scholarly journals Regulating immune memory and reversing tumor thermotolerance through a step-by-step starving-photothermal therapy

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Lihua Luo ◽  
Bing Qin ◽  
Mengshi Jiang ◽  
Lin Xie ◽  
Zhenyu Luo ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
Cd8 T Cells ◽  
Photothermal Therapy ◽  
Cd8 T Cell ◽  
Immune Memory ◽  
In Situ Vaccine

Abstract Background Photothermal therapy (PTT) is a highly effective treatment for solid tumors and can induce long-term immune memory worked like an in situ vaccine. Nevertheless, PTT inevitably encounters photothermal resistance of tumor cells, which hinders therapeutic effect or even leads to tumor recurrence. Naïve CD8+ T cells are mainly metabolized by oxidative phosphorylation (OXPHOS), followed by aerobic glycolysis after activation. And the differentiate of effector CD8+ T cell (CD8+ Teff) into central memory CD8+ T cell (CD8+ TCM) depends on fatty acid oxidation (FAO) to meet their metabolic requirements, which is regulated by adenosine monophosphate activated protein kinase (AMPK). In addition, the tumor microenvironment (TME) is severely immunosuppressive, conferring additional protection against the host immune response mediated by PTT. Methods Metformin (Met) down-regulates NADH/NADPH, promotes the FAO of CD8+ T cells by activating AMPK, increases the number of CD8+ TCM, which boosts the long-term immune memory of tumor-bearing mice treated with PTT. Here, a kind of PLGA microspheres co-encapsulated hollow gold nanoshells and Met (HAuNS-Met@MS) was constructed to inhibit the tumor progress. 2-Deoxyglucose (2DG), a glycolysis inhibitor for cancer starving therapy, can cause energy loss of tumor cells, reduce the heat stress response of tumor cell, and reverse its photothermal resistance. Moreover, 2DG prevents N-glycosylation of proteins that cause endoplasmic reticulum stress (ERS), further synergistically enhance PTT-induced tumor immunogenic cell death (ICD), and improve the effect of immunotherapy. So 2DG was also introduced and optimized here to solve the metabolic competition among tumor cells and immune cells in the TME. Results We utilized mild PTT effect of HAuNS to propose an in situ vaccine strategy based on the tumor itself. By targeting the metabolism of TME with different administration strategy of 2DG and perdurable action of Met, the thermotolerance of tumor cells was reversed, more CD8+ TCMs were produced and more effective anti-tumor was presented in this study. Conclusion The Step-by-Step starving-photothermal therapy could not only reverse the tumor thermotolerance, but also enhance the ICD and produce more CD8+ TCM during the treatment. Graphical Abstract

scholarly journals Regulating Immune Memory and Reversing Tumor Thermotolerance through a Step-by-Step Starving-Photothermal therapy

2021 ◽  
Author(s):  
Lihua Luo ◽  
Bing Qin ◽  
Mengshi Jiang ◽  
Lin Xie ◽  
Zhenyu Luo ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
Cd8 T Cells ◽  
Photothermal Therapy ◽  
Aerobic Glycolysis ◽  
Cd8 T Cell ◽  
Immune Memory

