Intestinal colonization with Candida albicans and mucosal immunity.
OBJECTIVE
To observe the relationship between intestinal lumen colonization with Candida albicans and mucosal secretory IgA (sIgA).


METHODS
A total of 82 specific-pathogen-free mice were divided randomly into control and colonization groups. After Candida albicans were inoculated into specific-pathogen-free mice, the number of Candida albicans adhering to cecum and mucosal membrane was counted. The lymphocyte proliferation in Peyer's patch and in lamina propria was shown by BrdU incorporation, while mucosal sIgA (surface membrane) isotype switch in Peyer's patch was investigated. IgA plasma cells in lamina propria were observed by immunohistochemical staining. Specific IgA antibodies to Candida albicans were measured with ELISA.


RESULTS
From d 3 to d 14 after Candida albicans gavaging to mice, the number of Candida albicans colonizing in lumen and adhering to mucosal membrane was sharply reduced. Candida albicans translocation to mesenteric lymph nodes occurred at early time points following gavage administration and disappeared at later time points. Meanwhile, the content of specific IgA was increased obviously. Proliferation and differentiation of lymphocytes in lamina propria were also increased.


CONCLUSIONS
Lymphocytes in lamina propria play an important role in intestinal mucosal immunity of specific-pathogen-free mice when they are first inoculated with Candida albicans. The decreasing number of Candida albicans in intestine is related to the increased level of specific IgA antibodies in the intestinal mucus.
Bai
Xiao-Dong
XD
Department of Burn Surgery, General Hospital of Armed Police Force, 69 Yong Ding Road, Hai Dian District, Beijing 100039, China. baixiaotmu@yahoo.com.cn
Liu
Xian-Hua
XH
Tong
Qing-Ying
QY
D000818:Animals; D002176:Candida albicans / Q000254:growth & development* / Q000378:metabolism / Q000502:physiology; D002455:Cell Division; D018928:Immunity, Mucosal; D007070:Immunoglobulin A / Q000378:metabolism; D007413:Intestinal Mucosa / Q000166:cytology / Q000276:immunology*; D007422:Intestines / Q000382:microbiology*; D008214:Lymphocytes / Q000166:cytology; D051379:Mice; D008807:Mice, Inbred BALB C
D007070:Immunoglobulin A