IFNG and plague: V-mediated IL-10 secretion is thought to be involved in plague pathogenicity by preventing the release, to serum, of proinflammatory cytokines, such as TNF-α and IFN-γ, postinfection, and by subsequently suppressing the innate immune responses to plague infection (Nakajima & Brubaker, 1993; Brubaker 2003).