Surprising impact of stromal TIL's on immunotherapy efficacy in a real-world lung cancer study.

INTRODUCTION: Immune checkpoint inhibitors (ICI), such as anti-PD-1 agents, have become part of the standard of care treatment of advanced non-small cell lung cancer (NSCLC). Predictive biomarkers are needed to identify patients that benefit from anti-PD-1 treatments. Tumor infiltrating lymphocytes (TILs) and PD-L1 are major players in the ICI mechanism of action. In this study, we assess the impact of real-world clinicopathological variables, including TILs and PD-L1, on anti-PD-1 efficacy. METHODS: We performed a monocenter retrospective study in advanced NSCLC treated with nivolumab or pembrolizumab between January 2015 and February 2019. The impact of baseline clinical and pathological variables was assessed by univariate and multivariate models. TILs, defined as CD8+T-cells, and PD-L1 were scored in tumor and stroma, and correlated with progression free survival (PFS) and overall survival (OS). RESULTS: We included 366 patients of whom 141 were assessed for tumor and stromal TILs. The median follow-up time was 487 days. In the whole cohort, PFS was associated with high tumor PD-L1, high albumin and good performance. OS was associated with low LDH, high albumin, good performance and 'first-line treatment'. In the TILs subcohort, stromal TILs had the strongest impact on PFS and OS. Stromal TILs were a stronger marker for PFS and OS than tumoral TILs, tumoral PD-L1 or stromal PD-L1. Remaining factors for PFS and OS were albumin and albumin with LDH, respectively. CONCLUSIONS: This real-world study on clinicopathological features shows that stromal CD8 + TILs were the strongest predictor for PFS and OS in patients with advanced NSCLC on anti-PD-1 therapy. Other predictors for PFS and OS included albumin and albumin together with LDH, respectively. This study highlights the pivotal role of the stromal compartment in the mechanisms of action of ICI, and the need for further studies aiming to overcome this stromal firewall.

Discrete roles of canonical and non-canonical Wnt signaling in hematopoiesis and lymphopoiesis.

The mechanisms that regulate proliferation, fate decisions and differentiation of hematopoietic stem cells (HSC) and thymic stem cells are highly complex. Several signaling pathways including Wnt signaling have important roles during these processes. Both canonical and non-canonical Wnt signaling are important in normal and malignant hematopoiesis and lymphoid development, yet their precise roles are controversial. In a side-by-side comparison, we investigated the roles of the canonical and non-canonical Wnt pathway in hematopoiesis and thymopoiesis. As complete loss-of-function models for non-canonical Wnt signaling are not yet available and highly complex for canonical Wnt signaling, we decided to use a gain-of-function approach. To this end, Wnt3a and Wn5a, two well-known prototypical canonical and non-canonical Wnt ligands were produced in hematopoiesis supporting stromal assays. High levels of Wnt3a signaling blocked T-cell development at early stages, whereas intermediate levels accelerated T-cell development. In contrast, Wnt5a signaling prompted apoptosis in developing thymocytes, without affecting differentiation at a particular stage. To explore the role of Wnt3a and Wnt5a in vivo, we transduced HSCs isolated from fetal liver, transduced with Wnt3a and Wnt5a vectors, and performed reconstitution assays in irradiated C57Bl/6 mice. Wnt3a overexpression led to increased lymphopoiesis, whereas Wnt5a augments myelopoiesis in the bone marrow (BM) and spleen. Thus, the canonical and non-canonical Wnt signaling have discrete roles in hematopoiesis and thymopoiesis, and understanding their right dose of action is crucial for prospective translational applications.

The interleukin-10 inducing effect of transforming growth factor-beta on human naive CD4+ T cells from cord blood is restricted to the TH1 subset.

Transforming growth factor (TGF-beta) seems to play a role in the regulation of immune responses, mainly by its suppressive function towards cells of the immune system. However, both in mice and human, conflicting data are published on the capacity of TGF-beta to induce interleukin (IL)-10 secretion in both naive and skewed T cell populations. Our aim was to test the IL-10-inducing capacity of TGF-beta in both naive and skewed cord blood mononuclear cells (CBMCs) and elucidate the mechanism by which TGF-beta exerts its effect. Therefore, naive CBMCs and CBMCs during skewing under T helper 1 (Th1) and Th2 polarizing conditions were stimulated with CD3 and/or CD28 in the presence or absence of TGF-beta. Proliferation, cytokine production and mRNA expression of transcription factors was measured. TGF-beta enhanced the IL-10 production in Th1 and naive cells only, and suppressed the T(H)1 phenotype as demonstrated in cytokine levels and T-box expression in T cells (T-bet) expression. Interestingly, forkhead box p3 (Foxp3) expression tended to increase in both Th1 and Th2 cells. These data indicate that TGF-beta can induce a regulatory phenotype in both naive and Th1-polarized cells derived from cord blood. The induction of IL-10 was not observed in Th2-polarized phenotype, indicating that TGF-beta might be especially of interest for immunomodulation in Th1 cells.

Moraxella catarrhalis sepsis in a patient with juvenile spinal muscle atrophy.

Moraxella catarrhalis rarely causes severe infections or bacteraemia in healthy subjects. In the literature only four cases of clinical sepsis with M. catarrhalis have been described, mostly in immunocompromised patients. We describe a case of a 34-year-old patient with Kugelberg-Welander disease and low body weight (28 kg) who developed clinical sepsis due to M. catarrhalis bacteraemia. A review of the literature is given.

Efficacy of birch-pollen immunotherapy on cross-reactive food allergy confirmed by skin tests and double-blind food challenges.

BACKGROUND: The effect of birch-pollen immunotherapy (IT) on cross-reactive food allergies is controversial. OBJECTIVE: The aim of this study was to investigate the effect of birch-pollen IT on apple allergy and to evaluate recombinant allergens and double-blind placebo-controlled food challenges (DBPCFCs) as monitoring tools. METHODS: Twenty-five adult birch-pollen- and apple-allergic patients were randomly divided into two groups, either receiving birch-pollen IT or symptomatic drugs only. IgE and IgG4 antibodies against birch pollen, apple, natural Bet v 1 and Mal d 1 were measured. In addition, skin prick tests (SPT) were performed using recombinant Bet v 1 (rBet v 1) and Mal d 1 (rMal d 1). Clinical outcome was evaluated by DBPCFC. CD4(+)CD25(+) regulatory T cells (Tregs) were isolated from peripheral blood and tested in functional assays. RESULTS: Birch-pollen IT resulted in a significant decrease of SPT reactivity for rBet v 1 (30-fold) and rMal d 1 (10-fold) already after 3 months. IgG4 antibodies were potently induced against Bet v 1, displaying cross-reactivity to Mal d 1. Visual analogue scale scores decreased >10-fold in 9/13 patients of the IT group, with three patients converting to negative. In the control group, no decrease was observed. Birch-pollen IT did not lead to detectable changes in the number or function of the CD4(+)CD25(+) Tregs. CONCLUSIONS: This trial supports the claims that birch-pollen IT also decreases allergy to foods containing Bet v 1-homologous allergens. Recombinant allergens and DBPCFCs have proven to be useful tools for monitoring the effect of birch-pollen IT on linked food allergies.