226 Checkpoint blockade hastens a switch from an NKT dominant, TNF-alpha-driven to a CD4+/CD8+ IFN-gamma-driven immune response within MC-38 tumor-infiltrating lymphocytes

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A244-A244
Author(s):  
Shota Aoyama ◽  
Ryosuke Nakagawa ◽  
Satoshi Nemoto ◽  
Patricio Perez Villarroel ◽  
James Mulé ◽  
...  

BackgroundIt is incompletely understood which populations of tumor-infiltrating lymphocytes (TIL) respond to checkpoint blockade (CB) and when. Recent studies in murine MC-38 colon carcinoma demonstrate CD4+ T cells are among the most prominent responders,1 but these studies were undertaken late in tumor growth, weeks after CB blockade was initiated. Here, we profile how the landscape of CB-responding TIL change between early and late MC-38 tumor growth, and uncover a novel switch that occurs between natural killer T (NKT) and conventional CD4/CD8 T cell responses.MethodsWe treated C57BL/6 mice bearing subcutaneous MC-38 tumors with anti-PD-1 and/or anti-CTLA-4 antibodies, and analyzed TIL 11 or 21 days later using a 23-paramter flow cytometry panel that includes three markers of effector function: TNF-alpha, IFN-gamma, and CD107a. We then investigated major populations, including NKT TIL, in ex vivo cytotoxicity assays and in vivo tumor growth studies using CD1d overexpressin MC-38 cells.ResultsOur analysis identified 37 TIL populations in MC-38 tumors, representing CD4+ or CD8+ T cells, natural killer (NK), and NKT cells. The distribution and effector function among TIL shift dramatically between early and late MC-38 growth. At 11 days, the immune response is dominated by TNF-alpha-producing NKT, which represent 53.5 ± 3.7% of all TIL. These are accompanied by modest frequencies of CD4+ and CD8+ TIL, producing low levels of IFN-gamma. After 21 days, NKT populations are reduced to 15.2 ± 1.5%, giving way to increased NK, CD4+, and CD8+ TIL, with increased IFN-gamma production. CB hastens this switch, markedly reducing NKT to less than 20% of all TIL, downregulating TNF-alpha production across NKT and CD4+ T cell subpopulations, increasing CD4+ and CD8+ TIL frequencies, and significantly up-regulating IFN-gamma production at 11 days. CD107a expression patterns suggest degranulation is most associated with NK and NKT TIL (figure 1). NKT displayed no CD1d-restricted cytotoxicity against MC-38 ex vivo. However, CD1d overexpression on MC-38 significantly delayed tumor growth in vivo, suggesting early NKT activity may indirectly suppress tumor progression, but by what precise mechanism(s) is currently unknown.Abstract 226 Figure 1t-SNE analysis of effector TIL populations identifies distinct, IFN-gamma and TNF-alpha-producing cells at early (day 11) and late (day 21) time points of subcutaneous MC38 growth. (a) Combined pseudocolored density plot of t-SNE parameters of viable, non-aggregated, CD45.2+, CD3+ and/or NK1.1+ cells from all time points and treatment conditions. (b) MFI values of clustering parameters from identified TIL populations were used in a hierarchical clustering analysis. Major clustering groups were then broadly identified as: TC, cytotoxic T cells; TH, helper T cells; gamma delta-like, gamma delta T cells or T cells clustering with gamma delta T cells; NK, natural killer cells; or O, other TIL. (c) Expression of effector molecules CD107a (top), IFN-gamma (middle), and TNF-alpha (bottom) among each identified TIL population. The extent of background signal for each effector molecule is denoted by a red-dashed FMO line. (d) A heat map of effector molecule MFIs overlaid onto the t-SNE analysis. (e) Analyses of TNF-alpha expression for P5 day 11. Included is the population location (upper left), TNF-alpha expression versus side-scatter (upper right), P5 frequency with check point blockade (lower left), and TNF-alpha MFI with check point blockade (lower right) (f) Analyses of IFN-gamma expression for P32 day 11. Included is the population location (upper left), IFN-gamma expression versus side-scatter (upper right), P32 frequency with check point blockade (lower left), and percent IFN-gamma with check point blockade (lower right).ConclusionsDespite evidence of an indirect benefit of early NKT activity, CB hastens a switch from TNF-alpha-driven NKT involvement toward a IFN-gamma-driven CD4+ and CD8+ T cell response in subcutaneous MC-38 tumors. These results corroborate earlier findings that CD4+ TIL are a major CB-responding population, and introduce a NKT/T cell switch that may be a key feature of the CB response in certain tumors.Ethics ApprovalAnimal experiments in this study were performed according to protocols approved by the University of South Florida’s institutional animal care and use committee (IACUC) committee, number R IS00005710.ReferenceWei S, Levine J, Coghill A, Zhao Y, Anang N, Andrews M, Sharma P, Wang J, Wargo J, Pe’er D, Allison J. Distinct cellular mechanisms underlie anti-CTLA-4 and anti-PD-1 checkpoint blockade. Cell 2017 Sep 7; 170(6): 1120–1133.e17.

