مقالات پذیرفته شده در هفتمین کنگره بین المللی زیست پزشکی
The Role of Immune Cells and Its Antibodies Against SARS-Cov-2 Infection
The Role of Immune Cells and Its Antibodies Against SARS-Cov-2 Infection
Mobina Fathi,1,*
1. B.s of Microbiology Department of biology, Tehran Branch, Islamic Azad university, Tehran Iran.
Introduction: The SARS‐CoV‐2 pandemic has demonstrated the importance of studying antiviral immunity within sites of infection to gain insights into mechanisms for immune protection and disease pathology. As SARS‐CoV‐2 is tropic to the respiratory tract, many studies of airway washes, lymph node aspirates, and postmortem lung tissue have revealed site‐specific immune dynamics that are associated with the protection or immunopathology but are not readily observed in circulation. This study investigates The role of immune cells and their antibodies against SARS-CoV-2 infection
Methods: This review study has been written from scientific databases such as Science Direct, Springer, Google Scholar, and PubMed for investigating The role of immune cells and their antibodies against SARS-CoV-2 infection.
Results: Almost everyone with SARS-CoV-2 infection seroconverts within 2 weeks post-symptom onset (PSO), producing IgM and IgG antibodies that predominantly recognize the viral spike and nucleocapsid proteins. However, high serum titers of total or neutralizing antibodies against SARS-CoV-2 are more frequently found in severe cases of COVID-19 and do not necessarily correlate with better disease outcomes of the primary infection. Transfusion of convalescent plasma was initially reported to be able to reduce the mortality rate of people hospitalized with COVID-19, although increased survival was not replicated in a subsequent large controlled trial. Neutralizing antibodies that block angiotensin-converting enzyme 2 (ACE2)-dependent viral entry into host cells correlate well with the efficacy of prophylactic vaccines. Serum levels of neutralizing antibodies to SARS-CoV-2 peak within the first few weeks after infection or vaccination and decline subsequently, leading to reduced protection and an increased risk of re-infection by the original strain or newly emerging variants of concern or interest (VOCs or VOIs). Vaccine booster shots can induce broader and more potent neutralizing antibodies in patients convalescing from COVID-19 compared with previously uninfected individuals. Antibodies that are cross-reactive because of previous exposure to other pathogenic and seasonal coronaviruses may affect the development of SARS-CoV-2-specific neutralizing antibodies as well. What emerges from these and other studies of humoral immunity to SARS-CoV-2 is the importance of the timing and context in which B cell activation and antibody responses are initiated and maintained.
Conclusion: More studies and continuous monitoring of ADE are warranted, because in principle cross-reactive antibodies from previous coronavirus infection could exacerbate SARS-CoV-2 infection and, as new VOCs continue to emerge, neutralizing antibodies against earlier strains may lose neutralizing potency and become capable of mediating ADE instead. This latter point is important from a vaccination perspective because vaccines appear to induce more binding antibodies than neutralizing antibodies, compared with natural infection.