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Biomedical subjects

B Dietzschold

Publications and source records attributed to B Dietzschold.

At least 109 records · Page 6Linked to original sources
PubMed1986

Rhodopsin and retinoblastoma. A monoclonal antibody histopathologic study.

Rhodopsin was identified in formaldehyde-fixed, paraffin-embedded human fetal retina, and in five retinoblastomas using monoclonal antibody (MAb) MAb-E. The binding pattern corresponding to rhodopsin immunoreactivity was then compared with S-antigen using another monoclonal antibody, MAbA9-C6. Rhodopsin and S-antigen were first observed in the 18-week-old human fetal eye, at a stage preceding photoreceptor differentiation. In adult eyes containing normal photoreceptor cells, rhodopsin immunoreactivity was restricted to the rod outer segments, whereas S-antigen immunoreactivity was localized to the entire photoreceptor cell. In retinoblastomas both monoclonal antibodies bound to the same area of the tumor; however, different and distinct staining patterns associated with each monoclonal antibody were recognized. In four cases, an intense well-circumscribed "halo" pattern, characteristic of cell-surface binding, was associated with rhodopsin, whereas the binding pattern associated with S-antigen was intense, well localized, and cytoplasmic in all cases. Our results show that some well-differentiated retinoblastomas express both rhodopsin and S-antigen, and as such express proteins that participate in the initial events in the phototransduction of vision.

Adult↗
PubMed1986

Stimulation of cytotoxic T-lymphocyte responses by rabies virus glycoprotein and identification of an immunodominant domain.

The cytotoxic T-lymphocyte (CTL) response to rabies virus glycoprotein has been studied. A primary in vivo CTL response was obtained following inoculation of A/J mice with 10 micrograms of glycoprotein, but only when in the form of reconstituted glycoprotein-lipid vesicles. These glycoprotein-lipid vesicles were prepared with lipids from BHK-21 cells, and did not incorporate mouse major histocompatibility complex (MHC) antigens. Secondary in vitro stimulation of rabies virus-specific CTL was obtained with inactivated virus and with larger quantities of glycoprotein. This response, but not that induced by rabies virus-infected stimulator cells, was dependent on the presence of radiation-resistant accessory cells which could not be replaced with T-cell growth factors. An analysis of the molecular requirements for stimulation of CTL by glycoprotein revealed that cleavage by cyanogen bromide (CNBr) or limited tryptic digestion actually enhanced stimulation of CTL. In contrast, reduction and alkylation destroyed activity. Following separation of CNBr or tryptic fragments by gel electrophoresis or high-pressure liquid chromatography (HPLC) (under nonreducing conditions), a nominal determinant of glycoprotein was identified. One CNBr peptide (residues 103-178) and one peak of tryptic peptides were found to stimulate rabies virus-specific CTL. The tryptic peak was further analyzed by Edman degradation-sequencing, and found to consist of three peptides with amino terminals at residues 130, 251 and 279. This evidence suggests that a nominal determinant of glycoprotein responsible for stimulating rabies virus-specific CTL is located between residues 130-178 of the glycoprotein, and incorporates a single disulfide loop (159-169) which is necessary for biologic activity.

Animals↗
PubMed1986

Oral immunization and protection of raccoons (Procyon lotor) with a vaccinia-rabies glycoprotein recombinant virus vaccine.

Animal rabies control has been frustrated by the existence of multiple wildlife reservoirs and the lack of efficacious oral vaccines. In this investigation, raccoons fed a vaccinia-rabies glycoprotein recombinant virus in a sponge bait developed rabies virus-neutralizing antibody (0.6-54.0 units) and resisted street rabies virus infection 28 and 205 days after feeding. Additional raccoons immunized by oral infusion with attenuated antigenic variants of rabies virus strains CVS-11 and ERA failed to develop rabies virus-neutralizing antibody. This work demonstrates the feasibility of a recombinant virus vaccine containing the rabies glycoprotein gene for immunization of raccoons, and possibly other wildlife, to obtain long-term protection against rabies.

Administration, Oral↗
PubMed1986

Immune responses to isolated human cytomegalovirus envelope proteins.

