Immunosuppression involving soluble CD83 induces tolerogenic dendritic cells that prevent cardiac allograft rejection.
BACKGROUND
Dendritic cells (DCs) are crucial regulators of immunity and important in inducing and maintaining tolerance. Here, we investigated the potential of a novel DC-immunomodulating agent, soluble CD83 (sCD83), in inducing transplant tolerance.


METHODS
We used the C3H-to-C57BL/6 mouse cardiac transplantation model that exhibits a combination of severe cell-mediated rejection and moderate antibody-mediated rejection and investigated whether sCD83 could augment a combination therapy consisting of Rapamycin (Rapa) and anti-CD45RB monoclonal antibody (α-CD45) to prolong allograft survival.


RESULTS
Monotherapies consisting of Rapa and α-CD45 were incapable of preventing rejection. However, all treatments involving sCD83 were capable of (1) down-modulating expression of various DC surface molecules, such as major histocompatibility complex class II and costimulatory molecules, (2) reducing the allogeneic stimulatory capacity of the DCs, and (3) significantly inhibiting antidonor antibody responses. Most striking results were observed in the triple therapy-treated group, sCD83Rapaα-CD45, where cell-mediated rejection and antibody-mediated rejection were abrogated for over 100 days. Donor-specific tolerance was achieved in long-term surviving recipients, because donor skin transplants were readily accepted for an additional 100 days, whereas third-party skin grafts were rejected. Success of triple therapy treatment was accompanied by enhancement of tolerogenic-DCs that conferred antigen-specific protection on adoptive transfer to recipients of an allogeneic heart graft.


CONCLUSIONS
Our study revealed that sCD83 is capable of attenuating DC maturation and function, and inducing donor-specific allograft tolerance, in the absence of toxicity. Thus, sCD83 seems to be a safe and valuable counterpart to current DC-modulating agents.
Ge
Wei
W
Department of Surgery, University of Western Ontario, London, ON, Canada.
Arp
Jacqueline
J
Lian
Dameng
D
Liu
Weihua
W
Baroja
Miren L
ML
Jiang
Jifu
J
Ramcharran
Siobhan
S
Eldeen
Firas Zahr
FZ
Zinser
Elisabeth
E
Steinkasserer
Alexander
A
Chou
Perry
P
Brand
Stephen
S
Nicolette
Charles
C
Garcia
Bertha
B
Wang
Hao
H
D019264:Adoptive Transfer; D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D015703:Antigens, CD / Q000235:genetics / Q000494:pharmacology*; D039521:CD11c Antigen / Q000276:immunology; D003713:Dendritic Cells / Q000187:drug effects* / Q000276:immunology / Q000637:transplantation; D004359:Drug Therapy, Combination; D006084:Graft Rejection / Q000276:immunology / Q000517:prevention & control*; D016027:Heart Transplantation / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006801:Humans; D007111:Immunity, Cellular / Q000187:drug effects; D056724:Immunity, Humoral / Q000187:drug effects; D007136:Immunoglobulins / Q000235:genetics / Q000494:pharmacology*; D016130:Immunophenotyping; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D017493:Leukocyte Common Antigens / Q000276:immunology; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics / Q000494:pharmacology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000494:pharmacology; D020123:Sirolimus / Q000494:pharmacology; D016038:Skin Transplantation; D013997:Time Factors; D023001:Transplantation Tolerance / Q000187:drug effects*; D014184:Transplantation, Homologous; D000097802:CD83 Antigen
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D039521:CD11c Antigen; D000949:Histocompatibility Antigens Class II; D007136:Immunoglobulins; D007166:Immunosuppressive Agents; D017493:Leukocyte Common Antigens; D008562:Membrane Glycoproteins; D011994:Recombinant Proteins; D020123:Sirolimus; D000097802:CD83 Antigen