IL-7 producing immunotherapy improves ex vivo T cell functions of immunosenescent patients, especially post hip fracture.

Following acute stress such as trauma or sepsis, most of critically ill elderly patients become immunosuppressed and susceptible to secondary infections and enhanced mortality. We have developed a virus-based immunotherapy encoding human interleukin-7 (hIL-7) aiming at restoring both innate an adaptative immune homeostasis in these patients. We assessed the impact of this encoded hIL-7 on the ex vivo immune functions of T cells from PBMC of immunosenescent patients with or without hip fracture. T-cell ex vivo phenotyping was characterized in terms of senescence (CD57), IL-7 receptor (CD127) expression, and T cell differentiation profile. Then, post stimulation, activation status, and functionality (STAT5/STAT1 phosphorylation and T cell proliferation assays) were evaluated by flow cytometry. Our data show that T cells from both groups display immunosenescence features, express CD127 and are activated after stimulation by virotherapy-produced hIL-7-Fc. Interestingly, hip fracture patients exhibit a unique functional ability: An important T cell proliferation occurred compared to controls following stimulation with hIL-7-Fc. In addition, stimulation led to an increased naïve T cell as well as a decreased effector memory T cell proportions compared to controls. This preliminary study indicates that the produced hIL-7-Fc is well recognized by T cells and initiates IL-7 signaling through STAT5 and STAT1 phosphorylation. This signaling efficiently leads to T cell proliferation and activation and enables a T cell "rejuvenation." These results are in favor of the clinical development of the hIL-7-Fc expressing virotherapy to restore or induce immune T cell responses in immunosenescent hip fracture patients.

Intravenous injection of a novel viral immunotherapy encoding human interleukin-7 in nonhuman primates is safe and increases absolute lymphocyte count.

Persistence of an immunosuppression, affecting both the innate and adaptive arms of the immune system, plays a role in sepsis patients' morbidity and late mortality pointing to the need for broad and effective immune interventions. MVA-hIL-7-Fc is a non-replicative recombinant Modified Vaccinia virus Ankara encoding the human interleukin-7 fused to human IgG2 Fc fragment. We have shown in murine sepsis models the capacity of this new virotherapy to stimulate both arms of the immune system and increase survival. Herein, an exploratory study in nonhuman primates was performed following a single intravenous injection of the MVA-hIL-7-Fc used at the clinical dose to assess its safety and biological activities. Four cynomolgus macaques were followed for 3 weeks post-injection (p.i), without observed acute adverse reactions. Circulating hIL-7-Fc was detected during the first 3-5 days p.i with a detection peaking at 12 h p.i. IL-7 receptor engagement and downstream signal transduction were detected in T cells demonstrating functionality of the expressed IL-7. Expansion of blood lymphocytes, mainly CD4 and CD8 naïve and central memory T cells, was observed on day 7 p.i. together with a transient increase of Ki67 expression on T lymphocytes. In addition, we observed an increase in circulating B and NK cells as well as monocytes were albeit with different kinetics and levels. This study indicates that a vectorized IL-7-Fc, injected by intravenous route at a relevant clinical dose in a large animal model, is active without adverse reactions supporting the clinical development of this novel virotherapy for treatment of sepsis patients.

Viral Delivery of IL-7 Is a Potent Immunotherapy Stimulating Innate and Adaptive Immunity and Confers Survival in Sepsis Models.

Persistence of an immunosuppressive state plays a role in septic patient morbidity and late mortality. Both innate and adaptive pathways are impaired, pointing toward the need for immune interventions targeting both arms of the immune system. We developed a virotherapy using the nonpropagative modified vaccinia virus Ankara (MVA), which harbors the intrinsic capacity to stimulate innate immunity, to deliver IL-7, a potent activator of adaptive immunity. The rMVA-human IL-7 (hIL-7)-Fc encoding the hIL-7 fused to the human IgG2-Fc was engineered and shown to express a dimeric, glycosylated, and biologically active cytokine. Following a single i.v. injection in naive mice, the MVA-hIL-7-Fc increased the number of total and activated B, T, and NK cells but also myeloid subpopulations (Ly6Chigh, Ly6Cint, and Ly6Cneg cells) in both lung and spleen. It triggered differentiation of T cells in central memory, effector memory, and acute effector phenotypes and enhanced polyfunctionality of T cells, notably the number of IFN-γ-producing cells. The MVA vector contributed significantly to immune cell activation, particularly of NK cells. The MVA-hIL-7-Fc conferred a significant survival advantage in the cecal ligation and puncture (CLP) and Candida albicans sepsis models. It significantly increased cell numbers and activation in both spleen and lung of CLP mice. Comparatively, in naive and CLP mice, the rhIL-7-Fc soluble counterpart overall induced less vigorous, shorter lasting, and narrower immune activities than did the MVA-hIL-7-Fc and favored TNF-α-producing cells. The MVA-hIL-7-Fc represents a novel class of immunotherapeutic with clinical potential for treatment of septic patients.

