autoreactive

adjective

au·​to·​re·​ac·​tive ˌȯt-ō-rē-ˈak-tiv 

: produced by an organism and acting against its own cells or tissues

It has been presumed that autoreactive B cells, like normal B cells, accumulate in the follicles of lymphoid tissues after encountering antigen and begin to proliferate, producing high-affinity autoantibodies and forming germinal centers.

—Yang-Xin Fu and Ursula Storb, Science

autoreactivity

ˌȯt-ō-(ˌ)rē-ˌak-ˈti-və-tē 

noun

plural autoreactivities

At the same time, autoreactivity of B cells and T cells is present in all normal persons, and a complex set of regulatory mechanisms is required to prevent overt destruction of tissue through autoimmunity.

—Peter K. Gregersen, The New England Journal of Medicine