This book encompasses the proceedings of a conference held at Trinity
College, Oxford on September 21-25, 1985 organized by a committee
comprised of Drs. M. Crumpton, M. Feldmann, A. McMichael, and E.
Simpson, and advised by many friends and colleagues. The immune response
gene workshops that took place were based on the need to understand why
certain experimental animal strains were high responders and others were
low responders. It was assumed that identification of the immune
response (Ir) genes and definition of their products would explain high
and low responder status. Research in the ensuing years has identified
the Ir gene products involved in antibody responses as the la antigens,
or MHC Class II antigens. These proteins are now well defined as members
of the immunoglobulin gene superfamily, and their domain structure is
known. Epitopes have been defined by multiple mono- clonal antibodies
and regions of hypervariability identified. Their genes have been
identified and cloned. The basic observation of high and low responsive-
ness to antigen is still not understood in mechanistic terms, however,
at either the cellular or molecular level. This is because the rate of
progress in immune regulation has been far slower than in the molecular
biology of the MHC Class II antigens. This is not surprising, since
immune regulation is a very complex field at the crossroads of many
disciplines.