Purpose of review: This review focuses on putative targets, including costimulatory and additional pathways involving T regulatory cells, that may be critical for modifying allergic responses.
Recent findings: Multiple costimulatory signals including CD28/CTLA4: CD80/CD86, ICOS: ICOSL, OX40:OX40L and PD-1: PD-L1/PD-L2 have been identified and implicated in the regulation of immune disorders. Recent studies indicate that T regulatory cells may also suppress T cell costimulation by the secretion of TGF-beta and IL-10, suggesting an important role of T regulatory cells in the regulation of allergic disorders.
Summary: Immune-mediated disorders, including allergic diseases, have been increasing in prevalence. Unravelling these immune pathways may suggest new targets for immunomodulation.