Search PubMed⌕ Search

Biomedical subjects

H Koprowski

Publications and source records attributed to H Koprowski.

At least 91 records · Page 5Linked to original sources
PubMed1992

A recombinant human Fab expressed in Escherichia coli neutralizes rabies virus.

A recombinant human anti-rabies monoclonal antibody (MAb-57) Fab was prepared by cloning the heavy (Fd)- and light-chain domains into the same bacterial expression vector. To construct the recombinant Fab, mRNA was extracted from MAb-57-producing hybridoma cells, reverse transcribed, and then amplified by polymerase chain reaction (PCR) by using oligonucleotides specific for immunoglobulin heavy- and light-chain DNA sequences. PCR-amplified Fd-chain cDNA was fused, in frame, between a bacterial leader peptide (PelB) at the amino terminus and a 10-amino-acid peptide tag at the carboxy terminus. The PCR-amplified lambda-chain cDNA was also fused to the PelB leader peptide. The immunoglobulin Fab was then expressed as a dicistronic message in bacteria by using the isopropyl-beta-D-thiogalactopyranoside-inducible lactose promotor (lacZ). DNA sequencing was used to define the gamma-chain isotype (immunoglobulin G1) and VH (VHI) chain and VL (V lambda II) chain gene usage. The recombinant Fab (rFab57) specifically bound the rabies virus coat glycoprotein, while the Fd and lambda chains, when expressed individually, did not. The binding specificity of rFab57 was indistinguishable from that of the intact MAb in direct enzyme-linked immunosorbent assays; however, the dissociation constant of rFab57 for rabies virus protein G was approximately 1 log10 U lower than that of complete MAb-57 in competition enzyme-linked immunosorbent assays. A fluorescent-focus inhibition assay showed that bacterially expressed rFab was capable of neutralizing rabies virus strain CVS-11. We conclude that a human Fab expressed in bacteria maintains its specificity and biologic activity.

Amino Acid Sequence↗
PubMed1992

Kinetics of virus spread and changes in levels of several cytokine mRNAs in the brain after intranasal infection of rats with Borna disease virus.

We have used the reverse transcriptase-polymerase chain reaction technique to gain insight into the pathogenesis of encephalitis caused by Borna disease virus (BDV). RNA specific for BDV was first detected in the olfactory bulb of intranasally infected rats at 6 days postinfection (p.i.). At 14 days p.i., high levels of BDV RNA were found in all brain regions, and at 26 days p.i., BDV-specific RNA was also present in the eye, nasal mucosa, and facial skin. In the chronic phase of the disease, BDV RNA was identified in many peripheral organs but not in blood. Analysis of brain tissue for the presence of cytokine mRNAs revealed that the mRNA levels of interleukin-6 (IL-6), tumor necrosis factor alpha, and IL-1 alpha had increased sharply at 14 and 26 days p.i. These cytokine mRNAs reached maximum levels at the peak of inflammatory reactions and decreased drastically in the chronic phase of the disease. Although IL-2 mRNA was also found in normal brain, it was markedly increased in BDV-infected brain at 14 days p.i. Expression of gamma interferon (IFN-gamma) mRNA, which was not observed in normal rat brain, was detected at 14 days p.i. and reached a maximum level at 38 days p.i. IL-2 and IFN-gamma mRNA expression correlated with expression of CD4 and CD8 mRNAs, indicating that both CD4+ and CD8+ T lymphocytes are induced in the early stages of BDV infection. Since IFN-gamma and CD8 mRNA levels were still highly elevated in the chronic phase of Borna disease, it is likely that CD8+ T lymphocytes act to reduce inflammation and to ameliorate neurological signs during the chronic phase of infection.

Animals↗
PubMed1992

Consideration of inactivated rabies vaccines as oral immunogens of wild carnivores.

An experimental beta-propiolactone (BPL)-inactivated rabies virus vaccine was evaluated for the oral immunization of captive raccoons (Procyon lotor) and red foxes (Vulpes vulpes). None of 10 red foxes administered a single 1.0 ml dose of BPL-inactivated rabies virus vaccine (PM strain; 100 or 500 micrograms protein) per os developed detectable anti-rabies virus-neutralizing antibodies (VNA) at any time over 8 wk of observation. Foxes were excluded from further study. In two different groups of five to six raccoons, each administered a single 1.0 ml dose of BPL-inactivated rabies virus vaccine (ERA strain) per os, at concentrations of 100 or 400 micrograms protein, only a single animal in each group demonstrated evidence of seroconversion within 4 wk. In contrast, instillation of a single dose (500 micrograms protein) of BPL-inactivated rabies virus vaccine (ERA strain), directly into the small intestine via fiberoptic endoscope, or ERA vaccine (800 micrograms protein) instillation to the buccal cavity by needle-less syringe, resulted in the production of rabies-specific VNA and protection against lethal rabies infection in three of six, and in four of six raccoons, respectively; all seven control raccoons succumbed to street virus challenge. These preliminary challenge studies, while somewhat encouraging, demonstrate that considerable quantities of purified viral antigen are required for even minimal oral efficacy against lethal rabies infection. At the present time, therefore, potent, self-replicating, attenuated, or recombinant viruses offer the most versatile, economic, efficacious, and safe solutions to terrestrial rabies control of free-ranging carnivores.

