- 2505 Monterey Glen , Escondido CA 92029
- ( 760 ) 470-3177
- Immunologist concentrating on the immune response to HBV and developing preventative and therapeutic vaccines using a VLP platform .edit
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In the absence of an inbred animal model of hepatitis B virus (HBV) infection, several laboratories have chosen to study the murine immune response to HBV-encoded proteins as immunogens as opposed to an infectious agent. This article... more
In the absence of an inbred animal model of hepatitis B virus (HBV) infection, several laboratories have chosen to study the murine immune response to HBV-encoded proteins as immunogens as opposed to an infectious agent. This article reviews the immunogenicity, the fine specificity of T and B cell recognition of HBV antigens, and the genetic influences that regulate these responses. It is anticipated that this approach will increase our understanding of immune-mediated viral clearance mechanisms during HBV infection, and may provide the framework for the design of second and third generation HBV vaccines.
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Page 1. VIRAL IMMUNOLOGY Volume 1, Number 2, 1987 Maiy Ann Lieben, Inc., Publishers Immunological Response to Pre-S Antigens of the Hepatitis B Virus DAVID R. MILICH Department ofBasic and Clinical Research, Scripps ...
Research Interests: Immunology, Biology, Virology, Medicine, Hepatitis B, and 7 moreHumans, Liver, Virus, Hepatitis B virus, Viral Immunology, Immunogenicity, and Antigen
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Abstract In the absence of an inbred animal model of hepatitis B virus (HBV) infection, several laboratories have chosen to study the murine immune response to HBV-encoded proteins as immunogens as opposed to an infectious agent. In this... more
Abstract In the absence of an inbred animal model of hepatitis B virus (HBV) infection, several laboratories have chosen to study the murine immune response to HBV-encoded proteins as immunogens as opposed to an infectious agent. In this article, David Milich reviews the immunogenicity and the fine specificity of T- and B-cell recognition of HBV antigens, and the genetic influences that regulate these responses. This approach should increase our understanding of immune-mediated viral clearance mechanisms during HBV infection, and may provide the framework for the design of second and third generation HBV vaccines.
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Research Interests: Immunology, Vaccines, Biology, Virology, Medicine, and 11 moreHumans, Virus, Animals, Proteins, T lymphocytes, Antibody, B Lymphocytes, Antigen, Nucleoprotein, binding sites, and epitope
The immune responses to hepatitis B virus envelope antigen were investigated in 16 vaccine recipients after immunization with a recombinant yeast-derived preS2 + S (adw) vaccine for hepatitis B virus. After the completion of the... more
The immune responses to hepatitis B virus envelope antigen were investigated in 16 vaccine recipients after immunization with a recombinant yeast-derived preS2 + S (adw) vaccine for hepatitis B virus. After the completion of the three-slot immunization series, all vaccine recipients developed antibody to the S domain and anti-preS2 antibody. In vitro proliferative responses to preS2 (120-174) peptide were demonstrated in 10 of 16 vaccine recipients. Although reactivity could be demonstrated through the length of the preS2 peptide, the principal site of proliferative activity was contained within the preS2 (146-165) region of the peptide. The principal T cell reactive site coincides with a region of significant amino acid variability of the different hepatitis B virus serotypes. Cross-reactivity with a serotype (ayw) not present in the preS2 + S vaccine could not be demonstrated at this widely recognized T cell epitope. The low level of cross-reactivity demonstrated in a limited subs...
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The antiviral compound ribavirin modulates the T helper (Th)1/Th2 subset balance in hepatitis B and C virus-specific immune responses
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In the absence of an inbred animal model of hepatitis B virus (HBV) infection, several laboratories have chosen to study the murine immune response to HBV-encoded proteins as immunogens as opposed to an infectious agent. This article... more
In the absence of an inbred animal model of hepatitis B virus (HBV) infection, several laboratories have chosen to study the murine immune response to HBV-encoded proteins as immunogens as opposed to an infectious agent. This article reviews the immunogenicity, the fine specificity of T and B cell recognition of HBV antigens, and the genetic influences that regulate these responses. It is anticipated that this approach will increase our understanding of immune-mediated viral clearance mechanisms during HBV infection, and may provide the framework for the design of second and third generation HBV vaccines.
