The beta chain of TRAV27*01J42*01C*01/TRBV19*01J2S7*01C*02 alpha-beta T cell receptor (TR) clonotype that is specific for HLA-A*02:01-restricted M/matrix protein 1 immunodominant epitope GILGFVFTL of influenza A virus (IAV). Classified as a public TCR clonotype, it is preferentially selected in effector memory CD8-positive T cells among multiple HLA-A*02:01 carriers/individuals and confers long-lived immunity against IAV infection. Can cross-recognize sporadically emerging IAV variants by molecular mimicry, inducing immunity toward different influenza strains. Antigen recognition initiates TR-CD3 clustering on the cell surface and intracellular activation of LCK that phosphorylates the ITAM motifs of CD3G, CD3D, CD3E and CD247 enabling the recruitment of ZAP70. In turn, ZAP70 phosphorylates LAT, which recruits numerous signaling molecules to form the LAT signalosome. The LAT signalosome propagates signal branching to three major signaling pathways, the calcium, the mitogen-activated protein kinase (MAPK) kinase and the nuclear factor NF-kappa-B (NF-kB) pathways, leading to the mobilization of transcription factors that are critical for gene expression and essential for T cell differentiation into effector/memory T cells (By similarity).