CD 57 expression on lymphocytes present in the caecum and caecal tonsils in broilers infected with Eimeria tenella

Abstract

In order to detect and establish the expression of the CD57 lymphocyte population in the caecum and caecal tonsils in broilers, immunohistochemical studies of tissue samples of broilers experimentally infected with E. tenella at 21 days of age were carried out. Immunohistochemical investigations were performed with the aid of the avidin-biotin technique (LSAB), by using mouse monoclonal anti- CD57 antibodies. Increased immunoreactivity of the lamina epithelialis, mucosal lamina propria and caecal submucosa was detected as early as two days after infection, increasing at its highest at the end of the fourth day after infection. On the fifth, sixth and seventh day after infection the degree of expression of CD57 lymphocytes in the caecal mucosa of experimental birds decreases. The immunoreactivity of the tissue of the stroma of the mucosal and submucosal lamina propria of the caecal tonsils was most intensive the fourth, sixth and seventh day after infection. A discrete immunoreactivity decrease was present during the fifth day after infection. The so established CD57 lymphocyte population activity in the caecum and caecal tonsils substantiates the existence of NK cytotoxic activity of intraepithelial lymphocytes, as well as the role of these cells in the intestinal mucosa defense mechanisms against intracellular microorganisms.

U cilju detekcije i utvrđivanja ekspresije CD57 populacije limfocita u cekumu i cekalnim tonzilama pilića, izvedeno je imunohistohemijsko ispitivanje tkivnih isečaka kod jedinki koje su 21. dana starosti eksperimentalno inficirane protozoom E. tenella. Ova ispitivanja su izvedena avidin-biotin tehnikom (LSAB), korišćenjem monoklonskih mišijih anti-CD57 antitela. Pojačana imunoreaktivnost laminae epithelialis, laminae propriae mukoze i submukoze cekuma zapažena je već drugog dana posle infekcije, sa najvećim intenzitetom krajem četvrtog dana. Petog, šestog i sedmog dana posle infekcije, stepen ekspresije CD57 limfocita u mukozi cekuma eksperimentalnih životinja se smanjivao. Imunoreaktivnost tkiva cekalnih tonzila najintenzivnija je četvrtog, šestog i sedmog dana posle infekcije, u stromi laminae propriae mukoze i submukozi, uz postojanje blagog pada u petom danu posle infekcije. Dokazana imunoreaktivnost CD57 populacije limfocita u cekumima i cekalnim tonzilama, potvrđuje NK ćelijsku citotoksičnu aktivnost populacije intraepitelnih limfocita i ukazuje na važnu ulogu ovih ćelija u organizaciji odbrane crevne mukoze protiv intracelularnih mikroorganizama.