B cells as a major source of IL-27 cytokine in antibody responses and anti-viral immunityThis proposal aims to understand a new regulatory role of B lymphocytes, i.e., induction of these cells to produceIL-27 cytokine, underlying molecular mechanisms, and function of B cell-produced IL-27 in the antibody responseand antiviral immunity. As critical immune effectors, B cells integrate innate and adaptive receptor signalstriggered by infections to undergo differentiation for antibody responses, such as class-switching to generatedifferent IgG isotypes.