CHARACTERIZATION OF THE TARGET-CELL FOR A THYMOCYTE SPECIFIC GROWTH-FACTOR IN GUINEA-PIGS

Google Scholar
  • 1 January 1983
    • journal article
    • research article
    • Vol. 5  (3-4) , 141-152
Abstract
A previously described growth factor prepared from calf thymus stimulated DNA synthesis in thymic cells but not in peripheral lymphocytes in guinea pigs. A further analysis of the target cell is presented. Thymic cells were fractionated into subpopulations based on their different adherence to plastic, buoyant density and agglutinability by peanut agglutinin (PNA), and the influence of the growth factor on DNA synthesis was studied. The responding cell was enriched in the population of non-adherent PNA-positive (PNA +) cells of low buoyant density. This cell population showed high spontaneous DNA synthesis in vitro, but did not contain the phytohemagglutinin-responsive thymocyte, which resided in the PNA-negative (PNA -) population of low density. The target cell of the thymic growth factor is evidently the immunologically immature proliferating thymocyte of the thymic cortex.