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Thymosin Induces Helper Function in OKT3‐Positive, E‐Rosette‐Negative Human Cord Blood T Cells
Author(s) -
TAN P.L.J.,
SHORE A.
Publication year - 1984
Publication title -
scandinavian journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.934
H-Index - 88
eISSN - 1365-3083
pISSN - 0300-9475
DOI - 10.1111/j.1365-3083.1984.tb00974.x
Subject(s) - thymosin , cord blood , rosette (schizont appearance) , biology , t lymphocyte , microbiology and biotechnology , monoclonal antibody , immunology , lymphocyte , t cell , antibody , immune system
E‐rosette‐negative lymphocytes (T E‐ ), which express monoclonal T‐cell markers (OKT3 + ) were found in higher frequencies in humnn cord blood (CB) (30% by phenotype and 11.7% by sequential rosette isolation) than in adult peripheral blood lymphocytes (13% by phenotype and 3.7% by isolation). T E‐ cells had very low levels of 5′‐nucleotidase. a lymphocyte maturational marker low in thymocytes. Like other CB T cells. T E‐ cells possessed marked suppressor capability. Irradiated T E‐ cells from two cord blood samples demonstrated helper activity tor Ig production hy adult B cells. In six cord blood samples, however, irradiated T E‐ cells lacked helper activity. When incubated with thymosin, these T E‐ cells became E ‐ and differentiated into inducer‐helper T cells. These observations confirm previous assumptions that CB T cells are not fully differentiated. Furthermore. T cells from different CB samples may be at various stages of ontogeny. We have also shown that thymosin fraction 5 is able to confer a new immunoregulatory function.