Interferon-gamma receptor signaling is not required in the effector phase of the alloimmune response.
BACKGROUND
Gene transcripts for the Thl cytokines interleukin (IL)-2 and interferon-gamma (IFN-gamma) are frequently detected during allograft rejection. The relative importance of these cytokines in facilitating allograft rejection is unclear. Recently, we have shown that IL-2-deficient mice reject islet allografts. In the IL-2-deficient system, IFN-gamma gene transcripts are abundantly expressed.


METHODS
To determine the relative importance of IFN-gamma-dependent effector mechanisms in mediating allograft rejection, the present study utilized IFN-gamma receptor-deficient mice as islet allograft recipients. Grafts were analyzed by immunohistology, and cytokine expression was measured by competitive template reverse transcriptase polymerase chain reaction.


RESULTS
IFN-gamma receptor-deficient mice reject islet allografts by a process that is T cell-dependent. Although IFN-gamma receptor signaling is absent, these mice do not show a clear Th2 type response.


CONCLUSIONS
Although the signals evoked through the IFN-gamma receptor may play a role, they are not essential to allograft rejection.
Steiger
J U
JU
Department of Research, University Hospital Basel, Switzerland. steigerj@ubaclu.unibas.ch
Nickerson
P W
PW
Hermle
M
M
Thiel
G
G
Heim
M H
MH
D000818:Animals; D006084:Graft Rejection; D007371:Interferon-gamma / Q000235:genetics; D007376:Interleukin-2 / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D017471:Receptors, Interferon / Q000235:genetics / Q000502:physiology*; D014184:Transplantation, Homologous / Q000276:immunology*; D000096743:Interferon gamma Receptor
D007371:Interferon-gamma; D007376:Interleukin-2; D017471:Receptors, Interferon; D000096743:Interferon gamma Receptor