Upregulation of molecules associated with T-regulatory function by thymoglobulin pretreatment of human CD4+ cells.
BACKGROUND
This study evaluated the immunologic effects of thymoglobulin in modulating human CD4+ cells.


METHODS
Human CD4+ cells were purified from peripheral blood mononuclear cells by negative selection method. CD4+ cells were pretreated with thymoglobulin and incubated for 72 hr. Cells and culture supernatants were collected and studied by real-time quantitative polymerase chain reaction, fluorescence activated cell scanning, multiplex cytokine assay, and mixed lymphocyte reaction (MLR).


RESULTS
Thymoglobulin pretreated CD4+ cells demonstrated up-regulation of gene transcripts for CTLA-4, OX40, forkhead box P3 (Foxp3), CD25, IFN-gamma, IL-10, and IL-2 as determined by real-time quantitative polymerase chain reaction. Fluorescence-activated cell scanning analysis demonstrated that CD4+ cells, pretreated with thymoglobulin, up-regulated CD25 expression on their surface, and the surface expression of CTLA-4 and OX40 and the expression of intracellular Foxp3 were observed in these CD4+CD25+ cells. Additionally, MLR demonstrated that thymoglobulin-pretreated cells partially inhibited proliferation of untreated autologous CD4+ cells in response to allogeneic cells. The high levels of IFN-gamma, IL-10, IL-2, and IL-4 were detected by multiplex cytokine assay in supernatants collected from cultures of thymoglobulin-pretreated CD4+ cells. The lymphocyte proliferation of allogeneic MLR was also partially blocked in the presence of supernatants from cultures of thymoglobulin-pretreated CD4+ cells.


CONCLUSIONS
This study demonstrates that the unique effects of thymoglobulin in modulating CD4+ cells may be an important mechanism for its action in inducing immunosuppression and transplant tolerance.
Liu
Zidong
Z
Transplantation Research Laboratory, Jinan City Central Hospital, Jinan, Shandong, People's Republic of China.
Fang
Yusong
Y
Wang
Xiaoping
X
Wang
Pu
P
Yun
Ping
P
Xu
He
H
D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D015703:Antigens, CD / Q000187:drug effects / Q000235:genetics / Q000276:immunology; D000961:Antilymphocyte Serum; D015704:CD4 Antigens / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D060908:CTLA-4 Antigen; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors / Q000187:drug effects / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects / Q000276:immunology; D006801:Humans; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology; D053278:OX40 Ligand / Q000187:drug effects / Q000235:genetics; D016133:Polymerase Chain Reaction; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects / Q000276:immunology*
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000961:Antilymphocyte Serum; D015704:CD4 Antigens; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D053645:Interleukin-2 Receptor alpha Subunit; D053278:OX40 Ligand; C089251:TNFSF4 protein, human; C512542:thymoglobulin