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Biomedical subjects

H Koprowski

Publications and source records attributed to H Koprowski.

At least 145 records · Page 8Linked to original sources
PubMed1989

Induction of rabies virus-specific T-helper cells by synthetic peptides that carry dominant T-helper cell epitopes of the viral ribonucleoprotein.

The T-helper cell response to the internal proteins of rabies virus was investigated. The rabies virus nucleoprotein was shown to be a major target antigen for T-helper cells that cross-react between rabies and rabies-related viruses. T-helper cells were assayed in vitro by testing virus-induced lymphocytes for lymphokine secretion in response to antigen. Immunodominant T-helper cell epitopes of the viral nucleoprotein were identified in vitro by using synthetic peptides delineated from the amino acid sequence of the nucleoprotein. The response to synthetic peptides were under Ir gene control. Antigenic peptides were tested in vivo for stimulation of rabies virus-specific T-helper cells. Inoculation of mice with peptides bearing immunodominant T-helper cell epitopes resulted in an accelerated and enhanced neutralizing antibody response upon booster immunization with inactivated rabies virus.

Amino Acid Sequence↗
PubMed1989

Use of mouse anti-rabies monoclonal antibodies in postexposure treatment of rabies.

Immunization of mice and hamsters with a cocktail of mouse MAbs specific for rabies virus nucleocapsid protein and glycoprotein protected animals not only when challenged with a lethal dose of rabies virus after immunization, but also in post-exposure situations. Hamsters treated with the MAb cocktail 3 h after virus inoculation were completely protected from lethal rabies virus infection, and 80% of the animals survived when the MAb cocktail was given 36 h after virus challenge. The potential usefulness of this MAb cocktail for the postexposure treatment of human rabies is discussed.

Animals↗
PubMed1989

Modulation of cancer patients' immune responses by anti-idiotypic antibodies.

The immunomodulatory role of anti-idiotypic antibodies (Ab2) in patients with gastrointestinal cancer has been demonstrated in two types of clinical trials. In the first, cancer patients were treated with a monoclonal antibody (MAb) defining a tumor-associated antigen (Ag). MAb administration initiated an idiotypic network as demonstrated by the induction of both Ab2 and anti-anti-idiotypic antibodies (Ab3) in the treated patients. The Ab3 bound to tumor cells and isolated tumor Ag with the same specificity as the Mab (Ab1) at the beginning of the idiotypic cascade. A beneficial role of Ab3 is postulated for patients showing delayed clinical responses to MAb therapy. In a recent trial, patients with advanced colorectal cancer responded to immunization with Ab2 that functionally mimicked in vitro and in vivo (animals) a gastrointestinal tumor-associated Ag by developing highly specific Ab3 with anti-tumor binding reactivities. Thus, Ab2 are promising agents in immunotherapy approaches to cancer. These studies suggest an immunoregulatory role for Ab2 in cancer patients. Modulation of cellular immune responses by Ab2 in cancer patients will be an important consideration in future studies.

Antibodies, Anti-Idiotypic↗
PubMed1989

Monoclonal antibodies with cytotoxic reactivities against human gliomas.

Monoclonal antibodies (MAb's) reactive with human malignant glioma cells were derived from mice inoculated with cells from fresh glioma tissue. Seven MAb's were selected for study based on their high-level binding in immunoperoxidase and immunofluorescence assay to most of the glioma tissues derived from various patients and based on the absence of binding to normal bone marrow cells. Four of the seven MAb's did not bind to any of the four normal brain tissues tested, whereas three MAb's bound to one or two of these tissues. Two MAb's bound to the surfaces of cultured glioma cells in radioimmunoassay. One of these MAb's (AS-AY1, immunoglobulin (Ig)(G1) lysed cultured glioma cells with human lymphocytes or murine macrophages as effector cells; the other MAb (AS-AY2, IgM) was reactive in complement-dependent cytotoxicity assay. These two MAb's therefore seem especially promising reagents in approaches to immunotherapy of human malignant glioma.

Antibodies, Monoclonal↗
PubMed1989

Selection and analysis of amino acid sequence of an antigenic domain of the rabies virus glycoprotein.

