The objective of this project is to use monoclonal antibodies to identify and characterize specific cell surface molecules of murine hematopoietic cells and to use these antibodies as probes to study hematopoietic differentiation. The Pgp-1 glycoprotein is present on a variety of hematopoietic cell lineages but is absent on most cells of the thymus. Only 5 to 20% of the cells in the thymus are Pgp-1?+?. We are studying the nature of these Pgp-1?+? thymus cells, using assays for thymic stem cells, and are studying the ontogeny of Pgp-1?+? cells in the thymus during fetal development. Intrathymic stem cells that can transiently repopulate the thymus of an irradiated animal are Pgp-1?+?. Furthermore, nearly all thymocytes in the 13 to 14 day fetal mouse are Pgp-1?+?. These results indicate that certain Pgp-1?+? cells have the properties expected of intrathymic progenitor cells. Antibody against the transferrin receptor has been considered as a possible immunotherapeutic reagent. We have isolated a number of monoclonal antibodies against the murine transferrin receptor, some of which block cell growth. Mutants of lymphoma cell lines that escape the growth inhibitory action of the antibodies have been isolated. We are studying the genetic mechanisms by which these mutant cells arise and are using the mutants and the antibodies to study aspects of transferrin receptor function. (CS)

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA025893-06
Application #
3167051
Study Section
Experimental Immunology Study Section (EI)
Project Start
1979-09-01
Project End
1987-02-28
Budget Start
1985-03-01
Budget End
1986-02-28
Support Year
6
Fiscal Year
1985
Total Cost
Indirect Cost
Name
Salk Institute for Biological Studies
Department
Type
DUNS #
005436803
City
La Jolla
State
CA
Country
United States
Zip Code
92037
Lesley, J; He, Q; Miyake, K et al. (1992) Requirements for hyaluronic acid binding by CD44: a role for the cytoplasmic domain and activation by antibody. J Exp Med 175:257-66
Hyman, R; Lesley, J; Schulte, R (1991) Somatic cell mutants distinguish CD44 expression and hyaluronic acid binding. Immunogenetics 33:392-5
Lesley, J; Trotter, J; Schulte, R et al. (1990) Phenotypic analysis of the early events during repopulation of the thymus by the bone marrow prothymocyte. Cell Immunol 128:63-78
Reynolds, P J; Lesley, J; Trotter, J et al. (1990) Changes in the relative abundance of type I and type II lck mRNA transcripts suggest differential promoter usage during T-cell development. Mol Cell Biol 10:4266-70
Lesley, J; Schulte, R; Hyman, R (1990) Binding of hyaluronic acid to lymphoid cell lines is inhibited by monoclonal antibodies against Pgp-1. Exp Cell Res 187:224-33
Lesley, J; Schulte, R; Woods, J (1989) Modulation of transferrin receptor expression and function by anti-transferrin receptor antibodies and antibody fragments. Exp Cell Res 182:215-33
Heyman, R A; Borrelli, E; Lesley, J et al. (1989) Thymidine kinase obliteration: creation of transgenic mice with controlled immune deficiency. Proc Natl Acad Sci U S A 86:2698-702
Lesley, J; Schulte, R; Hyman, R (1988) Kinetics of thymus repopulation by intrathymic progenitors after intravenous injection: evidence for successive repopulation by an IL-2R+, Pgp-1- and by an IL-2R-, Pgp-1+ progenitor. Cell Immunol 117:378-88
Lesley, J; Schulte, R; Trotter, J et al. (1988) Qualitative and quantitative heterogeneity in Pgp-1 expression among murine thymocytes. Cell Immunol 112:40-54
Trowbridge, I S; Lesley, J F; Domingo, D et al. (1987) Monoclonal antibodies to transferrin receptor and assay of their biological effects. Methods Enzymol 147:265-79

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