Interplay between plasmacytoid dendritic cells and tumor-specific T cells in peripheral blood influences long-term survival in non-small cell lung carcinoma.

Plasmacytoid dendritic cells (pDCs) represent a subset of antigen-presenting cells that play an ambivalent role in cancer immunity. Here, we investigated the clinical significance of circulating pDCs and their interaction with tumor-specific T cell responses in patients with non-small cell lung cancer (NSCLC, n = 126) . The relation between intratumoral pDC signature and immune checkpoint inhibitors efficacy was also evaluated. Patients with NSCLC had low level but activated phenotype pDC compared to healthy donors. In overall population, patients with high level of pDC (pDChigh) had improved overall survival (OS) compared to patients with pDClow, median OS 30.4 versus 20.7 months (P = 0.013). This clinical benefit was only observed in stage I to III patients, but not in metastatic disease. We showed that patients harboring pDChigh profile had high amount of Th1-diffentiation cytokine interleukin-12 (IL-12) in blood and had functional T cells directed against a broad range of tumor antigens. Furthermore, a high pDC signature in the tumor microenvironment was associated with improved clinical outcome in patients treated with anti-PD-(L)1 therapy. Overall, this study showed that circulating pDChigh is associated with long-term OS in NSCLC and highlighted the predictive value of intratumor pDC signature in the efficacy of immune checkpoint inhibitors.

Immune responses following tocilizumab therapy to desensitize HLA-sensitized kidney transplant candidates.

Kidney transplant candidates (KTCs) who are HLA highly sensitized (calculated panel-reactive alloantibodies >95%) have poor access to deceased kidney transplantation. In this single-center prospective study, 13 highly sensitized desensitization-naïve KTCs received IV tocilizumab (8 mg/kg) every 4 weeks. We evaluated tolerability as well as immune responses, that is, T cell, B cell, T follicular helper (Tfh) subsets, blood cytokines (IL-6, soluble IL-6 receptor-sIL-6R-, IL-21), blood chemokines (CXCL10, CXCL13), and anti-HLA alloantibodies. Tocilizumab treatment was well-tolerated except in one patient who presented spondylodiscitis, raising a note of caution. Regarding immune parameters, there were no significant changes of percentages of lymphocyte subsets, that is, CD3+ , CD3+ /CD4+ , CD3+ /CD8+ T cells, and NK cells. This was also the case for Tfh cell subsets, B cells, mature B cells, plasma cells, pre-germinal center (GC) B cells, and post-GC B cells, whereas we observed a significant increase in naïve B cells (p = .02) and a significant decrease in plasmablasts (p = .046) over the tocilizumab treatment course. CXCL10, CXCL13, IL-21, total IgG, IgA, and IgM levels did not significantly change during tocilizumab therapy; conversely, there was a significant increase in IL-6 levels (p = .03) and a huge increase in sIL-6R (p = .00004). There was a marginal effect on anti-HLA alloantibodies (class I and class II). To conclude in highly sensitized KTCs, tocilizumab as a monotherapy limited B cell maturation; however, it had almost no effect on anti-HLA alloantibodies.

Distinct prognostic value of circulating anti-telomerase CD4+ Th1 immunity and exhausted PD-1+/TIM-3+ T cells in lung cancer.

BACKGROUND: Despite the critical roles of Th1-polarised CD4+ T cells in cancer immunosurveillance, the translation of their potential to clinical use remains challenging. Here, we investigate the clinical relevance of circulating antitumor Th1 immunity in non-small cell lung cancer (NSCLC). METHODS: The circulating antitumor Th1 response was assessed by the ELISpot assay in 170 NSCLC patients using a mixture of HLA class II-restricted peptides from telomerase (TERT). Phenotyping of blood immune cells was performed by flow cytometry. RESULTS: TERT-reactive CD4 T-cell response was detected in 35% of NSCLC patients before any treatment. Functional analysis showed that these cells were effector memory and Th1 polarised capable to produce effector cytokines, such as IFN-γ, TNF-α and IL-2. The presence of anti-TERT Th1 response was inversely correlated with the level of exhausted PD-1+/TIM-3+CD4 T cells. The level of these two immune parameters differentially affected the survival, so that increased level of anti-TERT Th1 response and low rate of exhausted PD-1+TIM-3+CD4+ T cells were associated with a better prognosis. CONCLUSIONS: Systemic anti-TERT Th1 response plays a strong antitumor protective role in NSCLC. This study underlines the potential interest of monitoring circulating antitumor Th1 response for patients' stratification and therapy decision.

The Quality of Anti-SARS-CoV-2 T Cell Responses Predicts the Neutralizing Antibody Titer in Convalescent Plasma Donors.

Convalescent plasma therapy has been described as an attractive approach to treat critically ill patients with COVID-19 (Coronavirus disease 2019). The selection of convalescent plasma donors (CPD) is commonly based on neutralizing antibody titer. A better understanding of the quality of immune responses following COVID-19 will enable the optimization of convalescent donors' selection in convalescent plasma programs. The involvement of SARS-CoV-2 specific T cells in the induction and persistence of high affinity anti-SARS-CoV-2 neutralizing antibody is still poorly investigated. In this study, 115 CPD who presented SARS-CoV-2 and who were eligible for plasma donation were included. Comprehensive analysis of T cells together with humoral responses were performed in regards of sex, age and blood group type. High frequency of T cell responses against SARS-CoV-2 related protein such as spike glycoprotein (80.0%), nucleocapsid (NCAP) (70.4%) and membrane protein (VME1) (74.8%) were detected in CPD by ex vivo IFN-γ and TNF-α ELISpot assays. Among CPD responders, most exhibited poly-specific T cell responses (75%) defined by the ability to mount responses against at least two SARS-CoV-2 antigens. We found a positive correlation between the magnitude and the poly-specificity of anti-SARS-CoV-2 T cell responses in CPD. Notably, both the magnitude and poly-specificity of SARS-CoV-2 T cell responses were highly correlated with neutralizing antibody titer in CPD. The present study highlights that the poly-specificity and strength of SARS-CoV-2 specific T cell responses predicts neutralizing antibody titer following COVID-19. These observations show the interest to combine T cell assays and antibody titer for the selection of CPD and to a latter extend to assess COVID-19 vaccine efficacy in at-risk patients.

Immunoregulation and Clinical Implications of ANGPT2/TIE2+ M-MDSC Signature in Non-Small Cell Lung Cancer.

Myeloid-derived suppressor cells (MDSC) promote immunosuppression and are a target in the field of immuno-oncology. Accumulation of MDSCs is associated with poor prognosis and resistance to immunotherapy for several cancers. Here, we describe an accumulation of a subset of circulating monocytic MDSCs (M-MDSC) overexpressing TIE2, the receptor for angiopoietin-2 (ANGPT2), in patients with non-small cell lung cancer (NSCLC). Greater numbers of circulating TIE2+ M-MDSCs were detected in patients with NSCLC compared with healthy subjects, and this accumulation correlated with ANGPT2 concentration in blood. The presence of an ANGPT2-rich environment was associated with impairment of preexisting T-cell responses against tumor-associated antigens (TAA) in patients with NSCLC. We demonstrated that ANGPT2 sensitizes TIE2+ M-MDSCs such that these cells suppress TAA-specific T cells. In patients with NSCLC, upregulation of the ANGPT2/TIE2+ M-MDSC signature in blood was associated with a poor prognosis. Our results identify the ANGPT2/TIE2+ M-MDSC axis as a participant in tumor immune evasion that should be taken into account in future cancer immunotherapy.