A new procedure for the selection of antigenic determinant of rabies virus glycoprotein is described. The glycoprotein was purified by polyacrylamide gel electrophoresis (PAGE). The glycoprotein fragments digested with protease V8 were separated by 25% PAGE, transferred onto nitrocellulose membrane, immunostained with monoclonal antibodies (McAb) against glycoprotein. One McAb-positive fragment (G-V-6) was obtained by using the Western blot analysis. The amino acid sequence of the fragment was analysed. The data indicated that the antigenic determinant of glycoprotein was located in a region between residues 130-141. These suggest that the Western blot analysis will be a useful tool for the development of synthetic vaccines.

Amino Acid Sequence↗
PubMed1989

Monoclonal antibodies as applied to tumor-associated antigens: the CO17-1A antigen.

The development of antitumor MAbs has led to the identification of many TAAs but no TSAs. It now seems unlikely that there are antigens exclusively associated with any tumor type. Nonetheless, there are numerous applications of the antitumor MAbs. They are used in serum assays to monitor tumor burden and in histologic assays to identify the tumor type. Initial attempts to use MAbs therapeutically have benefited some patients, but much work is needed to better understand the mechanism and to enhance this tumoricidal effect. Finally, the antitumor MAbs will allow biochemical and genetic analyses of the roles of TAAs in tumor progression.

Animals↗
PubMed1988

Nerve growth factor receptors in chromatin of melanoma cells, proliferating melanocytes, and colorectal carcinoma cells in vitro.

Nuclear localization of nerve growth factor (NGF) in HS 294 melanoma cells and SW 707 colorectal carcinoma was determined by indirect immunofluorescence staining and by cell fractionation. NGF receptors were immunoprecipitated from the EcoRI-digested chromatin of HS 294 melanoma cells, of melanocytes proliferating in the presence of 12-O-tetradecanoylphorbol-13-acetate, and of SW 707 colorectal carcinoma cells, using a monoclonal antibody to the Mr 75,000 cell surface NGF receptor. Melanoma cells expressed a receptor species with a molecular weight of 230,000. Proliferating melanocytes expressed a small amount of Mr 230,000 receptor, whereas colorectal carcinoma cells expressed a Mr 35,000 receptor. Scatchard analysis indicated one type of NGF chromatin binding site in HS 294 cells with KD = 241 pM but two types of binding sites in chromatin of SW 707 cells with KD = 333 and 1718 pM, respectively. Both the Mr 230,000 and the 35,000 receptor species were tightly bound to DNase II-sensitive regions, which became DNase II-insensitive after nerve growth factor binding. [125I]NGF was detected in the chromatin in nondegraded form. Chromatin binding of NGF inhibited RNA synthesis and cell proliferation.

Cell Division↗
PubMed1988

Genetic restriction and fine specificity of human T cell clones reactive with rabies virus.

Rabies virus-specific T cell clones isolated from a human vaccine recipient were studied for their fine specificity and genetic restriction using synthetic peptides of the viral Ag and mouse fibroblasts transfected with human MHC genes. Two clones were found to react with an epitope present in the rabies glycoprotein, which was presented by the HLA-DR7 molecule. Other T cell clones recognized synthetic epitopes corresponding to the rabies nucleoprotein in association with the HLA-DR7 or HLA-DQw3 molecule, and one clone responded to the viral nucleocapsid Ag in the presence of HLA-DPw4. T cell clones that exhibited different cross-reactivity patterns among several virus strains were found to recognize closely situated epitopes (within 15 amino acid residues), which were presented in the context of the same MHC molecule. The lack of recognition of a particular virus strain by a T cell clone was attributable in some cases to amino acid variations of the Ag that appear to affect the T cell's receptor for Ag specificity and not the ability of that epitope to associate with the corresponding MHC molecule. Comparisons of the T cell cross-reactivity patterns with various rabies and rabies-related viruses, the fine antigenic specificity, and MHC restriction may aid in understanding the role of individual amino acid variations among virus strains in the induction of cross-protective immunity.

Amino Acid Sequence↗
PubMed1988

Molecular cloning and characterization of an antigen associated with early stages of melanoma tumor progression.