Abstract Background: Photothermal therapy (PTT) is a highly effective treatment for solid tumorsand can induce long-term immune memory worked like an in situ vaccine. Nevertheless, PTT inevitably encounters photothermal resistance of tumor cells, which hinders therapeutic effect or even leads to tumor recurrence. Naïve CD8+T cells are mainly metabolized by oxidative phosphorylation (OXPHOS), followed by aerobic glycolysis after activation. And the differentiate of effector CD8+ T cell (CD8+Teff) into central memory CD8+ T cell (CD8+TCM) depends on fatty acid oxidation (FAO) to meet their metabolic requirements, which is regulated by adenosine monophosphate activated protein kinase (AMPK). In addition, the tumor microenvironment (TME) is severely immunosuppressive, confering additional protection against the host immune response mediated by PTT.Methods: Metformin (Met) down-regulates NADH/NADPH, promotes the FAO of CD8+T cells by activating AMPK, increases the number of CD8+TCM, which boosts the long-term immune memory of tumor-bearing mice treated with PTT. Here, a kind of PLGA microspheres co-encapsulated hollow gold nanoshells and Met (HAuNS-Met@MS) was constructed to inhibit the tumor progress. 2-Deoxyglucose (2DG), a glycolysis inhibitor for cancer starving therapy, can cause energy loss of tumor cells, reduce the heat stress response of tumor cell, and reverse its photothermal resistance. Moreover, 2DG prevents N-glycosylation of proteins that cause endoplasmic reticulum stress (ERS), further synergistically enhance PTT-induced tumor immunogenic cell death (ICD), and improve the effect of immunotherapy. So 2DG was also introduced and optimized here to solve the metabolic competition among tumor cells and immune cells in the TME.Results: We utilized mild PTT effect of HAuNS to propose an in situ vaccine strategy based on the tumor itself. By targeting the metabolism of TME with different administration strategy of 2DG and perdurable action of Met, the thermotolerance of tumor cells was reversed, more CD8+TCMs were produced and more effective anti-tumor was presented in this study.Conclusion: The Step-by-Step starving-photothermal therapy could not only reverse thetumor thermotolerance, but also enhance the ICD and produce more CD8+TCM during the treatment.

PD-1 up-regulation is correlated with HIV-specific memory CD8+ T-cell exhaustion in typical progressors but not in long-term nonprogressors

Blood ◽  
2007 ◽  
Vol 109 (11) ◽  
pp. 4671-4678 ◽  
Author(s):  
Ji-Yuan Zhang ◽  
Zheng Zhang ◽  
Xicheng Wang ◽  
Jun-Liang Fu ◽  
Jinxia Yao ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
Effector Memory ◽  
T Cell Exhaustion ◽  
Cell Exhaustion ◽  
Specific Memory ◽  
Memory Cd8 T Cell

Abstract The immunoreceptor PD-1 is significantly up-regulated on exhausted CD8+ T cells during chronic viral infections such as HIV-1. However, it remains unknown whether PD-1 expression on CD8+ T cells differs between typical progressors (TPs) and long-term nonprogressors (LTNPs). In this report, we examined PD-1 expression on HIV-specific CD8+ T cells from 63 adults with chronic HIV infection. We found that LTNPs exhibited functional HIV-specific memory CD8+ T cells with markedly lower PD-1 expression. TPs, in contrast, showed significantly up-regulated PD-1 expression that was closely correlated with a reduction in CD4 T-cell number and an elevation in plasma viral load. Importantly, PD-1 up-regulation was also associated with reduced perforin and IFN-γ production, as well as decreased HIV-specific effector memory CD8+ T-cell proliferation in TPs but not LTNPs. Blocking PD-1/PD-L1 interactions efficiently restored HIV-specific CD8+ T-cell effector function and proliferation. Taken together, these findings confirm the hypothesis that high PD-1 up-regulation mediates HIV-specific CD8+ T-cell exhaustion. Blocking the PD-1/PD-L1 pathway may represent a new therapeutic option for this disease and provide more insight into immune pathogenesis in LTNPs.

Generation of CD8 T Cell-Mediated Protective Immunity against Tumor Escapees

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2623-2623 ◽  
Author(s):  
Bindu Varghese ◽  
Behnaz Taidi ◽  
Adam Widman ◽  
James Do ◽  
R. Levy
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Tumor Growth ◽  
Tumor Cells ◽  
Cd8 T Cells ◽  
Cell Lymphoma ◽  
Ex Vivo ◽  
B Cell Lymphoma ◽  
Cd8 T Cell

