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Biomedical subjects

B Dietzschold

Publications and source records attributed to B Dietzschold.

At least 91 records · Page 5Linked to original sources
PubMed1988

Genetic control of the development of experimental allergic encephalomyelitis in rats. Separation of MHC and non-MHC gene effects.

Experimental allergic encephalomyelitis (EAE)-susceptible Lew and EAE-resistant Brown Norway (BN) rats and the corresponding MHC congenic strains were examined for their ability to develop clinical and histologic EAE. The ability of T cells from these animals to proliferate in vitro in response to whole guinea pig (GP) myelin basic protein (MBP), rat MBP, and to the major encephalitogenic peptide of GP MBP 66-88 (GP 68-88) was also assessed. We found that Lewis (Lew) was highly susceptible and showed good T cell responses to GP, MBP, rat MBP, and GP 68-88. Lew.1N (BN MHC on Lew background) and BN were not susceptible and T cells from these strains showed significant responses to GP MBP, but not to rat MBP or GP 68-88. Although BN.B1 (Lew MHC on BN background) was not susceptible to actively induced EAE, MBP-specific Lew T cells could transfer severe disease to BN.B1. BN.B1 T cells showed responses to GP-MBP, rat MBP, and GP 68-88 and, when transferred to naive BN.B1 or Lew, induced only mild clinical EAE in both strains. Increasing the number of T cells from BN.B1 had no effect on the severity of clinical symptoms in either recipient, suggesting some deficiency in the T cell repertoire that is necessary for induction of severe EAE. These results suggest that 1) the T cell response to rat MBP and GP68-88 (but not to sites other than 68-88 in GP MBP) is necessary for susceptibility to EAE; 2) the ability to respond to both rat MBP and GP 68-88 is determined by the MHC gene products on APC; and 3) given a permissive MHC, the T cell response that results in EAE is influenced by non-MHC genes.

Animals↗
PubMed1988

Overlapping T cell antigenic sites on a synthetic peptide fragment from herpes simplex virus glycoprotein D, the degenerate MHC restriction elicited, and functional evidence for antigen-Ia interaction.

Analysis of the B10.A T cell response to synthetic peptides representing the NH2-terminal 23 amino acids from the HSV glycoprotein D sequence revealed two antigenic determinants for T cells: one localized between residues 1-16 and the other between residues 8-23. The 1-16 site, which is helical, was recognized in the context of the Ia molecule, whereas the 8-23 site, which is nonhelical, was recognized in the context of the I-E molecule. The I-E-restricted response was found to be highly MHC degenerate in that T cell hybridomas specific for the 8-23 peptide responded to antigen on APCs derived from B10.A, B10.A(5R), and B10.A(9R) mice and showed differences in antigenic fine specificity with APCs of different haplotypes. These data support the idea of antigen-Ia interaction.

Amino Acid Sequence↗
PubMed1988

Phosphorylation loops in synthetic peptides of the human neurofilament protein middle-sized subunit.

Peptides containing 13 and 39 amino acid residues and serine-side-chain-phosphorylated (P) analogues thereof, corresponding to human neurofilament protein middle-sized subunit (NF-M), have been synthesized in order to localize the phosphorylation site of this protein. The secondary structure of the nonphosphorylated peptides, determined by circular dichroism (CD) measurements, predicted secondary structural calculations and energy conformational calculations, was suggested to be a series of alternating type I (III). beta-turns and 3(10) or alpha-helices. By contrast, the phosphorylated peptides exhibit a unique conformation, probably due to salt bridges between the phosphoserine and the lysine residues. This has provided the first clear evidence that phosphorylation induces conformational changes among these synthetic peptides and presumably, in NF proteins as well. These phosphorylation loops might be the major recognition sites of the neurofilament protein-directed kinases.

Brain↗
PubMed1988

Identification of the major multiphosphorylation site in mammalian neurofilaments.

