Suppression of circulating IgD+CD27+ memory B cells in infants living in a malaria-endemic region of Kenya

• Published in: Malaria Journal
• Main Authors: Asito Amolo S, Piriou Erwan, Jura Walter GZO, Ouma Collins, Odada Peter S, Ogola Sidney, Fiore Nancy, Rochford Rosemary
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2011
• Subjects: B cells; Infant immunity; Plasmodium falciparum; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic
• Online Access: https://doi.org/10.1186/1475-2875-10-362; https://doaj.org/article/4adbba9a33d049d98644e026f62d050f

Abstract Background Plasmodium falciparum infection leads to alterations in B cell subset distribution. During infancy, development of peripheral B cell subsets is also occurring. However, it is unknown if infants living a malaria endemic region have alterations in B cell subsets that is independent of an age effect. Methods To evaluate the impact of exposure to P. falciparum on B cell development in infants, flow cytometry was used to analyse the distribution and phenotypic characteristic of B cell subsets in infant cohorts prospectively followed at 12, 18 and 24 months from two geographically proximate regions in western Kenya with divergent malaria exposure i.e. Kisumu (malaria-endemic, n = 24) and Nandi (unstable malaria transmission, n = 21). Results There was significantly higher frequency and absolute cell numbers of CD19+ B cells in Kisumu relative to Nandi at 12( p = 0.0440), 18( p = 0.0210) and 24 months ( p = 0.0493). No differences were observed between the infants from the two sites in frequencies of naïve B cells (IgD+CD27-) or classical memory B cells (IgD-CD27+). However, immature transitional B cells (CD19+CD10+CD34-) were higher in Kisumu relative to Nandi at all three ages. In contrast, the levels of non-class switched memory B cells (CD19+IgD+CD27+) were significantly lower overall in Kisumu relative to Nandi at significantly at 12 ( p = 0.0144), 18 ( p = 0.0013) and 24 months ( p = 0.0129). Conclusions These data suggest that infants living in malaria endemic regions have altered B cell subset distribution. Further studies are needed to understand the functional significance of these changes and long-term impact on ability of these infants to develop antibody responses to P. falciparum and heterologous infections.