The characterization, molecular cloning, and expression of a novel hematopoietic cell antigen from CD34+ human bone marrow cells.

The adhesion molecule BEN/SC1/DM-GRASP (BEN) is a marker in the developing chicken nervous system that is also expressed on the surface of embryonic and adult hematopoietic cells such as immature thymocytes, myeloid progenitors, and erythroid progenitors. F84.1 and KG-CAM, two monoclonal antibodies to rat neuronal glycoproteins with similarity to BEN, cross-react with an antigen on rat hematopoietic progenitors, but F84.

Abnormal T cell development in CD3-zeta-/- mutant mice and identification of a novel T cell population in the intestine.

The T cell antigen receptor (TCR)-associated invariable membrane proteins (CD3-gamma, -delta, -epsilon and -zeta) are critical to the assembly and cell surface expression of the TCR/CD3 complex and to signal transduction upon engagement of TCR with antigen. Disruption of the CD3-zeta gene by homologous recombination resulted in a structurally abnormal thymus which primarily contained CD4- CD8- and TCR/CD3very lowCD4+CD8+ cells. Spleen and lymph nodes of CD3-zeta-/- mutant mice contained a normal number and ratio of CD4+ and CD8+ single positive cells that were TCR/CD3very low.

Transgenic mice containing a human heavy chain immunoglobulin gene fragment cloned in a yeast artificial chromosome.

We have developed a method for the introduction of yeast artificial chromosomes (YACs) into transgenic mice. An 85 kilobase (kb) fragment of the human heavy chain immunoglobulin gene was cloned as a YAC, and embryonic stem cell lines carrying intact, integrated YACs were derived by co-lipofection of the YAC with an unlinked selectable marker. Chimaeric founder animals were produced by blastocyst injection, and offspring transgenic for the YAC were obtained.

Analysis of the signal for attachment of a glycophospholipid membrane anchor.

The COOH terminus of decay accelerating factor (DAF) contains a signal that directs attachment of a glycophospholipid (GPI) membrane anchor. To define this signal we deleted portions of the DAF COOH terminus and expressed the mutant cDNAs it CV1 origin-deficient SV-40 cells. Our results show that the COOH-terminal hydrophobic domain (17 residues) is absolutely required for GPI anchor attachment.

Signal peptide for protein secretion directing glycophospholipid membrane anchor attachment.

Decay accelerating factor (DAF) is anchored to the plasma membrane by a glycophospholipid (GPI) membrane anchor covalently attached to the COOH-terminus of the protein. A hydrophobic domain located at the COOH-terminus is required for anchor attachment; DAF molecules lacking this domain are secreted. Replacement of the COOH-terminal hydrophobic domain with a signal peptide that normally functions in membrane translocation, or with a random hydrophobic sequence, results in efficient and correct processing, producing GPI-anchored DAF on the cell surface.