2021 ◽  
Vol 9 (6) ◽  
pp. e002269
Author(s):  
Shota Aoyama ◽  
Ryosuke Nakagawa ◽  
Satoshi Nemoto ◽  
Patricio Perez-Villarroel ◽  
James J Mulé ◽  
...  

BackgroundThe temporal response to checkpoint blockade (CB) is incompletely understood. Here, we profiled the tumor infiltrating lymphocyte (TIL) landscape in response to combination checkpoint blockade at two distinct timepoints of solid tumor growth.MethodsC57BL/6 mice bearing subcutaneous MC38 tumors were treated with anti-PD-1 and/or anti-CTLA-4 antibodies. At 11 or 21 days, TIL phenotype and effector function were analyzed in excised tumor digests using high parameter flow cytometry. The contributions of major TIL populations toward overall response were then assessed using ex vivo cytotoxicity and in vivo tumor growth assays.ResultsThe distribution and effector function among 37 distinct TIL populations shifted dramatically between early and late MC38 growth. At 11 days, the immune response was dominated by Tumor necrosis factor alpha (TNFα)-producing NKT, representing over half of all TIL. These were accompanied by modest frequencies of natural killer (NK), CD4+, or CD8+ T cells, producing low levels of IFN-γ. At 21 days, NKT populations were reduced to a combined 20% of TIL, giving way to increased NK, CD4+, and CD8+ T cells, with increased IFN-γ production. Treatment with CB accelerated this switch. At day 11, CB reduced NKT to less than 20% of all TIL, downregulated TNFα across NKT and CD4+ T cell populations, increased CD4+ and CD8+ TIL frequencies, and significantly upregulated IFN-γ production. Degranulation was largely associated with NK and NKT TIL. Blockade of H-2kb and/or CD1d during ex vivo cytotoxicity assays revealed NKT has limited direct cytotoxicity against parent MC38. However, forced CD1d overexpression in MC38 cells significantly diminished tumor growth, suggesting NKT TIL exerts indirect control over MC38 growth.ConclusionsDespite an indirect benefit of early NKT activity, CB accelerates a switch from TNFα, NKT-driven immune response toward an IFN-γ driven CD4+/CD8+ T cell response in MC38 tumors. These results uncover a novel NKT/T cell switch that may be a key feature of CB response in CD1d+ tumors.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A438-A438
Author(s):  
Mara Shainheit ◽  
Devin Champagne ◽  
Gabriella Santone ◽  
Syukri Shukor ◽  
Ece Bicak ◽  
...  

