Immunity . . . The Tsinghua Dongchen team reported on the body fluids and cellular immune responses of patients recovering from new crown pneumonia.

On May 4, 2020, Dong Chen's team of Institute of immunology, Tsinghua University, Chen Fang's team of Chuiyangliu Hospital Affiliated to Tsinghua University and Qin Chengfeng Laboratory of Military Medical Research Institute, Academy of Military Sciences, published a research paper entitled "detection of sars-cov-2-specific human and cellular immunity in covid-19 valuable individuals" in the top immunology journal immunity.novel coronavirus pneumonia reported the humoral and cellular immune response in the rehabilitation of patients.this paper was previously published in medrxiv, and the relevant data was added when it was officially published. The novel coronavirus SARS-COV-2 discovered at the end of2019 has rapidly swept the globe, and has brought huge losses to the health and social economic development of people in different parts of the world.earlier clinical data showed that in patients with covid-19, especially in critically ill patients, lymphocytes in the blood decreased significantly and the levels of pro-inflammatory cytokines increased significantly, suggesting that the immune system plays an important role in the disease process.studies have shown that specific antibodies participate in the immune response of SARS and mers patients.the researchers tested 14 convalescent patients with covid-19 and analyzed their humoral and cellular immune responses.all samples were collected from patients with mild infection, including 8 discharged patients and 6 follow-up patients two weeks after discharge.using the purified sars-cov-2 N protein (nucleocapsid protein), major protease and s-rbd (spike glycoprotein receptor binding region) expressed and purified in vitro, the researchers detected specific IgM and IgG antibodies against these proteins in the sera of convalescent patients.no specific antibodies against the major protease of sars-cov-2 were detected in most samples.however, specific IgM and IgG antibodies to N protein and s-rbd were detected in the serum of patients who had just discharged from hospital.in vitro neutralization test of pseudovirus antibody showed that most patients had protective neutralizing antibody in serum.this suggests that covid-19 infection is accompanied by antibody production in all patients, and antibodies, especially IgG, can be maintained at a high level at least 2 weeks after discharge.there was a significant correlation between the titer of neutralizing antibody and the area under the curve (AUC) of anti-s-rbd IgG, but not with anti-NP IgG AUC, which suggested that anti-s-rbd IgG might be helpful to analyze the neutralization ability of serum in patients with covid-19.in terms of cellular immunity, through the analysis of PBMCs (peripheral blood mononuclear cells) of convalescent patients, the researchers found that there was no significant difference in the proportion of total T cells in the blood between the convalescent patients and the uninfected patients S-rbd specific T cells were the most widely distributed and the number of N protein specific T cells was the highest.in addition, the data of 14 convalescent subjects showed that there was a significant positive correlation between the level of neutralizing antibody and the number of N protein specific T cells.this suggests that specific humoral and cellular immunity may work together to effectively eliminate the virus in patients with covid-19. interestingly, s-rbd induces a wide range of T cell and humoral immune responses at the same time, which is the most promising target for the preparation of sars-cov-2 vaccine. The novel coronavirus (SARS-CoV-2) was removed by humoral immunity and cellular immunity. The specific humoral immunity still existed in two weeks after the recovery of . The study laid a theoretical foundation for the diagnosis of infectious diseases, the tracing of past infections, the development of therapeutic antibody drugs and the design of vaccines. However, further studies are needed to determine whether these patients have long-term immunity to sars-cov-2, and how those who do not produce neutralizing antibodies can eliminate the virus. paper links: