B cell flow cytometry gating strategy.

<p>a) Initial cell- inclusion and exclusion gating. b) The main B cell phenotypes from which cytokine production were assessed includes memory B cells (CD19⁺CD27⁺), mature B cells (CD19⁺CD27^-CD138^-), plasma B cells (CD19⁺CD138⁺) and plasma (memory) B cells (CD19⁺CD27⁺CD138⁺). c) Further downstream cytokine analysis were done following the identification of the main B cell subsets in b), by plotting respective cytokines against one another. Appropriate cut-off levels for the gating strategy were used as determined by using FMO control samples.