Autophagy in T and B cell homeostasis Recycling for sustainable growth

Macroautophagy often abbreviated by "autophagy" is an intracellular degradation mechanism linked to lysosomal activity. Autophagy is conserved from yeast to mammals and plays a role in the response to energetic stress and in organelle homeostasis. Autophagy is also involved in the regulation of immunity, in particular in the adaptive immune response, which involves B and T lymphocytes. It was indeed shown that autophagy impacts the development of B and T cells as well as the education of T cells in the thymus. Autophagy also modulates activation, survival and polarization of T cells. It plays a role in antigen presentation by B cells, and in their TLR-mediated activation, and thus likely in their initial activation. Finally, autophagy is required for the survival of memory lymphocytes and effector cells like antibody-producing plasma cells. Interestingly, autophagy is deregulated in several autoimmune pathologies. The modulation of this phenomenon could possibly lead to new treatments aiming at limiting lymphocyte activation driving these pathologies. © 2016 médecine/sciences-Inserm.