Submitted to: Journal of Dairy Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 7/31/2007
Publication Date: 11/6/2007
Citation: Foote, M.R., Nonnecke, B.J., Beitz, D.C., Waters, W.R. 2007. Antigen-specific B-cell responses by neonatal calves after early vaccination. Journal of Dairy Science. 90(11):5208-5217. Interpretive Summary: Responses of newborn calves to vaccination are variable and often characterized by marginal antibody responses. The immune cell (i.e., B cell) population pivotal in the production of antibody also has not been characterized completely in the newborn calf. Results from this research describe the composition and function of B cell populations in preruminant calves vaccinated at an early age. Although preliminary, these data indicate that the responsiveness of this immune cell in young calves is dependent on the nature of the vaccine and not animal maturity. This research provides important new information regarding the immune responsiveness of the neonatal calf to vaccination that may be useful in the development of effective vaccines for calves.
Technical Abstract: Objectives of these studies were to characterize B cell responses of neonatal calves to ovalbumin and to Mycobacterium bovis BCG vaccination. In the first experiment, six calves were vaccinated with ovalbumin at 3 and 5 wk of age. Three of the six calves also were vaccinated with BCG at 3 wk of age. M. bovis lipoarabinomannan-reactive IgG1 and IgG2 were detected in calf sera prior to vaccination, indicative of colostral transfer of maternal Ig cross-reactive to BCG; whereas ovalbumin-reactive IgG1 and IgG2 were not detected before vaccination. Vaccination of 3-wk-old calves to ovalbumin elicited antigen-specific IgG1 and IgG2 antibody responses that were amplified by secondary vaccination. Vaccination with BCG did not elicit a measurable antibody response. In the second experiment, six calves were vaccinated with ovalbumin at 3 and 5 wk of age in addition to BCG at 3 wk of age. In vitro stimulation of lymph node cells with ovalbumin resulted in decreased expression of CD5, CD21, and CD40 and increased expression of B-B2, CD25, and CD80 on IgM**+ cells. Stimulation of lymph node cells in vitro with purified protein derivative resulted in increased expression of CD25 and CD80 on IgM**+ cells. Expression of activation molecules on ovalbumin- and purified protein derivative-stimulated CD5**+/IgM**+ cells was similar to expression on the larger IgM**+ cell population. The increased expression of MHC class II on CD5**+/IgM**+ cells after stimulation with antigen was the only exception. Interestingly, IgM**+ cells isolated from the superficial cervical lymph node draining the vaccination site, but not from the opposing cervical lymph node, responded to antigen stimulation in vitro. In conclusion, calves generated B cell responses to both ovalbumin and BCG after vaccination. Additional studies are necessary to determine whether maternal immunologic experience transferred via colostral immunoglobulin inhibits production of mycobacteria-specific immunoglobulin production in the calf.