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.

Homosexual contact is one of the main transmission routes of HIV-1 epidemic in Hebei, China. Several subtypes of HIV are prevalent simultaneously in the population, which always lead to the emergency of unique recombinant forms (URFs). In this study, we reported two new URFs from two HIV-1 positive subjects infected through homosexual contact route in Hebei, China. Phylogenetic and recombinant analyses based on the near full-length genome of the two URFs both revealed the two URFs are the second generation of recombinant strains originated from CRF01_AE and CRF07_BC. The CRF01_AE segments of two URFs located in cluster 4 of CRF01_AE strains in the phylogenetic tree. The emergence of the novel CRF01_AE/CRF07_BC recombinant forms with complicated genomic structures indicated the importance of the continuous monitoring of the HIV-1 epidemic and new URFs among the men who have sex with men populations.