Abstract Introduction: Anti-idiotype antibodies against B cell lymphoma have shown remarkable success in causing tumor regression in the clinic. In addition to their known ability to mediate ADCC, anti-idiotype antibodies have also been shown to directly inhibit the proliferation of tumor cells by sending negative growth signals via the target idiotype. However, further studies to investigate this mechanism have been hindered by the failure of patient tumor cells to grow ex vivo. Methods and Results: In order to study this phenomenon further, we developed an antibody against the idiotype on an A20 mouse B lymphoma cell line. A radioactive thymidine incorporation assay showed decreased A20 cell proliferation in the presence of the anti-id antibody ex vivo. In vivo, when mice were treated intraperitoneally (i.p.) with 100 μg of antibody 3 hours post-tumor inoculation (1×106 A20 subcutaneously (s.c.)), tumor growth was delayed for greater than 40 days after which the tumor began to grow once again. Further analysis of these escaping tumor cells by flow cytometry showed that that the tumor cells escaped the antibody-mediated immune response by down-regulating expression of idiotype and IgG on their surfaces although the cells retained idiotype expression intracellularly. This down-regulation of surface idiotype rendered the tumor cells resistant to both ADCC and signaling-induced cell death. The addition of an immunostimulatory bacterial mimic (CpG-DNA; 100 μg × 5 intratumoral (i.t.) injections; Days 2, 3 4, 6 & 8) to antibody therapy (Day 0; 100 μg i.p.) cured large established tumors (Day 0 = 1 cm2) and prevented the occurrence of tumor escapees (p<0.0001). Antibody plus CpG combination therapy in tumor-bearing mice deficient for CD8+ T cells demonstrated the critical role of CD8+ T cells in A20 tumor eradication (p<0.005). Depletion of CD4+ T cells was found to have no significant impact on the therapy. We also found that when mice were inoculated with two tumors and treated with anti-idiotype antibody (i.p.) followed by intratumoral CpG in just one tumor (Day 0=1 cm2; anti-idiotype antibody 100 μg Day 0; 100 μg CpG Days 2, 3, 4, 6 & 8), untreated tumors regressed just as well as CpG-treated tumors indicating a systemic anti-tumor immune response was generated. Conclusion: Anti-idiotype therapy, although effective in delaying tumor growth, frequently generates antigen-loss variants. However, we found that when anti-idiotype antibodies were combined with CpG, even large established tumors were cured due to systemic CD8+ T cell-dependent tumor immunity. Rather than simply mediating ADCC against a single tumor antigen, which requires the constant infusion of antibody to hamper tumor growth, we hypothesize a cytotoxic T-cell response against many tumor antigens was also generated. Such a diverse T-cell repertoire can prevent the emergence of tumor escapees and collectively provide long-lasting tumor protection. These pre-clinical results suggest that anti-tumor antibodies combined with CpG warrant further study in patients with B cell lymphoma.

scholarly journals Donor T Cells Maintain Myeloma-Immune Equilibrium after Autologous Stem Cell Transplantation and Concurrent Immunotherapy Promotes Cure

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2031-2031
Author(s):  
Simone A Minnie ◽  
David Smith ◽  
Kate H Gartlan ◽  
Thomas S Watkins ◽  
Kate A Markey ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Stem Cell Transplantation ◽  
Autologous Stem Cell Transplantation ◽  
Median Survival ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
Post Transplant

