The Impact of TCR Signal Strength on Resident Memory T Cell Formation during Influenza Virus Infection

Resident memory T cells (T RM ) in the lung are vital for heterologous protection against influenza A virus (IAV). Environmental factors are necessary to establish lung T RM ; however, the role of T cell-intrinsic factors like TCR signal strength have not been elucidated. In this study, we investigated the impact of TCR signal strength on the generation and maintenance of lung T RM after IAV infection. We inserted high- and low-affinity OT-I epitopes into IAV and infected mice after transfer of OT-I T cells. We uncovered a bias in T RM formation in the lung elicited by lower affinity TCR stimulation. TCR affinity did not impact the overall phenotype or long-term maintenance of lung T RM Overall, these findings demonstrate that T RM formation is negatively correlated with increased TCR signal strength. Lower affinity cells may have an advantage in forming T RM to ensure diversity in the Ag-specific repertoire in tissues.