Feeding by the tick, Ixodes scapularis, causes CD4(+) T cells responding to cognate antigen to develop the capacity to express IL-4.
Effects of tick feeding on an early antigen-specific T cell response were studied by monitoring a clonotypic population of adoptively transferred T cell receptor (TCR) transgenic CD4 cells responding to a tick-associated antigen. When recipient mice were infested with pathogen-free Ixodes scapularis nymphs several days prior to T cell transfer and intradermal injection of soluble cognate antigen at the feeding site, the clonotypic CD4 cells gained the ability to express the Th2 effector cytokine IL-4. Notably, this effect was not only observed in BALB/c mice predisposed towards developing Th2 responses but also in B10.D2 mice predisposed towards Th1 responsiveness. Furthermore, tick feeding was able to superimpose IL-4 expression potential onto a strong Th1 response (indicated by robust IFN-gamma expression potential) elicited by immunization with a vaccinia virus expressing the cognate antigen. The magnitude to which tick feeding was able to programme IL-4 expression potential in CD4 cells was partially reduced in mice that had been previously exposed to pathogen-free tick nymphs 6 weeks earlier, as well as when the nymphs were infected with Borrelia burgdorferi. Intradermal injection of salivary gland extract programmed IL-4 expression potential similar to that of tick infestation, suggesting that IL-4 programming activity is contained within tick saliva.
Müller-Doblies
U U
UU
Pirbright Laboratory, Institute for Animal Health, Pirbright, UK.
Maxwell
S S
SS
Boppana
V D
VD
Mihalyo
M A
MA
McSorley
S J
SJ
Vella
A T
AT
Adler
A J
AJ
Wikel
S K
SK
D000818:Animals; D025065:Borrelia burgdorferi / Q000276:immunology / Q000502:physiology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D015847:Interleukin-4 / Q000276:immunology / Q000378:metabolism*; D018884:Ixodes / Q000276:immunology* / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009758:Nymph / Q000276:immunology / Q000382:microbiology; D012471:Salivary Proteins and Peptides / Q000276:immunology / Q000378:metabolism; D018417:Th1 Cells / Q000276:immunology / Q000378:metabolism; D018418:Th2 Cells / Q000276:immunology / Q000378:metabolism; D013984:Tick Infestations / Q000276:immunology*; D051195:Toll-Like Receptor 2 / Q000378:metabolism; D014616:Vaccinia virus / Q000276:immunology
D012471:Salivary Proteins and Peptides; C493486:Tlr2 protein, mouse; D051195:Toll-Like Receptor 2; D015847:Interleukin-4