CELL-MEDIATED-IMMUNITY TO EIMERIA IN THE FOWL - THE ABSENCE OF CROSS-SPECIES PROTECTION IS NOT DUE TO THE LACK OF CROSS-REACTIVE T-CELLS

Immunity to Eimeria species in the fowl has been shown to be species specific and it has been proposed that the lack of cross-protection between the species of Eimeria is due to the absence of T cells which recognize antigens from a heterologous species. When this hypothesis was tested the results showed that antigens from E. tenella elicited a strong specific response by cells from birds immune to E. tenella. In contrast cells from birds which were immune to E. acervulina responded to a similar magnitude to both E. tenella and E. acervulina antigens. This indicates that the lack of cross-protection is not due to the lack of cross-reactive T cells.