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L A Lasky

Publications and source records attributed to L A Lasky.

84 records · Page 5Linked to original sources
PubMed1985

Protection from genital herpes simplex virus type 2 infection by vaccination with cloned type 1 glycoprotein D.

Guinea pigs were vaccinated with truncated herpes simplex virus type-1 (HSV-1) glycoprotein D produced in the genetically engineered mammalian cell line gD10.2. Vaccinated animals formed antibodies that neutralized both HSV-1 and herpes simplex virus type 2 (HSV-2) in an in vitro neutralization assay. Vaccinated animals were challenged with HSV-2 by intravaginal infection. Animals that received the immunogen in Freund's complete adjuvant were completely protected from the clinical manifestations of genital HSV-2 infection. Animals that received the immunogen incorporated in alum adjuvants were partly protected from clinical disease; the infections that did develop were significantly less severe than those that occurred in control animals injected with adjuvant alone. The results demonstrate that immunization with a purified viral protein can provide significant protection against primary genital infection by HSV-2 in guinea pigs.

Adjuvants, Immunologic↗
PubMed1985

Bacterial expression of the acquired immunodeficiency syndrome retrovirus p24 gag protein and its use as a diagnostic reagent.

A retrovirus [lymphoadenopathy-associated virus, human T-cell leukemia virus type III, acquired immunodeficiency syndrome (AIDS)-related virus] suspected of causing AIDS has been isolated recently. The detection of exposure to this retrovirus in donors of various blood products is important to prevent transmission of the disease from these donors to recipients. In the majority of cases, the detection of antibodies directed against either the viral core protein, a Mr approximately equal to 24,000 protein termed p24 gag, or the viral envelope antigen is proof of previous viral infection. Thus, we have expressed the p24 gag antigen in Escherichia coli in order to produce a diagnostic reagent for the detection of virus exposure. The bacterially synthesized antigen reacts with human and rabbit antisera directed against the native p24 gag protein in both electrophoretic transfer blot assay and ELISA. In addition, the use of bacterially produced antigens for ELISAs gave results that were comparable to those obtained by using antigens isolated from the virus.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Base composition-independent hybridization in tetramethylammonium chloride: a method for oligonucleotide screening of highly complex gene libraries.

An oligonucleotide hybridization procedure has been developed that eliminates the preferential melting of A X T versus G X C base pairs, allowing the stringency of the hybridization to be controlled as a function of probe length only. This technique, which uses tetramethylammonium chloride, is especially helpful whenever a highly complex library is screened with a pool of oligonucleotide probes, which usually vary widely in base composition. The procedure can also be applied advantageously whenever an exact match to an oligonucleotide probe is desired, such as in screening for clones having as little as a single-base alteration generated by in vitro mutagenesis.

Base Composition↗
PubMed1985

Localization of epitopes of herpes simplex virus type 1 glycoprotein D.

We previously defined eight groups of monoclonal antibodies which react with distinct epitopes of herpes simplex virus glycoprotein D (gD). One of these, group VII antibody, was shown to react with a type-common continuous epitope within residues 11 to 19 of the mature glycoprotein (residues 36 to 44 of the predicted sequence of gD). In the current investigation, we have localized the sites of binding of two additional antibody groups which recognize continuous epitopes of gD. The use of truncated forms of gD as well as computer predictions of secondary structure and hydrophilicity were instrumental in locating these epitopes and choosing synthetic peptides to mimic their reactivity. Group II antibodies, which are type common, react with an epitope within residues 268 to 287 of the mature glycoprotein (residues 293 to 312 of the predicted sequence). Group V antibodies, which are gD-1 specific, react with an epitope within residues 340 to 356 of the mature protein (residues 365 to 381 of the predicted sequence). Four additional groups of monoclonal antibodies appear to react with discontinuous epitopes of gD-1, since the reactivity of these antibodies was lost when the glycoprotein was denatured by reduction and alkylation. Truncated forms of gD were used to localize these four epitopes to the first 260 amino acids of the mature protein. Competition experiments were used to assess the relative positions of binding of various pairs of monoclonal antibodies. In several cases, when one antibody was bound, there was no interference with the binding of an antibody from another group, indicating that the epitopes were distinct. However, in other cases, there was competition, indicating that these epitopes might share some common amino acids.

Antibodies, Monoclonal↗
PubMed1984

Use of recombinant mammalian cell lines for vaccine production.

Antiviral vaccines classically were composed of attenuated or inactivated whole virions produced by infection of eukaryotic cells. With the advent of recombinant DNA (rDNA) technology, the strategy for vaccine production has changed dramatically. The gene(s) encoding a specific protein(s) containing the virus neutralizing site(s) can be isolated and transfected into bacteria, yeast or mammalian cells in culture. These transfected or recombinant organisms or cells can be exploited to produce large quantities of the specific protein which subsequently can be developed in a highly purified form for use as a subunit vaccine. The issue which we would like to discuss is the selection of the host used for the expression of recombinant subunit vaccines.

Animals↗
PubMed1984

DNA sequence analysis of the type-common glycoprotein-D genes of herpes simplex virus types 1 and 2.

The DNA sequences for the coding and flanking regions of the type-common glycoprotein-D (gD) genes of herpes simplex virus (HSV) types 1 and 2 have been determined. The resultant protein sequences are approximately 80% homologous. Both gD proteins are 393 amino acids long and both have maintained three identical potential glycosylation sites. Amino acid changes are found throughout the proteins, with the majority of changes located in the amino and carboxyl/termini. Most of the amino acid differences were found to be conservative. Hydropathy analysis, which determines hydrophobic and hydrophilic regions, reveals a remarkable structural similarity between the proteins. Examination of 5' flanking sequences demonstrates extensive DNA sequence homology adjacent to the start of gD gene transcription. In addition, another homologous noncoding region was found 3' to the gD gene. This second homologous sequence is 5' to a 1.6-kb transcription unit.

