Cytokine gene expression by alloactivated cells in SCID mice.
OBJECTIVE
The severe combined immune deficient (SCID) mouse provides a neutral environment to study human immune responses. We therefore tested human gene expression of Interleukin (IL) 2, 4 and 10, interferon gamma (IFNgamma); transforming growth factor beta 1 (TGFbeta1); and CD40 ligand (CD40L) in splenic extracts of SCID mice after engraftment of PBLs from two persons (direct MLR) or one person plus allopeptides (indirect MLR) in the presence or absence of cyclosporin A (CsA) or FK506.


METHODS
Cytokine gene expression was detected by RT and quantitative (for IFN-gamma, TGFbeta1 and CD40L) PCR. All cells, allopeptides, CsA (25 mg/kg/day for 7 days) or FK 506 (0.5 mg/kg/day for 7 days) were administered intraperitoneally (IP).


RESULTS
In both direct and indirect MLR the numbers of SCID mice expressing the human cytokine genes varied between 33% for IL4 and 100% for IL10, IFN-gamma, TGFbeta1, and CD40L. There was significant interpersonal variation in levels of gene expression. Concomitant CsA or FK506 administration for 7 days did not abrogate early or late (1 week after discontinuation of CsA or FK506) cytokine gene expression in either the direct or indirect MLR, but paradoxically enhanced levels of IFN-gamma, TGFbeta1 and CD40L gene expression in some experiments.


CONCLUSIONS
The results explain late rejection after rapid calcineurin inhibitor withdrawal or reduction, and illustrate the potential use of SCID mice as a surrogate model to study graft outcome by determination levels of gene expression and sensitivity to immunosuppressive agents in the in vivo alloresponse.
Shoker
Ahmed S
AS
Department of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N OW8. shoker@sask.usask.ca
Lun
Zhao-Rong
ZR
Choudry
Rezvan
R
D000818:Animals; D023201:CD40 Ligand / Q000235:genetics; D016572:Cyclosporine / Q000494:pharmacology; D016207:Cytokines / Q000235:genetics*; D005260:Female; D015870:Gene Expression; D006801:Humans; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D016513:Mice, SCID; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016559:Tacrolimus / Q000494:pharmacology
D016207:Cytokines; D012333:RNA, Messenger; D023201:CD40 Ligand; D016572:Cyclosporine; D016559:Tacrolimus