DESMOGLEIN 1 IN OVINE MUZZLE SKIN DETECTED BY IMMUNOHISTOCHEMISTRY AND IMMUNOBLOTTING DESMOGLEINA 1 NEL MUSELLO DI PECORA: INDAGINE DI IMMUNOISTOCHIMICA E DI IMMUNOBLOTTING VINCENZO MIRAGLIOTTA, ELENA DONADIO, ALESSANDRA COLI, MARIA RITA STORNELLI, ELISABETTA GIANNESSI, MARIA PAOLA RICCIARDI SUMMARY Desmosomes are epithelial adhesion structures that assure the mechanical cell-cell adhe- sion, by linking the intermediate filaments of two adjacent cells. Several proteins have been characterised as component of these structures and, among them, desmogleins are known to be the autoantigens in some autoimmune diseases that go by the name of pemphigus complex diseases. In particular Desmoglein 1 is the targeted antigen in Pemphigus foliaceus. This study aims at revealing the presence of Desmoglein 1 in the ovine muzzle skin using a com- mercial monoclonal antibody, raised against human desmoglein-1, on samples obtained from sheep muzzle. Immunohistochemical analyses (streptavidin-peroxidase method) and immunoblotting analyses (chemiluminescence method) have been performed. Immunohistochemical evaluation allowed for detection of a pericellular staining of ker- atinocyte cell membranes in the spinous and the basal layers of epidermis. A positive immunoreaction was obtained when the anti-Dsg-1 antibody was reacted with human cheek epidermis used as positive control. Specificity of the immune reaction was confirmed by the lack of staining in samples incubated with the anti-vimentin antibody used as negative con- trol. Densitometric analyses of the chemiluminescence film showed three bands. One of them could be referred to Desmoglein 1, the second one to Desmoglein 3 and the last one to a Desmoglein-Plakoglobin complex. Key words: muzzle; sheep; desmoglein; immunohistochemistry; immunoblotting. RIASSUNTO I desmosomi sono strutture di adesione tipiche dei tessuti epiteliali che connettono i fila- menti intermedi del citoscheletro di due cellule adiacenti, assicurando la loro adesione mec- canica. Tra le proteine che compongono queste strutture, le desmogleine sono note come anti- gene target in alcune malattie autoimmuni riunite sotto il nome di malattie del complesso del pemfigo. La desmogleina 1, in particolare, si comporta da auto antigene nel pemfigo foliaceo. Lo scopo della presente ricerca è stato quello di mettere in evidenza questa proteina su cam- pioni di cute prelevate da musello di pecora con l’utilizzo di un anticorpo monoclonale indot- to contro la desmogleina 1 dell’uomo. Su di essi sono state condotte indagini immunois- tochimiche (metodo streptavidina-perossidasi) e di immunoblotting (metodo della chemilu- minescenza). L’indagine immunoistochimica ha rilevato una distribuzione della proteina uni- Dipartimento di Anatomia, Biochimica e Fisiologia Veterinaria, Direttore Prof. Franco Martelli.