Abstract Autologous stem cell transplantation (ASCT) remains an important consolidation treatment for multiple myeloma (MM) patients, even in the era of novel agents. The prolongation of plateau-phase induced by ASCT is generally attributed to intensive cytoreduction. However, ASCT generates inflammation and profound lymphodepletion, which may result in hitherto unexpected immunological effects. To investigate potential immunological contributions to myeloma control after ASCT, we developed preclinical models of transplantation for MM using Vk*MYC myeloma that generates bony lytic lesions, a serum M band and marrow plasmacytosis that are hallmarks of clinical disease. Myeloma-bearing B6 recipients underwent myeloablative conditioning and were transplanted with naïve B6 bone marrow (BM) grafts with or without T cells from donors that were myeloma-naïve (SCT) or had low M bands at the time of harvest to mimic ASCT. Surprisingly, we demonstrate the broad induction of T cell-dependent myeloma control with enhanced median survival in recipients of grafts containing T cells compared to T cell depleted (TCD) BM alone (SCT= 91 days and ASCT > 100 days post-transplant vs TCD BM alone= 44 days; p<0.0001). Myeloma was most efficiently controlled when recipients were transplanted with memory T cells (CD44+) from autologous grafts (median survival: ASCT-CD44+ T cells >90 days post-transplant vs. CD44─ T cells = 50 days; p = 0.0006). Importantly, T cells adoptively transferred from recipients surviving > 120 days (MM-primed) protected secondary recipients compared to T cells from naïve donors (median survival: MM-primed > 120 days post-transplant vs 65 days naïve T cells; p = 0.0003). Furthermore, MM-primed CD8 T cells were restricted in TCR repertoire and provided protection in a myeloma clone-specific fashion, indicative of a tumor-specific T cell response. Despite this immune-mediated control of myeloma after SCT, progression still occurred in the majority of recipients. We phenotyped CD8+ T cells from the BM of MM-relapsed, MM-controlled and MM-free (that had never seen myeloma) mice 8 weeks after SCT. Expression of the inhibitory receptors, programmed cell death protein 1 (PD-1) and T cell immunoreceptor with Ig and ITIM domains (TIGIT) on BM CD8+ T-cells strongly correlated with myeloma cell number (r = 0.729, p<0.0001 and r = 0.796, p<0.0001 respectively). Additionally, the co-stimulatory/adhesion receptor CD226 (DNAM-1) was markedly downregulated as myeloma progressed (r = - 0.865, p<0.0001), as was interferon-γ secretion (r = - 0.76, p = 0.0022). t-SNE analysis confirmed an irreversible exhaustion signature at myeloma progression, characterized by the absence of DNAM-1 and co-expression of PD-1, TIM-3, TIGIT together with CD101 and CD38. Immune-checkpoint inhibition (CPI) early post-SCT, using antibodies against PD-1 or TIGIT facilitated long-term myeloma control (median survival in both treatment arms > 120 days post-SCT vs. 60 and 68 days respectively; p <0.05). Furthermore, TIGIT blockade limited CD8+ T cell exhaustion, increased CD107a and IFNγ secretion and expanded a memory CD8+ T cell population in the BM. Genetic deletion of either IFNγ or the IFNγ receptor from the donor graft resulted in dramatic myeloma progression after SCT. Consequently, treatment with a CD137 (4-IBB) agonist early after SCT profoundly augmented CD8+IFNγ+GranzymeB+ T-cell expansion in the BM, such that majority of treated animals eliminated myeloma and survived long-term. These data provide insights into an unappreciated mechanism of action of ASCT whereby myeloma immune-equilibrium is established and suggest that combination with immunotherapeutic strategies is a rational approach to generate long term disease control. Disclosures Smyth: Bristol Myers Squibb: Other: Research agreement; Tizona Therapeutics: Research Funding.

Combining Early Heat Shock Protein Vaccination with Directed IL-2 Leads to Effective Anti-Tumor Immunity in Autologous Hematopoietic Cell Transplantation Recipients

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 998-998
Author(s):  
Robert G. Newman ◽  
Eckhard R. Podack ◽  
Robert B. Levy
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
Cd8 T Cells ◽  
Hematopoietic Cell Transplantation ◽  
Cd8 T Cell ◽  
Tumor Bearing ◽  
Donor T Cells ◽  
Vaccine Site ◽  
Autologous Hematopoietic Cell Transplantation

