Cytokines in brucellosis: biological rhythm at the interface of innate and adaptive immunity

Abstract

Cytokines play an important role in immunological responses and protection against Brucella spp. infection. This article gives an overview of the role of various cytokines involved in the outcome of brucellosis. The susceptibility or resistance to the Brucella infection relies on a finely regulated balance of cytokines rhythmically produced by distinct T cell subsets (Th1 and Th2). The Th1 cytokines (e.g. TNF-α, IFN-γ) induce the CD8+ CTL-mediated cytotoxicity against Brucella-infected Mφ (specific cellular immunity), whereas, the Th2 response (e.g. IL-10) activates B lymphocytes for antibody production, facilitating the opsonization of Brucella (specific humoral immunity). This paper further analyses the information available on the assessment of cytokine profiles underscoring the requirement of more research on the cytokine biomarkers and their rhythmic induction in brucellosis, which may be helpful in establishing quick diagnostic tests as well as developing vaccines against brucellosis.Abbreviations: Th: T helper; TNF-α: Tumour necrosis factor-alpha; IFN-γ: Interferon-gamma; CD: Cluster of differentiation; CTL: Cytotoxic T lymphocyte; Mφ: Macrophage; IL: Interleukin