Constitutive immune mechanisms: mediators of host defence and immune regulation

• The immune system enables organisms to combat infections and to eliminate endogenous challenges. Immune responses can be evoked through diverse inducible pathways. However, various constitutive mechanisms are also required for immunocompetence. The inducible responses of pattern recognition receptors of the innate immune system and antigen-specific receptors of the adaptive immune system are highly effective, but they also have the potential to cause extensive immunopathology and tissue damage, as seen in many infectious and autoinflammatory diseases. By contrast, constitutive innate immune mechanisms, including restriction factors, basal autophagy and proteasomal degradation, tend to limit immune responses, with loss-of-function mutations in these pathways leading to inflammation. Although they function through a broad and heterogeneous set of mechanisms, the constitutive immune responses all function as early barriers to infection and aim to minimize any disruption of homeostasis. Supported by recent human and mouse data, in this Review we compare and contrast the inducible and constitutive mechanisms of immunosurveillance. Constitutive innate immune mechanisms, such as restriction factors, RNA interference, antimicrobial peptides, basal autophagy and proteasomal degradation, exert early host defence activities that also aim to minimize tissue damage and homeostatic disruption by limiting the activation of inducible innate immunity.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Immunologi inom det medicinska området (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Immunology in the medical area (hsv//eng)

Keyword

aicardi-goutieres-syndrome

toll-like receptors

antimicrobial peptide

lc3-associated phagocytosis

mycobacterium-tuberculosis

inflammasome

activation

pattern-recognition

restriction factors

autophagy

protects

intrinsic immunity

Immunology

Publication and Content Type

ref (subject category)

art (subject category)