A group of envelope proteins of human cytomegalovirus, gA protein (L. Pereira, M. Hoffman, M. Tatsuno, and D. Dondero, Virology 139:73-86, 1984; L. Pereira, p. 383-404, in B. Roizman, ed., The herpesviruses, vol. 3, 1985), and two protein mixtures (58,000-molecular-weight [58K]-66K and 130K-66K), separated by serial columns prepared with anti-gA immunoglobulin G from sera of immunized guinea pigs, induced neutralizing antibodies and a cellular immune response in the animals. The gA is a disulfide-linked protein complex consisting of high-molecular-weight (greater than 200K), 130K-150K, and 55K-58K proteins.

Animals↗
PubMed1986

S-antigen: identification of the MAbA9-C6 monoclonal antibody binding site and the uveitopathogenic sites.

The location of the monoclonal antibody, MAbA9-C6, binding site and two uveitopathogenic sites in S-antigen have been determined. Using cyanogen bromide, S-antigen was cleaved into nine peptides, designated C1 to C9. MAbA9-C6 bound selectively to one large peptide designated C5, consisting of 122 amino acids. Six peptides (20 to 22 amino acids in length) designated 2,3,K,L,N and M, corresponding to the entire length of peptide C5, were synthesized chemically. In a radioimmunoassay and a dot-binding immunoassay, MAbA9-C6 bound selectively to one of the six peptides, peptide 3, indicating that this region of peptide C5 contains the MAbA9-C6 binding site. Twelve smaller peptides (ten amino acids in length), corresponding to the amino acid sequence of peptide 3, were synthesized and used in a competitive inhibition binding assay. These studies localized the MAbA9-C6 binding site to a small region within peptide 3. In addition, peptide K and peptide M were highly pathogenic for the induction of experimental auto-immune uveitis (EAU). Clinical and histological evidence of a severe uveo-retinitis, indistinguishable from that seen with native S-antigen, was documented in Lewis rats immunized with the synthetic peptides (50 micrograms), 11-12 days following immunization. Our results show that the MAbA9-C6 binding site and the two uveitopathogenic sites lie in close proximity to each other within the region of S-antigen corresponding to peptide C5. Furthermore, microcomputer analysis of the average hydrophilicity/hydrophobicity values of the amino acid sequence corresponding to peptide C5 shows that the MAbA9-C6 binding site and one uveitopathogenic site (peptide K) lie on the adjacent peaks. The significance of these findings and their relationship to the role of S-antigen in the pathogenesis of EAU and the phototransduction of vision is discussed.

Amino Acid Sequence↗
PubMed1986

Isolation and characterization of human T cell lines and clones reactive to rabies virus: antigen specificity and production of interferon-gamma.

By using a preparation of inactivated rabies virus, the blood mononuclear cells from five rabies vaccine recipients were stimulated in vitro in the presence of interleukin 2. T cell lines that displayed significant proliferative responses to whole rabies virus and to preparations of rabies glycoprotein and nucleocapsid were obtained from all the individuals. Other antigens, such as diphtheria and tetanus toxoids, influenza A virus, hepatitis B surface antigen, and serum albumin, failed to induce the proliferation of the T cell lines. One of these rabies-specific T cell lines was found to proliferate in response to rabies antigens only when the antigen-presenting cells expressed homologous HLA-DR antigens. The use of mouse monoclonal antibodies specific for human T cell surface markers revealed that most of the cells of these rabies-reactive lines were of the helper/inducer class of T lymphocytes. Stimulation of the T cell lines with the rabies antigens induced the production of interferon-gamma, a lymphokine with potent antiviral activity. Several T cell clones were isolated from two of these cell lines, and most of them appeared to be specific for the antigenic components of the viral nucleocapsid. Two T cell clones specific for the rabies glycoprotein were also isolated from one of these lymphocyte interleukin 2-dependent lines. Further in vitro studies with rabies-specific T cells could help us to understand in more depth the role of regulatory T cells in the human immune response to rabies virus.

Antigens, Viral↗
PubMed1985

Isolation and amino terminal sequencing of a novel melanoma-associated antigen.

