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In allogeneic hematopoietic stem cell transplantation (HSCT), controlling graft-versus-host disease (GVHD) while maintaining graft-versus-tumor (GVT) responses is of critical importance. Using a mouse model of allogeneic HSCT, we hereby demonstrate that NKG2D expression by CD8(+) T cells plays a major role in mediating GVHD and GVT effects by promoting the survival and cytotoxic function of CD8(+) T cells. The expression of NKG2D ligands was not induced persistently on normal tissues of allogeneic HSCT-recipient mice treated with anti-NKG2D antibody, suggesting that transient NKG2D blockade might be sufficient to attenuate GVHD and allow CD8(+) T cells to regain their GVT function. Indeed, short-term treatment with anti-NKG2D antibody restored GVT effects while maintaining an attenuated GVHD state. NKG2D expression was also detected on CD8(+) T cells from allogeneic HSCT patients and trended to be higher in those with active GVHD. Together, these data support a novel role for NKG2D expression by CD8(+) T cells during allogeneic HSCT, which could be potentially therapeutically exploited to separate GVHD from GVT effects.

Resistance to immunotherapy is one of the biggest problems of current oncotherapeutics. While T cell abundance is essential for tumor responsiveness to immunotherapy, factors that define the T cell-inflamed tumor microenvironment are not fully understood. We used an unbiased approach to identify tumor-intrinsic mechanisms shaping the immune tumor microenvironment (TME), focusing on pancreatic adenocarcinoma because it is refractory to immunotherapy and excludes T cells from the TME. From human tumors, we identified ephrin-A receptor 2 (EPHA2) as a candidate tumor-intrinsic driver of immunosuppression. Epha2 deletion reversed T cell exclusion and sensitized tumors to immunotherapy. We found that prostaglandin endoperoxide synthase 2 (PTGS2), the gene encoding cyclooxygenase- 2, lies downstream of EPHA2 signaling through TGF-[beta] and is associated with poor patient survival. Ptgs2 deletion reversed T cell exclusion and sensitized tumors to immunotherapy; pharmacological inhibition of PTGS2 was similarly effective. Thus, EPHA2/PTGS2 signaling in tumor cells regulates tumor immune phenotypes; blockade may represent a therapeutic avenue for immunotherapy-refractory cancers. Our findings warrant clinical trials testing the effectiveness of therapies combining EPHA2/TGF-[beta]/PTGS2 pathway inhibitors with antitumor immunotherapy and may change the treatment of notoriously therapy-resistant pancreatic adenocarcinoma., Introduction Immunotherapies, including immune checkpoint blockade (ICB), have led to significant improvement of clinical care for cancer patients (1-4). Patients with melanoma, lung adenocarcinoma, or kidney cancer have a 20%-40% [...]

BACKGROUND. We conducted a phase I clinical trial that infused CCR5 gene-edited [CD4.sup.+] T cells to determine how these T cells can better enable HIV cure strategies. METHODS. The aim of trial was to develop RNA-based approaches to deliver zinc finger nuclease (ZFN), evaluate the effect of CCR5 gene-edited [CD4.sup.+] T cells on the HIV-specific T cell response, test the ability of infused CCR5 gene- edited T cells to delay viral rebound during analytical treatment interruption, and determine whether individuals heterozygous for CCR5 [DELTA]32 preferentially benefit. We enrolled 14 individuals living with HIV whose viral load was well controlled by antiretroviral therapy (ART). We measured the time to viral rebound after ART withdrawal, the persistence of CCR5-edited [CD4.sup.+] T cells, and whether infusion of 10 billion CCR5-edited [CD4.sup.+] T cells augmented the HIV-specific immune response. RESULTS. Infusion of the [CD4.sup.+] T cells was well tolerated, with no serious adverse events. We observed a modest delay in the time to viral rebound relative to historical controls; however, 3 of the 14 individuals, 2 of whom were heterozygous for CCR5 [DELTA]32, showed post-viral rebound control of viremia, before ultimately losing control of viral replication. Interestingly, only these individuals had substantial restoration of HIV-specific [CD8.sup.+] T cell responses. We observed immune escape for 1 of these reinvigorated responses at viral recrudescence, illustrating a direct link between viral control and enhanced [CD8.sup.+] T cell responses. CONCLUSION. These findings demonstrate how CCR5 gene-edited [CD4.sup.+] T cell infusion could aid HIV cure strategies by augmenting preexisting HIV-specific immune responses. REGISTRATION. ClinicalTrials.gov NCT02388594. FUNDING. NIH funding (R01AI104400, UM1AI126620, U19AI149680, T32AI007632) was provided by the National Institute of Allergy and Infectious Diseases (NIAID), the National Institute on Drug Abuse (NIDA), the National Institute of Mental Health (NIMH), and the National Institute of Neurological Disorders and Stroke (NINDS). Sangamo Therapeutics also provided funding for these studies., Introduction Prolonged HIV-1 infection results in massive [CD4.sup.+] T cell loss and profound immunodeficiency (1). Even with effective antiretroviral therapy (ART), the resident [CD4.sup.+] T cell response does not fully [...]

