Figure 2.

Quantity and quality alterations of T cells in HIV/AIDS patients with incomplete immune reconstitution. The naïve T (T_N) cells produced by the thymus can be activated by multiple factors, including persistent viral reservoir, low residual viremia, co-infections, microbial translocation and dysbiosis. Difficult-to-remove risk factors may lead to persistent chronic immune activation, contributing to the development of T cell exhaustion and immune senescence. Exhausted and senescent T cells are qualitatively altered and prone to death, possibly through apoptosis, pyroptosis, and ferroptosis. LPS, lipopolysaccharide; HLA-DR, human leukocyte antigen DR; TNF-α, tumor necrosis factor-alpha; IFN-γ, interferon-gamma; IL-2, interleukin-2; PD-1, programmed death-1; TIGIT, T cell immunoglobulin and ITIM domain; TIM3, T cell immunoglobulin domain and mucin domain-containing protein 3; CTLA-4, cytotoxic T lymphocyte antigen-4.