The melanoma-associated antigen ME491 is expressed strongly during the early stages of tumor progression. The ME491 gene was molecularly cloned by means of DNA-mediated gene transfer followed by screening a lambda genomic library with human repetitive Alu sequences as a probe. The cloned DNA, after transfection into mouse L-cells, generated a protein with characteristics that were indistinguishable in Western blot analysis from the ME491 antigen expressed by human melanoma cells. Repeat-free subfragments of the cloned DNA were used for further studies. By Northern blot analysis, the subfragments detected a single 1.2-kilobase mRNA in the transformants and various human melanoma cell lines. ME491 complementary DNA clones were then obtained by probing a melanoma complementary DNA library with the genomic subfragments. Nucleotide sequence analysis of the cloned complementary DNA indicated that the ME491 antigen consists of 237 amino acids (Mr 25,475) with four transmembrane regions and three putative N-glycosylation sites. No significant structural homology was observed with other proteins thus far reported. We observed that the amounts of mRNA varied greatly with different melanoma cell lines. Southern blot analysis revealed no amplification or rearrangement of the ME491 gene in the human melanoma cell lines tested, including both high and low expressors of this antigen. The ME491 gene has been mapped to chromosome region 12p12----12q13 by somatic cell hybrid analysis and more narrowly localized to 12q12----12q14 by in situ hybridization.

Amino Acid Sequence↗
PubMed1988

Biosynthetic pathways for the Leb and Y glycolipids in the gastric carcinoma cell line KATO III as analyzed by a novel assay.

The biosynthetic pathways for the difucosylated type 1 and 2 glycolipids, Leb and Y, respectively, were investigated in the gastric carcinoma cell line KATO III, using a novel chromatogram binding assay. The type of fucosylation obtained was deduced from the binding pattern of monoclonal antibodies specific for the biosynthesized glycolipid products using microsomal fractions as the source of enzyme, pure glycolipids and non-radioactive GDP-fucose as acceptor and donor substrates, respectively. The Leb glycolipid (Fuc alpha 1----2Gal beta 1----3GlcNAc(4----1 alpha Fuc) beta 1----3LacCer) was synthesized mainly via the blood group H, type 1, precursor (Fuc alpha 1----2Gal beta 1----3GlcNAc beta 1----3LacCer). However, the Lea glycolipid (Gal beta 1----3GlcNAc(4----1 alpha Fuc)beta 1----3LacCer) also served as a precursor for the alpha 1----2 fucosyltransferase, thus allowing conversion of Lea to Leb. This biosynthetic route represents either an "aberrant" specificity of the Fuc alpha 1----2 transferase associated with these gastric carcinoma cells and/or a new member of the alpha 1----2 fucosyltransferase family. The Y glycolipid (Fuc alpha 1----2Gal beta 1----4GlcNAc(3----1 alpha Fuc)beta 1----3LacCer) was synthesized exclusively via the classical pathway using the blood group H type 2 glycolipid (Fuc alpha 1----2Gal beta 1----4GlcNAc beta 1----3LacCer) as precursor. The X glycolipid (Gal beta 1----4GlcNAc(3----1 alpha Fuc)beta 1----3LacCer) did not serve as an acceptor substrate for the alpha 1----2 fucosyltransferase(s) present. The use of non-radioactive sugar-nucleotides as donor substrate, defined glycolipid precursors as acceptor substrates and of specific monoclonal anti-glycolipid antibodies for detection provides a rapid and highly specific assay for analyzing biosynthetic pathways of glycosyltransferases.

Antigens↗
PubMed1988

Divergent dose-related effects of gamma-interferon therapy on in vitro antibody-dependent cellular and nonspecific cytotoxicity by human peripheral blood monocytes.

