.


2021 ◽  
Vol 11 ◽  
Author(s):  
Philipp Adams ◽  
Gilles Iserentant ◽  
Jean-Yves Servais ◽  
Linos Vandekerckhove ◽  
Guido Vanham ◽  
...  

Antiretroviral therapy (ART) is not curative as HIV-1 persists in long-lived viral reservoirs. Consequently, patients are dependent on life-long drug adherence with possible side effects. To overcome these limitations strategies of a functional cure aim at ART free viral remission. In this study, we sought to identify detailed subsets of anti-viral CD8+ T cell immunity linked to natural long-term control of HIV-1 infection. Here, we analyzed HIV controllers and ART suppressed progressors for in vitro viral suppressive capacity (VSC) at baseline and after peptide stimulation. Functional properties and phenotypes of CD8+ T cells were assessed by IFN-γ ELISPOT and 18 color flow cytometry. HIV controllers showed significantly increased suppression at baseline as well as after peptide stimulation. IFN-γ secretion and the proliferation marker Ki67 positively correlated with VSC. Moreover, the detailed phenotype of three distinct multifunctional memory CD8+ T cell subsets were specific traits of HIV controllers of which two correlated convincingly with VSC. Our results underline the importance of multifunctional CD8+ T cell responses during natural control. Especially the role of CXCR5 expressing cytotoxic subsets emphasizes potential surveillance in sites of reservoir persistence and demand further study.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3241-3241
Author(s):  
Minsuk Kwon ◽  
Eui-Cheol Shin ◽  
Yoon Seok Choi

Programmed cell death (PD)-1/PD-Ligand 1(PD-L1) blockade that reinvigorates exhausted T cells has been approved for the treatment of various solid tumors and hematological malignancies. However, in a clinical trial of multiple myeloma (MM) patients, anti-PD-1 monotherapy did not result in a clinical response. Furthermore, clinical trials of combining PD-1 blockade with immunomodulatory drugs or anti-CD38 monoclonal antibody failed to demonstrate clinical benefits in MM patients. To overcome the limitation of anti-PD-1 therapy in MM, the phenotype and differentiation of CD8+ T cells need to be characterized in the bone marrow (BM) of MM patients, particularly by analyzing myeloma antigen-specific CD8+ T cells. In addition, the role of immunosuppressive factors abundant in the MM microenvironment should be considered, including TGF-β. First, we confirmed the upregulation of PD-1 and PD-L1 expression in CD8+ T cells and myeloma cells, respectively, from the BM of MM patients. PD-1-expressing CD8+ T cells from the BM of MM patients co-expressed other checkpoint inhibitory receptors including Tim-3, LAG-3, and TIGIT. We also investigated the expression of T-cell transcription factors, such as T-bet, and EOMES, which are related to T-cell differentiation. In BM from MM patients, PD-1+CD8+ T cells had a higher percentage of EomeshiT-betlo cells than PD-1-CD8+ T cells. These data demonstrate that PD-1-expressing CD8+ T cells from the BM of MM patients exhibit a terminally differentiated phenotype with co-expression of multiple immune checkpoint inhibitory receptors. These results were also observed in BM CD8+ T cells specific to myeloma antigens NY-ESO-1 and HM1.24. Next, we investigated proliferation and cytokine production of BM CD8+ T cells from MM patients. BM CD8+ T cells from MM patients exhibited reduced proliferation and cytokine production upon T cell receptor (TCR) stimulation, compared to BM CD8+ T cells from other control group such as of undetermined significance. However, both anti-PD-1 alone and combined blockade of PD-1 with other immune checkpoint receptors, such as Tim-3, Lag-3, or TIGIT, did not increase the proliferation of BM CD8+ T cells from MM patients. Likewise, anti-PD-1 treatment failed to induce reinvigoration of BM CD8+ T cells stimulated with HLA-A*0201-restricted myeloma antigen peptides, including NY-ESO-1157-165 and HM1.2422-30 peptides. These data demonstrate that blocking PD-1 is not sufficient to restore the function of BM CD8+ T cells from MM patients. It has been known that TGF-β, which is actively secreted by malignant plasma cells and BM stromal cells, can inhibit T-cell responses. We confirmed that the major source of TGF- β1 is plasma cells including myeloma cells among BMMCs from MM patients, and the number of TGF- β1-producing plasma cells, including myeloma cells, is increased in the BM of MM patients. We investigated whether blocking TGF-β signaling enhances reinvigoration of BM CD8+ T cells from MM patients. The combined blockade of PD-1 and TGF- β significantly increased the proliferation of BM CD8+ T cells from MM patients in the presence of TCR stimulation. The production of IFN-γ and TNF by BM CD8+ T cells was also rescued by combined blockade of PD-1 and TGF-β. Moreover, combination of anti-PD-1 antibody and TGF-β inhibitors increased proliferative responses of BM CD8+ T cells from HLA-A2+ MM patients stimulated with a mixture of HLA-A*0201-restricted myeloma antigen peptides (NY-ESO-1157-165 and HM1.2422-30 peptides). Thus, PD-1 blockade reinvigorates BM CD8+ T cells from MM patients in the presence of TGF-β inhibitors. Taken together, BM CD8+ T cells and myeloma antigen-specific CD8+ T cells express increased levels of PD-1 and have a terminally exhausted phenotype in MM patients. Under TGF-β inhibition, anti-PD-1 reinvigorates BM CD8+ T cells from MM patients, but PD-1 blockade alone does not restore the function of BM CD8+ T cells. Blocking both TGF-β and PD-1 can be a promising therapeutic strategy for the treatment of MM. Disclosures No relevant conflicts of interest to declare.


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