Dietary allergen induces trafficking of CXCR5-expressing peripheral leukocytes to the central nervous system in subclinically sensitized individuals 2944

Abstract Description Food allergen consumption has been suspected to influence mood and behavior in individuals who are sensitized but tolerant to the food. Using a mouse model of subclinical cow’s milk allergy, we previously showed that C57BL/6J mice sensitized to β-lactoglobulin (BLG, Bos d 5) exhibited behavioral changes after consuming a whey-containing diet for 2 weeks. Cortical demyelination, neuroinflammation, and CD45+ cell infiltration were also evident in the brain. Hypothesizing that allergen consumption would trigger gut-brain communication through chemokine-mediated leukocyte trafficking, we performed flow cytometric immunoprofiling of CD45+ cells in the brain. After mice were orally sensitized to BLG and placed on the whey-containing diet for 2 weeks, single-cell preparations from the whole brain were stained for immune cell markers and chemokine receptors. We observed significant increases in CXCR5+CD3+ and CXCR5+CD19+ cells in BLG-sensitized mice compared to naïve or sham-sensitized mice. Immunofluorescence staining of brain sections showed that the differences in the number of CXCR5+ cells among the groups were most prominent in the cortical regions. The adoptive transfer of BLG-sensitized donor splenocytes resulted in the trafficking of CXCR5+ donor cells to the dura mater of naïve recipients, supporting the involvement of CXCR5+ in allergen-induced peripheral-to-central leukocyte trafficking. The role of CXCR5+ leukocytes in neurobehavioral pathology is yet to be elucidated. Funding Sources Supported by NIH grant 1R01AI168563 Topic Categories Neuroimmunology (NEUR)