The biochemical characteristics are described for a melanoma-associated glycoprotein antigen, whose expression depends on stage of tumor progression and melanocytic differentiation. This antigen, identified using a monoclonal antibody which specifically stains melanoma cells in immunoperoxidase assay of fixed tissue sections, is synthesized as a 30,000-Da precursor and then processed to a 30,000- to 60,000-Da sialylated glycoprotein. Two-dimensional gel electrophoresis of the antigen resolved more than 20 forms, heterogeneous in both charge and molecular weight. The kinetics of post-translational processing, the sensitivity of processing to tunicamycin, and the molecular weight of the oligosaccharide chains indicate that the oligosaccharides are N-linked. Amino acid sequencing of the antigen purified by immunoaffinity chromatography and by high-pressure liquid chromatography or polyacrylamide gel electrophoresis allowed the assignment of the first 20 acids.

Amino Acid Sequence↗
PubMed1985

Antigenic variants of CVS rabies virus with altered glycosylation sites.

The virion-associated glycoprotein of the CVS-11 strain of rabies virus exists in two forms, GI and GII, which differ in their carbohydrate content. The structural relationship between GI and GII is investigated in order to account for the difference in glycosylation. Partial sequence analysis and mapping of tryptic glycopeptides isolated from the parent CVS-11 GI and GII glycoprotein forms revealed that two of the three predicted glycosylation sites (at Asn-204 and Asn-319) were utilized in the GI form whereas only one of these two sites (at Asn-319) was utilized in the GII form. One predicted glycosylation site (at Asn-37) was not utilized in either species. In the variant virus, RV231-22, a single glycoprotein species was detected which corresponded in electrophoretic mobility to the GI form of the parent virus. Nucleotide sequence analysis of the variant glycoprotein gene revealed a base mutation which specifies an amino acid change six residues upstream from the predicted glycosylation site at Asn-204. This single amino acid substitution apparently results in utilization of the signal at Asn-204 in the GII form of RV231-22 virus. The amino acid substitution is discussed in relation to altered conformation. In the variant virus RV194-2 (F3), both GI and GII glycoprotein forms were present, but each revealed slower electrophoretic mobilities compared with the corresponding parent glycoprotein forms in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). An extra glycosylation site was identified in both glycoprotein forms of this variant virus.

Amino Acid Sequence↗
PubMed1985

Human T-lymphocyte response in vitro to synthetic peptides of herpes simplex virus glycoprotein D.

Immunization of mice with a synthetic peptide that corresponds to a murine antibody-defined immunodominant domain of herpes simplex virus (HSV) glycoprotein D (gD) induced neutralizing antibodies against HSV types 1 and 2 and protected animals against a lethal challenge with HSV type 2 (Dietzschold, B., Eisenberg, R., Ponce de Leon, M., Golub, E., Hudecz, F., Varicchio, A. & Cohen, G. (1984) J. Virol. 52, 431-435). We report here that human peripheral blood T cells from HSV-seropositive and -seronegative adult donors are activated by this synthetic peptide in vitro. Interleukin-2-dependent T-cell lines established from these cultures respond specifically to peptides containing residues 1-23 of HSV gD and to a panel of overlapping peptides within this domain. The T-cell proliferative response was maximal when the majority of interleukin-2-propagated T cells were of the helper phenotype and the peptides were at least 16 amino acids long. Peptides of 8 or 12 amino acids from the carboxyl terminus were nonstimulatory. Peptide-activated T-cell lines from sero-negative donors less than 11 years old could be established in vitro, but most cells were of the suppressor/cytotoxic phenotype and demonstrated no antigen-specificity when tested with the panel of synthetic peptides.

Amino Acid Sequence↗
PubMed1985

Differences in cell-to-cell spread of pathogenic and apathogenic rabies virus in vivo and in vitro.

Pathogenic parental rabies virus and apathogenic variant virus were shown to differ in their ability to infect neurons in vivo and neuroblastoma cells in vitro. After intracerebral inoculation, the distribution of infected neurons in the brain was similar for both viruses, but the rate of spread throughout the brain, the number of infected neurons, and the degree of cellular necrosis were much lower in the case of apathogenic virus. After adsorption to mouse neuroblastoma cells, apathogenic virus was less rapidly internalized than pathogenic virus, and cell-to-cell spread of apathogenic variant virus was completely prevented by the addition of rabies virus-neutralizing antibody, whereas the spread of pathogenic virus was not affected.

