title: A protective and agonistic function of IL-12p40 in mycobacterial infection.
abstract: IL-12p35(-/-)p40(-/-) mice are highly susceptible to Mycobacterium bovis bacillus Calmette-Guérin (BCG) or Mycobacterium tuberculosis infection. In this study IL-12p35(-/-) mice, which are able to produce endogenous IL-12p40, cleared M. bovis BCG and showed reduced susceptibility to pulmonary M. tuberculosis infection, which was in striking contrast to the outcome of mycobacterial infection in IL-12p35(-/-)p40(-/-) mice. Resistance in wild-type and IL-12p35(-/-) mice was accompanied by protective granuloma formation and Ag-specific delayed-type hypersensitivity responses, which were impaired in susceptible IL-12p35(-/- )p40(-/-) mice. Furthermore, IL-12p35(-/-) mice, but not IL-12p35(-/-)p40(-/-) mice, mounted Ag-specific Th1 and cytotoxic T cell responses. In vivo therapy with rIL-12p40 homodimer restored the impaired delayed-type hypersensitivity responses in M. bovis BCG-infected IL-12p35(-/-)p40(-/-) mice and reverted them to a more resistant phenotype. Together, these results show evidence for a protective and agonistic role of endogenous and exogenous IL-12p40 in mycobacterial infection, which is independent of IL-12p70.
authors.affiliation: Medical Research Council Unit Immunology in Infectious Diseases, Department of Immunology, University of Cape Town, Cape Town, South Africa.
authors.forename: C
authors.initials: C
authors.lastname: Hölscher
authors.forename: R A
authors.initials: RA
authors.lastname: Atkinson
authors.forename: B
authors.initials: B
authors.lastname: Arendse
authors.forename: N
authors.initials: N
authors.lastname: Brown
authors.forename: E
authors.initials: E
authors.lastname: Myburgh
authors.forename: G
authors.initials: G
authors.lastname: Alber
authors.forename: F
authors.initials: F
authors.lastname: Brombacher
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology; D002478:Cells, Cultured; D015169:Colony Count, Microbial; D006099:Granuloma / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D006968:Hypersensitivity, Delayed / Q000276:immunology; D018664:Interleukin-12 / Q000235:genetics / Q000494:pharmacology / Q000502:physiology*; D053759:Interleukin-23; D053760:Interleukin-23 Subunit p19; D007378:Interleukins / Q000096:biosynthesis; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009163:Mycobacterium bovis / Q000254:growth & development / Q000276:immunology; D009169:Mycobacterium tuberculosis / Q000254:growth & development / Q000276:immunology; D021122:Protein Subunits; D015996:Survival Rate; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology; D014397:Tuberculosis, Pulmonary / Q000188:drug therapy / Q000276:immunology* / Q000473:pathology
chemical_list: D000942:Antigens, Bacterial; C508841:Il23a protein, mouse; D053759:Interleukin-23; D053760:Interleukin-23 Subunit p19; D007378:Interleukins; D021122:Protein Subunits; D018664:Interleukin-12