DOCK2 is involved in the host genetics and biology of severe COVID-19

「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

Relationship between patterns of immunohistochemical conventional neuroendocrine markers and efficacy of immune check point inhibitors in patients with extensive disease small cell lung cancer

Abstract Background Which patients benefit from the addition of immune checkpoint inhibitors (ICIs) to chemotherapy for small cell lung cancer (SCLC) remains unclear. There have been few reports on the efficacy of ICIs based on conventional immunohistochemical neuroendocrine (NE) markers (synaptophysin, chromogranin A, and neural cell adhesion molecule [NCAM]). In the present study, we aimed to analyze the relationship between the expression of immunohistochemical NE markers and the efficacy of ICIs in patients with extensive disease (ED)‐SCLC, to assess whether conventional NE markers are predictive of ICIs. Methods Patients with untreated ED‐SCLC who received first‐line therapy at the Shizuoka Cancer Center between November 2002 and July 2021 were retrospectively reviewed. We evaluated the efficacy of first‐line chemotherapy according to the expression status of each immunohistochemical NE marker in patients treated with ICI plus chemotherapy (ICI‐chemo group) and with chemotherapy alone (chemo group). Results A total of 227 patients were included in the ICI‐chemo and chemo groups, respectively. The progression‐free survival (PFS) tended to be better in patients in the ICI‐chemo group than those treated with chemotherapy alone in patients with NE marker‐positive SCLC. In particular, it was statistically significant in patients with chromogranin A‐positive SCLC (p = 0.036). In patients with NE marker‐negative SCLC, no significant differences were observed in PFS between the two groups. There were no significant differences in overall survival (OS), regardless of the expression of any conventional NE marker. Conclusion Our study suggests that the efficacy of ICIs in addition to chemotherapy may be poor in patients with NE marker‐negative SCLC