Red blood cells promote survival and cell cycle progression of human peripheral blood T cells independently of CD58/LFA-3 and heme compounds.
Red blood cells (RBC) are known to modulate T cell proliferation and function possibly through downregulation of oxidative stress. By examining parameters of activation, division, and cell death in vitro, we show evidence that the increase in survival afforded by RBC is due to the maintenance of the proliferative capacity of the activated T cells. We also show that the CD3+CD8+ T cell subset was preferentially expanded and rescued from apoptosis both in bulk peripheral blood lymphocyte cultures and with highly purified CD8+ T cells. The ability of RBC to induce survival of dividing T cells was not affected by blocking the CD58/CD2 interaction. Moreover, addition of hemoglobin, heme or protoporphyrin IX to cultures of activated T cells did not reproduce the effect of intact RBC. Considering that RBC circulate throughout the body, they could play a biological role in the modulation of T cell differentiation and survival in places of active cell division. Neither CD58 nor the heme compounds studied seem to play a direct relevant role in the modulation of T cell survival.
Fonseca
Ana Mafalda
AM
Laboratory of Molecular Immunology, Institute for Molecular and Cell Biology, Rua do Campo Alegre, 823, Portugal.
Pereira
Carlos Filipe
CF
Porto
Graça
G
Arosa
Fernando A
FA
D017209:Apoptosis / Q000502:physiology; D018801:CD2 Antigens / Q000276:immunology / Q000378:metabolism; D017252:CD3 Complex / Q000502:physiology; D018968:CD58 Antigens / Q000276:immunology / Q000378:metabolism*; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000378:metabolism; D002450:Cell Communication / Q000502:physiology*; D002453:Cell Cycle / Q000502:physiology*; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D004912:Erythrocytes / Q000166:cytology / Q000378:metabolism*; D006418:Heme / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology; D013601:T-Lymphocytes / Q000166:cytology / Q000378:metabolism*
D018801:CD2 Antigens; D017252:CD3 Complex; D018968:CD58 Antigens; D006418:Heme