Rotavirus-Specific B Cells Induced by Recent Infection in Adults and Children Predominantly Express the Intestinal Homing Receptor α4β7

Abstract

In vivo replication of rotaviruses is generally limited to enterocytes. Because of this restriction, most blood circulating rotavirus-specific B cells are hypothesized to originate in Peyer's patches and should express the intestinal homing receptor alpha4beta7. To test this hypothesis in humans, we used a flow cytometry assay that identifies antigen-activated (IgD-) B cells (CD19+) that express surface rotavirus-specific immunoglobulin. With this assay we could detect rotavirus-specific B cells in both children and adults with an acute rotavirus (RV) infection. Staining with an anti-alpha4beta7 monoclonal antibody, we could determine that B cells that express rotavirus-specific surface immunoglobulin predominantly express alpha4beta7. The response of rotavirus-specific antibody-secreting cells in the peripheral blood of children and adults with acute rotavirus infection was also studied by ELISPOT. The antibody-secreting cells of children were mainly of the IgM isotype, while the antibody-secreting cells of adults were predominantly of the IgA and IgG isotype. alpha4beta7+ and alpha4beta7- subsets of peripheral blood mononuclear cells were purified using paramagnetic beads and then tested in the ELISPOT assay. Rotavirus-specific antibody-secreting cells were predominantly present in the alpha4beta7+ subpopulation. The flow cytometry assay we have described will permit future studies to characterize the phenotype of virus-specific B cells and could be useful in the study of the immunogenicity and protective efficacy of RV vaccines and the identification of markers of protective immunity.

Distribution and phenotype of murine rotavirus-specific B cells induced by intranasal immunization with 2/6 virus-like particles

“…Some of the earlier cells observed here may result from the activation of the IgD + B cell fraction reacting with 2/6-VLP that was detected in NALT and CLN. Such cells present in all the lymphoid tissues analyzed from non-immune mice have already been reported within murine splenic cells [11] and, recently, within human B cells from adults, infants and cord blood, and have been proposed to be responsible for an innate B cell response resulting from the interaction of 2/6-VLP with natural surface anti-VP6 Ab [19,20]. Thus, the high frequency of 2/6-VLP-specific B cells observed here may result from both innate and adaptive B cell responses.…”

“…However, compared to results obtained with the same method, our results show that a4b7 expression by RV-specific B lymphocytes induced by i.n. administered nonreplicating Ag is lower than that observed in intestinal lymphoid tissues after oral administration of live virus in mice [15] (in this case up to 50% and 60% of RV-specific extrafollicular B cells expressed a4b7 in PP and MLN, respectively) or during an acute infection in children and adults [20,24]. This result suggests that a4b7 expression may probably not be a critical requirement for protection against RV infection after i.n.…”

Interaction of Rotavirus with Human Myeloid Dendritic Cells

“…To develop new strategies for treating or preventing this disease, our laboratory is currently characterizing human virus-specific T and B cells in children and adults (16,23,24,48). We recently showed that healthy adults have very low frequencies of circulating CD4 ϩ and CD8…”

VH1–46 Is the Dominant Immunoglobulin Heavy Chain Gene Segment in Rotavirus-Specific Memory B Cells Expressing the Intestinal Homing Receptor α4β7

“…B cells migrating through peripheral blood back to the gut should express the intestinal homing receptor ␣ 4 ␤ 7. Gonzales et al (6) found a mean percentage of 1.9 of memory B cells that bound RV DLP by flow cytometry analysis of peripheral blood cells obtained from healthy adults in Columbia, South America. In that study, the mean frequency of IgD Ϫ B cells that were both RV-specific and expressed ␣ 4 ␤ 7 was 3.3% in "large-" and 0.6% in "small-" sized memory B cells in acutely infected adults.…”

“…We also showed that adoptively transferred IgD Ϫ /␣ 4 ␤ 7 ϩ B cells, but not IgD ϩ /␣ 4 ␤ 7 ϩ or IgD Ϫ /␣ 4 ␤ 7 Ϫ B cells, cleared chronic RV infection in RAG-2-deficient mice that lack T and B cells (5). Recent studies determined that human RV-specific surface Ig ϩ B cells often express the ␣ 4 ␤ 7 molecule, as detected by a novel mAb specific for that heterodimer (6). We reasoned that analysis of the Ab repertoire in human RV-specific B cells should focus on these intestinal homing cells.…”