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.

Signal for attachment of a phospholipid membrane anchor in decay accelerating factor.

Decay accelerating factor (DAF) belongs to a novel group of membrane proteins anchored to the cell surface by a glycophospholipid membrane anchor that is covalently attached to the carboxyl terminus of the protein. The last 37 amino acids of membrane DAF, when fused to the carboxyl terminus of a secreted protein, are sufficient to target the fusion protein to the plasma membrane by means of a glycophospholipid anchor. This approach provides a novel means of targeting proteins to the cell-surface membrane.

Cloning of decay-accelerating factor suggests novel use of splicing to generate two proteins.

Decay-accelerating factor (DAF), a glycoprotein that is anchored to the cell membrane by phosphatidylinositol, binds activated complement fragments C3b and C4b, thereby inhibiting amplification of the complement cascade on host cell membranes. Here, we report the molecular cloning of human DAF from HeLa cells. Analysis of DAF complementary DNAs revealed two classes of DAF messenger RNA, one apparently derived from the other by a splicing event that causes a coding frameshift near the C terminus.

Nucleotide and amino acid sequence coding for polypeptides of foot-and-mouth disease virus type A12.

The coding region for the structural and nonstructural polypeptides of the type A12 foot-and-mouth disease virus genome has been identified by nucleotide sequencing of cloned DNA derived from the viral RNA. In addition, 704 nucleotides in the 5' untranslated region between the polycytidylic acid tract and the probable initiation codon of the first translated gene, P16-L, have been sequenced. This region has several potential initiation codons, one of which appears to be a low-frequency alternate initiation site.

Sequence variation in the gene for the immunogenic capsid protein VP1 of foot-and-mouth disease virus type A.

The nucleotide sequences have been determined and compared from cloned cDNA genes coding for the foot-and-mouth disease virus (FMDV) immunogenic capsid protein, VP1, from eight different A subtypes: A5 Westerwald/58, A12 119ab (large plaque variant), A22 550 USSR/65, A24 Cruzeiro Brazil/55, A27 Cundinamarca Colombia/76, A32 Venezuela/70, A Venceslau Brazil/76, and A Argentina/79. We have also found sequence variations among different cDNA clones of the A5 and A24 subtypes. There are regions of nucleotide sequence within the VP1 gene that vary considerably among the subtypes as well as other regions that remain relatively constant.

Identification of amino acid and nucleotide sequence of the foot-and-mouth disease virus RNA polymerase.

Foot-and-mouth disease virus (FMDV) RNA polymerase was purified from the polyethylene glycol (PEG)-treated supernatant of infected cell media by a combination of ion-exchange chromatography, membrane molecular filtration, and affinity chromatography. The purified RNA polymerase which migrated as a single band of 56,000 molecular weight on a polyacrylamide gel was subjected to automated Edman degradation and the sequence of the first 30 amino acid residues established. On the basis of previous evidence, which indicated that the RNA polymerase was the most 3'-translated polypeptide, plasmids containing cDNA mapping at the 3' end of the genome were characterized by restriction enzyme analysis and nucleotide sequencing.

Disorders of peripheral cutaneous nerves.

The histopathology of leprosy is described with particular reference to its effects on peripheral cutaneous nerves. Mycobacterium leprae invade the Schwann and perineurial cells of peripheral cutaneous nerves preferentially. The organisms are eventually destroyed with their host cells by a cell-mediated immune response.

Neural intersegmental connection in the spinal root and ganglion region of the rat.

A study has been made of the macroscopic, microscopic and electron-microscopical appearance of intersegmental neural connections in the rat. Macroscopically, spinal roots and ganglia of adjacent segments were frequently observed to be linked by discrete, slender strands, mainly in the lumbosacral region where the roots are long. When examined under the light microscope, even the smallest was found to contain as many as 72 myelinated fibres with a range of diameters between 1.

Leprosy--histopathologic aspects of nerve involvement.

The most striking single feature of the clinical manifestations of leprosy is the very wide range of appearances shown by the skin lesions. These include the vague, hypopigmented macules of indeterminate leprosy; the large, sharply defined hypopigmented anaesthetic lesions of tuberculoid leprosy; the nodules and diffuse infiltration of lepromatous leprosy; and a wide range of plaques and annular lesions of the intermediate (borderline or dimorphous) types of disease. From superficial appearances it would be impossible to say that these were manifestations of the same infection.