miR-142 constrains TGFß activity for optimal ABC formation

B lymphocytes are critical cells belonging to the branch of the immune system capable of discriminating between invading pathogens. In this context, the immune reaction most adequate to neutralize a faced threat will be turned on. B lymphocytes are well-known to be uniquely responsible for the making of all antibodies. They are, however, endowed with additional functionalities participating in the bodys defense mechanisms as well. Notably, a specific behavior adopted by B lymphocytes in response to pathogens present inside cells, like viruses, has been recently described. As such, these so-called ABC cells produce distinctive antibodies and molecules modulating inflammation. Remarkably, ABC cells have been also detected in various disorders, like systemic lupus erythematosus, in which they seem to contribute to the damaging of tissues. Furthermore, the latter cells are commonly observed at increased frequency in old individuals, apparently taking part in the shaping of an inadequate immune system. Thoroughly understanding the underlying biological processes regulating the generation and activity of ABC cells could therefore be helpful with not only improving our comprehension of immunity but also the designs of treatments for diseases. Progress has been made in identifying several molecular modulators of gene activity in ABC cells. In contrast, a role for the class of molecules called miRNAs, which can suppress the synthesis of specific sets of proteins, remains obscure. We proposed to investigate the action of this other regulatory layer in ABC cells. Overall, we expect to demonstrate the essential function of specific members of the miRNA family in the generation and/or functioning of the latter B lymphocytes. The gained knowledge should also highlight the usefulness of these miRNAs as targets for therapeutic interventions, potentially by manipulating their abundance in pathologies.