ABSTRACT
Background. Interferon is a marker of host antiviral immunity, which is disordered in COVID-19 patients. ERV can affect the secretion of interferon through the cGAS-STING pathway. In this study, we explored whether IFN-I and HERV-K (HML-2) were activated in COVID-19 patients and whether there was an interaction between them. Methods. We collected blood samples from COVID-19 patients and healthy controls. We first detected the expression of HERV-K (HML-2) gag, env, and pol genes and IFN-I-related genes between patients and healthy people by qPCR, synchronously detected VERO cells infected with SARS-CoV-2. Then, the chromosome distributions of highly expressed HERV-K (HML-2) gag, env, and pol genes were mapped by the next-generation sequencing results, and GO analysis was performed on the related genes. Results. We found that the HERV-K (HML-2) gag, env, and pol genes were highly expressed in COVID-19 patients and VERO cells infected with SARS-CoV-2. The interferon-related genes IFNB1, ISG15, and IFIT1 were also activated in COVID-19 patients, and GO analysis showed that HERV-K (HML-2) can regulate the secretion of interferon. Conclusions. The high expression of HERV-K (HML-2) might activate the increase of interferon in COVID-19 patients, proving that HERV-K does not only play a negative role in the human body.
Subject(s)
COVID-19 , Endogenous Retroviruses , Interferons , Animals , Antiviral Agents , COVID-19/virology , Chlorocebus aethiops , Endogenous Retroviruses/genetics , Genes, Viral , Humans , Interferons/genetics , SARS-CoV-2 , Vero CellsABSTRACT
Since the beginning of the SARS-CoV-2 pandemic, the emergence of multiple new variants posed an increased risk to global public health. The aim of this study is to investigate SARS-CoV-2 variants and possible transmission of variants of concern (VOCs) in Sierra Leone. A total of 65 nasal swab samples were collected from COVID-19 cases in Sierra Leone, among which 24 samples were collected during the second wave and 41 samples were collected during the third wave. Nanopore sequencing generated 54 SARS-CoV-2 whole genomes. The second COVID-19 wave was mainly caused by R.1 lineage while the third COVID-19 wave was dominated by B.1.617.2 lineage (Delta variant). The phylogenetic analysis suggested multiple introductions of SARS-CoV-2 Delta variant into Sierra Leone and subsequent local transmission in this country. Our findings highlight the importance of genomic surveillance of SARS-CoV-2 variants and the urgent need for implementation of strengthened public health and social measures (PHSM) to control the spread of virus variants.
Subject(s)
COVID-19/genetics , Mutation , SARS-CoV-2/genetics , Genetic Variation , Genotype , Humans , Pandemics , Sierra LeoneABSTRACT
Objectives: Our objective was to determine the antibody and cytokine profiles in different COVID-19 patients. Methods: COVID-19 patients with different clinical classifications were enrolled in this study. The level of IgG antibodies, IgA, IgM, IgE, and IgG subclasses targeting N and S proteins were tested using ELISA. Neutralizing antibody titers were determined by using a toxin neutralization assay (TNA) with live SARS-CoV-2. The concentrations of 8 cytokines, including IL-2, IL-4, IL-6, IL-10, CCL2, CXCL10, IFN-γ, and TNF-α, were measured using the Protein Sample Ella-Simple ELISA system. The differences in antibodies and cytokines between severe and moderate patients were compared by t-tests or Mann-Whitney tests. Results: A total of 79 COVID-19 patients, including 49 moderate patients and 30 severe patients, were enrolled. Compared with those in moderate patients, neutralizing antibody and IgG-S antibody titers in severe patients were significantly higher. The concentration of IgG-N antibody was significantly higher than that of IgG-S antibody in COVID-19 patients. There was a significant difference in the distribution of IgG subclass antibodies between moderate patients and severe patients. The positive ratio of anti-S protein IgG3 is significantly more than anti-N protein IgG3, while the anti-S protein IgG4 positive rate is significantly less than the anti-N protein IgG4 positive rate. IL-2 was lower in COVID-19 patients than in healthy individuals, while IL-4, IL-6, CCL2, IFN-γ, and TNF-α were higher in COVID-19 patients than in healthy individuals. IL-6 was significantly higher in severe patients than in moderate patients. The antibody level of anti-S protein was positively correlated with the titer of neutralizing antibody, but there was no relationship between cytokines and neutralizing antibody. Conclusions: Our findings show the severe COVID-19 patients' antibody levels were stronger than those of moderate patients, and a cytokine storm is associated with COVID-19 severity. There was a difference in immunoglobulin type between anti-S protein antibodies and anti-N protein antibodies in COVID-19 patients. And clarified the value of the profile in critical prevention.