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Research Interests:
Page 1. VIRAL IMMUNOLOGY Volume 1, Number 2, 1987 Maiy Ann Lieben, Inc., Publishers Immunological Response to Pre-S Antigens of the Hepatitis B Virus DAVID R. MILICH Department ofBasic and Clinical Research, Scripps ...
Research Interests: Immunology, Biology, Virology, Medicine, Hepatitis B, and 7 moreHumans, Liver, Virus, Hepatitis B virus, Viral Immunology, Immunogenicity, and Antigen
Research Interests:
Abstract In the absence of an inbred animal model of hepatitis B virus (HBV) infection, several laboratories have chosen to study the murine immune response to HBV-encoded proteins as immunogens as opposed to an infectious agent. In this... more
Abstract In the absence of an inbred animal model of hepatitis B virus (HBV) infection, several laboratories have chosen to study the murine immune response to HBV-encoded proteins as immunogens as opposed to an infectious agent. In this article, David Milich reviews the immunogenicity and the fine specificity of T- and B-cell recognition of HBV antigens, and the genetic influences that regulate these responses. This approach should increase our understanding of immune-mediated viral clearance mechanisms during HBV infection, and may provide the framework for the design of second and third generation HBV vaccines.
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Summary. Serological and biochemical studies indicate that acute HBV infection is resolved in the context of an efficient cell‐mediated immune (CMI) response, whereas, chronic infection is characterized by weak to undetectable CMI... more
Summary. Serological and biochemical studies indicate that acute HBV infection is resolved in the context of an efficient cell‐mediated immune (CMI) response, whereas, chronic infection is characterized by weak to undetectable CMI responses and relatively efficient humoral immunity. Because humoral immunity and CMI are regulated by different TH subsets, factors which influence the induction of TH1 vs TH2 cells specific for the HBV nucleocapsid antigens (HBcAg, HBeAg) were examined in a murine model system. The factors which affected the HBc/HBeAg‐specific TH1/TH2‐cell balance included: (1) the structure of the antigen (i.e. HBcAg vs HBeAg); (2) the host MHC and T‐cell site recognized; (3) crossregulation between TH1 and TH2 cells; (4) T‐cell tolerance, which is more complete in TH1 than in TH2 cells; (5) secreted HBeAg, which preferentially depletes TH1 cells; (6) the HBV‐specific subset response could be skewed towards either TH1 or TH2 predominance by cytokine treatment in vivo. T...
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The clinical consequences of hepatitis B virus (HBV) infection are extremely variable. It is likely that nonviral, host factors are involved in the pathogenesis of hepatocellular injury since the hepatitis B virus does not appear to be... more
The clinical consequences of hepatitis B virus (HBV) infection are extremely variable. It is likely that nonviral, host factors are involved in the pathogenesis of hepatocellular injury since the hepatitis B virus does not appear to be directly cytopathic for hepatocytes (Barker et al. 1973). It has been suggested that variation in immune responsiveness to HBV infection may, at least partially, account for the diversity of clinical syndromes including fulminant, acute, chronic active and chronic persistent hepatitis as well as the asymptomatic chronic carrier state (Dudley et al. 1972). During HBV infection, at least four antigen-antibody systems are observed: hepatitis B surface antigen (HBsAg) and its antibody (anti-HBs); the pre-S antigens associated with HBsAg particles and their antibodies; the particulate nucleocapsid antigen (HBcAg) and anti-HBc; and an antigen structurally related to HBcAg, namely HBeAg and its antibody (anti-HBe). The specific serological marker of HBV infection is the HBsAg which is present both in the intact virion and as free circulating filamentous and spherical 22-nm subviral particles. The HBsAg is composed of a major polypeptide, P25, and its glycosylated form, GP28. The HBsAg is a complex, T-dependent antigen possessing a common group-specific determinant, designated a, and two sets of subtype-specific determinants, d/y and w/r. Therefore, the four subtypes of HBsAg (adw. ayw. adr. and ayr) represent the major viral phenotypes. Additional polypeptides of higher molecular weight (P39/GP42 and GP33/GP36) have recently been identified (Heermann et al. 1984). The P25 polypeptide is encoded by the S gene beginning from the third possible translational initiation site of a large open reading frame (ORF) and is preceded in phase by 174 codons (adw subtype) designated the pre-