Amino Acid Sequence↗
PubMed1984

Extensive homology between the herpes simplex virus type 2 glycoprotein F gene and the herpes simplex virus type 1 glycoprotein C gene.

The region of the herpes simplex virus type 2 (HSV-2) genome which maps colinearly with the HSV-1 glycoprotein C (gC) gene has been cloned, and the DNA sequence of a 2.29-kilobase region has been determined. Contained within this sequence is a major open reading frame of 479 amino acids. The carboxyterminal three-fourths of the derived HSV-2 protein sequence showed a high degree of sequence homology to the HSV-1 gC amino acid sequence reported by Frink et al. (J. Virol. 45:634-647, 1983). The amino-terminal region of the HSV-2 sequence, however, showed very little sequence homology to HSV-1 gC. In addition, the HSV-1 gC sequence contained 27 amino acids in the amino-terminal region which were missing from the HSV-2 protein. Computer-assisted analysis of the hydrophilic and hydrophobic properties of the derived HSV-2 sequence demonstrated that the protein contained structures characteristic of membrane-bound glycoproteins, including an amino-terminal signal sequence and carboxy-terminal hydrophobic transmembrane domain and charged cytoplasmic anchor. The HSV-2 protein sequence also contained seven putative N-linked glycosylation sites. These data, in conjunction with mapping studies of Para et al. (J. Virol. 45:1223-1227, 1983) and Zezulak and Spear (J. Virol. 49:741-747, 1984), suggest that the protein sequence derived from the HSV-2 genome corresponds to gF, the HSV-2 homolog of HSV-1 gC.

Amino Acid Sequence↗
PubMed1983

Detection of antibodies to herpes simplex virus with a continuous cell line expressing cloned glycoprotein D.

The gene for glycoprotein D of herpes simplex virus type 1 (HSV-1) was expressed in stable mammalian cell lines. Glycoprotein D produced in these cells has a number of antigenic determinants in common with the native glycoprotein. Cell lines expressing glycoprotein D were used in an enzyme-linked immunosorbent assay to detect human antibodies to glycoprotein D. This strategy should prove useful in determining the extent to which the immune response to HSV-1 is directed toward glycoprotein D.

Antibodies, Viral↗
PubMed1980

Messenger RNA prevalence in sea urchin embryos measured with cloned cDNAs.

mRNA prevalence during sea urchin development was measured by treating cDNA clone colonies with labeled cDNAs transcribed from unfertilized egg and embryo poly(A)-RNAs. The number of cytoplasmic transcripts per embryo complementary to several clones was determined independently by titration with poly(A)-RNA in solution, and the amount of cDNA bound to these clones in colony hybridizations was shown to be proportional to the concentration of the respective poly(A)-RNAs in the embryo cytoplasm. At the gastrula stage, the most prevalent mRNA species occur in about 10(6) molecules per embryo. If all cells were equivalent, this would be a few hundred molecules per cell. By pluteus stage, the prevalence of some sequences has increased more than 10-fold. Most, though not all, sequences prevalent in later embryos are also present in the maternal RNA of the unfertilized egg. For most poly(A)-RNA sequences, the prevalence levels determined during oogenesis are maintained through the pluteus stage, whereas a minority of sequences display sharp stage-specific changes in representation during development.

Animals↗
PubMedDate not supplied

Nucleic acid structure and expression of the human AIDS/lymphadenopathy retrovirus.

The 9,213-nucleotide structure of the AIDS/lymphadenopathy virus has been determined from molecular clones representing the integrated provirus and viral RNA. The sequence reveals that the virus is highly polymorphic and lacks significant nucleotide homology with type C retroviruses characterized previously. Together with an analysis of the two major viral subgenomic RNAs, these studies establish the coding frames for the gag, pol and env genes and predict the expression of a novel gene at the 3' end of the genome unrelated to the X genes of HTLV-1 and -II.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Variable and conserved neutralization antigens of human immunodeficiency virus.

Human immunodeficiency virus type 1 (HIV-1, HTLV-III/LAV), the retrovirus responsible for acquired immune deficiency syndrome (AIDS), shows a high degree of genetic polymorphism, particularly in the env gene. We have examined sera from rabbits and guinea pigs immunized with gp130, a recombinant env glycoprotein, and sera from HIV-1-infected subjects, to test their capacity to neutralize a panel of genetically divergent HIV-1 isolates. The sera raised against recombinant antigen specifically neutralized the virus strain from which the env gene was cloned (HTLV-IIIB), but not an independent isolate (HTLV-IIIRF). One rabbit serum tested on seven isolates cross-neutralized two at lower titres. In contrast, human sera from Britain and Uganda, chosen for ability to neutralize HTLV-IIIRF, cross-neutralized six other HIV-1 isolates. When serum and isolate were derived from the same subject, the serum was in some cases effective at slightly lower concentrations (higher titres). Human complement did not affect neutralization titres. These findings indicate that genetically diverse HIV-1 isolates carry both variable and widely conserved antigenic epitopes for neutralizing antibodies. The identification of shared epitopes may help the development of protective vaccines.

Acquired Immunodeficiency Syndrome↗