immunoregulatory

Immunoregulatory refers to the processes, cells, and molecules that control the immune response to maintain balance between defending against pathogens and tolerating self and harmless antigens. It encompasses mechanisms that suppress excessive inflammation and prevent autoimmunity while still allowing protective immunity to function.

Key players in immunoregulation include regulatory T cells (Tregs), regulatory B cells, tolerogenic dendritic cells, and myeloid-derived suppressor cells. Tregs, typically marked by FOXP3 expression, restrain immune activity through cell-contact–dependent mechanisms and anti-inflammatory cytokines. Regulatory B cells contribute to tolerance chiefly via interleukin-10 (IL-10). Inhibitory receptors such as CTLA-4, PD-1, and LAG-3 on immune cells help shift responses toward regulation.

Cytokines such as IL-10, transforming growth factor-beta (TGF-β), and IL-35 create anti-inflammatory environments that dampen effector T cell responses and promote the development or function of regulatory cells. Mechanisms of regulation include suppression of proliferation, induction of T cell anergy or deletion, altered antigen presentation, and expansion of regulatory cell populations.

Physiological role and clinical relevance: Immunoregulation is essential for preventing autoimmunity and limiting tissue damage during immune responses, and it contributes to transplant tolerance and maintenance of mucosal and organ-specific homeostasis. Dysregulation can contribute to autoimmune diseases, allergies, chronic infections, and cancer, where enhanced regulatory activity can hinder anti-tumor immunity. Therapeutic approaches aim to modulate immunoregulatory pathways, such as strategies to enhance regulatory responses in autoimmunity or transplantation, or transiently reduce regulation to improve cancer immunotherapy.