ReviewPro- and anti-inflammatory cytokines in tuberculosis: A two-edged sword in TB pathogenesis

- Cytokines, because of their nature of soluble mediators, represent key elements in mediating and tuning the immune response against Mycobacterium tuberculosis.
- Mycobacterium tuberculosis orchestrates the cytokine storm to induce or evade host immune responses.
- Granuloma formation is tightly regulated by lung-secreted cytokines.
- Perturbation of cytokine signaling represents a critical checkpoint of the immune response against Mycobacterium tuberculosis.
- Understanding the balance between pro- and anti-inflammatory cytokines is crucial for developing more effective measures of immune intervention against tuberculosis.

A major challenge in tuberculosis (TB) is to improve current vaccination and therapeutic strategies and this requires a fine understanding of the mechanisms that mediate protection and pathogenesis. We need to discern how the host perceives Mycobacterium tuberculosis (Mtb) infection, what are the danger signals that activate the immune system and, in turn, how the immune response controls the life-cycle of Mtb. Cytokines, because of their nature of soluble mediators, represent key elements in mediating and tuning these complex processes.In this review, we provide an overview of recent studies on cytokines expression and function in active (mainly human) TB. Understanding of the balance between pro- and anti-inflammatory networks is crucial to refine our knowledge on the immune responses directed against Mtb.