T peripheral helper cells in autoimmune diseases*
Kathryne E. Marks, Deepak A. Rao
Abstract
Abstract Pathologic T cell–B cell interactions underlie many autoimmune diseases. The T cells that help B cells in autoimmune diseases vary in phenotype and include T cells that lack typical features of T follicular helper cells, such as expression of CXCR5 and BCL6. A population of PD‐1 hi CXCR5 ‐ T peripheral helper (Tph) cells has now been recognized in multiple autoantibody‐associated diseases. Tph cells display a distinctive set of features, merging the ability to provide B cell help with the capacity to migrate to inflamed peripheral tissues. Here, we review the scope of immune‐related conditions in which Tph cells have been implicated and provide a perspective on their potential contributions to pathologic B cell activation in autoimmune diseases. We discuss Tph cells as a promising therapeutic strategy in autoimmunity and consider the utility of tracking Tph cells in blood as a biomarker to quantify aberrant T cell–B cell activation in patients with autoimmune diseases.