Expression of MHC class II DQ alpha/beta heterodimers from recombinant polycistronic retroviral genomes.
OBJECTIVE
In the swine model, the transfer of the polymorphic DRbeta or DQalpha/beta cDNAs in vivo via double copy retroviruses led to a prolonged survival or tolerance of subsequent kidney grafts which were matched for DR or DQ, respectively. However, DQ-induced tolerance required the expression of the alpha/beta heterodimers in the same target cell, a task not reproducibly achieved with double copy vectors. Therefore, the present study was designed to evaluate the ability of polycistronic proviral constructs to express class II DQ alpha/beta heterodimers in transduced cells.


METHODS
A swine class II DQ recombinant polycistronic construct (JAB) was developed to contain two internal ribosomal entry sites (IRES) for sequential translation of the DQalpha and DQbeta chains.


RESULTS
Although a genomic recombination occurred between the two identical IRES, flow cytometry analyses of JAB-transfected virus-packaging cells demonstrated the cell surface expression of DQalpha/DQbeta heterodimers, indicative of a correct transcription, translation, and transport of swine class II.


CONCLUSIONS
JAB-transfected virus-packaging cells demonstrated the cell surface expression of DQalpha/DQbeta heterodimers. We believe that our study represents an essential step in the design of efficient protocols to transfer graft-matched class II molecules in recipient bone marrow cells and thereby induce transplantation tolerance.
Shimada
Hideaki
H
Department of Academic Surgery, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Japan.
Germana
Sharon
S
Hayashi
Hideki
H
Sachs
David H
DH
LeGuern
Christian
C
D000818:Animals; D005434:Flow Cytometry; D005802:Genes, MHC Class II; D005822:Genetic Vectors; D006085:Graft Survival / Q000276:immunology; D006683:HLA-DQ Antigens / Q000276:immunology*; D015151:Immunoblotting; D016030:Kidney Transplantation / Q000276:immunology*; D012190:Retroviridae; D013552:Swine; D013556:Swine, Miniature; D014161:Transduction, Genetic
D006683:HLA-DQ Antigens