Phenotypic heterogeneity within the circulating human neonatal T4-positive T cell subset.

An indirect immunofluorescence staining technique was employed to evaluate the TQ1 and 5/9 monoclonal antibody lymphocyte reactivity in 10 cord blood mononuclear cell (MC) preparations enriched of E-rosette-forming cells (E+). Ten adult E+ MC populations were used as controls. Unfractionated T4+ cord and adult MC positively selected by panning procedure were also assayed. The results of these experiments, taken together, suggest that there is an overexpanded neonatal T cell subset which displays a previously unrecognized immunophenotype (T4+, TQ1+, 5/9+). Whether these lymphocytes are involved in the wellknown fetal-maternal immunosuppressive mechanisms of whether they are a further example of neonatal phenotypic immaturity remains to be elucidated.

Acute infectious lymphocytosis: phenotype of the proliferating cell.

A case of acute infectious lymphocytosis in an otherwise healthy 2-year-old child is reported. Marker analysis of the expanded blood lymphocytes showed that they were predominantly T cells and that there was a considerable increase in the helper/inducer phenotype (OKT4+) population. However, the lymphocyte response to polyclonal T-cell activators was low. This is the first report on T-cell subset distribution in acute infectious lymphocytosis.

Plasma cell generation inhibition in lymphocyte cultures containing cerebrospinal fluid from children with central nervous system viral infections.

Plasma cell generation in pokeweed mitogen-pulsed lymphocyte cultures was markedly suppressed when the experiments were carried out by adding cell-depleted cerebrospinal fluid (CSF) from 5 acute aseptic meningitis or meningoencephalitis children known to have an overexpanded cell population with the suppressor-cytotoxic T-cell surface phenotype in their CSF. In contrast, B-cell terminal differentiation was not affected by the addition of CSF from 5 control children with non-neurological diseases, thereby indicating that CSF from central nervous system virus-infected children contains soluble factors which are themselves capable of exerting regulatory influences on immunocompetent cells.

Phenotypic analysis of T cell subsets in the blood of chronically aborting women.

A relative decrease in helper and a parallel increase in suppressor-cytotoxic T lymphocytes was found in the blood of six habitually aborting women, as compared with the T-cell subset distribution in ten normal multiparae and eight multigravid post-partum women. It is suggested that an imbalance between the immunoregulatory T-cell subpopulations may contribute to the rejection of the semiallogenic fetus.