Figure 2.

Immune responses in patients with LC-TB

The immune responses against mutant tumor cells or invading bacteria involve the rapid activation of macrophages, NK cells, and DCs within the body. These immune cells act upon encountering the threat. The tumor or bacterial antigens are captured by APCs, notably DCs, which then migrate to the draining lymph node. In this location, the DCs activate immature T cells that subsequently differentiate into effector T cells. This activation occurs as the DCs present the captured antigens using MHC class I and II molecules on their surface. Activated T cells then enter the bloodstream and infiltrate the tumor or infection site, carrying out their function of eliminating tumor cells or MTB by releasing cytotoxic cytokines. APCs: Antigen-presenting cells; CTL: Cytotoxic T lymphocytes; DCs: Dendritic cells; IFN-γ: Interferon gamma; MHC: major histocompatibility complex class; NK cells: Natural killer cells; ROS: Reactive oxygen species; TGF-β: Transforming growth factor β; TLR: Toll-like receptors; TNF-α: Tumor necrosis factor alpha.