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W L Havran

Publications and source records attributed to W L Havran.

40 records · Page 3Linked to original sources
PubMed1981

Identification of a brain theta-positive, secretory cell from hematopoietic tissues.

We have characterized a population of large, brain-theta antigen-positive, secretory cells that occur in high frequency among murine bone marrow (approximately 6%), spleen (approximately 0.5%), and fetal liver (approximately 5%) cell populations. They do not occur in significant numbers among lymph node, thymus, and peritoneal exudate cells. These cells are Ly1, Ly2, and Thy1.2 negative, adherent to nylon wool, Sephadex G-10, and plastic, but peroxidase and Sudan black negative. They are radiation, cyclophosphamide, and cortisone resistant. These cells secrete a product of 30,000 to 40,000 m.w. of unknown function. Production of antisera specific for this molecule has facilitated identification of the cell by using a reverse hemolytic plaque-forming cell assay. Possible functions of this cell and its product are discussed.

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PubMedDate not supplied

Characterization of murine cytolytic-helper hybrid T cell clones.

L3T4, Lyt-2 and the T-cell receptor for antigen are cell-surface molecules involved in antigen specific T cell activation. We have constructed functional murine cytolytic-helper T-cell hybrid clones to study the link between expression of cell-surface molecules and specific cell function. Three of the clones express two antigen receptors and both Lyt-2 and L3T4, normally expressed on mutually exclusive subsets of mature T lymphocytes. The pattern of lymphokines produced by the hybrid cells in response to antigen was not controlled by the specific antigen receptor; both T-cell growth factor, produced only by the helper T-cell partner, and gamma-interferon, produced only by the cytolytic T-cell partner, were secreted when either antigen receptor was stimulated. However, cytolytic activity appeared to be restricted to the recognition of antigen by the T-cell receptor of the cytolytic partner. Thus cytolysis appears to be rightly linked to the antigen receptor of the cytolytic parent but lymphokine release is not tightly linked.

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PubMedDate not supplied

Expression and function of the CD3-antigen receptor on murine CD4+8+ thymocytes.

Mature T cells arise from progenitor cells by a complex and poorly understood process of differentiation in the thymus. Thymocytes can be divided into four major compartments on the basis of surface expression of the murine equivalents of CD8 (Lyt-2) and CD4 (L3T4) (refs 1,2). Functionally mature thymocytes express only CD4 or CD8. The CD4-8- subset contains progenitor cells capable of giving rise to all the phenotypic and functional classes of T cells on adoptive transfer. The function of the major population, the CD4+8+ cells, which carry both the CD4 and CD8 antigens, in thymic differentiation is controversial. It has been variously proposed that they represent terminally differentiated cells which die in the thymus or that they represent an intermediate stage and can differentiate into functionally and phenotypically mature single positive T cells. The CD3-antigen receptor complex is probably important in thymic differentiation. The receptor has two functions: recognition and transmembrane signalling. To help clarify the function of CD4+8+ thymocytes in thymic differentiation, the expression and function of the antigen receptor complex on these cells should be determined. We show here that most CD4+8+ thymocytes express CD3 which functions in transmembrane signalling. The consequences of this signalling differ from those in mature T cells, however, in that the CD4+8+ cells do not secrete IL-2, express IL-2 receptor, or proliferate.

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