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B Chesebro

Publications and source records attributed to B Chesebro.

151 records · Page 9Linked to original sources
PubMed1967

Ultrastructure of gamma-M immunoglobulin and alpha macroglobulin: electron-microscopic study.

Electron microscopy of purified Waldenström macroglobulins and normal human and rabbit gammaM immunoglobulins revealed spider-like structures with five legs varying in length and often joining a central ring. Usually only the central more rigid part of this structure (about 150 by 170 angstroms) was clearly visible, but occasionally particles were seen with longer very flexible legs having a total span of about 350 angstroms. Molecules of gammaM antibody retained antibody activity during preparation for electron microscopy. Human and rabbit alpha macroglobulins revealed more rigid symmetric structures (100 by 200 angstroms) which resembled the Russian letter .

Animals↗
PubMedDate not supplied

Identification of scrapie prion protein-specific mRNA in scrapie-infected and uninfected brain.

To date no nucleic acid has been found in the purified infectious agent which causes the spongiform encephalopathy known as scrapie. In an attempt to identify a unique scrapie virus-associated messenger RNA in tissues of infected animals, we have synthesized an oligonucleotide probe complementary to the mRNA sequence corresponding to the amino-acid sequence of the prion protein, PrP27-30 (ref. 1). We report here that, with this probe, a complementary DNA clone representing PrP27-30 was obtained from scrapie-infected mouse brain; the DNA sequence of this clone could be translated into a protein that matches exactly the published sequence of PrP27-30. The cDNA clone hybridized to a single 2.4-2.5-kilobase (kb) mRNA from both normal and scrapie-infected brain. Thus, the PrP27-30 mRNA is not uniquely associated with scrapie infectivity, suggesting that PrP27-30 may be a normal component of mouse and hamster brain.

Amino Acid Sequence↗
PubMedDate not supplied

Different H-2 subregions influence immunization against retrovirus and immunosuppression.

Friend murine leukaemia virus complex (FV) causes an immunosuppressive retrovirus-induced disease. In certain mouse strains, FV shows striking similarities to human immunodeficiency virus (HIV) infection in man in that infected mice have severe T-cell immunosuppression but also develop virus-neutralizing antibodies incapable of eliminating infected cells. Previously we noted the influence of mouse major histocompatibility complex (H-2) genes on both FV-induced immunosuppression and on ability to protect mice against FV by immunizing with a vaccinia-Friend murine leukaemia helper virus (F-MuLV) envelope (env) recombinant virus. Here we show that different subregions of H-2 are involved in susceptibility to virus-induced immunosuppression (H-2D subregion) and protective immunization with a recombinant vaccinia virus (H-2K or I-A subregions). Thus, susceptibility to virus-induced immunosuppression does not preclude protection by vaccinia-Friend immunization. The mechanism of protection seems to involve priming of immune T cells, and not initial induction of neutralizing antibodies or cytotoxic T lymphocytes (CTL) (ref.2). Subsequent virus challenge generates a secondary response, resulting in appearance of IgG antibodies and CTL. In human HIV infection there could also be host genetic influences on elements of disease pathogenesis, such as immunosuppression, and on the success of T-cell priming by potential protective vaccines.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Prion protein and the scrapie agent: in vitro studies in infected neuroblastoma cells.

The mouse neuroblastoma cell line N2a was persistently infected with the Chandler strain of the mouse scrapie agent. Although the infection did not spread to infect > 1% of the cells, clones were established that had from 50 to 100% infected cells. These clones expressed the abnormal protease-resistant form of prion protein (PrP), which is believed to mediate brain degeneration in animals with scrapie and bovine spongiform encephalopathy and in humans with kuru, Creutzfeldt-Jakob disease, and Gerstmann-Straussler-Scheinker syndrome. With this in vitro system, Congo red and several sulfated polysaccharides, including heparin and pentosan polysulfate, were found to inhibit accumulation of protease-resistant PrP. These results and additional data confirming PrP binding to heparin suggested a possible role for sulfated glycosaminoglycans in the generation of protease-resistant PrP during scrapie infection. Accumulation of protease-resistant PrP was also blocked in vitro by expression of foreign PrP molecules, indicating that PrP from different species might compete for common substrates in this process. These results using scrapie-infected cell lines provide new opportunities for development of drugs capable of blocking the brain degeneration caused by scrapie and other transmissible spongiform encephalopathies.

Animals↗