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This paper reviews data on the use of hepatitis B virus (HBV) core (HBcAg) particles as a carrier moiety for B-cell epitopes of the HBV envelope proteins (Schodel et al., 1990a; b, 1991 and 1992a;b). Virus neutralizing epitopes of the HBV... more
This paper reviews data on the use of hepatitis B virus (HBV) core (HBcAg) particles as a carrier moiety for B-cell epitopes of the HBV envelope proteins (Schodel et al., 1990a; b, 1991 and 1992a;b). Virus neutralizing epitopes of the HBV pre-S region were inserted at the N-terminus, the N-terminus through a precore linker sequence, the C-terminus and an internal position of HBcAg by genetic engineering in E. coli. The hybrid HBc/pre-S proteins were purified and their antigenicity and immunogenicity analyzed. All purified HBc/pre-S particles were particulate. Pre-S epitopes inserted at the N-terminus through a precore polylinker, the truncated C-terminus and at the internal position between HBcAg amino acids 75 and 81 were accessible on the particle surface. N-terminal fusions required the presence of the linker sequence to become surface accessible and immunogenic. Fusions to the N- and C-termini of HBcAg did not interfere with HBcAg antigenicity and immunogenicity. In contrast, insertion at the internal site abrogated recognition of HBcAg by 5 of 6 monoclonal antibodies and diminished recognition by human polyclonal anti-HBc antibodies as well as HBcAg immunogenicity. A pre-S(2) sequence fused to the C-terminus of HBcAg was surface accessible and weakly immunogenic. Pre-S(l) sequences fused to the N-terminus through a precore linker were surface accessible and highly immunogenic. The same sequence fused to the core methionine was not surface accessible or immunogenic. Insertion of the same pre-S(1) sequence at an internal position of HBcAg resulted in the most efficient anti-pre-S(1) antibody response. Hybrid HBc/pre-S particles were also expressed in avirulent aroA or Δcya Δcrp Salmonella typhimurium and S. dublin. Oral immunisation of mice with Salmonella expressing C-terminally fused hybrid HBc/pre-S (2) particles resulted in high titered serum anti HBc antibodies and low titered anti-pre-S(2) antibodies. Oral immunisation with Δcya Δcrp S. typhimurium expressing internally fused HBc/pre-S hybrid elicited high titered serum anti-pre-S(l) antibodies.
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The objective of the studies reported herein was to identify and characterize T cell and B cell recognition sites within the pre-S regions of HBsAg/p39, and to analyze functional T-cell-B cell interactions at the level of in vivo antibody... more
The objective of the studies reported herein was to identify and characterize T cell and B cell recognition sites within the pre-S regions of HBsAg/p39, and to analyze functional T-cell-B cell interactions at the level of in vivo antibody production. The results indicate: (1) several peptides within the pre-S(1) region of HBsAg were identified which can induce and elicit HBsAg/p39-specific T-cell proliferation; (2) a 10 amino acid peptide, p12-21, and the 94-117 sequence define pre-S(1)-specific T-cell recognition sites; (3) five distinct, pre-S(1)-specific antibody binding sites and 2 pre-S(2)-specific antibody binding sites were identified; (4) synthetic pre-S(1) region T-cell determinants can prime in vivo antibody production to multiple B-cell epitopes within the pre-S(2) and S regions, as well as within the pre-S(1) region; and (5) specificity of the primed T cell population can influence the specificity of the B-cell response.