BackgroundATLASTM is a cell-based bioassay that utilizes a cancer patient‘s own monocyte-derived dendritic cells and CD4+ and CD8+ T cells to screen their mutanome and identify neoantigens that elicit robust anti-tumor T cell responses, as well as, deleterious InhibigensTM.1 GEN-009, a personalized vaccine comprised of 4–20 ATLAS-identified neoantigens combined with Hiltonol®, harnesses the power of neoantigen-specific T cells to treat individuals with solid tumors. The safety and efficacy of GEN-009 is being assessed in a phase 1/2a clinical trial (NCT03633110).MethodsA cohort of 15 adults with solid tumors were enrolled in the study. During the screening period, patients received standard of care PD-1-based immunotherapies appropriate for their tumor type. Subsequently, patients were immunized with GEN-009 with additional doses administered at 3, 6, 12, and 24 weeks. Peripheral blood mononuclear cells (PBMCs) were collected at baseline, pre-vaccination (D1), as well as 29, 50, 92, and 176 days post first dose. Vaccine-induced immunogenicity and persistence were assessed by quantifying neoantigen-specific T cell responses in ex vivo and in vitro stimulation dual-analyte fluorospot assays. Polyfunctionality of neoantigen-specific T cells was evaluated by intracellular cytokine staining. Additionally, potential correlations between the ATLAS-identified profile and vaccine-induced immunogenicity were assessed.ResultsGEN-009 augmented T cell responses in 100% of evaluated patients, attributable to vaccine and not checkpoint blockade. Furthermore, neoantigen-induced secretion of IFNγ and/or TNFα by PBMCs, CD4+, and CD8+ T cells was observed in all patients. Responses were primarily from polyfunctional TEM cells and detectable in both CD4+ and CD8+ T cell subsets. Some patients had evidence of epitope spreading. Unique response patterns were observed for each patient with no apparent relationship between tumor types and time to emergence, magnitude or persistence of response. Ex vivo vaccine-induced immune responses were observed as early as 1 month, and in some cases, persisted for 176 days. Clinical efficacy possibly attributable to GEN-009 was observed in several patients, but no correlation has yet been identified with neoantigen number or magnitude of immune response.ConclusionsATLAS empirically identifies stimulatory neoantigens using the patient‘s own immune cells. GEN-009, which is comprised of personalized, ATLAS-identified neoantigens, elicits early, long-lasting and polyfunctional neoantigen-specific CD4+ and CD8+ T cell responses in individuals with advanced cancer. Several patients achieved clinical responses that were possibly attributable to vaccine; efforts are underway to explore T cell correlates of protection. These data support that GEN-009, in combination with checkpoint blockade, represents a unique approach to treat solid tumors.AcknowledgementsWe are grateful to the patients and their families who consented to participate in the GEN-009-101 clinical trial.Trial RegistrationNCT03633110Ethics ApprovalThis study was approved by Western Institutional Review Board, approval number 1-1078861-1. All subjects contributing samples provided signed individual informed consent.ReferenceDeVault V, Starobinets H, Adhikari S, Singh S, Rinaldi S, Classon B, Flechtner J, Lam H. Inhibigens, personal neoantigens that drive suppressive T cell responses, abrogate protection of therapeutic anti-tumor vaccines. J. Immunol 2020; 204(1 Supplement):91.15.


2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii111-ii111
Author(s):  
Lan Hoang-Minh ◽  
Angelie Rivera-Rodriguez ◽  
Fernanda Pohl-Guimarães ◽  
Seth Currlin ◽  
Christina Von Roemeling ◽  
...  