Administration, Oral↗
PubMed1992

Nuclear translocation of monoclonal antibody directed against cell-surface carbohydrate Y determinant.

Monoclonal antibody (MAb) Br 15-6A directed against the carbohydrate Y determinant expressed on tumor cells was found to be internalized and translocated to the nucleus of SK Br 5 breast carcinoma and SW 1116 and SW 707 colorectal carcinoma cells. Intracellular localization of MAb Br 15-6A was determined by cell fraction and by indirect immunofluorescence staining. Internalization of MAb Br 15-6A seems to be mediated by a specific cell surface protein of M(r) 108,000 in colorectal carcinoma cells and M(r) 92,000-96,000 in breast carcinoma cells. The MAb Br 15-6A precipitates an 88,000 M(r) chromatin protein and appears to be bound specifically to two EcoRI-digested and two HincII-chromatin fragments. Another MAb against the Y determinant (MAb Br 55.2) recognizes the same antigens as MAb Br 15-6A, but is not internalized.

Antibodies, Monoclonal↗
PubMed1991

Human melanoma cells transcribe interleukin 1 genes identical to those of monocytes.

Two molecular species of the pleotropic cytokine interleukin 1 (IL-1) are produced as products of two distinct genes transcribed by cells of the monocyte-macrophage lineage. We have shown previously that a significant proportion of human melanoma cell lines express IL-1 biological activity, but it has not been demonstrated that this activity is the same as authentic monocyte IL-1 alpha and -beta. Here we report the cloning and sequencing of IL-1 complementary DNAs from a metastatic melanoma cell line and demonstrate that they encode bona fide IL-1 alpha and IL-1 beta. In addition, IL-1 complementary DNAs encoding a different amino acid at position 145 were revealed.

Cell Line↗
PubMed1991

Retroviral sequences related to human T-lymphotropic virus type II in patients with chronic fatigue immune dysfunction syndrome.

Chronic fatigue immune dysfunction syndrome (CFIDS) is a recently recognized illness characterized by debilitating fatigue as well as immunological and neurological abnormalities [Straus, S.E. (1988) J. Inf. Dis. 157, 405-412]. Once thought to be caused by Epstein-Barr virus, it is now thought to have a different but unknown etiology. We evaluated 30 adult and pediatric CFIDS patients from six eastern states for the presence of human T-lymphotropic virus (HTLV) types I and II by Western immunoblotting, polymearse chain reaction, and in situ hybridization of blood samples. The majority of patients were positive for HTLV antibodies by Western blotting and for HTLV-II gag sequences by polymerase chain reaction and in situ hybridization. Twenty nonexposure healthy controls were negative in all assays. These data support an association between an HTLV-II-like virus and CFIDS.

Adolescent↗
PubMed1991

Rabies virus nucleoprotein expressed in and purified from insect cells is efficacious as a vaccine.

A cDNA copy of the RNA gene that encodes the nucleoprotein N of rabies virus Evelyn-Rokitnicki-Abelseth strain was cloned into baculovirus. The recombinant baculovirus expressed the N protein abundantly in Spodoptera frugiperda cells. The N protein was extracted from infected Spodoptera frugiperda cells and purified to near homogeneity by affinity chromatography. The purified N protein reacted with 31 of 32 monoclonal antibodies that recognize native rabies virus ribonucleoprotein. Like the ribonucleoprotein, the purified N protein was a major antigen capable of inducing virus-specific helper T cells. Priming of mice with the purified N protein prior to a booster inoculation with inactivated Evelyn-Rokitnicki-Abelseth virus vaccine resulted in a 20-fold increase in the production of virus-neutralizing antibodies. After immunization with the purified N protein, mice developed a strong anti-ribonucleoprotein antibody response and were protected against a lethal challenge of rabies virus. These data indicate that the N protein expressed in insect cells is antigenically and immunogenically comparable to the authentic rabies virus ribonucleoprotein and therefore represents a potential source of an effective and economical vaccine for large-scale immunization of humans and animals against rabies.