Research Interests: Biology, Medicine, Mice, Animals, Cell, and 9 morePhenotype, T lymphocytes, In Vivo, Experimental, Antibody, Epitopes, HBsAg, epitope, and Medical and Health Sciences
The hepatitis C virus (HCV) nonstructural (NS) 3 protein has been shown to possess at least two enzymatic domains. The amino terminal third contains a serine-protease domain, whereas the carboxy terminal two thirds is comprised of an... more
The hepatitis C virus (HCV) nonstructural (NS) 3 protein has been shown to possess at least two enzymatic domains. The amino terminal third contains a serine-protease domain, whereas the carboxy terminal two thirds is comprised of an adenosine triphosphatase (ATPase)/helicase domain. These domains are essential for the maturation of the carboxy-terminal portion of the HCV polyprotein and catalyze the cap synthesis of the RNA genome. In this report, human and murine antibody responses induced by NS3 were characterized using a recombinant full-length NS3 (NS3-FL) protein, or the isolated protease or ATPase/ helicase domains, expressed and purified from Escherichia coli. Sera from 40 patients with chronic HCV infection were assayed in enzyme-linked immunoassays (EIAs) for antibody binding to the panel of NS3 proteins. Virtually all patient sera contained antibodies specific for NS3-FL and the ATPase/helicase domain, whereas only 10% of sera reacted with the protease domain of NS3. Human antibodies reactive with NS3-FL were highly restricted to the immunoglobulin G1 (IgG1) isotype and were inhibited by soluble ATPase/helicase, but not by the protease domain. The anti-NS3 (ATPase/helicase) reactivity decreased on denaturation by sodium dodecyl sulfate (SDS) and beta-mercaptoethanol (2ME), suggesting the recognition of nonlinear or conformational B-cell determinants. Similar to infected humans, mice immunized with NS3-FL developed high-titered primary antibody responses to the NS3 ATPase/ helicase domain, whereas an anti-NS3 protease response was not observed after primary or secondary immunizations. Thus, the human and murine humoral immune responses to the HCV NS3 protein are focused on the ATPase/helicase domain, are restricted to the IgG1 isotype in humans, and are conformationally dependent. Unexpectedly, in both species, the NS3 protease domain, present in the context of the full-length NS3, appears to possess low intrinsic immunogenicity in terms of antibody production.
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Previous studies of murine T cell recognition of the pre-S(2) region of the hepatitis B surface Ag (HBsAg) identified high (H-2b,d,q), intermediate (H-2s,k), and low to nonresponder (H-2f) haplotypes. However, these studies utilized the y... more
Previous studies of murine T cell recognition of the pre-S(2) region of the hepatitis B surface Ag (HBsAg) identified high (H-2b,d,q), intermediate (H-2s,k), and low to nonresponder (H-2f) haplotypes. However, these studies utilized the y subtype of HBsAg. The purpose of this study was to examine the influence of viral subtype on T cell recognition of the pre-S(2) region and to identify specific T cell recognition sites in a panel of H-2 congenic strains. Immunization with pre-S(2) containing HBsAg particles of the d and y subtypes indicated that T cell recognition of the pre-S(2) region is predominantly subtype-specific in murine strains of eight different H-2 haplotypes. Furthermore, the B10.M strain (H-2f) classified as a T cell nonresponder to the y subtype of the pre-S(2) region responds efficiently to the d subtype, indicating that pre-S(2) responder status can be subtype-dependent as well as subtype-specific. Studies using a truncated pre-S(2) polypeptide and synthetic peptides illustrated that the C-terminal sequence (p148-174) of the pre-S(2) region is the dominant focus of T cell recognition in multiple murine strains. Specifically, 17 distinct T cell recognition sites were defined within the C-terminal half of the pre-S(2) region. The fine specificity of T cell recognition of the pre-S(2) region was dependent on the H-2 haplotype of the responding strain. T cell recognition of all 17 sites was subtype specific, which is consistent with the fact that the C-terminal sequence is highly polymorphic between the d and y subtypes of the pre-S(2) region. Lastly, it was shown that the ability of synthetic peptides to elicit T cells cross-reactive with the native pre-S(2) region was variable and depended on the nature of the immunizing peptide. The pre-S(2)-containing HBsAg vaccines currently in clinical trials are composed of ra single subtype, either d or y. The results of this study suggest that both subtypes should be incorporated to increase the frequency of T cell responders to the pre-S(2) region, and to insure Th cell memory relevant to infection with hepatitis B virus of either the d or y subtypes.