Abstract Abstract 998 Tumor relapse is still the major cause of morbidity and mortality in patients with hematologic cancers that undergo aggressive chemo-radiotherapy followed by autologous hematopoietic cell transplantation (auto-HCT). Hence, there is a critical need for new anti-tumor therapies. Heat shock protein (HSP) based vaccines elicit innate and adaptive immune responses in murine studies and have shown promise in clinical trials. The pre-clinical studies here investigated the efficacy of vaccination with tumor cells secreting the HSP fusion gp96-Ig together with directed IL-2 in tumor bearing auto-HCT recipients. To mimic clinical T cell replete auto-HCT, transplanted donor T cells were obtained from congenic tumor bearing mice (C57BL/6 CD45.2+ CD90.1+) that had been previously inoculated intraperitoneally (ip) with 4×106 OVA expressing lymphoma cells (E.G7). Some of these donor mice received 0.5×106 CD8 T cells specific for OVA257–264 (OT-I) to allow for tumor antigen specific T cell monitoring. Three weeks later, T cells were harvested from these animals bearing progressively growing tumor for use in T cell replete auto-HCT. Recipient mice (C57BL/6 CD45.2+ CD90.2+) received 9.5 Gy TBI with subsequent infusion of 5×106 congenic T cell depleted bone marrow cells (C57BL/6 CD45.1+ CD90.2+) supplemented with 2×106 enriched T cells from the tumor bearing donors. The following day, recipients were inoculated ip with 1×105 viable E.G7 lymphoma cells. Based on our prior findings, a multiple vaccination protocol was employed utilizing 1×107 irradiated E.G7 cells transfected to secrete the HSP fusion gp96-Ig (E.G7-gp96-Ig). Some recipients were administered IL-2 via specific antibody-cytokine complexes comprised of IL-2 and αIL-2 mAb clone S4B6 (IL-2/αIL-2CD122). This specific IL-2 complex has been shown to interact with cells expressing the β chain (CD122) of the IL-2 receptor, such as memory CD8 T cells and NK cells, but not with cells expressing the α chain (CD25). Compared to recipients of T cell replete auto-HCT vaccinated with parental E.G7 tumor cells who exhibited virtually no increase in antigen-specific CD8 T cells, marked expansion was detected in the blood after 2 vaccinations with E.G7-gp96-Ig, i.e. within 1 week of auto-HCT. This response reached a plateau after 3 vaccinations, and persisted throughout the 5 vaccine protocol. To quantitate this vaccine induced CD8 T cell expansion, analysis of the vaccine site, splenic and lymph node compartments was performed following 3 vaccinations, i.e. 2 weeks post-HCT. In contrast to the modest 25× increase observed after vaccination with parental E.G7 cells, a 175× expansion was detected following E.G7-gp96-Ig vaccination (6.8×106 vs. 3.8×104 input). Moreover, 75% of these gp96-Ig expanded CD8 T cells at the vaccine site were bifunctional, expressing IFN-γ and TNF-α following antigen specific stimulation ex vivo. Strikingly, combined treatment with vaccine cells secreting gp96-Ig together with IL-2/αIL-2CD122 complex resulted in a 1000× enhancement of antigen specific CD8 T cell numbers in all compartments analyzed. Tumor bearing auto-HCT recipients exhibited a median survival time (MST) of 1 month if not vaccinated or if vaccinated with parental E.G7 cells (Figure). However, vaccination with E.G7-gp96-Ig extended the MST by more than 2 weeks and ∼20% of recipients survived long term (>100 days). This effect was dependent on T cells since gp96-Ig vaccination alone without donor T cells resulted in no MST extension. Combination therapy with tumor cells secreting gp96-Ig and IL-2/αIL-2CD122 complex markedly elevated total CD8 T cells as well as NK cells at the vaccine site and in secondary lymphoid tissues, two populations that have been shown to facilitate HSP based vaccines. Notably, this strategy resulted in a MST >100 days with ∼60% of mice surviving indefinitely. We propose that 3 components are required together with auto-HCT to avoid relapse related mortality: (1) transplanted autologous T cells, (2) a pan-antigen vaccination approach that induces potent antigen presentation and activation of multiple antigen specific T cells, i.e. tumor cells secreting gp96-Ig, and (3) an adjuvant that potentiates this vaccine induced response, i.e. IL-2 delivered in the form of an antibody-cytokine complex. In total, this combinatorial protocol represents a promising regimen that could be translated into the clinic for patients with hematologic cancers. Disclosures: Podack: Heat Biologics, Inc.: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding.

scholarly journals CD8 Effector T Cells Function Synergistically With Broadly Neutralizing Antibodies to Enhance Suppression of HIV Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
Rebecca T. Veenhuis ◽  
Caroline C. Garliss ◽  
Justin R. Bailey ◽  
Joel N. Blankson
Keyword(s):  
T Cells ◽  
T Cell ◽  
Viral Replication ◽  
Cd8 T Cells ◽  
Neutralizing Antibodies ◽  
Cd8 T Cell ◽  
Combinatorial Approach ◽  
Broadly Neutralizing Antibodies

HIV-specific CD8 T cells and broadly neutralizing antibodies (bNAbs) both contribute to the control of viremia, but in most cases, neither can completely suppress viral replication. To date, therapeutic vaccines have not been successful in eliciting HIV-specific CD8 T cell or bNAb responses that are capable of preventing long-term viral rebound upon ART cessation. These challenges suggest that a combinatorial approach that harnesses both bNAbs and CD8 T cell responses may be necessary for long term control of viral replication. In this study we demonstrate a synergistic interaction between CD8 T cells and bNAbs using an in vitro model. Our data suggest that this combinatorial approach is very effective at suppressing viral replication in vitro and should be considered in future therapeutic studies.

