Monoclonal antibody (mAb) MR6 recognises a 200 kDa glycoprotein, @entity52066 , which is expressed at high levels on the surface of @entity1 thymic cortical epithelium. In order to produce further mAbs against the @entity52066 molecule, @entity19 were immunised with purified @entity1 @entity52066 , hybridomas produced and supernatants screened for MR6-like reactivity on @entity1 thymic sections. Surprisingly this conventional hybridoma technique failed to produce stable hybridoma cells producing MR6-like antibodies. However, antibodies with specificities other than MR6-like were obtained. Three such antibodies (1B2, 3A3 and 4B3) were analysed further. Expression of 1B2-antigen, 3A3-antigen and 4B3-antigen was analysed on skin, tonsil and thymic sections, on cultured thymic epithelial cells (TEC), thymocytes and peripheral blood mononuclear cells (PBMC), and found to be expressed by both lymphocytes and epithelial cell populations. Furthermore, the antigens were also expressed on @entity19 thymic epithelial cells. The regulation of expression of these antigens was analysed following mitogen or cytokine stimulation of PBMC and cultured TEC, respectively. Expression on T cells was clearly affected by mitogens that mimic activation through the T cell receptor and expression on cultured TEC was affected by T cell-derived cytokines. Thus, the shared epithelial-lymphocyte molecules identified in this study may play a role in the cross-talk between the developing thymocytes and their epithelial microenvironment. The production of mAbs with specificities other than that of purified @entity52066 indicates that a wide range of B cells with specificity for components of the @entity1 thymic microenvironment exist in the normal @entity19 . These may detect epitopes that are shared with common pathogens to which the animals are exposed. Alternatively, they may be autoreactive B cells that are normally silent in the absence of T cell help. This help may be provided by T cells specific for @entity1 @entity52066 , or nonspecifically by polyclonal activation induced by the adjuvant.

Antibodies to XXXX thymic epithelium form part of the @entity19 autoreactive repertoire.

@entity1 :: ('9606', 'Species') :: ['human'] @entity19 :: ('10090', 'Species') :: ['mice', 'mouse'] @entity52066 :: ('4065', 'Gene') :: ['gp200-MR6']
@entity1 :: (9606,Species) :: ['human']
