Current influenza vaccines target mutated viral surface proteins and therefore have the disadvantage of being effective only against certain types of viruses.In addition, since the immune response-inducing effect on the respiratory mucosa, which is the gateway to viral entry, cannot be expected, it is impossible to prevent the infection itself.

　On the other hand, CD8T cells, which are responsible for protection against influenza virus infection, directly destroy infected cells by targeting virus internal proteins common to all viral strains.Therefore, if CD8T cells can be effectively induced and maintained in the respiratory mucosa, it is considered to be an effective countermeasure against influenza virus infection.

　In previous studies, the memory CD8 T cells, which are known to stay in tissues even after the virus is eliminated and are at the forefront of defense against reinfection, cause tissue damage in the lungs due to infection. Was found to accumulate in the cell clumps formed to repair the virus.And this time, as a result of further research, we found that stay-type memory CD8T cells were maintained for a long time at this accumulation site, completely independent of the circulating memory CD8T cells circulating throughout the body. We found that memory CD8 T cells were continuously supplied to the pulmonary airway epithelium, which was the first to be infected by the virus.It was also clarified that the chemokine receptor CXCR6, which is characteristically expressed at the accumulation site, and the ligand of CSCR6 (CXCL16), which is constantly expressed in lung epithelial cells, enable this cell migration.

　Based on this finding, it is expected that if CD8 T cells can be effectively induced and maintained at the infected site in the future, it will be possible to develop a new vaccine that is effective against all influenza virus strains.

Paper information:[Journal of Experimental Medicine] Interstitial-resident memory CD8 + T cells sustain frontline epithelial memory in the lung