Interleukin-12 in infectious diseases.
Interleukin-12 (IL-12) is a potent immunoregulatory cytokine that is crucially involved in a wide range of infectious diseases. In several experimental models of bacterial, parasitic, viral, and fungal infection, endogenous IL-12 is required for early control of infection and for generation and perhaps maintenance of acquired protective immunity, directed by T helper type 1 (Th1) cells and mediated by phagocytes. Although the relative roles of IL-12 and gamma interferon in Th1-cell priming may be to a significant extent pathogen dependent, common to most infections is that IL-12 regulates the magnitude of the gamma interferon response at the initiation of infection, thus potentiating natural resistance, favoring Th1-cell development; and inhibiting Th2 responses. Treatment of animals with IL-12, either alone or as a vaccine adjuvant, has been shown to prevent disease by many of the same infectious agents, by stimulating innate resistance or promoting specific reactivity. Although IL-12 may enhance protective memory responses in vaccination or in combination with antimicrobial chemotherapy, it is yet unclear whether exogenous IL-12 can alter established responses in humans. Continued investigation into the possible application of IL-12 therapy to human infections is warranted by the role of the cytokine in inflammation, immunopathology, and autoimmunity.
Romani
L
L
Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Italy. iromani@unipg.it
Puccetti
P
P
Bistoni
F
F
D000818:Animals; D001424:Bacterial Infections / Q000276:immunology; D003141:Communicable Diseases / Q000276:immunology* / Q000378:metabolism; D015658:HIV Infections / Q000276:immunology; D006373:Helminthiasis / Q000276:immunology; D006801:Humans; D007113:Immunity, Innate; D018664:Interleukin-12 / Q000276:immunology* / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D009181:Mycoses / Q000276:immunology; D011528:Protozoan Infections / Q000276:immunology; D018123:Receptors, Interleukin / Q000276:immunology / Q000378:metabolism / Q000502:physiology; D014611:Vaccination; D014777:Virus Diseases / Q000276:immunology
D018123:Receptors, Interleukin; D018664:Interleukin-12