Abstract SIGNIFICANCE Adoptive T cell therapy (ACT) has emerged as the most effective treatment against advanced malignant melanoma, eliciting remarkable objective clinical responses in up to 75% of patients with refractory metastatic disease, including within the central nervous system. Immunologic surrogate endpoints correlating with treatment outcome have been identified in these patients, with clinical responses being dependent on the migration of transferred T cells to sites of tumor growth. OBJECTIVE We investigated the biodistribution of intravenously or intraventricularly administered T cells in a murine model of glioblastoma at whole body, organ, and cellular levels. METHODS gp100-specific T cells were isolated from the spleens of pmel DsRed transgenic C57BL/6 mice and injected intravenously or intraventricularly, after in vitro expansion and activation, in murine KR158B-Luc-gp100 glioma-bearing mice. To determine transferred T cell spatial distribution, the brain, lymph nodes, heart, lungs, spleen, liver, and kidneys of mice were processed for 3D imaging using light-sheet and multiphoton imaging. ACT T cell quantification in various organs was performed ex vivo using flow cytometry, 2D optical imaging (IVIS), and magnetic particle imaging (MPI) after ferucarbotran nanoparticle transfection of T cells. T cell biodistribution was also assessed in vivo using MPI. RESULTS Following T cell intravenous injection, the spleen, liver, and lungs accounted for more than 90% of transferred T cells; the proportion of DsRed T cells in the brains was found to be very low, hovering below 1%. In contrast, most ACT T cells persisted in the tumor-bearing brains following intraventricular injections. ACT T cells mostly concentrated at the periphery of tumor masses and in proximity to blood vessels. CONCLUSIONS The success of ACT immunotherapy for brain tumors requires optimization of delivery route, dosing regimen, and enhancement of tumor-specific lymphocyte trafficking and effector functions to achieve maximal penetration and persistence at sites of invasive tumor growth.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2623-2623 ◽  
Author(s):  
Bindu Varghese ◽  
Behnaz Taidi ◽  
Adam Widman ◽  
James Do ◽  
R. Levy

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.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3721-3721
Author(s):  
Yinmeng Yang ◽  
Christopher Daniel Chien ◽  
Elad Jacoby ◽  
Haiying Qin ◽  
Waleed Haso ◽  
...  

Abstract Adoptive therapy using T cells genetically engineered to express chimeric antigen receptors (CAR) has proven extremely effective against acute lymphoblastic leukemia (ALL) in clinical trials with the use of anti-CD19 CAR T cells. Most CAR T cell protocols use autologous T cells, which are then activated, transduced with the anti-CD19 CAR, and expanded ex-vivo before infusion back into the patient. This approach minimizes the risk of graft-versus-host disease (GVHD) even in allogeneic transplant recipients, due to tolerization of the donor T cell repertoire in the recipient. However, many patients have heavy disease burden and lymphopenia due to previous treatments, which makes the isolation of healthy T cells difficult. Thus, centers are exploring the potential of allogeneic T cell donors and the possibility of universal T cell donors for CAR-based therapy including the use of virus-specific T cells. In these cases, in addition to the chimeric receptor specificity, the transduced T cell population will also have reactivity against target antigens through the endogenous TCR. However, little is known about the impact of signaling of the endogenous TCR on CAR T cell activity, particularly in vivo. To test this, we used a syngeneic transplantable ALL murine model, E2aPBx, in which CD19 CAR T cells can effectively eradicate ALL. CD4 (Marilyn) and CD8 (Matahari) T cells from syngeneic HY-TCR transgenic donors specific for the minor histocompatibility male antigen, HY, were used as CAR T cell donors to control for endogenous TCR reactivity. Splenic T cells isolated from Matahari, Marilyn, or B6 mice were activated ex-vivo using anti-CD3/anti-CD28 beads, with the addition of IL2 and IL7. T cells were transduced with a retroviral vector expressing a murine CAR composed of anti-CD19 scfv/CD28/CD3ζ on days two and three. CAR T cells are evaluated in vitro by CD107a degranulation assay and INF gamma ELISA. In response to HY peptide alone or HY+CD19- line M39M, transduced CD8 HY (Matahari) cells produced IFN gamma and expressed CD107a whereas transduced CD4 HY (Marilyn) cells only produced IFN gamma. Interestingly, in response to CD19+HY- ALL, both Matahari and Marilyn expressed CD107a and produced IFN gamma indicating that CD4 T cells can acquire CD8-like lytic activity when stimulated through a CAR receptor. When CD19 CAR transduced Marilyns and Mataharis were stimulated in the presence of HY and CD19, CD8 Mataharis had an attenuated effect against CD19, suggesting that the presence of antigen activated TCR adversely affects the potency of the CAR receptor. Efficacy of the HY and polyclonal CAR T cells were next tested in-vivo in male and female B6 mice. Mice were given 1E6 E2aPBx ALL leukemia cells on day 1, and received 500 rads sub-lethal total body irradiation on day 4 as a lymphodepleting regimen. On day 5, mice were given a low (1E5) or high (5E6) dose of CAR T cells. There was a statistically significant (p=0.0177) improvement in the survival of female versus male mice after treatment with the CD4+ HY specific anti-CD19 CAR T cells, and female mice that received HY anti-CD19 CAR T cells survived longer than untreated control females (p=0.01). Remarkably, the survival of male mice that received HY anti-CD19 CAR T cells was statistically worse than untreated control males (p=0.008). This suggests that the presence of TCR antigen negatively impacts the function of CAR T cells. Furthermore, in a separate experiment using an equally mixed population of Marilyn (CD4+) and Matahari (CD8+) HY specific T cells, males has a statistically significantly (p=0.0116) worse survival compared to females after receiving 5E5 HY specific T cells. In conclusion, simultaneous stimulation through both CAR and TCR results in attenuated cytokine production and degranulation by CD8 T cells. In vivo, in the presence of the endogenous TCR antigen, both CD4 and CD8 CAR T cells are less potent at eradicating leukemia. These have implications for the development of universal donors for CAR T cell therapy. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1427-1427
Author(s):  
Suzanne L Tomchuck ◽  
Jin He ◽  
Ross W. Perko ◽  
Scarlett Evans ◽  
Amy McKenna ◽  
...  

