Presence of a receptor for albumin on individual HBsAg polypeptides and on HBsAg produced by a hepatoma cell line.
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Biomedical subjects
Publications and source records attributed to G R Dreesman.
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Four major polypeptides with mol. wt. of 22000, 25000, 52000 and 68000 were isolated from solubilized preparations of hepatitis type B surface antigen (HBsAg). These four populations, referred to as P22, P25, P52 and P68, respectively, were used to immunize guinea-pigs. Guinea-pigs were also inoculated with HBsAg and with purified human serum albumin (HuSA). These antisera were utilized to establish that intact HBsAg particles are associated with HuSA antigenic reactivity. HuSA antigenic determinants were associated with purified preparations of P68. HuSA antigenic activity was not detected with purified preparations of P22, P25 and P52 or with respective specific antisera to each of the above. However, purified P68 contained the antigenic determinants of both host protein and hepatitis B virus-specified protein origin.
Complete Freud adjuvant, aluminum gel, and liposomes were compared for their ability to enhance the immunogenicity of an intact 22-nm HBsAg particle vaccine and an HBsAg-derived polypeptide vaccine in guinea pigs. Both humoral and cell-mediated immune responses were evaluated. The greatest immune response was obtained with complete Freund adjuvant, regardless of the antigen preparation. Aluminum gel appeared to be a better adjuvant for 22-nm HBsAg particles, but the liposomes rendered polypeptide preparations more immunogenic. The possibility that various proportions were entrapped in aqueous compartments instead of being inserted into the lipid bilayers of liposomes might account for this difference. The development of both humoral and cellular immunity was dependent upon the use of an adjuvant, because aqueous preparations had poor immunogenicity.
A micro solid phase radioimmunometric assay has been developed which measures type-specific antibody in human sera to herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2). The test is performed by coating wells of microtiter plates with purified HSV-specified glycoproteins, VP123 and VP119, derived from HSV-1- and HSV-2-infected cells, respectively. The coated wells are then incubated with diluted unadsorbed sera and subsequently with radioiodinated goat anti-human IgG reagent. Because these major viral envelope glycoproteins contain type-specific antigenic determinants, type-specific antibodies are preferentially detected in our assay.
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Guinea pigs immunized with hepatitis B surface antigen (HBsAg), types adw, adr and ayw, and with two major polypeptides derived from HBsAg/adw developed cell-mediated immunity as determined by the macrophage migration inhibition assay. Peritoneal exudate cells from animals immunized with a 22000- or a 25000-mol. wt. polypeptide derived from HBsAg/adw showed significant migration inhibition after challenge with either polypeptide or with purified HBsAg. Significant inhibition of macrophage migration was not observed when polypeptide-sensitized cells were challenged with normal human serum or with normal human liver extract. Similarly, a cell-mediated immune response was not observed in peritoneal exudate cells from animals sensitized to normal human serum or normal human liver extract which were challenged with either of the polypeptides. The humoral immune response to either of the polypeptides, as measured by radioimmunoassay, was substantially lower than that observed in animals immunized with intact particles. This apparent difference between cellular and humoral responses suggests that the macrophage migration assay is a sensitive indicator of the immunogenicity of the smaller mol. wt. HBsAg-derived polypeptides in guinea pigs.
Radioimmunoprecipitation (RIP) assays were developed to selectively quantitate class-specific antibodies to purified hemagglutinins (HA) of type A influenza virus in nasal secretions. Rabbit anti-human secretory piece of immunoglobulin A (IgA) and rabbit anti-human IgG were used as second antibodies. A third antibody, goat anti-rabbit IgG, was incorporated into the system to separate immune complexes formed between iodinated HA, nasal wash test specimen, and second antibody. The utilization of this reagent avoided the need for large quantities of IgA and IgG antibody-negative carrier secretions. Nasal was specimens obtained from 14 adults immunized with an inactivated type A influenza virus vaccine were evaluated by RIP and viral neutralization assays. Significant homologous postvaccination secretory IgA and IgG antibody levels were demonstrable in 13 (93%) of individuals by RIP, whereas only 5 (36%) exhibited rises by viral neutralization tests. Moreover, the geometric mean IgA and IgG antibody levels were at least 20- and 37-fold greater than the neutralizing antibody titer. The pattern of heterologous immunoglobulin-specific antibody responses tended to be similar to those observed with the homologous HA subunit.
Muscle biopsy specimens of a patient with polymyositis showed crystalline structures resembling picornavirus aggregates within muscle cells. The patient's serum reacted in an indirect immunofluorescence assay with autologous muscle cells. A strongly positive immunofluorescence staining was also noted when a section of muscle tissue was reacted with coxsackievirus A9 antiserum, and a weakly positive reaction was noted with coxsackievirus B2 antiserum. No staining was observed after treatment with antiserum to poliovirus type 1 or echovirus types 11 and 22.
Hepatitis B core antigen (HBcAg) was purified from Dane particles and from infected hepatocytes. An identical isoelectric pH of 4.0 was determined for labeled preparations of both Dane-derived and liver-derived HBcAg. Unlabeled liver-derived HBcAg demonstrated a lower isoelectric pH of 3.7. Molecular weight determinations by Sepharose 4B column chromatogrpahy revealed that liver-derived HBcAg had a molecular weight of 8.5-9.0 X 10(6) daltons. The sedimentation coeficient of both Dane- and liver-derived HBcAg was found to be 124S. PAGE revealed that iodinated HBcAg derived from Dane particles was very similar in polypeptide structure to HBcAg derived from infected liver tissue. Twelve polypeptides were resolved from Dane core particles, and seven to nine were resolved from liver core particles. Several of the polypeptides in both preparations co-migrated with iodinated hepatitis B surface antigen (HBsAg). However, three polypeptides (mol. wt. 88,000, 79,000 and 59,000) were found in both Dane- and liver-derived HBcAg but not in HBsAg, which suggests that these polypeptides are HBcAg-specific. Endogenous DNA polymerase activity was observed in both Dane- and liver-derived core particles.
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Virus-induced polypeptides of cells infected by herpes simplex virus (HSV) types 1 and 2 were investigated by analysis on polyacrylamide gels and by determination of their antigenicity. Some polypeptides, VP154 and VP134, had immunological reactivity common to both virus types, while others (VP175 and VP123) were type specific. Only the glycosylated polypeptides were able to induce neutralizing antibody. The expression of viral genetic information was studied in newborn mice infected with wild-type and ts mutant viruses; some mutants had become attenuated and had lost pathogenicity for newborn mice while others had not. From induction experiments in HSV=transformed hamster cells, it appears that detection of enhanced replication of ts mutants in human cancer cells would be an indication of resident HSV genetic information. Sera obtained from cancer patients were examined for antibodies to early proteins synthesized in HSV-infected cells. The method used was an indirect radioimmune precipitation test followed by polyacrylamide gel electrophoretic analysis of immune precipitates. Cervical cancer patients had sera with a higher reactivity to early nonstructural polypeptides than to breast cancer patients or to matched healthy women. In contrast to the results with early polypeptides, little difference was detectable between the matched sera in their reactivity with a major capsid polypeptide, which is synthesized late in the infectious cycle.
Several technics are currently being used to detect hepatitis type A antigen or its antibody. These include immunoelectronmicroscopy, immune adherence, and complement fixation. This paper describes another promising technic, a microtiter solid-phase immunoradiometric assay, in which hepatitis A antigen and antibody are detected. Such a method can be utilized for biochemical and biophysical analysis of purified particles, for the seroepidemiology of type A hepatitis, and as a means for monitoring hepatitis A antigen in cell cultures.
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