T cell chemokine receptor patterns as pathogenic signatures in autoimmunity.

Autoimmune diseases arise from aberrant activation of immune cells directed against endogenous autoantigens expressed throughout the human body. While the initiating triggers remain poorly understood, the self-perpetuating phase of these diseases is directly linked to the ongoing recruitment of inflammatory cells that traffic to the affected anatomical sites. T lymphocytes are prominent drivers of many autoimmune diseases and the targeted trafficking of these cells to infiltrate the affected organs is often a common denominator. The regulation of T cell trafficking involves the coordinated expression of specific patterns of chemokines and the reciprocal expression of cognate chemokine receptors on T cell membranes. Thereby, chemokines direct the specific trafficking of a wide array of responsive activated immune cells. Specific patterns of chemokine receptor expression can correlate with disease activity in an autoimmune disease, confirming the importance of further characterizing the T cells that infiltrate specific sites of autoimmunity. Herein, we will review our current understanding of the roles of chemokines in two common autoimmune diseases: rheumatoid arthritis and multiple sclerosis. We also discuss the implications for chemokine receptor signatures in autoimmune pathogenesis, and how these may provide novel targets for therapeutic intervention.