Abstract Cord blood (CB) T cells are known to be naïve cells, but can be activated to respond similar to adult peripheral blood (PB) T cells. Reports indicate that culture with aminobisphosphonate (NBP) stimulates CB gamma delta T cell proliferation ex vivo, specifically the TCRγ9δ2 subset, which has been extensively studied in PB gamma delta T cells. As CB gamma delta T cells are not well described, we compared CB gamma delta T cell proliferation, phenotype and genotype to PB gamma delta T cells when culturing cells with the NBP, Zometa (zoledronic acid), and IL-2. Fourteen days in culture resulted in significant fold increase in the proliferation of gamma delta T cells and in the percent of lymphocytes in both sample types. PB gamma delta T cells proliferated more robustly than CB with a 288.60 versus 21.32 fold increase, respectively. Additionally, in freshly isolated samples, CB gamma delta T cells comprised an average of 1.404% of the lymphocyte population, which was similar to PB gamma delta T cells, with an average of 2.319%. However, by day 14, PB gamma delta T cells increased to 70.15% of lymphocytes whereas CB gamma delta T cells increased to 12.49%. Phenotypically, both CB and PB had similar percent of CD45RA+ and CD45RO+ gamma delta T cell memory subsets in freshly isolated samples. Following culture, PB gamma delta T cells were mostly CD45RO+ memory cells, with significantly fewer CD45RA+ naïve cells, whereas more CB gamma delta T cells were of the intermediate CD45RA+CD45RO+ subset. Further phenotypic analysis of the memory subsets indicated that cultured PB gamma delta T cells were either effector memory cells (CD27-CD45RA-) or central memory cells (CD27+CD45RA-), while CB gamma delta T cells were mostly naïve (CD27+CD45RA+). The cytokines secreted by these cells were also assessed and the culture of PB and CB gamma delta T cells resulted in differing cytokine secretion profiles. After 14 days of culture, PB gamma delta T cells secreted more IFNγ and TNFα, while CB gamma delta T cells secreted more IL-10 and RANTES. We also examined TCRγ9 and TCRδ2 phenotypic expression and found that the TCRγ9δ2 was a common clone in freshly isolated PB gamma delta T cells, which predominated after 14 days in culture. However, while the TCRγ9δ2 variant was expressed in CB gamma delta T cells, it was low before and after culture, suggesting that Zometa may not stimulate gamma delta T cells in CB the same as PB. As limited TCRγδ phenotypic reagents are available, we developed a single cell PCR assay for genotypic analysis of the TCRγδ repertoire. PCR analysis suggests that the TCRγδ repertoire is diverse in both samples, yet TCRγ9δ2 is most prevalent. Further analysis of the variant subsets is warranted and may give insight into how each of these receptor pairings affects function. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 468-468
Author(s):  
Steven C Goldstein ◽  
Bruce Levine ◽  
Jacqueline Smith ◽  
Joanne Hinkle ◽  
Selina Luger ◽  
...  