The sequence Lys-Ser-Pro-Val-Pro-Lys-Ser-Pro-Val-Glu-Glu-Lys-Gly repeats six times serially in the human midsized neurofilament (NF) protein (NF-M). To establish whether Lys-Ser-Pro-Val(Ala) is the major site for in vivo NF phosphorylation, peptides based on the human NF-M repeat were synthesized and chemically phosphorylated. These synthetic peptides were probed with 515 monoclonal antibodies (mAbs) that were raised to, and distinguished, several differentially phosphorylated forms of NF proteins. Studies with 95 of those mAbs that recognized the peptides before and after chemical phosphorylation demonstrated that a highly immunogenic epitope shared by the peptides is present in NFs from all species tested, including invertebrates. This suggests the phylogenetic conservation of a major NF phosphorylation site. Lastly, a cross-reactive antigenic determinant shared by the peptides and the major NF phosphorylation site was shown to exist in neurofibrillary tangles of patients with Alzheimer disease as well as in two neuron-specific microtubule-associated proteins (MAPs)--i.e., MAP2 and tau.

Animals↗
PubMed1988

Recognition of rabies and rabies-related viruses by T cells derived from human vaccine recipients.

Human peripheral blood mononuclear cells and T-cell lines and clones from individuals immunized with rabies PM vaccine were tested for the ability to recognize antigenic determinants in rabies and rabies-related viruses in an antigen-induced proliferation assay. Some, but not all, of the T cells from these individuals cross-reacted with various laboratory strains of rabies virus with rabies-related viruses such as Duvenhage and Mokola. In addition, these T cells were shown to react with epitopes of either the ribonucleoprotein or the viral glycoprotein. Rabies-specific cytotoxic T-cell responses by a CD4+ T-cell line were evident against antigenic determinants of the ribonucleoprotein and glycoprotein.

Antibodies, Viral↗
PubMed1988

Organization of the middle RNA segment of snowshoe hare Bunyavirus.

The genetic organization of the M RNA segment of snowshoe hare (SSH) virus, a member of the Bunyavirus genus of the family Bunyaviridae, has been determined. The middle (M) RNA segment has a single open reading frame (ORF) of 1441 amino acids. We have used amino- and carboxy-terminus sequencing and synthetic peptides to map proteins within the ORF. The order of the proteins translated from the single large open reading frame is G2, NSm, G1. The G2 protein extends from amino acids 14 to 299. The molecule is 286 residues long, with a computed nonglycosylated molecular weight of 31,973 Da. It is preceded by a cleaved 13 amino acid signal sequence. G2 includes a long highly hydrophobic sequence and contains three potential N-linked glycosylation sites. The G1 protein occupies the C-terminal end of the open reading frame from amino acids 474 to 1441 (968 amino acid residues) and has a computed nonglycosylated, molecular weight of 108,981 kDa. It has two potential N-linked glycosylation sites, and a potential transmembrane region followed by a potential cytoplasmic domain at the C-terminal end. If membrane associated it has an orientation of N-terminus outer, C-terminus inner. Limited trypsin digestion removes a 33-kDa fragment from the N-terminal end, leaving a virion-associated truncated G1 molecule (amino acids 762 to 1441) with a single N-linked glycosylation site. Between the G2 and G1 molecules there are 174 amino acids, sufficient to code for 19 kDa of protein. Some antibodies raised against peptides within this region react with proteins of 11 kDa (NSm) and 10 kDa present in infected cell lysates, but the exact relationship of these proteins to the open reading frame remains to be determined.

Amino Acid Sequence↗
PubMed1987

A synthetic peptide induces long-term protection from lethal infection with herpes simplex virus 2.

Immunization against viral pathogens is generally directed toward the induction of virus neutralizing antibody (VNA) and the maintenance of the potential for a second-set (IgG) response. Indeed, an elevated level of specific antibody is considered a reliable clinical indicator that a state of immunity exists in the host. However, in the case of herpes simplex virus (HSV), the presence of circulating VNA does not necessarily correlate with protection. Thus, it has been found that secondary infections occur in individuals even with high neutralizing titers to HSV, suggesting that antibody to the virus may be useless or even deleterious. In consideration of these facts, we were interested in inducing a T cell response to HSV. We had already shown that synthetic peptides corresponding to the NH3-terminal region of the glycoprotein D (gD) molecule of HSV could induce a strong T cell response when injected into mice, but did not, by themselves, confer protection. In this report, we examined the ability of peptides, covalently coupled to palmitic acid and incorporated into liposomes, to induce virus-specific T cell responses that confer protection against a lethal challenge of HSV-2. We have demonstrated that long-term protective immunity is achieved with a single immunization in the absence of neutralizing antibody when antigen is presented in this form. Furthermore, T cells but not serum from such immune mice can adoptively transfer this protection.

Acylation↗
PubMed1987

Mechanisms of rabies virus neutralization by glycoprotein-specific monoclonal antibodies.

