Cell-mediated immunity in neonatal calves: delayed-type hypersensitivity and lymphocyte blastogenesis following immunization with a mycobacterial immunopotentiating glycolipid and tuberculoproteins of Mycobacterium bovis
Woodard, L.F.; Renshaw, H.W.; Burger, D.
American Journal of Veterinary Research 39(4): 579-584
1978
ISSN/ISBN: 0002-9645 PMID: 347995 Document Number: 136421
Neonatal calves were intradermally inoculated with oil-in-water emulsions containing 150 .mu.g of mycobacterial glycolipid (P3) with and without 150 .mu.g of purified protein derivative of M. bovis (PPDb). Delayed hypersensitivity [DH] skin testing and lymphocyte-stimulation assays revealed cell-mediated immune responses to tuberculoproteins in 5 calves immunized with P3-PPDb emulsion (EP3-PPDb); comparative in vivo and in vitro studies did not detect tuberculin sensitivity in 5 calves inoculated with P3 emulsion (EP3) without PPDb. DH responses were evaluated at 28 and 200 days by intradermal tuberculin testing. Calves injected with EP3 did not develop a DH response to the tuberculin; calves inoculated with EP3-PPDb developed positive skin test responses to tuberculin proteins of M. bovis (PPDb) and Mycobacterium avium (PPDa). Before and at intervals after inoculation of newborn calves with EP3 or EP3-PPDb, the in vitro blastogenic response of lymphocytes to PPDb and PPDa was assessed, using whole blood and peripheral blood lymphocyte-stimulation assays. The peripheral blood lymphocyte-stimulation assay was more sensitive than the whole blood culture technique. A diphasic response was noticed in peripheral lymphocyte cultures taken from calves inoculated with EP3-PPDb and incubated with PPDb. Following an initial depression (P < 0.05), significant increases (P < 0.01) in lymphocyte transformation were noticed at day 10 and later at days 28 and 42 when compared to animals injected with EP3 only. Skin test responses and lymphocyte blastogenic responses to the homologous test antigen (PPDb) equalled or exceeded responses to the heterologous test antigen (PPDa). Adjuvant activity and potential applications of nonliving P3 immunopotentiator in eliciting cellular immunity to specific antigens was discussed.