Abstract Enhancing the graft versus tumor (GvT) effect without graft versus host disease (GvHD) is critical to the success of reduced intensity (RIC) strategies for allogeneic transplantation. Despite establishing donor lymphohematopoiesis, relapse rates remain high. Standard DLI given at relapse or prophylactically to enhance donor chimerism has met with limited success in improving transplant outcomes. Co-stimulation of donor T-cells, using anti-CD3/CD28 coated beads to serve as artificial APCs (IND #6914), may reverse functional T cell tolerance, thereby restoring immune responsiveness, potentiate GVT, and maintain remission. Unlike standard DLI, ex vivo co-stimulation may indirectly enhance T cell activity by removing and activating T cells outside of a potentially tumor-induced immunosuppressive milieu. We report the preliminary results of a ‘first in humans’ feasibility trial of ex vivo co-stimulated (activated/expanded) DLI from sibling and unrelated donors given ‘prophylactically’ at 4 and 6 months after RIC, T-cell depleted, allogeneic transplantation for patients (pts) with high-risk hematologic malignancy. Methods: 15 pts have undergone RIC with alemtuzumab (100 mg SQ divided over D -9 to D-6), Fludarabine (30 mg/m2/d, D -6 to -3), Busulfan (0.8mg/kg IV Q6h D-4,-3) with peripheral blood stem cell transplantation (PBSCT) and planned activated DLI (pADLI) at 4 months (1 × 107 CD3+/kg recipient) and 6 months (1 × 108 CD3+/kg recipient) post-transplant in the absence of GvHD or relapse. All pts received tacrolimus and methotrexate as GvHD prophylaxis with initiation of rapid tacrolimus taper at ~d+40 and discontinuation before the infusion of pADLI#1. Results: 8 pts (AML, secondary n=2; CR2 n=3; CR1 n=1; ALL CR1 n=1; CR2 n=1) received grafts from HLA-identical sibling donors, 7 (AML, secondary n=3; CR2 n=1; CR1 n=1; MDS, n=1; ALL, CR2 n=1) from 6/6 matched unrelated donors. Donor hematopoiesis (□ 90%D) was established in all patients. The median is f/u 272 days, (range 25–424d). Exvivo co-stimulation and expansion was successful in all products, except in one instance where the second infusion fell below the targeted dose. Of the 11 infusions given to date (both fresh and cryopreserved), there has been no infusion-related side effects or toxicity, confirming the safety and feasibility of this novel strategy. 8 pts have received the first of 2 planned infusions of pADLI from their original donor. Of the remaining 7 pts, 4 infusions are upcoming, 1 was precluded by early relapse, and 2 were precluded by early non-relapse related mortality (1 GvHD with sepsis, 1 hepatic failure). Of the 8 pts who received their initial pADLI#1 at ~d+120 (range; d+119 – d +172), 3 have received a second infusion at ~d+180 (range; d+180 – d+237). 5 pts did not receive pADLI#2 because of relapse (n=3), GvHD (n=1), and transient uveitis in the absence of GvHD (n=1). Overall incidence of acute GvHD (aGvHD) has been low; only 1 pt developed aGvHD prior to pADLI#1, and only 1 pt developed aGvHD after pADLI #1. To date, no patient has developed chronic GvHD. T-cell functional assays performed on a DLI product from a CMV-positive unrelated donor before and after activation/expansion [analysis of proliferative capacity (CFSE assay) and interferon (IFN)-gamma secretion (ELISPOT)] suggest potential enhancement of immune function in the activated product. Using CMV, SEB, and autologous tumor as antigen, CD8 proliferation was increased after stimulation with all 3 antigens as well as media after activation of DLI, whereas a decrease in CD4 proliferation after activation was noted (except against SEB, as expected). Prior to activation/expansion, the number of effector cells secreting IFN-gamma in response to CMV or autologous tumor was below the threshold for a positive assay via ELISPOT (likely secondary to low levels of circulating CMV-specific T-cells); whereas a >10 fold increase in the number of effector cells/million was noted after activation/expansion in response to both CMV and autologous tumor. Serial functional analyses of recipient T-cells, before and after infusion of activated DLI, are underway. Conclusion: Preliminary results of this trial demonstrates that RIC with PBSCT followed by ex vivo costimulated pADLI for poor prognosis hematologic malignancies is safe and feasible with potential for enhancing GvT without increasing GvHD.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A915-A915
Author(s):  
Phuong Nguyen ◽  
Ryan Phennicie ◽  
Kevin Kauffman ◽  
Dominika Nowakowska ◽  
Mohammad Zafari ◽  
...  