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Research Interests: Molecular Biology, Biology, Medicine, Gene expression, Biological Sciences, and 15 moreDNA, Cell line, Humans, Gene, Gen, Enhancer, Base Sequence, Hepatitis B virus, Antigen, Nucleic Acid, Molecular Sequence Data, Nucleotide sequence, Chromosome deletion, Liver neoplasms, and Medical and Health Sciences
Research Interests: Molecular Biology, Biology, Medicine, Cell Culture, Biological Sciences, and 15 moreCell line, Cell Differentiation, Humans, Mice, Animals, Promoter, Gene, Luciferase, HeLa, Base Sequence, Hepatitis B virus, DNA binding proteins, Molecular Sequence Data, Liver neoplasms, and Medical and Health Sciences
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Previous studies of murine T cell recognition of the pre-S(2) region of the hepatitis B surface Ag (HBsAg) identified high (H-2b,d,q), intermediate (H-2s,k), and low to nonresponder (H-2f) haplotypes. However, these studies utilized the y... more
Previous studies of murine T cell recognition of the pre-S(2) region of the hepatitis B surface Ag (HBsAg) identified high (H-2b,d,q), intermediate (H-2s,k), and low to nonresponder (H-2f) haplotypes. However, these studies utilized the y subtype of HBsAg. The purpose of this study was to examine the influence of viral subtype on T cell recognition of the pre-S(2) region and to identify specific T cell recognition sites in a panel of H-2 congenic strains. Immunization with pre-S(2) containing HBsAg particles of the d and y subtypes indicated that T cell recognition of the pre-S(2) region is predominantly subtype-specific in murine strains of eight different H-2 haplotypes. Furthermore, the B10.M strain (H-2f) classified as a T cell nonresponder to the y subtype of the pre-S(2) region responds efficiently to the d subtype, indicating that pre-S(2) responder status can be subtype-dependent as well as subtype-specific. Studies using a truncated pre-S(2) polypeptide and synthetic peptides illustrated that the C-terminal sequence (p148-174) of the pre-S(2) region is the dominant focus of T cell recognition in multiple murine strains. Specifically, 17 distinct T cell recognition sites were defined within the C-terminal half of the pre-S(2) region. The fine specificity of T cell recognition of the pre-S(2) region was dependent on the H-2 haplotype of the responding strain. T cell recognition of all 17 sites was subtype specific, which is consistent with the fact that the C-terminal sequence is highly polymorphic between the d and y subtypes of the pre-S(2) region. Lastly, it was shown that the ability of synthetic peptides to elicit T cells cross-reactive with the native pre-S(2) region was variable and depended on the nature of the immunizing peptide. The pre-S(2)-containing HBsAg vaccines currently in clinical trials are composed of ra single subtype, either d or y. The results of this study suggest that both subtypes should be incorporated to increase the frequency of T cell responders to the pre-S(2) region, and to insure Th cell memory relevant to infection with hepatitis B virus of either the d or y subtypes.
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The purpose of this study was to identify and characterize T cell and B cell recognition sites within the pre-S(1) region of HBsAg/p43, and to then analyze functional T cell-B cell interactions at the level of in vivo antibody production.... more
The purpose of this study was to identify and characterize T cell and B cell recognition sites within the pre-S(1) region of HBsAg/p43, and to then analyze functional T cell-B cell interactions at the level of in vivo antibody production. The results indicate: three peptide sequences within the pre-S(1) region of HBsAg were identified which can induce and elicit HBsAg/p43-specific T cell proliferation; a 10-amino acid peptide, p12-21, defines one pre-S(1)-specific T cell recognition site, and residues 18 and 19 are critical to the recognition process; the p12-21 sequence can function as a T cell carrier for a synthetic B cell epitope within the pre-S(2) region; the p94-117 sequence contains at least two T cell recognition sites; five distinct, pre-S(1)-specific antibody binding sites were identified; synthetic pre-S(1) region T cell determinants can prime in vivo antibody production to multiple B cell epitopes within the pre-S(2) and S regions, as well as within the pre-S(1) region; the specificity of the primed T cell population can influence the specificity of the B cell response; and T cell recognition of pre-S(1) region peptides is regulated by H-2-linked genes.
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Research Interests: Molecular Biology, Biology, Medicine, Biological Sciences, Cell line, and 15 moreHumans, Animals, Promoter, Proline, Plasmids, Transcription Factor, Rats, Glutamine, Base Sequence, Hepatitis B virus, DNA binding proteins, Molecular Sequence Data, binding sites, Liver neoplasms, and Medical and Health Sciences
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1: Hepatology. 1991 May;13(5):977-94. Immunology and the liver. ... Louis, Missouri 63110. Publication Types: Review. Mesh Terms: Animals; Autoimmune Diseases/immunology*; Cytokines/immunology; Hepatitis B/pathology*; Hepatitis B... more
1: Hepatology. 1991 May;13(5):977-94. Immunology and the liver. ... Louis, Missouri 63110. Publication Types: Review. Mesh Terms: Animals; Autoimmune Diseases/immunology*; Cytokines/immunology; Hepatitis B/pathology*; Hepatitis B Antigens/immunology; ...