Interleukin-4 secretion by the allograft fails to affect the allograft-specific interleukin-4 response in vitro.
BACKGROUND
The role of the cytokine, interleukin (IL)-4, in allograft rejection and protection is not clear. We have previously shown that IL-4 transgenically expressed in a pancreas allograft does not protect the allograft from rejection. Here, we analyze the effect of the transgenically expressed IL-4 on the cytokine profile of the allograft-specific immune response.


METHODS
C57BL/6SCID mice were infused with small numbers of spleen cells from C57BL/6 donors. The former received pancreas grafts from 1- to 2-day-old BALB/c donors which did or did not transgenically express IL-4 in the graft. Three weeks after the cell infusion, the spleens were removed and the splenocytes were restimulated in vitro with BALB/c APC, and third party BALB.K APC. IL-2 and IL-4 levels in the culture supernatants were measured.


RESULTS
The presence of a pancreatic allograft induced an increase in the levels of both IL-2 and IL-4 in culture supernatants from splenocytes of mice receiving grafts compared with mice not receiving grafts. The presence of IL-4 transgenically expressed in the pancreas allograft had no effect on the in vitro cytokine profile.


CONCLUSIONS
from these results we conclude that the failure of transgenically expressed IL-4 to protect the allograft was not associated with up-regulation of a graft antigen-specific IL-4 response.
Department of Immunology, The Scripps Research Institute, La Jolla, CA 92037, USA.
J D
JD
Davies
R
R
Mueller
S
S
Minson
E
E
O'Connor
T
T
Krahl
N
N
Sarvetnick
D000818:Animals; D000939:Epitopes / Q000235:genetics; D006084:Graft Rejection / Q000517:prevention & control; D007376:Interleukin-2 / Q000378:metabolism; D015847:Interleukin-4 / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D016513:Mice, SCID; D008822:Mice, Transgenic; D016035:Pancreas Transplantation; D013154:Spleen / Q000166:cytology; D019076:Transgenes; D014184:Transplantation, Homologous / Q000276:immunology / Q000502:physiology*
D000939:Epitopes; D007376:Interleukin-2; D015847:Interleukin-4