Cord Blood T Lymphocytes Lack Constitutive Perforin Expression in Contrast to Adult Peripheral Blood T Lymphocytes

• Published in: Blood 1995-03, Vol.85 (6), p.1540-1546
• Main Authors: Berthou, Christian, Legros-Maïda, Sabine, Souliέ, Annie, Wargnier, Alain, Guillet, Jacqueline, Rabian, Claire, Gluckman, Eliane, Sasportes, Marilyne
• Format: Article
• Language: English
• Subjects: Adult; Antigens, CD - analysis; Antigens, Differentiation, T-Lymphocyte - analysis; Biological and medical sciences; Bone Marrow Cells; CD11 Antigens - analysis; CD3 Complex - analysis; CD57 Antigens; Cytotoxicity, Immunologic; Fetal Blood - immunology; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Granzymes; Humans; Immunobiology; Lymphoid cells: ontogeny, maturation, markers, receptors, circulation and recirculation; Membrane Glycoproteins - analysis; Perforin; Pore Forming Cytotoxic Proteins; Serine Endopeptidases - metabolism; T-Lymphocytes - chemistry
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V85.6.1540.bloodjournal8561540

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 γδ-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.