Incubation of radiolabeled rabies virus with neutralizing monoclonal antibodies (MAbs) resulted in complete neutralization of the virus but only partial inhibition of virus binding to, and internalization by, BHK cells. Several of the neutralizing MAbs were capable of preventing infection after virus adsorption to cells; up to 30% of the bound virus was released when cells containing adsorbed virus were incubated with these MAbs at 4 degrees, indicating that the release of bound virus accounts only in part for the neutralization of adsorbed virus. To study the mechanism of neutralization of cell-bound virus, temperature shift experiments were carried out to follow the fate of neutralized cell-adsorbed virus at 37 degrees. Treatment of infected cells with each of the tested neutralizing MAbs had no effect on virus uptake at 37 degrees and the MAbs were endocytosed together with the virus; however, the ability of some of the MAbs to neutralize cell-adsorbed rabies virus correlated with the fusion inhibition activity of these MAbs. We hypothesize from these data that these MAbs neutralize rabies virus by inhibiting the intraendosomal acid-catalyzed fusion step that leads to virus uncoating.

Adsorption↗
PubMed1987

Localization and immunological characterization of antigenic domains of the rabies virus internal N and NS proteins.

To locate epitopes on internal antigens of rabies virus, purified N and NS proteins of the nucleocapsid were cleaved at methionine, tryptophan or glutamic acid residues, transferred to nitrocellulose and immunostained using monoclonal antibodies (MAbs) specific for N and NS proteins, respectively. Five MAb-positive fragments of N protein and one fragment of NS protein were located after NH2-terminal amino acid sequence analysis within the deduced amino acid sequences of N and NS proteins. Antigenic analysis of synthetic overlapping peptides corresponding to the amino acid sequences of these fragments localized two major antigenic sites of N protein and one antigenic site of NS protein. Like the N- and NS-specific MAbs, anti-peptide antisera produced against the different synthetic antigens either reacted in a type-common fashion with all rabies virus strains, or in a type-specific manner with a restricted number of strains. The synthetic peptides corresponding to the three antigenic regions of the N and NS proteins also stimulated proliferation of human T lymphocytes derived from vaccinees who received inactivated rabies virus vaccine. This suggested that the antigenic regions of N and NS proteins are recognized by both B and T cells.

Amino Acid Sequence↗
PubMed1987

Primary and secondary structure of bovine retinal S antigen (48-kDa protein).

The complete amino acid sequence of bovine S antigen (48-kDa protein) has been determined by cDNA and partial amino acid sequencing. A 1623-base-pair (bp) cDNA contains an open reading frame coding for a protein of 404 amino acids (45,275 Da). Tryptic peptides and cyanogen bromide peptides of native bovine S antigen were purified and partially sequenced. All of these peptides were accounted for in the long open reading frame. Searching of the National Biomedical Research Foundation data bank revealed no extensive sequence homology between S antigen and other proteins. However, there are local regions of sequence similarity with alpha transducin, including the sites subject to ADP-ribosylation by Bordetella pertussis and cholera toxins and the phosphoryl binding-sites. Secondary structure prediction and circular dichroic spectroscopy show that S antigen is composed predominantly of beta-sheet conformation. Acid-catalyzed methanolysis suggests the presence of low levels of carbohydrate in the molecule.

Amino Acid Sequence↗
PubMed1987

Induction of protective immunity against rabies by immunization with rabies virus ribonucleoprotein.

We have studied the ability of rabies virus ribonucleoprotein (RNP) to induce a protective immune response in animals against lethal challenge with rabies and rabies-related lyssa viruses. Liposomes containing either RNP or the glycoprotein (G protein) of a variant virus with multiple alterations in the G antigenic structure conferred no or poor protection, respectively, against lethal intracerebral challenge with rabies virus. By contrast, liposomes containing RNP and the variant G protein induced a good protective response, comparable to that achieved with inactivated virus vaccine against intracerebral challenge. Moreover, mice or raccoons immunized with RNP alone resisted lethal peripheral challenge with homologous or heterologous virus strains. These results indicate that the RNP of rabies virus plays a crucial role in induction of protective immunity.

Animals↗
PubMed1987

Antigenic variation in rabies and rabies-related viruses: cross-protection independent of glycoprotein-mediated virus-neutralizing antibody.

