Umbilical cord blood T lymphocytes are induced to apoptosis after being allo-primed in vitro.
In this study, the immunity of umbilical cord blood (UCB) T lymphocytes against allo-antigens was investigated by a standard MLC. No significant difference, between the UCB T cells or peripheral blood (PB) mature T cells, was observed in the primary responses (stimulation index (SI), 51.8 +/- 14.8 and 46.5 +/- 15.0, respectively). In contrast, in the secondary response, the SI obtained with the CD4 T cells from UCB decreased dramatically (16.3 +/- 6.4), while it increased with the CD4 T cells from PB (118.5 +/- 21.7). UCB (CD4 and CD8) T cells separately showed much higher frequencies of apoptosis after a primary allo-priming, compared with PB CD4 and CD8 T cells (CD4, UCB 30.5% vs PB 0.8%; CD8, UCB 32% vs PB 1.3%). The higher apoptotic level of the UCB CD4 T cells was confirmed by a second, ELISA-based, Tunel assay (OD values, UCB CD4 1.93 +/- 0.31 vs PB CD4 0.59 0.9; P < 0.01). Those apoptotic steps were not attributed to the amount of cytokine (IL-2, 4 and IFN-gamma) production, which was found to be similar in both cases. In conclusion, UCB lymphocytes are much more likely to be induced to apoptosis by allo-priming than adult lymphocytes. This supports their possible, successful engraftment across barriers of HLA incompatibility.
Hagihara
M
M
Department of Hematology and Rheumatology, Tokai University School of Medicine, Kanagawa, Japan.
Chargui
J
J
Gansuvd
B
B
Tsuchida
F
F
Sato
T
T
Hotta
T
T
Kato
S
S
D000328:Adult; D017209:Apoptosis / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D016207:Cytokines / Q000378:metabolism; D005312:Fetal Blood / Q000166:cytology* / Q000276:immunology*; D006801:Humans; D007519:Isoantigens / Q000097:blood / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology; D007959:Lymphocyte Culture Test, Mixed; D010835:Phytohemagglutinins / Q000494:pharmacology; D012307:Risk Factors; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D013936:Thymidine / Q000493:pharmacokinetics; D014316:Tritium
D016207:Cytokines; D007519:Isoantigens; D010835:Phytohemagglutinins; D014316:Tritium; D013936:Thymidine