Identification of Ostertagia ostertagi specific cells in bovine abomasal lymph nodes

To investigate the contribution of different bovine cell subpopulations in the development of in vitro induced responses by Ostertagia ostertagi third larval antigen extract (L3), bovine abomasal lymph node cell suspensions w ere depleted of specific cell populations. The depleted cell suspensions we re subsequently assayed for their proliferative responses to O. ostertagi L 3 antigen extract. Proliferative responses to O. ostertagi L3 antigen extra ct were restricted to a CD2(+)CD4(-)CD8(-) cell population and MHC II+ cell s different from B-cells were of major importance. Depletion of CD4, CD8, C D4CD8, IgM or CD21 positive cells did not decrease proliferation to L3 anti gen extract. Depletion of gamma delta T-cells, which also comprise a subpop ulation of CD2+CD4-CD8- cells, reduced proliferation to L3 antigen extract only in one animal, The results suggest that either gamma delta T-cells cou ld be involved in the proliferation or that another as yet unidentified pop ulation is important for proliferation. The precise role of these populatio ns during infection with O. ostertagi and the mechanism by which these cell s may influence the host immune response are important issues that remain t o be elucidated, (C) 2000 Elsevier Science B.V. All rights reserved.