Immunization experiments with vaccines prepared from the PM and ERA strains of rabies virus demonstrated that in mice, only ERA vaccine primes for an anamnestic response to the rabies-related strain Duvenhage (DUV6); in rabbits, both ERA and PM vaccines induced immunologic memory to DUV6 virus. In mice, ERA vaccine, but not an equal concentration of PM vaccine, conferred protection against a lethal challenge infection with DUV6 virus. This result indicated that the protective activity correlated with the vaccine's ability to induce immunologic memory. A vaccine prepared from a sequentially selected, neutralization-resistant, multiple-variant virus conferred protection against challenge with the parental strain, a result indicating that antigenic variation of the glycoprotein may not be the sole factor in determining the relative efficacy of rabies prophylaxis. We found no correlation between titers of neutralizing antibody and mortality rates in mice immunized with purified glycoprotein from these viruses.

Animals↗
PubMed1987

Purification and amino terminal sequencing of human melanoma nerve growth factor receptor.

The nerve growth factor (NGF) receptor, solubilized with Triton X-100 detergent, has been purified from human melanoma cell line A875. Purification to near-homogeneity was achieved by chromatography on wheat germ agglutinin-agarose, followed by immunoaffinity chromatography on Sepharose columns coupled with anti-NGF receptor monoclonal antibody (MAb). The purified receptor, a 75,000-dalton protein, retains the capacity to bind NGF as well as anti-receptor MAbs. Final purification was achieved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The sequence of amino acid residues at the amino terminus has been determined. Possible sequence homology between the NGF receptor and several other proteins is discussed. Using the purified receptor as immunogen, new MAbs to the NGF receptor have been produced. The NGF receptor was visualized by immunoperoxidase staining in tissue sections of dorsal root ganglia from monkeys.

Amino Acid Sequence↗
PubMed1987

S-antigen: characterization of a pathogenic epitope which mediates experimental autoimmune uveitis and pinealitis in Lewis rats.

S-antigen (48K protein) is a photoreceptor cell protein highly pathogenic for the induction of experimental autoimmune uveitis (EAU) and intimately involved in the visual process. EAU is characterized, in part, as a T-cell mediated autoimmune disease which results in a severe inflammation of the uveal tract, and pineal gland. In order to determine specific sites in S-antigen responsible for its pathogenicity we synthesized twenty-three peptides, corresponding to the entire 404 amino acid sequence, and tested each peptide for its ability to induce EAU in Lewis rats. One peptide, peptide M (18 amino acids in length), was found to be highly pathogenic and consistently induced an EAU that was identical to the disease caused by native S-antigen. Clinically, the disease that developed in the eye was characterized by iris and pericorneal hyperemia, followed by inflammatory exudates in the anterior and vitreous chambers. Histopathologically a severe inflammatory response was observed which resulted in the complete destruction of the photoreceptor cell layer of the retina. In order to more fully characterize this pathogenic site, 14 additional smaller peptides (eight to eighteen amino acids in length) corresponding to the left and right portions of peptide M were synthesized. Of these peptides, peptide M16L, M15L, and M12L induced EAU, further localizing this pathogenic site to a small well-characterized region of S-antigen consisting of twelve amino acids. In addition, animals with ocular inflammatory disease had an associated pinealitis characterized by a lymphocytic infiltration of the subcapsular and central area of the pineal gland. The significance of these findings and the relationship of S-antigen in the pathogenesis of EAU and other autoimmune diseases is discussed.

Amino Acid Sequence↗
PubMed1987

The structure of bovine retinal S-antigen: sequence analysis and identification of monoclonal antibody epitopes and uveitogenic site.

cDNA clones for bovine retinal S-antigen (48K protein) have been isolated and sequenced. Secondary structure prediction for the deduced amino acid sequence suggest that the protein has predominantly beta-conformation with a helical region at the C-terminus. Local regions of sequence similarity with alpha-transducin have been observed, including the sites subject to ADP-ribosylation by pertussis and cholera toxins. Thirty-nine tryptic peptides and ten CNBr peptides of native S-antigen were purified and partially sequenced, showing good agreement with the sequence deduced from the cDNA analysis. The locations of two monoclonal epitopes have been determined by different methods. Furthermore, one synthetic peptide corresponding to the determined amino acid sequence was found to be highly pathogenic for the induction of experimental autoimmune uveitis (EAU). Native S-antigen has further been shown to be glycosylated, which has implications for its antigenicity.

Amino Acid Sequence↗