Live-Attenuated Influenza Vaccine Induces Tonsillar Follicular T Helper Cell Responses That Correlate With Antibody Induction.

摘要: Background Influenza remains a major threat to public health. Live-attenuated influenza vaccines (LAIV) have been shown be effective, particularly in children. Follicular T helper (TFH) cells provide B-cell help and are crucial for generating long-term humoral immunity. However the role of TFH LAIV-induced immune responses is unknown. Methods We collected tonsils, plasma, saliva samples from children adults receiving LAIV prior tonsillectomy. measured influenza-specific TFH-cell after by flow cytometry immunohistochemistry. Systemic local antibody were analysed hemagglutination inhibition assay enzyme-linked immunosorbent assay. Results report that induced early (3-7 days post-vaccination) activation tonsillar follicles (CXCR5+CD57+CD4+ cell) children, lesser extent adults. Serological analyses showed elicited rapid (day 14) (up 1 year (hemagglutination inhibition, IgG) but not There was an inverse correlation between pre-existing salivary IgA concentrations responses, positive systemic IgG induction LAIV. Conclusions Our data, taken together, demonstrate important immunity humans.