Animals↗
PubMed1991

Chromatin and cell surface receptors mediate melanoma cell growth response to nerve growth factor.

Growth response to nerve growth factor (NGF) was tested in the primary melanoma cell line WM 164, which expressed a low level of NGF cell-surface receptor, and in WM 164 cells transfected with cDNA for the cell-surface receptor (TrWM 164 cells), which expressed a higher level of the cell-surface receptor. Neither cell line expressed the chromatin receptor for NGF or internalized NGF. Both cell lines were stimulated to growth by NGF. After 10 d of exposure to NGF, a 230,000 Mr chromatin protein (receptor) was induced in both cell lines; as a result, NGF bound to the chromatin, and ribosomal RNA synthesis and cell proliferation were inhibited. We suggest that the cell-surface and chromatin receptors each mediate a different function of NGF.

Cell Division↗
PubMed1991

Biological activity in the human system of isotype variants of oligosaccharide-Y-specific murine monoclonal antibodies.

The capacity of isotype variants of BR55-2, an anti-tumor monoclonal antibody directed against Y oligosaccharide, to mediate antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) in the human system was evaluated using freshly isolated peripheral blood mononuclear cells, lymphocytes, monocytes and complement. The ADCC activities of the BR55-2 IgG3 isotype and its switch variants (IgG1, IgG2b, and IgG2a) with human monocytes were high for all isotypes, whereas the activity of all isotypes was lower with freshly isolated lymphocytes, IgG1 being the least effective. The CDC on the other hand was strong with IgG3, IgG2b and IgG2a and negative with the IgG1 variant. The IgG3 and IgG2a isotypes were selected for further development. Their strong ADCC and CDC activity against mammary carcinoma, colon carcinoma and small-cell lung tumor cell lines was confirmed quantitatively using proteins highly purified from tissue-culture supernatants. Significant variations in ADCC and CDC competence was observed among human donors.

Antibodies, Monoclonal↗
PubMed1991

Immunization of monkeys with rabies ribonucleoprotein (RNP) confers protective immunity against rabies.

The ability of rabies virus ribonucleoprotein (RNP) to induce protective immunity against rabies and to prime for production of virus-neutralizing antibodies (VNA) was studied in monkeys. Following two immunizations with RNP, monkeys developed a strong anti-RNP response and were protected against a challenge infection with a lethal dose of street rabies virus. Monkeys that were primed with RNP and then immunized with a single dose of human diploid cell vaccine (HDCV) developed VNA titres comparable to the VNA titres in non-primed monkeys after a second HDCV immunization. The utility of rabies RNP for the pre-exposure prophylaxis of human rabies is discussed.

Animals↗
PubMed1991

Anti-idiotypic antibodies against anti-CD4 antibodies MT151 and OKT4A.

Anti-idiotypic antibodies (Ab2) binding to the antigen-combining site of other antibodies may functionally and even structurally mimic antigen. Ab2 to antibodies directed against the lymphocyte CD4 receptor for human immunodeficiency virus type 1 (HIV-1) may mimic the receptor and therefore inhibit viral infectivity. We have produced Ab2 against monoclonal anti-CD4 receptor antibodies (Ab1). The Ab1 strongly inhibit HIV-1 binding to the receptor. Six monoclonal rat Ab2 and two polyclonal rabbit Ab2 were produced against the Ab1 MT151 and nine monoclonal Ab2 against the Ab1 OKT4A. These Ab2 bound only to Ab1 and not to a panel of nine unrelated murine monoclonal antibodies (MAbs). The Ab2 completely inhibited the binding of the homologous Ab1 to CD4-positive target cells, and recombinant soluble CD4 inhibited binding of Ab2 to Ab1. Thus, the Ab2 seemed to mimic the Ab1-binding site of the CD4 receptor, although the results of inhibition assays did not exclude steric hindrance of antibody-combining sites. However, none of the 17 Ab2 bound to gp120 of HIV-1 envelope or inhibited syncytia formation between cells infected and uninfected with HIV-1. These results suggest that the Ab2 do not mimic the HIV-1 binding site of the CD4 receptor. They further suggest that the Ab1 may not bind within the virus-binding site of the CD4 receptor.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Initial clinical evaluation of two murine IgG2a monoclonal antibodies for immunotherapy of gastrointestinal carcinoma.