Animals↗
PubMed1985

Amplification of rabies virus-induced stimulation of human T-cell lines and clones by antigen-specific antibodies.

The effect of antigen-specific antibodies on the response of human T-cell lines and clones to rabies virus was studied. Plasmas from rabies-immune vaccine recipients, but not those from nonimmune individuals, enhanced the proliferative response of rabies-reactive T cells to whole inactivated virus or to the purified glycoprotein and nucleocapsid from the rabies virion. Rabies-immune plasma also increased the antigen-induced production of gamma interferon by the rabies-specific T-cell lines. Experiments performed on T-cell clones specific for either rabies glycoprotein or nucleocapsid showed that immune plasma as well as antiglycoprotein and antinucleoprotein murine monoclonal antibodies possessed the capacity to increase significantly the antigen-induced proliferative responses of these clones. The overall results indicate that this in vitro effect of antigen-specific antibodies on the response of regulatory T lymphocytes to rabies virus could be an important factor in the development of effective immune responses in vivo to rabies virus.

Antibodies, Viral↗
PubMed1985

Synthetic glycoprotein D-related peptides protect mice against herpes simplex virus challenge.

Glycoprotein D (gD) of herpes simplex virus (HSV) protects mice from a lethal challenge by either HSV type 1 (HSV-1; oral) or HSV-2 (genital). We evaluated whether synthetic peptides representing residues 1 through 23 of gD (mature protein) can be used as a potential synthetic herpesvirus vaccine. The immunogenicity of the peptides was demonstrated by the biological reactivity of antipeptide sera in immunoprecipitation and neutralization assays. All sera which immunoprecipitated gD had neutralizing against both HSV-1 and HSV-2. The highest titers were found in animals immunized with the longest peptides. The region of residues 1 through 23 was immunogenic regardless of whether the type 1 or type 2 sequence was presented to the animal. Immunization of mice with gD or synthetic peptides conferred solid protection against a footpad challenge with HSV-2. However, the peptides were not as effective as gD in protection against an intraperitoneal challenge. The results suggested that synthetic vaccines based on gD show promise and should be more rigorously tested in a variety of animal models.

Immunization↗
PubMed1985

The T cell response to the glycoprotein D of the herpes simplex virus: the significance of antigen conformation.

Synthetic peptides corresponding to the first 23 amino acids of the glycoprotein D molecule of herpes simplex virus have been used to immunize mice and examine the role of antigen conformation in T cell responses. The structure of the peptides was determined by circular dichroism studies and was shown to be consistent with theoretical structure predictions. T cell clones were found that could respond to peptides that were nonhelical, and this response, which was directed to the C-terminal determinant (residues 8-23), could be modified by a constrained N-terminal sequence (residues 1-7) of the peptide. Namely, substitution of Ala for Pro at position 7 induced an alpha-helix and inhibited the response. Furthermore, a response to the N-terminal part of the molecule seemed to be directed to the alpha-helix and correlated positively with calculated degree of helicity. This response was also modified, in this case, by the C-terminal part of the molecule. These results suggest that local secondary structure of an antigen may regulate T cell responses and that structural changes in the peptide antigen downstream from the determinant modify recognition of that determinant. Furthermore, antigen processing by the macrophage and antigen presentation of T cells appears to conserve antigen structural integrity.

Amino Acid Sequence↗
PubMed1985

A synthetic decapeptide of influenza virus hemagglutinin elicits helper T cells with the same fine recognition specificities as occur in response to whole virus.

