To get this semester's blogging off and running (no one wants to be the first to post on an empty blog!), here is my take on a new PNAS paper from the Cantor lab:
At its core, RA is a disease of multiple immune cell types. One component is B cells, which produce antibodies that recognize “self” proteins found in connective tissue. A second component is “helper” T cells (also termed CD4 T cells), which help B cells produce antibody, and which contribute to an inflammatory state in the joints. A study published this week in the Proceedings of the National Academy of Sciences by Leavenworth and colleagues further refines the contribution of different CD4 T cell subsets in RA, and defines a new role for yet a third cell type, natural killer (NK) cells, in suppressing the development of RA. To do this, the authors used an experimental mouse model of RA, induced by injection of type II collagen, a prominent component of connective tissue, under the skin. This model (collagen-induced arthritis; CIA) causes many of the same symptoms as human RA, and has been used to test a number of new treatments for RA (1).