Donor CD8+ T Cells Mediate GVL without GVHD in Recipients Conditioned with Anti-CD3 mAb.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 192-192
Author(s):  
Chunyan Zhang ◽  
Jingwei Lou ◽  
Naninong Li ◽  
Ivan Todorov ◽  
Chia-Lei Lin ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cell Expansion ◽  
Critical Role ◽  
Cd8 T Cell ◽  
Effector Cells ◽  
T Cell Expansion ◽  
Marrow Cells

Abstract Donor CD8+ T cells play a critical role in mediating graft versus leukemia (GVL), but also induce graft versus host disease (GVHD) in recipients conditioned with total body irradiation (TBI). Here, we report that injections of donor C57BL/6 (H-2b) or FVB/N (H-2q) CD8+ T with bone marrow cells induced chimerism and eliminated BCL1 leukemia/lymphoma cells without GVHD in anti-CD3-conditioned BALB/c (H-2d) recipients. In contrast, the same dose of donor CD8+ T and marrow cells induced lethal GVHD in TBI-conditioned recipients. In addition, the anti-CD3-conditioned long-term complete chimeras without prior exposure to host-type BCL1 cells also eliminated the tumors when being challenged with BCL1 cells 120 days after HCT. This is in contrast to the report that long-term complete chimeras induced with delayed donor lymphocyte infusion lost GVL activity. Using in vivo and ex vivo bioluminescent imaging, we observed that donor CD8+ T cells expanded rapidly and infiltrated GVHD target tissues in TBI-conditioned recipients, but donor CD8+ T cell expansion in anti-CD3-conditioned recipients was confined to lympho-hematological tissues. This confinement was associated with lack of up-regulated expression of α4β7 integrin and chemokine receptors (i.e. CXCR3) on donor CD8+ T cells. In addition, host-reactive donor CD8+ T cells in anti-CD3-conditioned recipients were only partially deleted, and the residual cells were rendered heterogeneous: some unresponsive/anergic, some Tc2, some Foxp3+ suppressive cells, and some effector cells. The whole population of residual donor CD8+ T cells from anti-CD3-conditioned recipients mediated GVL without GVHD in TBI-conditioned secondary recipients. These results indicate that anti-CD3-conditioning separates GVL from GVHD via confining donor CD8+ T cell expansion to host lympho-hematological tissues as well as tolerization of the residual donor CD8+ T cells, in which the residual host-reactive effector cells mediate persistent GVL, and the regulatory CD8+ T cells prevent them from damaging host tissues.

Enforced Co-Stimulation and Co-Inhibitory Blockade Synergize to Enhance the Functions of Exhausted CTL

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1911-1911
Author(s):  
Barry Flutter ◽  
Noha Edwards ◽  
Lei Zhang ◽  
Shivajanani Sivakumaran ◽  
Michael Croft ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
Cd4 Cells ◽  
Isotype Control ◽  
Cd8 Cells ◽  
T Cell Transfer

