Proliferação de linfócitos e apoptose de células CD 5+ de bovinos infectados pelo vírus da leucose enzoótica bovina

Abstract

The purpose of the present trail was to evaluate the lymphocyte proliferation and the apoptosis rates of CD5 + cells in dairy cows infected with bovine leukemia virus (BLV) with distinct lymphocyte profiles in infected animals known as alymphocytotic (AL) and persistent lymphocytosis (PL). A total of 100 Holstein cows were sera tested for bovine leukemia virus through agar gel immunodiffusion (AGID) and enzyme-linked immunosorbent-assay (ELISA). From these animals, 15 cows were selected and divided uniformly in 3 groups (negative, AL, LP). The lymphocyte proliferation was performed using flow cytometric measurement of CFSE-DA dye, where 2x10 6/mL lymphocytes were plated per well. The apoptosis of CD5 + cells from peripheral blood was performed using the annexin V-FITC to measure the apoptosis rates and the identification of CD5 + was accessed using monoclonal antibodies. Animals from the LP group showed lower lymphocyte proliferation and also lower apoptosis rates of CD5 + cells compared with negative and AL animals. The development of PL which resulted from an increase in B cell count, is due to the decrease in the apoptosis rates of CD5 + cells, and the higher lymphocyte proliferation appears to be limited only in the initial stages of development of LP.