Background Infection with the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes a wide range of symptoms including gastrointestinal manifestations, and intestinal epithelial cells are a target of the virus. However, it is unknown how the intestinal immune system contributes to systemic immune responses in coronavirus disease 2019 (COVID-19). Methods We characterized peripheral blood lymphocytes from patients with active COVID-19 and convalescent patients as well as healthy controls by flow cytometry. Results The frequency and absolute number of circulating memory T and B cells expressing the gut homing integrin α4β7 integrin was reduced during COVID-19, whether gastrointestinal symptoms were present or not. While total IgA-expressing B cells were increased, gut-imprinted B cells with IgA expression were stable. Conclusion COVID-19 is associated with a decrease in circulating adaptive immune cells expressing the key gut homing marker α4β7 suggesting that these cells are preferentially recruited to extra-intestinal tissues independently of α4β7 or that the systemic immune response against SARS-CoV-2 is at least numerically dominated by extraintestinal, particularly pulmonary, immune cell priming.
【저자키워드】 COVID-19, SARS-COV-2 infection, Integrins, T cell trafficking, gut homing, 【초록키워드】 coronavirus disease, SARS-CoV-2, Coronavirus disease 2019, coronavirus, Lymphocytes, adaptive, Symptom, immune system, virus, flow cytometry, Peripheral blood, B cell, Convalescent patients, IgA, immune responses, Patient, Manifestations, immune cells, target, epithelial cells, respiratory, expression, convalescent patient, marker, gastrointestinal symptoms, Frequency, Immune cell, integrin, Gut, systemic immune response, systemic immune responses, acute respiratory syndrome, acute respiratory syndrome coronavirus, tissue, peripheral blood lymphocytes, acute respiratory syndrome coronavirus 2, healthy control, These cells, healthy controls, priming, circulating, intestinal epithelial cells, while, memory T, wide range of symptoms, Gastrointestinal symptom, decrease, homing, intestinal, Result, recruited, characterized, contribute, cause, expressing, these cell, was reduced, intestinal epithelial cell, IgA-expressing, peripheral blood lymphocyte, 【제목키워드】 immune cells, Decreased,