The immunogenicity of an isolated murine helper T cell determinant was studied. Mice were immunized with a synthetic peptide corresponding to amino acid residues 111-120 of the influenza PR8 hemagglutinin (HA) heavy chain, a region previously identified as a major target of the helper T cell response to the HA molecule in virus-primed BALB/c mice. Lymph node T cells from these mice were fused with BW 5147 cells to produce T hybrids for clonal analysis of their recognition specificities. Three T cell hybridoma clones, obtained from two different mice, responded to the immunizing peptide when presented by syngeneic antigen-presenting cells. All of these clones responded also to antigen provided as intact wild-type PR8 virus. The fine specificity of the peptide-induced T cell hybridomas, in response to a panel of mutant and variant influenza viruses, was indistinguishable from the fine specificities of T cells to the corresponding region of the HA1 chain of the HA molecule which had been generated by priming of mice with intact wild-type virus. These results suggest that an immunogenic determinant is contained within the 111-120 sequence that is able to elicit anti-influenza virus T cells with a similar repertoire to those elicited by immunization with whole virus.

Amino Acid Sequence↗
PubMed1985

Identical RT1 class II molecules are expressed by rat RT1m and RT1c haplotypes.

The RT1m haplotype of MNR rats has been suggested to be a recombinant RT1 haplotype inheriting RT1.A (class I) alleles from RT1a (DA) and RT1.B (class II) alleles from RT1c (AUG). Additional serologic and biochemical assays, however, have suggested that RT1m and RT1c share a single identical RT1.B molecule, although differing in the expression of the second RT1.B molecule. To resolve this contradiction, RT1.B class II molecules, comparable to I-A and I-E molecules in mice, expressed by the RT1c and RT1m haplotypes were immunoprecipitated by cross-reactive mouse anti-Ia antibodies and were compared by two-dimensional gel electrophoresis and by high pressure liquid chromatographic separation of tryptic peptides. Respective subunits expressed by the two haplotypes co-migrate on two-dimensional gels and have identical tryptic peptide maps. The results at the protein level were confirmed at the DNA level by Southern blot analysis of MNR and AUG genomic DNA. Identical restriction fragments associated with the RT1m and RT1c haplotypes hybridized with each of the DC1 beta, DR alpha, and DR beta cDNA probes. The results at both the protein and DNA levels suggest that the RT1m and RT1c haplotypes share identical expressed alleles at the RT1.Ba, RT1.Bb, RT1.Bc, and RT1.Bd loci.

Animals↗
PubMed1984

Protection from rabies by a vaccinia virus recombinant containing the rabies virus glycoprotein gene.

Inoculation of rabbits and mice with a vaccinia-rabies glycoprotein recombinant (V-RG) virus resulted in rapid induction of high concentrations of rabies virus-neutralizing antibodies and protection from severe intracerebral challenge with several strains of rabies virus. Protection from virus challenge also was achieved against the rabies-related Duvenhage virus but not against the Mokola virus. Effective immunization by V-RG depended on the expression of a rabies glycoprotein that registered proline rather than leucine as the eighth amino acid from its NH2 terminus (V-RGpro8). A minimum dose required for effective immunization of mice was 10(4) plaque-forming units of V-RGpro8 virus. beta-propiolactone-inactivated preparations of V-RGpro8 virus also induced high levels of rabies virus-neutralizing antibody and protected mice against intracerebral challenge with street rabies virus. V-RGpro8 virus was highly effective in priming mice to generate a secondary rabies virus-specific cytotoxic T-lymphocyte response following culture of lymphocytes with either ERA or PM strains of rabies virus.

Animals↗
PubMed1984

Localization and synthesis of an antigenic determinant of herpes simplex virus glycoprotein D that stimulates the production of neutralizing antibody.

An antigenic determinant capable of inducing type-common herpes simplex virus (HSV)-neutralizing antibodies has been located on glycoprotein D (gD) of HSV type 1 (HSV-1). A peptide of 16 amino acids corresponding to residues 8 to 23 of the mature glycoprotein (residues 33 to 48 of the predicted gD-1 sequence) was synthesized. This peptide reacted with an anti-gD monoclonal antibody (group VII) previously shown to neutralize the infectivity of HSV-1 and HSV-2. The peptide was also recognized by polyclonal antibodies prepared against purified gD-1 but was less reactive with anti-gD-2 sera. Sera from animals immunized with the synthetic peptide reacted with native gD and neutralized both HSV-1 and HSV-2.

Animals↗