Abstract Abstract 1911 A major limitation of adoptive T cell therapies for cancer is the failure to maintain durable anti-tumor immunity. Graft-versus-tumor responses following bone marrow transplantation (BMT) may only be short-lived due to 1) defects in memory precursor generation and 2) exhaustion of surviving CTL that results from direct recognition of alloantigen upon non-hematopoietic cells {Flutter et al. JCI 2010}. In this study, we have explored the potential for enhancing co-stimulatory signals either alone, or in combination with co-inhibitory PD-1-PD-L1 blockade to improve the long term CTL response. Signalling through OX40, a TNF-receptor family member, has been shown to have an important role in long-term immunity, including an enhancement in the generation of CD8 T cell memory precursors. The mechanisms of action are complex and may include both direct effects on CD8 cells and indirect effects on CD4 helper cells or via inhibition of Treg. In initial experiments, we evaluated the effects of early enforced OX40 co-stimulation following delayed transfer of donor T cells to haplo MHC-mismatched chimeras, 10 weeks following nonmyeloablative BMT. OX40 expression peaked on transferred CD4 and CD8 T cells in the first 1–2 weeks following transfer and was sustained thereafter, especially in the CD4 subset. 48 hours after T cell transfer, recipient mice were treated with agonistic anti-OX40 antibody (OX86) or isotype control. OX86 treatment led to a 9-fold increase in the expansion of CTL in comparison to isotype control treated mice, enhanced production of Granzyme B and IFNγ and led to more rapid eradication of host hematopoietic targets or host tumor cells. Moreover, OX86 antibody acted directly on CD8 T cells and bypassed the requirement for help from donor CD4 cells. However, although enforced OX40 co-stimulation boosted the primary effector response, it did not increase numbers of memory precursor cells, as assessed by survival and recall responses following transfer to antigen free hosts, and was unable to prevent eventual exhaustion of surviving donor CTL as tested at 60 days following transfer. Similarly, OX86 was unable to prevent exhaustion of CD8 cells transgenic for the male antigen-specific Matahari (Mh) TCR following adoptive transfer to male BMT recipients reconstituted with female BM. We have shown previously that the functions of exhausted donor CD8 cells are partially restored by blockade of the co-inhibitory PD-1 pathway in both haplo mismatched and MHC-matched mHAg mismatch models. We hypothesized that provision of co-stimulatory signals when exhaustion had become established would increase the effectiveness of co-inhibitory blockade. Therefore, 6 weeks after Mh CD8 T cell transfer to male BMT recipients, we examined the effect of OX86, with or without additional blockade of the PD-1 pathway. Only a minority of Mh CD8 cells from animals receiving isotype control antibody were proliferating in vivo as measured by BrdU incorporation over a 7 day pulse (20 +/−3% BrdU+) and few cells were able to produce IFNγ following antigen stimulation in vitro (3.5+/−1.4 x104 IFNγ+ cells/spleen). OX86 alone offered no restoration of function (15 +/− 2% BrdU+; 3.3+/−0.4 x104 IFNγ+ cells; p=ns). Blockade of PD-L1 modestly increased turnover of cells (37 +/− 6 % BrdU+; p<0.01 vs isotype), but in the absence of CD4 cells, did not significantly increase production of IFNγ (4.4+/−0.9 x104 IFNγ+ cells; p=ns). However, in vivo administration of OX86 combined with anti-PD-L1 blockade dramatically increased turnover of Mh CD8s (77 +/− 8% BrdU+; p<0.001 vs anti-PD-L1 alone, OX86 alone or Isotype) and enhanced their effector function ∼ 9-fold (27.4 +/− 6.8 x104 IFNγ+ cells/spleen; p<0.01 vs all others). In conclusion, forced co-stimulation via OX40 alone is unable either to prevent CTL exhaustion or restore CD8 T cell function when exhaustion has become established. In contrast, the marked synergy observed when agonistic OX40 signals are combined with co-inhibitory blockade, is consistent with a model in which the PD-1 pathway acts at a critical checkpoint that regulates the response to co-stimulation. Thus, these data suggest a novel approach to restoring the functions of exhausted anti-tumor CTL by modulating co-stimulatory and co-inhibitory pathways simultaneously. Disclosures: No relevant conflicts of interest to declare.

Improving efficacy of PD-1 blockade in unresponsive lymphoma tumors with in situ vaccination through induction of a highly efficient cross-presenting dendritic cell subset.