Twenty-seven patients with advanced gastrointestinal malignancies received recombinant gamma-interferon (rIFN-gamma, Biogen) prior to treatment with the murine monoclonal antibody 17-1A (Centocor), which mediates human monocyte antibody-dependent cellular cytotoxicity (ADCC). rIFN-gamma was used because it enhances human monocyte Fc receptor expression, nonspecific monocyte cytotoxicity (NSMC) and ADCC in vitro. The study was designed to identify a rIFN-gamma dose with acceptable toxicities which enhanced NSMC and ADCC. Patients received one course of therapy consisting of rIFN-gamma by 4-h infusions daily for 4 days at doses ranging from 0.001 to 80.0 X 10(6) units/m2/d, followed by 400 mg of 17-1A on day 5. The maximally tolerated dose of rIFN-gamma in this study was 40 X 10(6) units/d. Significant toxicity was seen at the high (greater than 1 X 10(6) units) but not low (less than or equal to 1 X 10(6) units) dose levels. Monocytes were isolated from patients' peripheral blood at baseline and on Days 3 and 5 for cytotoxicity studies which measured 111-In release from SW1116 cells which bear the target antigen of 17-1A. Low dose rIFN-gamma enhanced NSMC by Day 5 as well as did high dose therapy. ADCC enhancement was seen with low dose therapy (% specific lysis on Day 5 = 23.5 +/- 6.4 SEM versus baseline of 9.6 +/- 3.3, P = 0.03), but not with high dose rIFN-gamma treatment. Total (i.e., NSMC + ADCC) monocyte cytotoxicity was equivalent in the low and high dose treatment groups, although ADCC contributed more to total values in the low dose group. These findings were particularly striking if monocytes were exposed to additional rIFN-gamma in vitro prior to incubation with labeled target cells. We conclude that low dose rIFN-gamma therapy is at least equivalent, and possibly superior to high doses in this setting. Furthermore, low dose therapy, supplemented by ex vivo incubation of purified monocytes with rIFN-gamma, may be an optimal treatment strategy for this cytokine.

Adenocarcinoma↗
PubMed1988

HTLV-I and chronic nervous diseases: present status and a look into the future.

Three entities--multiple sclerosis, tropical spastic paraparesis, and human T-lymphotropic virus type I (HTLV-I)-associated myelopathy (HAM)--may represent manifestations of the same disease, with HTLV-I-like virus playing a role in their etiology. Tests for the presence of antibodies reacting with either HTLV-I-like virions or with p24 (gag) antigen, expression of HTLV-I antigen by cells of peripheral blood lymphocytes or cerebrospinal fluid, and viral sequences detected by in situ hybridization are essential to establish the role of HTLV-I-like virus in the disease. It is not yet known whether an incomplete form of the virus persists in the tissue following initial infection or whether the virus in question shares the gag protein with HTLV-I but carries the envelope of a different virus. It is recommended that investigative units comprising neurologists and laboratory workers be established as soon as possible to pursue vigorously the leads that may throw some light on the etiology of chronic neurological diseases such as multiple sclerosis.

Adult↗
PubMed1988

Killing of human tumor cell lines by human monocytes and murine monoclonal antibodies.

We evaluated the capacity of freshly isolated blood monocytes to mediate antibody-dependent cellular-mediated cytotoxicity (ADCC) in cooperation with murine anti-tumor monoclonal antibodies (MAbs). Blood monocytes isolated from most donors by adherence selection to fibronectin-coated plastic surfaces and subsequently depleted of natural killer/killer (NK/K) cells exhibited significant ADCC activity against tumor cell lines in combination with an IgG3 antitumor MAb (BR55-2). However, significant variation in ADCC competence was observed among donors. Culture parameters influencing monocyte ADCC activity were evaluated and optimized. The influence of MAb isotype on ADCC capacity of anti-tumor MAbs was also evaluated using anti-tumor class-switch variant hybridoma proteins and a panel of anti-tumor MAbs. MAbs of the IgG2a and IgG3 subclasses exhibited high ADCC potential, whereas MAbs of the IgG2b subclass exhibited no ADCC activity. One of two IgG1 MAbs tested exhibited high ADCC activity with monocyte effectors. The role of monocytes or macrophages in tumor remission of cancer patients undergoing MAb immunotherapy is not known. However, correlative studies of monocyte ADCC capacity and responsiveness of cancer patients to MAb immunotherapy may help to establish the role of these effectors in MAb-mediated tumor remissions.

Animals↗
PubMed1988

Expression of nerve growth factor receptor during human peripheral nerve development.

The expression of NGF receptors on human Schwann cells during development and myelination and in culture was analyzed using a murine monoclonal antibody to human NGF receptor. Nonmyelinated femoral nerves from 13- to 14-week fetuses stained strongly for NGF receptor, whereas tissues from later stages of development showed a decrease in the staining intensity. These changes correlated with the initiation of myelination (17-19 weeks), as observed by phase-contrast and electron microscopy, and the reactivity with monoclonal antibody 4C5, a marker of mature Schwann cells. In adult nerves, only the perineurium and few endoneurial cells were stained with anti-NGF receptor antibody. Cultured human fetal Schwann cells were positive for NGF receptor by immunofluorescence irregardless of donor age or length of time in culture. The decreased staining of NGF receptor with nerve maturation may reflect a dependence of antigen expression on Schwann cell differentiation and/or neuron-Schwann cell interaction.