Eleven patients with advanced gastrointestinal (GI) carcinoma were entered in Phase I initial clinical trials with IgG2a antiGI carcinoma monoclonal antibodies (MAbs) GA733 (five patients) or CO19-9 (six patients). Infusion of MAb GA733 in doses greater than 30 mg was accompanied by mild and short-lasting GI toxicity. Infused MAb GA733 was bound to each patient's tumor tissue in vivo. MAb circulated in the blood for 10-25 days. All patients developed anti-mouse antibodies between 15 and 60 days post infusion. Furthermore, all but one patient raised anti-idiotypic antibodies against MAb GA733. Following administration of 10-600 mg of MAb CO19-9, no immediate or delayed toxicity symptoms were noted. Binding of infused MAb CO19-9 to tumor cells in vivo could not be detected in any of the six patients studied. The MAb circulated in the bloodstream between 5 and 12 days. Human anti-mouse antibody was detected in sera of three patients. None of the eleven patients treated with either MAb had anti-tumor responses in this Phase I clinical trial. The strong binding reactivity of MAb GA733 to tumors in vivo suggests the use of this MAb in cancer patients with less tumor burden to determine the tumoricidal efficacy of this antibody.

Animals↗
PubMed1991

Direct entry of rabies virus into the central nervous system without prior local replication.

Rabies virus pathogenesis was studied in a mouse model by inoculation of the masseter muscle. At different intervals, the masseter muscle, trigeminal ganglia, and brain were analyzed for virus-specific RNA with a polymerase chain reaction assay, which revealed that as early as 18 h postinfection (p.i.), virus-specific RNA was present in the trigeminal ganglia, and at 24 h p.i., viral RNA was identified in the brain stem. Analysis of the masseter muscle demonstrated virus at 1 h p.i. but no virus-specific RNA between 6 and 30 h p.i., indicating that virus invaded the nerve ending directly, without prior replication in the muscle. At 36 h p.i., viral RNA was detected again in the masseter muscle. Selective amplification of plus- and minus-strand RNA isolated from the masseter muscle at 96 h p.i. revealed that the majority of the rabies virus-specific RNA was in the positive sense, suggesting virus replication in muscle tissue during late stages of infection.

Animals↗
PubMed1991

Epitope- and antigen-specific cancer vaccines.

Anti-idiotypic antibodies (Ab2) that functionally mimic epitopes associated with human cancer cells are the most specific cancer vaccines currently available. Ab2 can induce specific humoral anti-tumor immunity in cancer patients. However, the potential of Ab2 for inducing cellular immunity in cancer patients still requires demonstration. Clonotypic antibodies directed against the combining site for tumor Ag on human T-cell clones may provide highly effective reagents for inducing protective T-cell immunity against human cancer. A new generation of cancer vaccines, molecularly cloned tumor-associated antigens (Ag), has recently been developed. Recombinant Ag have been successfully expressed in vectors allowing large scale production of Ag for immunization of cancer patients. Recombinant tumor Ag was shown to induce specific and protective immunity in experimental animals. In contrast to Ab2, which may mimic a single cancer-associated epitope, recombinant Ag express multiple epitopes that are potentially immunogenic. Ag vaccines, therefore, may be more effective in arresting tumor growth than single epitope (Ab2) vaccines because tumor destruction by antibodies is dependent on antibody density on tumor cell surfaces. In light of the important roles that both B and T cells play in the control of tumor growth, the demonstration of induction of specific B and T cell-immunity by recombinant tumor Ag and Ab2 in experimental animals is encouraging. Ultimately, the immunomodulatory role of both types of vaccines has to be compared in cancer patients who are immunologically tolerant to many Ag/epitopes expressed by their growing tumors. The development of both Ab2 and recombinant Ag for single antigenic systems provides the first step towards this goal.

Antibodies, Anti-Idiotypic↗
PubMed1990

Evaluation of an inactivated rabies virus vaccine in domestic ferrets.

Efficacy of an SC-administered commercial inactivated vaccine for prevention of rabies was evaluated in domestic ferrets. Ferret immunity was challenged by the IM inoculation of street rabies virus. All ferrets developed titers of rabies virus-neutralizing antibodies within 30 days of vaccination (geometric mean titer [GMT] = 154, n = 41) that were maintained for at least one year (GMT = 106, n = 36), compared with no seroconversion in controls (GMT less than 5, n = 39). Following rabies virus challenge inoculation, 89% (32/36) of vaccinated ferrets survived vs less than 6% (2/38) survival in control ferrets. These results demonstrate the protective efficacy of a commercial, inactivated rabies vaccine of at least one year's duration for domestic ferrets.

Animals↗