2018 ◽  
Vol 36 (5_suppl) ◽  
pp. 76-76
Author(s):  
Linda Hammerich ◽  
Maxime Dhainaut ◽  
Thomas A. Davis ◽  
Tibor Keler ◽  
Andres M. Salazar ◽  
...  
Keyword(s):  
T Cells ◽  
Tumor Cells ◽  
Cd8 T Cells ◽  
Tumor Regression ◽  
Low Grade ◽  
Dendritic Cell Subset ◽  
Term Survival ◽  
Intratumoral Injections

76 Background: Low-grade non-Hodgkin’s B-cell lymphomas are generally incurable; preliminary results with anti-PD-1 therapy have yielded low response rates. Tumoral DC infiltration correlates with efficacy of checkpoint blockade and tumor-targeted vaccines represent promising, novel treatment strategies to induce anti-tumor T cells. Methods: A20 lymphoma-bearing mice were treated with a PD-1 blocking antibody with an in situ vaccine (ISV) consisting of intratumoral injections of FMS-like tyrosine kinase-3 ligand (Flt3L), local irradiation (XRT) of the tumor and intratumoral injections of the TLR3 agonist poly-ICLC (pIC). Results: Untreated lymphoma tumors contained very low numbers of DC and treatment with anti-PD1 alone did not induce tumor regression or increase survival. Flt3L treatment resulted in a dramatic increase of IRF8+TLR3+ DC at the tumor site, the draining lymph node and the spleen. XRT of A20 cells induced activation of Flt3L-treated splenic DC in vitro and local XRT of the tumor in vivo induced expression of CD103 on infiltrating TLR3+ DC. Local XRT also enhanced uptake of dying tumor cells by DC. Interestingly, tumor antigens were taken up mainly by CD103+ DC and not CD103- subtypes. CD103+ expression distinguishes a subset of migratory cross-presenting DC. Accordingly, CD103+ DC isolated from the tumor induced proliferation of tumor-specific CD8+ T cells more efficiently than CD103- subsets. The combination of Flt3L with XRT and pIC induced tumor-reactive, IFNg-producing T cells, but delayed tumor growth and improved survival only in 40% of mice. ISV also increased expression of PD-L1 on tumor cells and tumor infiltrating DC. Consistently, combination of ISV with PD-1 blockade led to complete tumor regression and increased long-term survival in the majority of mice. PD-1 blockade also increased the number of tumor-reactive T cells and depletion of CD8+ T cells abrogated the anti-tumor effect. Conclusions: In situ vaccination can improve efficacy of anti-PD-1 in checkpoint-unresponsive lymphoma tumors through induction of a cross-presenting DC subset leading to long-term regression of established lymphoma tumors.

scholarly journals Depletion of CD4 T cells enhances immunotherapy for neuroblastoma after syngeneic HSCT but compromises development of antitumor immune memory

Blood ◽  
2009 ◽  
Vol 113 (18) ◽  
pp. 4449-4457 ◽  
Author(s):  
Weiqing Jing ◽  
Jill A. Gershan ◽  
Bryon D. Johnson
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Tumor Antigens ◽  
Cell Activity ◽  
Cd8 T Cell ◽  
Immune Memory ◽  
Hematopoietic Stem ◽  
Immunotherapeutic Approach

Abstract High-risk neuroblastoma remains a clinically challenging disease. Here, we report that a multifaceted immunotherapeutic approach including syngeneic hematopoietic stem cell transplantation (HSCT), adoptive transfer of sensitized T cells (from syngeneic donors vaccinated to tumor antigens), and early posttransplantation tumor vaccination can effectively treat mice with established neuroblastoma. Vaccination was an important component of this immunotherapy, as it resulted in enhanced and prolonged tumor-specific CD8 T-cell activity and improved antitumor efficacy. Surprisingly, CD4 cell depletion of mice given sensitized T cells resulted in better tumor-free survival, which was associated with an early increased expansion of CD8 T cells with an effector phenotype, increased numbers of tumor-reactive CD8 T cells, and increased tumor infiltration by CD8 T cells. However, in the absence of CD4 T cells, development of long-term tumor immunity (memory) was severely compromised as reflected by diminished CD8 T-cell recall responses and an inability to resist tumor rechallenge in vivo. Based on these results, a major challenge with this immunotherapeutic approach is how to obtain the ideal initial antitumor response but still preserve antitumor immune memory. These data suggest that identification and selective depletion of immune inhibitory CD4 T cells may be a strategy to enhance early antitumor immunity and induce a long-lasting tumor response after HSCT.

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