Immunofluorescent tracing of cytoplasmic components involved in keratinocyte differentiation

Abstract

Sera with epidermal cytoplasmic antibodies (E.C.A.) produced by human subjects after bone marrow transplantation have been studied by indirect immunofluorescen on rabbit lip sections. These sections were used in order to give on a single specimen, areas of mucosa, of parakeratotic and of orthokeratotic epithelium. It has been demonstrated that E.C.A. distinguished the basal cell layer from the upper cell layers on the three areas. Moreover, E.C.A. were not found to react identically on mucosal, parakeratotic and orthokeratotic epithelium. These findings strongly suggest that the target antigens for E.C.A. are molecules involved in keratinocyte differentiation.

Regional variations of cell surface carbohydrates in human oral stratified epithelium

“…Similar observations have been made in studies of epidermal cytoplasmic antibodies [24]. These reacted only with the basal cells in non-keratinized epithelium, while several additional cell layers were stained in parakeratinized and orthokeratinized epithelium.…”

Epidermis and thymus. similar antigenic properties in hassall's corpuscle and subsets of keratinocytes

“…In contrast, when the antibodies known to react with cytoplasmic antigens of the basal cell layer (proliferative compartment) (Saurat et al, 1978b(Saurat et al, , c, 1980 were used, they did not crossreact with thymic tissue antigens. Sun & Green (1978) and Sun (1979) have actually shown that 'keratin', as detected by an antiserum raised in rabbit against human keratin, was demonstrable in the cytoplasm of keratinocytes as well as in different tissues one of which was HC of the thymus.…”

“…Four were known to react with the antigens localized in the upper compartment of orthokeratinized epitheha giving a so called U.CYT pattern (Bystryn et al, 1978). The other three were known to react exclusively with the antigens contained within the proliferative, basal cell compartment of epidermis (the so called B.CYT pattern) regardless of the type of differentiation (ortho-, parakeratinization and mucosa) expressed by the tissue (Saurat et al, 1978b). Titres and specificities of these sera have previously been reported.…”

“…Four micrometre sections of the tissues were made using a cryostat microtome. Rabbit Up was taken simultaneously and processed in the same way in order to have tissue containing areas of orthokeratosis, parakeratosis and mucosa (Saurat et al, 1978b); normal human skin specimens were also used.…”

“…Titres and specificities of these sera have previously been reported. Briefiy, the titres ranged from i 50 to 1,200 (see Table 2); there was no species specificity, but organ specificity existed bone marrow, brain, trachea, thyroid, pylorus, stomach, duodenum, colon, liver, gall bladder, spleen, aorta, kidney and bladder were not found to express the antigens (Saurat et al, 1976(Saurat et al, , 1978b.…”