Cell Biol. were observed at 12 months for oral/DXM and oral/M group calves. Immunoblot analyses with a whole-cell sonicate of subsp. exhibited the most reactivity with sera from i.p. group calves and the least reactivity with sera from oral group calves. Further evidence of subsp. subsp. subsp. subsp. contamination, yet it is widely accepted that antibodies secreted by B cells provide little benefit to the host in controlling or clearing the infection (17). However, B cells also present cognate antigen to CD4+ T cells and secrete cytokines and, as such, play a significant role in maintaining the full match of immunity necessary to control intracellular infections (14). A loss of cell-mediated immunity dominated by CD4+ T cells has been observed in the later stages of subsp. contamination and is concomitant with increasing numbers of B cells and an increase in humoral immune responses (16, 20). Yet little work has been carried out to define B cell Rabbit Polyclonal to Ezrin (phospho-Tyr146) responses or to elucidate B cell subpopulations during subsp. contamination. There are several markers for B cells that are indicative of activation, such as CD5, CD25, and CD45. CD5 is usually a membrane glycoprotein that is expressed on T cells as well as B-1a lymphocytes (4). CD5 is recognized as a mediator of T cell-B cell interactions, and increased expression of this cell surface marker has been noted on B cells in autoimmune diseases such as systemic lupus erythematosus, rheumatoid arthritis, and inflammatory bowel disease (13, 15, 21). Similarly, CD25 expression increases upon activation of B cells, and this activation has been associated with increased antigen presentation by cells (6, 9). The CD45 marker is usually associated with the memory phenotype when it is expressed on CD4+ T cells (CD4+ CD45RO+), but it has also been exhibited for B cell populations, suggesting that a memory B cell phenotype is present (14). In human patients with inflammatory bowel diseases such as Crohn’s disease and ulcerative colitis, the CD45 marker on B cells can be used as an indication of the stage of disease (23). Expression of CD45RO on CD19+ B cells in the lamina propria and the peripheral blood was indicative of patients transitioning to more advanced stages of disease (23). Previous observations have exhibited KPT 335 that this stage of paratuberculosis has a significant impact on the number and phenotype of circulating B cells in cattle that are naturally infected with subsp. (18). We proposed to further evaluate the expression of B cell KPT 335 markers in concordance with the appearance of subsp. subsp. subsp. (oral versus intraperitoneal [i.p.]) and the strain of subsp. utilized for inoculation (laboratory strain versus clinical isolate) impacted the degree of tissue colonization in a 12-month study (19). Calves inoculated orally with a clinical isolate of subsp. had the largest quantity of positive tissue sites (15/22 sites), whereas calves in the i.p. group experienced the smallest number (8.5/22 sites). Here we present further observations around the impact of oral or i.p. inoculation and KPT 335 bacterial strain on the temporal changes in activated B cell subpopulations. MATERIALS AND METHODS Animals and experimental contamination. As previously explained (19), neonatal Holstein dairy calves obtained from status level 4 herds enrolled in the Voluntary Bovine Johne’s Control Program were purchased at 1 to 2 2 days of age and housed in biosafety level 2 containment barns for the duration of the study. Control calves were housed in a barn individual from your experimentally infected animals. Calves were allowed to acclimate.