Studies on the Immune System o native Egyptian Cattle Using Flow Cytometry

Abstract

The Baladi cattle is considered an essential component of the Egyptian animal wealth and so, the Egyptian government tries hard on cbntrolling the infectious agents among such species by the application of control programs based primarily on immunological aspects.

One of the major difficulties for the application of such control programs was the slow progress in elucidating the mechanisms regulating the immune response to the infectious agents and their derived vaccines. This was the result of lack of mAbs reagents needed for studying the immune system and immune response. So, the aim of the present study was to provide an insight toward the immune system of Baladi cattle using mAbs and flow cytometry technology. This was achieved by;

1- Determination of cellular composition of the immune system of apparently healthy Baladi cattle at two different ages, including young age and adult age. This was performed by screening the percentage of different leukocyte subpopulations using mAbs that recognize orthologous molecules on these subpopulations in four young animals and four adult animals. It was noted:

a- The whole leukocyte population in young animals composed of granulocytes representing about 30%, monocytes representing about 11% and lymphocytes representing about 59% while in adult animals, the granulocytes represent about 22%, monocytes represent about 7% and lymphocytes represent about 71%.

b- T cells (CD3+ lymphocytes) represent about 37% of circulating lymphocyte population in young animals and about 39% in adult animals.

c- Presence of higher frequency of CD4+ T cells over the CD8+ T cells, as it was found that CD4+ T cells represent about 41% and 44% of circulating lymphocytes in • young and adult animals respectively. Mean while the CD8+ T cell subset was found