Cells, Cultured↗
PubMed1988

Regulatory factors that determine growth and phenotype of normal human melanocytes.

Normal human melanocytes, unlike malignant melanoma cells, required at least three growth-promoting agents, i.e., phorbol ester for protein kinase C activation and the growth factors basic fibroblast growth factor (bFGF) and insulin, for growth in chemically defined W489 medium. Cell growth was further stimulated by addition of agents that increase intracellular levels of cyclic adenosine 3',5'-monophosphate (cAMP) to the medium. Among these agents, the pituitary hormones alpha-melanocyte-stimulating hormone (alpha-MSH) and follicle-stimulating hormone were the most potent, whereas bacterial toxins, including cholera, tetanus, and pertussis toxin and their subunits either were less mitogenic or gave variable results depending on the culture tested. Medium containing phorbol ester PMA, growth factors bFGF and insulin (or insulin-like growth factor-I), and synthetic alpha-MSH supported melanocyte growth for more than 5 months with doubling times between 5 and 8 days. Two copper-binding proteins, ceruloplasmin and tyrosinase, were mitogenic when added to medium and ceruloplasmic induced a long bi- to tripolar-shape of cells. Addition of 1 mM dibutyryl cAMP to the medium led to the formation of dendrites in all cells, with an average of 28 extensions per cell. Although cell growth was inhibited by dibutyryl cAMP, cells were not terminally differentiated and continued to proliferate. Dendritic melanocytes showed a 2.2-fold increase in activity of the tyrosine kinase pp60c-src. The induction of dendritic processes in melanocytes by dibutyryl cAMP or sodium butyrate was reversible and appears to reflect the expression of the mature melanocytic phenotype in situ.

Bucladesine↗
PubMed1988

Blood group antigens in the intrahepatic biliary tree. I. Distribution in the normal liver.

The distribution of six blood group-related antigens, A, B, H, Lea, Leb and sialylated Lea antigens, in the intrahepatic biliary tree was studied. These carbohydrate antigens in fixed normal liver tissues were immunostained with the use of highly specific monoclonal antibodies in an avidin-biotin-peroxidase complex method. Bile ducts expressed both ABH and Lewis blood group antigens. However, only Lewis blood group antigens could be detected in the bile ductules. Canaliculo-ductular junctions could be clearly delineated with the anti-Lewis blood group antibodies, especially with anti-Lea antibody. Small Lewis antigen-positive cells were scattered intralobularly. They were adjacent to parenchymal liver cells, mainly in Rappaport zone 1, and apparently in continuity with the portal biliary tree. Sialylated Lea antigen was found in some septal bile ducts. No blood group antigen could be detected in the bile canaliculi. These results indicate that (1) biliary tract of a given size has its own pattern of blood group antigen expression, and (2) biliary epithelial cells are not identical with regard to the phenotypic expression of their structural carbohydrates. In future, it will be possible to classify biliary epithelial cells by their blood group antigen expression.

Adult↗
PubMed1988

Structural alteration in the MYB protooncogene and deletion within the gene encoding alpha-type protein kinase C in human melanoma cell lines.

A correlative study was done to determine possible relationships between nonrandom aberrations in chromosomes 1, 6, and 7 occurring in human cutaneous malignant melanoma and the structure of oncogenes as well as specific genes encoding growth factors and growth factor receptors. Thirty cell lines derived from primary or metastatic melanomas of 28 patients were analyzed by Southern blotting with nick-translated probes for 28 different genes, some of which map near frequent chromosomal breakpoints observed in melanoma. An alteration in the MYB protooncogene was observed in a cell line derived from a primary melanoma in the vertical growth phase, which correlated with a 6q22 chromosomal abnormality. Another primary melanoma cell line had a cytogenetically undetected tumor-specific deletion within the gene for alpha-type protein kinase C. Polymorphic alleles for the genes encoding the epidermal growth factor receptor and alpha-type protein kinase C were also observed.

Cell Line↗