Cord blood T lymphocytes lack constitutive perforin expression in contrast to adult peripheral blood T lymphocytes.
Perforin is the cytolytic pore-forming protein, which alone can be responsible for the lethal hit in one of the killing mechanisms used by natural killer (NK) cells or cytotoxic T lymphocytes. In this study, perforin expression was investigated in cord blood (CB) lymphocytes to determine their killing potential in vivo. The majority of CB CD3- NK cells had the protein. Compared with adult perforin-positive NK cells, a significantly lower percentage of cells expressing CD56 and CD57, the related neural cell adhesion molecules, was found (P = .0001). Perforin was also present in a unique immature CB NK-cell subset, characterized by cytoplasmic CD3 antigen (Ag) expression. In CB, very few CD8 perforin-positive T lymphocytes could be detected, but they were in significant numbers in adult peripheral blood (P = .02). A substantial proportion of these cells (70% +/- 23%) lacked the CD28 T-cell coactivation Ag, and they were able to exert NK-like, major histocompatibility complex nonrestricted cytolytic activity. CD4+ and gamma delta-T cells expressing perforin were absent from CB, but low numbers of such cells were detected in adult peripheral blood (P = .0001). Therefore, the spontaneous cytolytic activity of CB lymphocytes appeared to be dependent on well-represented perforin-positive NK cells, which were shown to efficiently lyse NK-sensitive target cells.
Berthou
C
C
INSERM U 93, Laboratory of Immunology and Histocompatibility, St Louis Hospital, Paris, France.
Legros-Maïda
S
S
Soulié
A
A
Wargnier
A
A
Guillet
J
J
Rabian
C
C
Gluckman
E
E
Sasportes
M
M
D000328:Adult; D015703:Antigens, CD / Q000032:analysis; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D001854:Bone Marrow Cells; D018845:CD11 Antigens / Q000032:analysis; D017252:CD3 Complex / Q000032:analysis; D018959:CD57 Antigens; D003602:Cytotoxicity, Immunologic; D005312:Fetal Blood / Q000276:immunology*; D053804:Granzymes; D006801:Humans; D008562:Membrane Glycoproteins / Q000032:analysis*; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D012697:Serine Endopeptidases / Q000378:metabolism; D013601:T-Lymphocytes / Q000737:chemistry*
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D018845:CD11 Antigens; D017252:CD3 Complex; D018959:CD57 Antigens; D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D054353:Perforin; C509213:GZMB protein, human; D053804:Granzymes; D012697:Serine Endopeptidases