Protective roles of gamma delta T cells and interleukin-15 in Escherichia coli infection in mice.
The number of gamma delta T cells in the peritoneal cavity was increased after an intraperitoneal (i.p.) infection with Escherichia coli in lipopolysaccharide (LPS)-responsive C3H/HeN mice but not in LPS-hyporesponsive C3H/HeJ mice. The gamma delta T cells preferentially expressed invariant Vgamma6 and Vdelta1 chains and proliferated to produce a large amount of gamma interferon in the presence of LPS. Mice depleted of gamma delta T cells by T-cell receptor delta gene mutation showed impaired resistance against E. coli as assessed by bacterial growth. Macrophages from C3H/HeN mice infected with E. coli expressed higher levels of interleukin-15 (IL-15) mRNA than those from the infected C3H/HeJ mice. Administration of anti-IL-15 monoclonal antibody inhibited, albeit partially, the appearance of gamma delta T cells in C3H/HeN mice after E. coli infection and diminished the host defense against the infection. These results suggest that LPS-stimulated gamma delta T cells play an important role in the host defense against E. coli infection and that IL-15 may be partly involved in the protection via an increase in the gamma delta T cells.
Takano
M
M
Laboratory of Host Defense and Germfree Life, Research Institute for Disease Mechanism and Control, Nagoya University School of Medicine, Nagoya, Japan.
Nishimura
H
H
Kimura
Y
Y
Mokuno
Y
Y
Washizu
J
J
Itohara
S
S
Nimura
Y
Y
Yoshikai
Y
Y
D000818:Animals; D016207:Cytokines / Q000096:biosynthesis; D004926:Escherichia coli / Q000254:growth & development; D004927:Escherichia coli Infections / Q000276:immunology*; D005260:Female; D019409:Interleukin-15 / Q000502:physiology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008099:Liver / Q000276:immunology; D008213:Lymphocyte Activation; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D010537:Peritoneum / Q000276:immunology; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000235:genetics / Q000502:physiology*; D013601:T-Lymphocytes / Q000502:physiology*
D016207:Cytokines; D019409:Interleukin-15; D008070:Lipopolysaccharides; D016692:Receptors, Antigen, T-Cell, gamma-delta