We report long-term clinical outcomes and immune responses observed from a phase 1 trial of agonist CD40 monoclonal antibody (mAb) and blocking CTLA-4 mAb in patients with metastatic melanoma. Twenty-four patients previously untreated with checkpoint blockade were enrolled. The agonistic CD40 mAb CP-870,893 and the CTLA-4 blocking mAb tremelimumab were dosed concomitantly every 3 weeks and 12 weeks, respectively, across four dose combinations. Two patients developed dose-limiting grade 3 immune-mediated colitis that led to the definition of the maximum tolerated dose (MTD). Other immune-mediated toxicity included uveitis (n = 1), hypophysitis (n = 1), hypothyroidism (n = 2), and grade 3 cytokine release syndrome (CRS) (n = 1). The estimated MTD was 0.2 mg/kg of CP-870,893 and 10 mg/kg of tremelimumab. In 22 evaluable patients, the objective response rate (ORR) was 27.3%: two patients (9.1%) had complete responses (CR) and four (18.2%) patients had partial responses (PR). With a median follow-up of 45 months, the median progression-free survival (PFS) was 3.2 months (95% CI, 1.3-5.1 months) and median overall survival (OS) was 23.6 months (95% CI, 11.7-35.5 months). Nine patients are long-term survivors (> 3 years), 8 of whom subsequently received other therapy including PD-1 mAb, surgery, or radiation therapy. Elevated baseline soluble CD25 was associated with shorter OS. Immunologically, treatment was associated with evidence of T cell activation and increased tumor T cell infiltration that was accomplished without therapeutic PD-1/PD-L1 blockade. These results suggest opportunities for immune activation and cancer immunotherapy beyond PD-1. [ABSTRACT FROM AUTHOR]

In allogeneic hematopoietic stem cell transplantation (HSCT), controlling graft-versus-host disease (GVHD) while maintaining graft-versus-tumor (GVT) responses is of critical importance. Using a mouse model of allogeneic HSCT, we hereby demonstrate that NKG2D expression by CD8+ T cells plays a major role in mediating GVHD and GVT effects by promoting the survival and cytotoxic function of CD8+ T cells. The expression of NKG2D ligands was not induced persistently on normal tissues of allogeneic HSCT-recipient mice treated with anti-NKG2D antibody, suggesting that transient NKG2D blockade might be sufficient to attenuate GVHD and allow CD8+ T cells to regain their GVT function. Indeed, short-term treatment with anti-NKG2D antibody restored GVT effects while maintaining an attenuated GVHC; state. NKG2D expression was also detected on CD8+ T cells from allogeneic HSCT patients and trended to be higher in those with active GVHD. Together, these data support a novel role for NKG2D expression by CD8+ T cells during allogeneic HSCT, which could be potentially therapeutically exploited to separate GVHD from GVT effects. [ABSTRACT FROM AUTHOR]