Tissue-Specific Contributions to Control of T Cell Immunity

Tissue-specific factors contributing to T cell immunity.

T cell differentiation is influenced by the interaction and direct signals provided by APCs but also by the surrounding environment (larger blue circle) in which it sees Ag and becomes activated. This environment can be influenced by a myriad of factors (pink and green circles), leading to alterations in T cell differentiation and function. External factors in the environment (green circles), including foreign Ags, the microbiome, and altered metabolic contexts, create tissue-specific homeostatic niches that are set early in life and can maintain a persistent state for surrounding cells, whereas cell types intrinsic to the organism (pink circles) can be modulated by the environment to promote tissue-specific contexts during homeostasis and upon infection or pathogenic insult.