Injection of donor-derived OX62+ splenic dendritic cells with anti-CD4 monoclonal antibody generates CD4+CD25+FOXP3+ regulatory T cells that prolong allograft skin survival indefinitely and abrogate production of donor-specific antibodies in a rat model.
OBJECTIVE
To examine in a rat model the ability of donor dendritic cells and anti-CD4 monoclonal antibody (mAb) to generate donor-specific CD4+CD25+ regulatory T cells (Tregs) and to evaluate the capacity of these Tregs to prolong skin allograft survival and abrogate the production of donor-specific antibodies after skin grafting.


METHODS
OX62+ (nonplasmacytoid) splenic dendritic cells were isolated from Fischer rats using magnetic beads and injected (2 x 10(6)) into Lewis rat recipients with or without treatment with a nondepleting anti-CD4 (W3/25) mAb. After 4 weeks, splenic CD4+CD25+FOXP3+ T cells were harvested using magnetic beads from conditioned animals and injected (1 x 10(6)) into naïve Lewis recipients (day 1) before they received a skin graft from a Fischer (n = 4) or a third-party (Norway; n = 4) donor rat. Donor-specific antibodies were detected in recipient blood using flow cytometric cross-matches with donor lymphocytes from day 0 to day 30 after grafting.


RESULTS
After injection of conditioned CD4+CD25+FOXP3+ T cells, Lewis recipients accepted skin grafts from Fischer donors indefinitely (>100 days) but rejected third-party skin grafts. Donor-specific antibodies were detected at low levels in only 1 recipient receiving conditioned Tregs before grafting. Naive Tregs did not prolong skin graft survival.


CONCLUSIONS
These preliminary data suggest that splenic dendritic cells in combination with an anti-CD4 mAb induce donor-specific Tregs that indefinitely prolong allogeneic skin graft survival and inhibit donor-specific antibody production. Experiments are under way to determine whether this protocol can inhibit chronic lesions after heart transplantation in this model.
Insitut Fédératif de Recherche Santé-STIC (IFR 100), University of Burgundy, Dijon, France.
M
M
Alawieh
G
G
Rifle
O
O
Bouchot
G
G
Malapert
C
C
Mousson
L
L
Martin
D000818:Animals; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D015704:CD4 Antigens / Q000276:immunology*; D003713:Dendritic Cells / Q000637:transplantation*; D051858:Forkhead Transcription Factors / Q000276:immunology; D006085:Graft Survival / Q000276:immunology*; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology; D007518:Isoantibodies / Q000276:immunology; D023421:Models, Animal; D051381:Rats; D011914:Rats, Inbred BN; D011916:Rats, Inbred F344; D011917:Rats, Inbred Lew; D016038:Skin Transplantation / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D014184:Transplantation, Homologous / Q000276:immunology
D000911:Antibodies, Monoclonal; D015704:CD4 Antigens; D051858:Forkhead Transcription Factors; C500522:Foxp3 protein, rat; D053645:Interleukin-2 Receptor alpha Subunit; D007518:Isoantibodies