Purpose: The success of immune checkpoint inhibitors strengthens the notion that tumor growth and regression are immune regulated. To determine whether distinct tissue immune microenvironments differentially affect clinical outcome in nonsmall cell lung cancer (NSCLC), an extended analysis of PD-L1 and tumor-infiltrating lymphocytes (TIL) was performed.Experimental Design: Samples from resected adenocarcinoma (ADC 42), squamous cell carcinoma (SCC 58), and 26 advanced diseases (13 ADC and 13 SCC) treated with nivolumab were analyzed. PD-L1 expression and the incidence of CD3, CD8, CD4, PD-1, CD57, FOXP3, CD25, and Granzyme B TILs were immunohistochemically assessed.Results: PD-L1 levels inversely correlated with N involvement, although they did not show a statistically significant prognostic value in resected patients. The incidence and phenotype of TILs differed in SCC versus ADC, in which EGFR and KRAS mutations conditioned a different frequency and tissue localization of lymphocytes. NSCLC resected patients with high CD8 pos lymphocytes lacking PD-1 inhibitory receptor had a longer overall survival (OS: HR ¼ 2.268; 95% CI, 1.056-4.871, P ¼ 0.03). PD-1-to-CD8 ratio resulted in a prognostic factor both on univariate (HR ¼ 1.952; 95% CI, 1.34-3.12, P ¼ 0.001) and multivariate (HR ¼ 1.943; 95% CI, 1.38-2.86, P ¼ 0.009) analysis. Moreover, low PD-1 incidence among CD8 pos cells was a distinctive feature of nivolumab-treated patients, showing clinical benefit with a prolonged progressionfree survival (PFS: HR ¼ 4.51; 95% CI, 1.45-13.94, P ¼ 0.004).Conclusions: In the presence of intrinsic variability in PD-L1 expression, the reservoir of PD-1-negative effector T lymphocytes provides an immune-privileged microenvironment with a positive impact on survival of patients with resected disease and response to immunotherapy in advanced NSCLC.

The emerging epidemic caused by the new coronavirus SARS-CoV-2 represents the most important socio-health threat of the 21st century. The high contagiousness of the virus, the strong impact on the health system of the various countries and the absence to date of treatments able to improve the prognosis of the disease make the introduction of a vaccine indispensable, even though there are currently no approved human coronavirus vaccines. The aim of the study is to carry out a review of the medical literature concerning vaccine candidates for the main coronaviruses responsible for human epidemics, including recent advances in the development of a vaccine against COVID-19. This extensive review carried out on the vaccine candidates of the main epidemic coronaviruses of the past has shown that the studies in animal models suggest a high efficacy of potential vaccines in providing protection against viral challenges. Similar human studies have not yet been carried out, as the main trials are aimed at assessing mainly vaccine safety and immunogenicity. Whereas the severe acute respiratory syndrome (SARS-CoV) epidemic ended almost two decades ago and the Middle East respiratory syndrome (MERS-CoV) epidemic is now better controlled, as it is less contagious due to the high lethality of the virus, the current SARS-CoV-2 pandemic represents a problem that is certainly more compelling, which pushes us to accelerate the studies not only for the production of vaccines but also for innovative pharmacological treatments. SARS-CoV-2 vaccines might come too late to affect the first wave of this pandemic, but they might be useful if additional subsequent waves occur or in a post-pandemic perspective in which the virus continues to circulate as a seasonal virus.

OBJECTIVES Tumour-infiltrating lymphocytes (TILs) are critically implicated in the clinical outcome and response to immunotherapy in non-small-cell lung cancer (NSCLC) patients. The functional competence of lymphocyte subpopulations is strongly conditioned by their spatial arrangement within the tumour immune microenvironment. The aim of this study was to determine whether the tissue localization of specific TIL subpopulations might have an impact on the risk of recurrence in surgically resected NSCLC. METHODS High-speed scanning of whole slide images was performed on immunohistochemically stained tissue sections from 97 NSCLC patients to assess the number and ratio of CD3+, CD8+ and PD-1+ T-lymphocytes. TIL distribution was computed considering the intratumoural (proximal or distal) and peripheral (invasive margin) localization as well as their location within the fibrotic tissue (immune excluded). The tumour proliferative index was assessed by Ki67 labelling. The impact of TILs number and distribution on clinical-pathological characteristics and outcomes were statistically analysed. RESULTS High density and percentage of proximal CD8+ TILs and low PD-1-to-CD8 ratio had a positive impact on disease-free-survival (P = 0.03) and overall survival (P = 0.003). An inverse correlation was observed between the abundance of intratumoural CD8+ TILs carrying PD-1 inhibitory receptor and cancer cell proliferation. Cases with high compared to low fraction of immune excluded CD8+ TILs had significantly reduced 5-year overall survival (n events: 22 vs 12; P = 0.04) and disease-free survival (n events: 24 vs 16; P = 0.03) rates while the amount of CD3+ and CD8+ TILs located at the invasive margin had a favourable effect on the clinical course. CONCLUSIONS Mapping TIL subpopulations may implement the definition of prognostic parameters in surgically resected NSCLC.

Microvessels are an essential component of the cancer immune microenvironment. The clinical impact of the PD-1/PD-L1-based immune contexture may be implemented by the assessment of microvascular density to potentially identify patients with non-small-cell lung cancer who could benefit from immunotherapy and antiangiogenic treatment.