α-galactosylceramide-stimulated invariant natural killer T-cells play a protective role in murine vulvovaginal candidiasis by Candida albicans

• Published in: PloS one 2021-11, Vol.16 (11), p.e0259306
• Main Authors: Abe, Masahiro, Kinjo, Yuki, Sadamoto, Sota, Shinozaki, Minoru, Nagi, Minoru, Shibuya, Kazutoshi, Miyazaki, Yoshitsugu
• Format: Article
• Language: English
• Subjects: Animals; Antiinfectives and antibacterials; Antimicrobial peptides; Biology and Life Sciences; Calgranulin A - metabolism; Candida albicans; Candida albicans - immunology; Candidiasis; Candidiasis, Vulvovaginal - immunology; Candidiasis, Vulvovaginal - microbiology; CD8 antigen; Cell activation; Chemotherapy; Cytokines; Disease Models, Animal; Enzymes; Estrogens; Experiments; Female; Female reproductive system; Flow cytometry; Funding; Fungi; Galactosylceramide; Galactosylceramides; Immune system; Immunology; Infectious diseases; Infiltration; Inoculation; Lavage; Leukocytes; Lymphocytes T; Medical research; Medicine; Medicine and Health Sciences; Mice; Mice, Inbred C57BL; Natural killer cells; Natural Killer T-Cells - immunology; Neutrophils; Pathology; Research and Analysis Methods; Uterus; Vagina; Vagina - immunology; Vagina - microbiology
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0259306

Vulvovaginal candidiasis is a common superficial candidiasis; however, a host's immunological mechanism against vaginal Candida infection remains unknown. In this study, we aimed to elucidate the effect of iNKT cell activation on vulvovaginal candidiasis. Using a vulvovaginal candidiasis model with estrogenized mice, we evaluated the fungal burden and number of leukocyte infiltrations in the vaginal lavage of wild-type C57BL/6J mice after Candida albicans inoculation. One day before C. albicans inoculation, α-galactosylceramide (the α-GalCer group) or sterile phosphate-buffered saline (the sham group) was intraperitoneally injected into the mice. We also evaluated the level of antimicrobial peptide S100A8 in the vaginal lavage and analyzed the correlation between S100A8 concentration and the number of vaginal leukocyte infiltrations. Moreover, the number of uterine and vaginal immune cells were evaluated using flow cytometry. The number of vaginal leukocyte infiltrations was significantly higher in the α-GalCer group than in the sham group 3 days after C. albicans inoculation. In addition, the fungal burden was significantly lower in the α-GalCer group than the sham group at 7 days after inoculation. In the analysis of S100A8 concentration of vaginal lavage, there were no significant differences between these two groups, although S100A8 concentration and the number of vaginal leukocyte infiltrations were positively correlated in the α-GalCer group. Moreover, the number of vaginal iNKT cells, NK cells and CD8+ T-cells was significantly higher in the α-GalCer group 3 days after inoculation. α-GalCer-stimulated iNKT cells likely play a protective role against vulvovaginal candidiasis.