MHC-restricted recognition by antigen-specific B cells: fact or artefact?

Over the past several years it has become generally accepted that T cells and B cells, the two classes of antigen-specific lymphoid cells, differ fundamentally in their modes of antigen-specific recognition. Thus, it has been widely accepted that most T cells do not recognise conventional (nominal) antigens alone, but rather recognise these antigens in association with cell-surface products encoded within the major histocompatibility complex (MHC. In contrast, it has generally been concluded that B cells do not exhibit similar requirements for recognition of self-MHC products, and do recognise antigen alone. Here Richard Hodes and Alfred Singer discuss a formulation, consistent with these notions, which attributes to T cells and B cells two distinct and potentially complementary functions in the defense of the host organism.