IFNG and infection: It is well known that for an intracellular pathogen represented by Brucella, the production of IFNγ, TNFα, and IL-12 from the T helper cells (Th1 response), as well as CD8+ and CD4+ T lymphocytes, activated macrophages and dendritic cells are necessary for the control of the infection; whereas Th2 components have a minor role in the control of infection [21, 35, 36].