Fish oil disrupts B cell MHC class II lateral organization in the murine immunological synapse

Abstract

Fish oil enriched long chain n‐3 polyunsaturated fatty acids disrupts the lateral organization of proteins on the T cell side of the immunological synapse. However, the impact of fish oil on the antigen presenting cell side of the immunological synapse is unclear. We previously demonstrated that B cells isolated from mice fed fish oil suppressed B cell microdomain clustering as well as the ability to activate naïve CD4+ T cells through antigen presentation. In this study, using a combination of quantitative imaging methods, we tested the effect of fish oil on the lateral organization of B cell major histocompatibility complex (MHC) class II molecules involved in forming the immunological synapse. Fish oil had no impact on pre‐synaptic B cell MHC II clustering. However, fish oil did suppress the recruitment of MHC class II to the synapse. As a consequence, T cell PKCθ recruitment to the synapse was also diminished. The effects were independent of changes in B‐T cell adhesion. Finally, we compared the impact from fish oil to cholesterol depletion using methyl‐β‐cyclodextrin treatment and found similar results. Overall, the results reveal commonality in the mechanism by which fish oil manipulates protein lateral organization of B cells compared to T cells. Furthermore, the data establish MHC class II lateral organization on the B cell side of the immunological synapse as a novel molecular target of fish oil.NIH R15AT006122