BackgroundMacrophages play an important role in cancer by modulating both the innate and adaptive parts of the immune system. In non-pathological conditions, multiple subsets of macrophages balance the immune response. In cancer, M2-like immune-suppressive tumor-associated macrophages (TAMs) dominate the tumor microenvironment (TME). TAMs promote tumor growth, support neo-angiogenesis and enable metastasis formation. Macrophage modulators driving macrophage repolarization from the M2-like to a pro-inflammatory M1-like phenotype are an attractive novel class of cancer immunotherapy. Here we present identification, validation, and pre-clinical data of a novel macrophage checkpoint, PSGL-1, which supports targeting this molecule for immune-oncology.MethodsTo assess the therapeutic potential of using anti-PSGL-1 antibodies to convert macrophage phenotype and the tumor microenvironment toward a more inflammatory state, we employed in vitro primary macrophage and multi-cellular assays, ex vivo patient-derived tumor cultures, and a humanized mouse PDX model.ResultsWithin the multiple subsets of macrophages, PSGL-1 is expressed at high levels on immune-suppressive TAMs and in vitro differentiated M2 macrophages. We show that targeting PSGL-1 via an antagonistic antibody repolarized M2 macrophages to a more M1-like state, both phenotypically and functionally as assessed in primary in vitro macrophage assays. Further, these repolarized M1-like macrophages enhanced the inflammatory response in complex multi-cellular assays, including SEB stimulated PBMC assays and mixed-lymphocyte reactions (MLRs).To establish a pre-clinical proof-of-concept for targeting PSGL-1, we turned to ex vivo cultures of fresh patient-derived primary tumors, where the complexity of the TME can be most preserved. RNA-seq data show that ex vivo cultures treated with anti-PD-1 antibody recapitulate TME changes in anti-PD-1 treated patients, including a strong T-cell IFN-gamma signature and a reduction in oncogenic pathway activation. Blocking PSGL-1 resulted in a robust pro-inflammatory signature driven by TNF-alpha/NF-kappa-B and chemokine-mediated signaling. The increase in TNF-alpha signaling was accompanied by reduction in oxidative phosphorylation and fatty acid metabolism. The increase in pro-inflammatory cytokine and chemokine production was confirmed by measuring secreted protein levels, further confirming the re-polarization of macrophages within a tumor setting.Lastly, we employed a humanized mouse PDX model of melanoma and show that anti-PSGL-1 treatment resulted in suppression of tumor growth favorably compared to anti-PD-1. At the cellular and molecular levels, anti-PSGL-1 treatment lead to a more enhanced inflammatory microenvironment, including a reduced M2:M1 macrophage ratio, increased antigen presentation, pro-inflammatory mediators, and effector T cell infiltration and activation.ConclusionsOur data support anti-PSGL-1 as a macrophage repolarizing agent and an effective macrophage-targeted therapy for Immuno-Oncology.


