Variable major proteins of Borrelia hermsii. Epitope mapping and partial sequence analysis of CNBr peptides.

The variable major proteins (VMP) of serotypes 7 and 21 of the relapsing fever agent Borrelia hermsii were isolated by detergent extraction and high performance liquid chromatography. Cyanogen bromide (CNBr) digestion of the isolated VMP yielded two peptides of apparent molecular weights 20,000 (20 K) and 16 K from VMP7, and three peptides of 14.5, 14, and 7 K mol wt from VMP21. Serotype-specific monoclonal antibodies bound in Western blots to one of each of the two or three CNBr fragments from the homologous VMP. A single monoclonal antibody bound to the whole cells, the isolated VMP, and a CNBr fragment of both serotype 7 and serotype 21. (This crossreactive antibody did not, however, bind to any of four other serotypes examined.) Regional conservation of structure between VMP7 and VMP21 was also shown by amino acid sequence analysis of the N-termini of the five CNBr fragments. One pair of aligned fragments from VMP7 and VMP21 had 80% amino acid homology in sequence; a second pair had 40% homology. The partial amino acid homologies between two VMP suggest that these proteins are products of members of a polygene family

DNA sequence of the mouse H-2Dd transplantation antigen gene

The inbred BALB/c mouse has three transplantation antigens, H2-Kd, H2-Ld, and H2-Dd. We present the complete nucleotide sequence of the H2-Dd gene as well as 777 residues of previously unpublished H-2Dd protein sequence. These data complete the sequences of all the BALB/c transplantation antigen genes and permit detailed comparison with each other and with their counterparts from the inbred C57BL/10 mouse. Transplantation antigens may differ from one another by as much as 5%-15% of their amino acid sequence for the external domains. These extensive differences may arise by gene conversion. The H-2D region of the BALB/c mouse encodes the H2-Dd and the H2-Ld genes. Serologic data suggest that at least two additional transplantation antigen molecules, H2-Rd and H2-Md, are encoded in the H-2D region of the major compatibility complex. Paradoxically, gene cloning studies have only identified the H2-Dd and the H2-Ld genes in the H-2D region. A complete DNA sequence of the H2-Dd gene shows that a variety of alternative splice sites exist throughout the gene, which may lead to additional gene products and may explain the multiplicity of H-2D-encoded polypeptides

Production of a T cell hybridoma that expresses the T cell receptor gamma/delta heterodimer.

We have produced a T cell hybridoma line by fusion of an IL-2-dependent, long-term T cell receptor (TCR) gamma/delta+ Thy-1+, bone marrow-derived, dendritic epidermal cell line to the BW5147 tumor line. The resultant hybridoma was rapidly growing, lymphokine independent, and expressed T3 in association with the TCR gamma/delta heterodimer. Several subclones of the hybridoma line produced easily detectable levels of IL-2 after stimulation by anti-T3 or Con A. The availability of these cloned cell lines should greatly facilitate further functional, biochemical, and molecular studies of the TCR delta chain

Aberrant Development of Thymocytes in Mice Lacking Laminin-2

In previous in vitro studies, we proposed a role for the extracellular matrix component, laminin- 2, and its integrin receptor, VLA-6, in thymocyte development. The characterization of two dystrophic mouse strains with different defects in laminin-2 allowed us to examine this proposal in vivo. Mice deficient in laminin-2, dy/dy, show a significant reduction in thymus size and number of thymocytes compared to normal littermates. These mice also exhibited apparent alterations of thymic architecture. Examination of the CD4/CD8 populations in dy/dy thymi showed large relative increases in the DN (CD4-CD8-) and SP (CD4+CD8-, CD4-CD8+) populations and a significant decrease in the DP (CD4+CD8+) population. Further examination of the DN population for CD44 and CD25 expression showed a remarkable decrease in the more mature pre-T cell populations. Analysis of apoptosis in situ, and by flow cytometry, in dy/dy thymi revealed a significant increase in apoptotic DN thymocytes in the capsule and subcapsular regions. Interestingly, thymocyte development appeared to proceed normally in dystrophic mice expressing a mutant form of laminin-2, dy2J, as well as, in fetal and neonatal dy/dy mice. We propose that laminin-2 plays an active role in thymocyte development by delivering cell survival and differentiation signals at specific stages of development in young adult mice

The Grizzly, March 27, 2003

America at War: President Bush says Victory is Certain in Iraq • A Day in the Life of a UN Weapons Inspector • Celebrate Women\u27s History Month • A Fine Ursinus Fellow • Project Vote Smart Approves Five Scholarships for Ursinus College Students • Psyched up for Psycho Beach Party • Calling All Talents • Silence Broken: Korean Comfort Women • Men\u27s Basketball Falls to Scranton • Howard Earns All-American Honors • Dougherty 11th at NCAA Track Championshipshttps://digitalcommons.ursinus.edu/grizzlynews/1532/thumbnail.jp