NKT cells play a limited role in the neutrophilic inflammatory responses and host defense to pulmonary infection with Pseudomonas aeruginosa.
CD1d-restricted NKT cells are reported to play a critical role in the host defense to pulmonary infection with Pseudomonas aeruginosa. However, the contribution of a major subset expressing a Valpha14-Jalpha18 gene segment remains unclear. In the present study, we re-evaluated the role of NKT cells in the neutrophilic inflammatory responses and host defense to this infection using mice genetically lacking Jalpha18 or CD1d (Jalpha18KO or CD1dKO mice). These mice cleared the bacteria in lungs at a comparable level to wild-type (WT) mice. There was no significant difference in the local neutrophilic responses, as shown by neutrophil counts and synthesis of MIP-2 and TNF-alpha, in either KO mice from those in WT mice. Administration of alpha-galactosylceramide, a specific activator of Valpha14+ NKT cells, failed to promote the bacterial clearance and neutrophilic responses, although the same treatment increased the synthesis of IFN-gamma, suggesting the involvement of this cytokine downstream of NKT cells. In agreement against this notion, these responses were not further enhanced by administration of recombinant IFN-gamma in the infected Jalpha18KO mice. Our data indicate that NKT cells play a limited role in the development of neutrophilic inflammatory responses and host defense to pulmonary infection with P. aeruginosa.
Kinjo
Takeshi
T
Department of Medicine and Therapeutics, Control and Prevention of Infectious Diseases, Faculty of Medicine, University of the Ryukyus, Okinawa, Japan.
Nakamatsu
Masashi
M
Nakasone
Chikara
C
Yamamoto
Natsuo
N
Kinjo
Yuki
Y
Miyagi
Kazuya
K
Uezu
Kaori
K
Nakamura
Kiwamu
K
Higa
Futoshi
F
Tateyama
Masao
M
Takeda
Kazuyoshi
K
Nakayama
Toshinori
T
Taniguchi
Masaru
M
Kaku
Mitsuo
M
Fujita
Jiro
J
Kawakami
Kazuyoshi
K
D000818:Animals; D002452:Cell Count; D054426:Chemokine CXCL2; D018925:Chemokines / Q000032:analysis; D005699:Galactosylceramides / Q000008:administration & dosage / Q000494:pharmacology; D007155:Immunologic Factors / Q000008:administration & dosage / Q000494:pharmacology; D007249:Inflammation / Q000276:immunology; D007371:Interferon-gamma / Q000096:biosynthesis / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology*; D008168:Lung / Q000382:microbiology; D016131:Lymphocyte Subsets / Q000276:immunology; D051379:Mice; D018345:Mice, Knockout; D009504:Neutrophils / Q000276:immunology*; D018410:Pneumonia, Bacterial / Q000276:immunology* / Q000382:microbiology; D011552:Pseudomonas Infections / Q000276:immunology* / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
D054426:Chemokine CXCL2; D018925:Chemokines; C404915:Cxcl2 protein, mouse; D005699:Galactosylceramides; D007155:Immunologic Factors; D014409:Tumor Necrosis Factor-alpha; C493154:alpha-galactosylceramide; D007371:Interferon-gamma