The research team from China and the US found that Covid-19 can attack the immune system in the human body and cause similar damage in HIV patients. Researchers Lu Lu of Fudan University in Shanghai and Jang Shibo of the New York Blood Center introduced live nCoV into a laboratory-grown T-cell lymphoid cell line. T lymphocytes, also known as T cells, play an important role in the identification and elimination of pathogens that invade the body. They capture virus-infected cells, drill a hole in the cell membrane, and inject toxic chemicals through it. These chemicals then destroy both the virus and the host cell, tearing them into pieces.
The researchers were surprised to observe that T cells fell prey to nCoV in the experiment. They found a special structure in the viral spike protein that promotes the fusion of the viral envelope and the cell membrane when in contact. The virus gene then enters the T cell and "abducts" the cell, disabling its body's defenses.
The team conducted a similar experiment with the severe acute respiratory syndrome (SARS) virus in the same family as nCoV and found that the SARS virus was not able to infect T cells. They assumed it was because of the SARS virus. inability to fuse with cell membranes. The SARS virus can only infect cells that carry the ACE2 receptor protein, which is extremely rare in T cells. A deeper understanding of nCoV's ability to infect T cells will pave the way for new ideas about the mechanism. pathogen activity and treatment interventions, the team concludes in a paper awaiting peer review in this week's journal Cellular & Molecular Immunology.
In February, researcher Chen Yongwen and colleagues at the Institute of Immunology at the Chinese Liberation Army Laboratory (PLA) shared a clinical report that warned that the number of T cells could be drastically reduced in Covid patients. -19, especially among those who are elderly or need special care. The lower the T-cells, the higher the health risk. This observation was later confirmed by autopsies of more than 20 patients, whose immune systems were almost completely destroyed.
The medical examiner said the damage to the patient's internal organs resembled a combination of SARS and HIV. The gene that promotes membrane fusion function in nCoV is not present in other human or animal corona virus strains. But some dangerous viruses like HIV and Ebola have similar consequences, prompting speculation that nCoV may have spread silently in human society long before causing a pandemic. But the study by Lu and Jang also reveals an important difference between nCoV and HIV. That is, HIV can multiply in T cells, turning them into factories to make more copies to infect other cells. But they did not observe nCoV replication after entering T cells, indicating that this virus and T cells can die together.
The new study also raises some questions. For example, the coronavirus can persist for weeks in some asymptomatic patients. The researchers do not yet know how it interacts with the T cells in these patients.