T cell-intrinsic PRR signaling in immunity and pathology.

The immune system orchestrates a delicate balance between robust defense against pathogens and restraint to prevent tissue damage, with T cells serving as central mediators of adaptive immunity. The canonical pathway for T-cell activation hinges on the precise recognition of peptide antigens presented by major histocompatibility complex (MHC) molecules via the T-cell receptor (TCR), which is complemented by essential co-stimulatory signals. However, this model alone cannot fully explain the nuanced contextualization of immune responses, particularly how T cells integrate signals related to the nature of the threat. Pattern recognition receptors (PRRs), which are traditionally studied in innate immune cells, are recognized as critical regulators of T cell function, challenging the conventional dichotomy between innate and adaptive immunity. T cell-intrinsic PRR signaling integrates endogenous danger signals and microbes to modulate critical processes, including cytokine production, proliferation, and polarization, thereby shaping immune responses and disease outcomes in contexts ranging from viral infections to chronic inflammation and cancer. However, the molecular mechanisms underlying PRR-mediated T cell regulation and their contributions to immune homeostasis or pathology remain incompletely understood. This study investigates the role of T cell-intrinsic PRR signaling in shaping immune responses and its implications for disease. By elucidating key signaling pathways and their impact on T cell function, we aim to offer novel insights into the complex regulation of T cell-mediated immunity and uncover an underappreciated paradigm for immune-related disorders, providing new insights into the pathogenesis of inflammatory and neoplastic diseases.