In vivo activated cord blood lymphocytes express high affinity interleukin-2 receptor: evaluation of their responsiveness to in vitro stimulation with recombinant interleukin-2.
We report the phenotypical and functional characterization of a cord blood mononuclear lymphocyte subset (CBMC) which expresses the p55 chain of interleukin-2 receptor (IL-2R, CD25). The great majority of CD25-positive CBMC are activated CD3-positive T lymphocytes in that most of them are HLA-DR-positive, coexpress both CD4 and CD8 antigens and at least a part of them display high affinity IL-2R. In keeping with the expression of both chains of IL-2R (p55 and p75), enriched CD25-positive CBMC are able to display strong IL-2-induced proliferation and lymphokine-activated killing activity. The percentage of CD25-positive cells is higher in cord blood than in adult peripheral blood and their presence could be peculiarly important in the neonatal period, when specific T-cell-mediated immune responses are still on their way to full maturation.
Montagna
D
D
Department of Pediatrics, University of Pavia, Italy.
Moretta
A
A
Marconi
M
M
Mingrat
G
G
Gasparoni
A
A
Giarola
M
M
Maccario
R
R
D003602:Cytotoxicity, Immunologic; D005312:Fetal Blood / Q000166:cytology*; D006801:Humans; D016130:Immunophenotyping; D007231:Infant, Newborn; D007376:Interleukin-2 / Q000494:pharmacology*; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000166:cytology / Q000276:immunology; D015375:Receptors, Interleukin-2 / Q000032:analysis / Q000378:metabolism*; D011994:Recombinant Proteins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology
D007376:Interleukin-2; D015375:Receptors, Interleukin-2; D011994:Recombinant Proteins