Responses of bovine T cells to fractionated lysate and culture filtrate proteins of Mycobacterium bovis BCG.

Bacterial cell lysates and culture filtrate proteins of Mycobacterium bovis BCG were each separated in a two-dimensional system that yields soluble protein fractions immediately available for probing with T cells. The fractions were used in lymphocyte proliferation assays using blood lymphocytes from cattle immunized with either viable or gamma-irradiated BCG. Cattle immunized with either form of BCG responded similarly to fractionated lysate proteins. Cattle immunized with viable BCG responded to culture filtrate proteins that were not recognized by cattle immunized with dead BCG. Marked heterogeneity of the responses to the culture filtrate proteins was seen.