Detection of squamous epithelial intercellular substance antigen(s) in Hassall's corpuscles of human and animal thymus.

Using pemphigus sera containing high titres (1:1000) of non-species-specific antibodies to tissue-specific intercellular substance (ICS) antigen(s) of cover stratified epithelia (skin, oesophagus, vagina and so forth), we detected analogous antigen(s) by immunofluorescence in the ICS of the epithelium of Hassall's corpuscles of human and animal thymus. The results obtained, together with well-known data from histological and embryological studies, confirm the histogenetic relationship of the epithelium of thymus corpuscles and cover epithelia of ectodermal origin. ICS antigen(s) is related to the series of hetero-organic antigens, which probably take part in the natural immunological tolerance formation to the antigens of the organism's own tissues.