T-cell receptor family, signal transduction, and transcription factors in T-cell immune response

Abstract

This study investigated signal transduction in T-lymphocytes, whose cell receptors are categorized into several groups based on their signaling mechanisms and the intracellular biochemical pathways they activate, including modular signaling proteins and adapter molecules that perform scaffolding or catalytic functions. Adapter proteins facilitate signaling complexes by linking various enzymes. Immune receptors, which are composed of integral membrane proteins from the immunoglobulin superfamily, interact with specific tyrosine-containing motifs within transmembrane signaling proteins in their cytoplasmic domains. The intensity of T-cell receptor signaling influences the development and activation of T-lymphocytes. Signal transduction is regulated by coreceptor activation and suppressed by inhibitory receptors. The interaction between T-cell receptors and major histocompatibility complex molecules induces coreceptor clustering and tyrosine phosphorylation of immunoreceptor tyrosine-based activation motifs within the cluster of differentiation 3 complex. Protein and lipid phosphorylation is a key regulatory mechanism in T-cell receptor and coreceptor signaling. Activated zeta-chain-associated protein kinase 70 phosphorylates adapter proteins, promoting interactions with downstream signaling molecules. G-proteins stimulate mitogen-activated protein kinases, which activate transcription factors. Phospholipase C activates T-cell transcription factors, resulting in enhanced gene transcription. T-cell receptor signal modulation is mediated by protein tyrosine phosphatases, which dephosphorylate tyrosine residues on signaling proteins, inhibiting T-cell receptor-mediated signal transduction.