Multiparametric flow cytometry analysis of peripheral blood B cell trafficking differences among Epstein-Barr virus infected and uninfected subpopulations.

Aims. Epstein-Barr virus (EBV) targets predominantly B cells and these cells could acquire new phenotype characteristics. Here we analyzed whether EBV-infected and -uninfected B cells from healthy subjects differ in proportion of dominant phenotypes, maturation stage, and homing receptors expression. Methods. EBV-infected and -uninfected cells were identified by flow cytometry using fluorophore-labeled EBV RNAspecific DNA probes combined with fluorophore-labeled antibody to surface lineage markers, integrins, chemokine receptors, and immunoglobulin isotypes, including intracellular ones. Results. Our results show that the trafficking characteristics of EBERpos B cells are distinct from EBERneg B cells with most dominant differences detected for a4ß1 and a4ß7 and CCR5 and CCR7. EBV-positive cells are predominantly memory IgM+ B cells or plasmablasts/plasma cells (PB/PC) positive for IgA or less for IgM. In comparison to uninfected B cells, less EBV-positive B cells express a4ß7 and almost no cells express a4ß1. EBV-positive B cells contained significantly higher proportion of CCR5+ and CCR7+ cells in comparison to EBV-negative cells. In vitro exposure of blood mononuclear cells to pro-inflammatory cytokine IL-6 reduces population of EBV-positive B cell. Conclusion. Although EBV-infected B cells represent only a minor subpopulation, their atypical functions could contribute in predisposed person to development abnormities such as some autoimmune diseases or tumors. Using multi-parameter flow cytometry we characterized differences in migration of EBV-positive and -negative B cells of various maturation stage and isotype of produced antibodies particularly different targeting to mucosal tissues of gastrointestinal and respiratory tracts. [ABSTRACT FROM AUTHOR]