Characterization of immature T cell subpopulations in neonatal blood

Abstract

A series of monoclonal antibodies directed against T cell differentiation antigens was used to identify circulating T cells in normal human neonates. Twenty-five cord blood samples, taken after cesarean or vaginal delivery, and 16 venous blood samples from normal adult controls were examined using monoclonal antibodies in an indirect immunofluorescence technique. The percentage of circulating OKT3 positive (pan-T cell) cells was significantly lower in the neonatal blood (52.8%) compared with the adult controls (74.9%) (P less than .001). Of the cord mononuclear cells, 58% showed reactivity with OKT10 (common thymocyte antigen) compared with only 7% in adult controls (P less than .001). The helper:suppressor T cell ratio was lower in cord blood (1:2) as compared with 1:3 for adult blood (P less than .005) as observed in these studies. These figures reflect the presence of a significant population (25%) of immature T cells in cord blood that expresses simultaneously both helper (OKT4) and suppressor (OKT8) phenotypes. Twenty-four percent of the T cells in cord blood also expressed OKT6 antigen (cortical thymocyte), a feature not found in adult blood. Double-labeling studies characterized a previously undescribed blood T cell phenotype, which was simultaneously OKT6 and OKT3 (pan-T cell) positive; of the cells reactive with OKT3, 43% also were positive with OKT6. This study reveals the presence of immature populations of T cells in normal human neonatal blood exhibiting phenotypes characteristic of normal developing thymocytes and a previously undescribed cell phenotype.

Circulating CD4+CD8+ T lymphocytes in patients with Kawasaki disease

“…CD4 þ CD8 þ T cells are present in small amounts (2-3%) in normal individuals [9], and their level occasionally reaches 10% [18,20,21]. Their number is also known to be high in cord blood cells [11,12]. The number of CD4 þ CD8 þ T cells is relatively high in patients with myasthenia gravis [13,14], idiopathic thrombocytopenic purpura [15], multiple sclerosis [16], Behçet's syndrome [17] and infectious mononucleosis [18].…”

“…The identification of cell surface markers on T cells revealed CD4 þ CD8 ¹ and CD4 ¹ CD8 þ T cells in the peripheral blood, in addition to a small number of CD4 þ CD8 þ and CD4 ¹ CD8 ¹ T cells [9,10]. An abnormal increase in the number of CD4 þ CD8 þ T cells in the peripheral blood is known to occur in cord blood [11,12] and in patients with certain diseases including myasthenia gravis [13,14], idiopathic thrombocytopenic purpura [15], multiple sclerosis [16], Behçet's syndrome [17] and infectious mononucleosis [18].…”

The use of monoclonal antibodies in the in situ identification of T‐cell subpopulations in cutaneous T‐cell lymphoma

“…Recent studies, however, have shown an intermediate stage between Stage II and Stage III in which cells are reactive with OKT3 (acquired at Stage III) and OKT6 stimultaneously (Griffiths- Chu et al 1983). Cireulating T-cells are not reaetive with this antibody in normal adult individuals.…”