Sequential administration of a MVA-based MUC1 cancer vaccine and the TLR9 ligand Litenimod (Li28) improves local immune defense against tumors.

TG4010 is an immunotherapeutic vaccine based on Modified Vaccinia virus Ankara (MVA) encoding the human tumor-associated antigen MUC1 and human IL-2. In combination with first-line standard of care chemotherapy in advanced metastatic non-small-cell lung cancer (NSCLC), repeated subcutaneous injection of TG4010 improved progression-free survival in phase 2b clinical trials. In preclinical tumor models, MVATG9931, the research version of TG4010, conferred antigen-specific responses against the weak antigen human MUC1. The combination of a suboptimal dose of MVATG9931 and the type B TLR9 ligand Litenimod (Li28) markedly increased survival in a subcutaneous RMA-MUC1 tumor model compared to the treatment with MVATG9931 or Li28 alone. The requirements for this protection were (i) de novo synthesis of MUC1, (ii) Li28 delivered several hours after MVATG9931 at the same site, (iii) at least two vaccination cycles, and (iv) implantation of MUC1-positive tumor cells in the vicinity to the vaccination site. Subcutaneously injected MVATG9931 allowed transient local gene expression and induced the local accumulation of MCP-1, RANTES, M-CSF, IL-15/IL-15R and IP-10. After repeated injection, CD4+ and CD8+ T lymphocytes, B lymphocytes, NK cells, pDCs, neutrophils, and macrophages accumulated around the injection site, local RANTES levels remained high. Delayed injection of Li28 into this environment, led to further accumulation of macrophages, the secretion of IL-18 and IL-1 beta, and an increase of the percentage of activated CD69+ NK cell. Combination treatment augmented the number of activated CD86+ DCs in the draining lymph nodes and increased the percentage of KLRG1+ CD127-CD8+ T cells at the injection site. In vivo depletion of macrophages around the injection site by Clodronate liposomes reduced local IL-18 levels and diminished survival rates significantly. Thus, sequential administration of MVATG9931 and Li28 improves local innate and adaptive immune defense against tumors, arguing for intratumoral delivery of this peculiar sequential combination therapy.

Lymphocytic infiltration in the cutaneous lymphoma microenvironment after injection of TG1042.

BACKGROUND: Primary cutaneous lymphomas (CLs), characterized by an accumulation of clonal T or B lymphocytes preferentially localized in the skin, have been successfully treated with interferons (IFNs) which counterbalance the Th2-immunosuppressive state associated with this pathology. In a phase I/II clinical trial, we correlated the local immune infiltrate and the anti-tumor effects of repeated intralesional administrations of an adenovirus vector expressing human interferon-gamma (IFN-g) termed TG1042, in patients with advanced primary cutaneous T-cell lymphomas (CTCL) or multilesional cutaneous B-cell lymphomas (CBCL). METHODS: For each patient, variation in time of specific lymphocyte populations, defined by immunohistochemical stainings, was assessed in biopsies of injected lesions. For each patient, the change in local immune response was associated with the patient's objective response at the end of the study. RESULTS: Immunohistochemical analyses of biopsies indicate that infiltration of CD8+ T lymphocytes and of TIA-1+ cytotoxic T-cells in lesions injected with TG1042 correlates with clinical benefit. CONCLUSIONS: These data suggest for the first time that a CD8+ cytotoxic infiltrate, induced by local expression of IFN-g correlates with a clinical response. TRIAL REGISTRATION: The phase I step (TG1042.01) does not have a registration number. The phase II step (TG1042.06) registration number was NCT00394693.