Immunohistochemical investigation of cells expressing CD21, membrane IgM, CD32 and a follicular dendritic cell marker in the lymphoid tissues of neonatal calves

Abstract

a b s t r a c tActivation of B lymphocytes in the presence of passive maternal antibodies depends on expression of CD21, membrane IgM and CD32. On colligation with IgM, CD32 inhibits activation whereas CD21 enhances it. Recently, we assessed expression of CD21 and CD32 on IgM + cells from lymphoid tissues of newborn calves by flow cytometry, but this approach does not provide information about spatial distribution within lymphoid compartments. Therefore, histologic sections of lymphoid tissues from newborn and 7-month-old calves were examined using an immunoperoxidase technique. In all calves, CD21 and IgM stained cells were collocated in the cortex and paracortex of the retropharyngeal lymph node, in the marginal zone of the spleen and in lymphoid aggregates of palatine tonsils. Most CD32 + cells were in the mantle zone of lymphoid follicles in 7-month-old calves, whereas only weak staining was observed in newborns. A few CD32 + cells were also observed in the paracortex at both ages. Absence of CD32 + cells in the center of follicles suggests that IgM + CD32 − cells observed previously by flow cytometry were from germinal centers. Overall, there were few organized lymphoid aggregates within lymphoid tissues of newborn calves, and follicular dendritic cells were virtually undetectable. Their absence may be an important limitation for neonatal immunization.

Strategies for Design and Application of Enteric Viral Vaccines

“…The in vitro antibody-producing activity following activation by mitogens is lower for B cells of calves until at least three weeks of age (79). Moreover, follicular dendritic cells, which are important for germinal center reaction, for Ig class switching, and for affinity maturation, are lower in number in lymphoid tissues, including ileal PPs of neonatal as compared with older calves (80). Interestingly, soluble CD14 present in bovine or porcine colostrum has been shown to be a mitogen for B cells of neonatal mice (81,82), which may have important implications for mucosal B cell responses to vaccines in colostrum-fed domestic animals.…”

Expression of complement receptors 1 (CR1/CD35) and 2 (CR2/CD21), and co-signaling molecule CD19 in cattle

“…CD21+ cells are also observed in the subcapsular sinus of lymph nodes (Chattha et al, 2010c). The monoclonal antibody CC--21 also labels cells in tonsil follicles in a manner consistent with human follicular dendritic cells (Naessens et al, 1990).…”

“…Chattha for use in a Blow cytometry study (Chattha et al, 2010c). BrieBly, tissues were diced into 1 mm cubes, then passed once through a Cellector™ tissue sieve (Sigma, size 60 mesh), twice through 4 layers of cheesecloth, and Binally through a 40 μm cell strainer (BD Biosciences) to yield a single cell preparation.…”