Blood ◽  
1995 ◽  
Vol 86 (6) ◽  
pp. 2429-2438 ◽  
Author(s):  
M Sykes ◽  
GL Szot ◽  
PL Nguyen ◽  
DA Pearson

Interleukin-12 (IL-12) is a potent immunostimulatory cytokine and an inducer of type-1 T-helper cell activity and of cytotoxic T lymphocyte and natural killer cell function. We report here the paradoxical observation that a single injection of 4,900 IU of recombinant murine IL-12 inhibits acute graft-versus-host disease (GVHD) in a fully major histocompatibility complex (MHC) plus multiple minor antigen-mismatched bone marrow transplantation (BMT) model (A/J-->B10). The protective effect was enhanced by administration of T-cell-depleted host-type BM cells, and complete donor-type lymphohematopoietic reconstitution was observed in most animals. Treatment with a protective course of IL-12 led to increased serum interferon-gamma (IFN-gamma) levels as compared with those for GVHD controls at early time points, when IFN-gamma was produced predominantly by host-type natural killer cells, but led to almost complete inhibition of the later GVHD-associated increase in serum IFN-gamma levels, when IFN-gamma is produced predominantly by CD4+ T cells. Furthermore, IL-12 treatment was associated with marked alterations in the kinetics of donor T-cell expansion. Reductions in donor CD4+ and CD8+ T cells were observed in the spleen on day 4 post- BMT, but a marked increase in donor CD8+ cells was observed on day 7. Unlike broadly immunosuppressive methods for inhibiting GVHD, which are associated with loss of antileukemic effects, IL-12 has the potential to mediate antileukemic effects of its own; therefore, the GVHD- inhibitory effects of IL-12 described here suggest a potential application for this cytokine in clinical BMT.


2021 ◽  
Author(s):  
Shirin Lak ◽  
Valérie Janelle ◽  
Anissa Djedid ◽  
Gabrielle Boudreau ◽  
Ann Brasey ◽  
...  

AbstractBackgroundThe stimulation and expansion of antigen-specific T cells ex vivo enables the targeting of a multitude of cancer antigens. However, clinical scale T-cell expansion from rare precursors requires repeated stimulations ex vivo leading to T-cell terminal effector differentiation and exhaustion that adversely impact therapeutic potential. We leveraged immune checkpoint blockade relevant to antigen-specific CD8+ human T cells to improve the expansion and function of T cells targeting clinically relevant antigens.MethodsA clinically-compliant protocol relying on peptide-pulsed monocyte-derived dendritic cells and cytokines was used to expand antigen-specific CD8+ targeting the oncogenic Epstein-Barr virus (EBV) and the tumor associated antigen (TAA) Wilms Tumor 1 (WT1) protein. The effects of antibody-mediated blockade of immune checkpoints applied to the cultures (T-cell expansion, phenotypes and function) were assessed at various time points. Genomic studies including single cell RNA (scRNA) sequencing and T-cell receptor sequencing were performed on EBV-specific T cells to inform about the impact of immune checkpoint blockade on the clonal distribution and gene expression of the expanded T cells.ResultsSeveral immune checkpoints were expressed early by ex vivo expanded antigen-specific CD8+ T cells, including PD-1 and TIM-3 with co-expression matching evidence of T-cell dysfunction as the cultures progressed. The introduction of anti-PD-L1 (expressed by the dendritic cells) and anti-TIM-3 antibodies in combination (but not individually) to the culture led to markedly improved antigen-specific T-cell expansion based on cell counts, fluorescent multimer staining and functional tests. This was not associated with evidence of T-cell dysfunction when compared to T cells expanded without immune checkpoint blockade. Genomics studies largely confirmed these results, showing that double blockade does not impart specific transcriptional programs or patterns on TCR repertoires. However, our data indicate that combined blockade may nonetheless alter gene expression in a minority of clonotypes and have donor-specific impacts.ConclusionsThe manufacturing of antigen-specific CD8+ T cells can be improved in terms of yield and functionality using blockade of TIM-3 and the PD-L1/PD-1 axis in combination. Overcoming the deleterious effects of multiple antigenic stimulations through PD-L1/TIM-3 blockade is a readily applicable approach for several adoptive-immunotherapy strategies.


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