Chlamydia trachomatis pulmonary infection induces greater inflammatory pathology in immunoglobulin A deficient mice.
Chlamydia trachomatis is an intracellular bacterial pathogen that primarily infects via mucosal surfaces. Using mice with a targeted disruption in IgA gene expression (IgA(-/-) mice), we have studied the contribution of IgA, the principal mucosal antibody isotype, in primary immune defenses against pulmonary C. trachomatis infection. Bacterial burden was comparable between IgA(-/-) and IgA(+/+) animals following C. trachomatis challenge. Serum and pulmonary anti-Chlamydia antibody levels were higher in IgA(-/-) animals, with the exception of IgA. Lung sections of challenged IgA(-/-) mice showed more extensive immunopathology than corresponding IgA(+/+) animals. Real-time PCR analysis demonstrated significantly greater IFN-gamma and TGF-beta mRNA expression in IgA(-/-) as compared to IgA(+/+) animals. Together, these results suggest that IgA may not be necessary for clearance of primary C. trachomatis infection. However, IgA(-/-) mice displayed exaggerated lung histopathology and altered cytokine production, indicating an important role for IgA in regulating C. trachomatis induced pulmonary inflammation and maintenance of mucosal homeostasis.
Murthy
Ashlesh K
AK
Department of Biology, University of Texas at San Antonio, San Antonio, TX 78249, USA.
Sharma
Jyotika
J
Coalson
Jacqueline J
JJ
Zhong
Guangming
G
Arulanandam
Bernard P
BP
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology; D002690:Chlamydia Infections / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology / Q000473:pathology*; D002692:Chlamydia trachomatis / Q000502:physiology*; D017353:Gene Deletion; D006367:HeLa Cells; D006801:Humans; D007070:Immunoglobulin A / Q000235:genetics / Q000276:immunology*; D007371:Interferon-gamma / Q000235:genetics; D008168:Lung / Q000276:immunology / Q000382:microbiology* / Q000473:pathology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000235:genetics
D000907:Antibodies, Bacterial; D007070:Immunoglobulin A; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D007371:Interferon-gamma