The role of CD1d-restricted NK T lymphocytes in the immune response to oral infection with Salmonella typhimurium.
CD1d-restricted natural killer T (NKT) cells belong to the innate-like lymphocytes which respond rapidly to stress and infectious challenge. We have studied murine CD1d-restricted NKT cells in the early immune response to virulent Salmonella enterica serovar Typhimurium after oral infection. In the liver and spleen, neutrophil and macrophage numbers had increased several-fold by day 5 post-infection, while the frequency of B and T lymphocytes decreased. These cellular changes occurred independently of CD1d-restricted NKT cells, and further, CD1d-restricted T cells did not influence the bacterial load. However, in CD1d(+) mice NK1.1(+) T cells and invariant CD1d-restricted T cells were activated by the infection, as demonstrated by an increase in size, up-regulation of CD69 and production of IFN-gamma. The NK1.1 antigen was down-modulated on these cells during the course of infection, while TCR levels were unaffected. While dendritic cells (DC) up-regulated CD1d-levels upon 24 h of in vitro exposure to the bacteria, increased CD1d expression was not evident on DC in vivo during infection. Furthermore, in vitro re-stimulation of CD1d-restricted T cells isolated from infected mice demonstrated a significant skewing of the cytokine profile, with suppressed IL-4 and increased IFN-gamma production.
Berntman
Emma
E
Section for Infection and Immunology, Lund University, Lund, Sweden.
Rolf
Julia
J
Johansson
Cecilia
C
Anderson
Per
P
Cardell
Susanna L
SL
D000818:Animals; D018949:Antigens, CD1 / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D055610:Antigens, CD1d; D016207:Cytokines / Q000378:metabolism; D003713:Dendritic Cells / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009059:Mouth Diseases / Q000276:immunology / Q000378:metabolism / Q000382:microbiology; D012481:Salmonella Infections, Animal / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D012486:Salmonella typhimurium / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D015854:Up-Regulation / Q000235:genetics / Q000276:immunology
D018949:Antigens, CD1; D055610:Antigens, CD1d; D016207:Cytokines