Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Many infections evoke a strong humoral immune response. Some (e.g., HIV-1, EBV, CMV) also lead to disorders of the B-cell system. Data concerning cell dysfunction are largely derived from in vitro studies, which necessarily exclude all microenvironmental influences. The aim of this study was to develop a tool for the investigation of epitope specific humoral immune responses in vivo. Mice were immunized with one of two synthetic peptides, both 21 amino acids long and homologous to regions of the HIV-1 gp160. Cryostat sections of spleen and lymph nodes were incubated with the corresponding peptide coupled to alkaline phosphatase and simultaneously incubated with peroxidase-conjugated rabbit antisera specific for mouse immunoglobulin isotypes. We were able to show simultaneous detection of epitope specificity, isotype, and localization of antibody-forming cells and immune complexes in tissue sections. It should prove useful for in vivo investigation of the development of specific (e.g., anti-HIV-1) humoral immune response, the determination of B-cell specificity in lymph node infiltrates, and the role of immune complexes in lymph node pathology.
 ...
PMID:Double immunocytochemical staining for in vivo detection of epitope specificity and isotype of antibody-forming cells against synthetic peptides homologous to human immunodeficiency virus-1. 169 Jul 64

Knowledge about B-cell dysfunction and HIV-specific antibody production is necessary for the understanding of both HIV-1-related immunopathology and the (vaccine-induced) humoral immunity involved in protection against AIDS. This paper describes the application of recently developed methods to detect epitope specificity of B cells in lymph-node biopsies with antigen-enzyme conjugates. Cryosections of five lymph-node biopsies from HIV-1-infected individuals and four control tissues were stained with a panel of HIV-1 antigen-enzyme conjugates: recombinant HIV-1 proteins (gp 160, gp 120 and p24), labelled with peroxidase, and synthetic peptides representing neutralizing epitopes from gp120 and gp41, labelled with alkaline phosphatase. Antibody-forming cells (AFCs) were detected in all the HIV-1-infected biopsies with gp160, gp120 and/or p24, in numbers up to 350 per section. AFCs producing specific antibodies against peptide 101 (SP 101), representing the neutralizing epitope 586-608 of gp41, were detected in one patient. These techniques allow correlation of in vivo function of B cells with lymph-node pathology, clinical stage of the disease and serological data. Their potential for the elucidation of HIV-related immunopathogenesis and the development of vaccines is discussed.
 ...
PMID:Immunocytochemical determination of antigen and epitope specificity of HIV-1-specific B cells in lymph-node biopsies from HIV-1-infected individuals. 171 61

Monoclonal antibodies (MAbs) raised against the core proteins of human immunodeficiency virus type 1 (HIV-1; laboratory strain HTLV-IIIB) and HIV-2 (strain ROD) were investigated in a variety of tests, e.g., enzyme-linked immunosorbent assay (ELISA), immunostaining of Western immunoblots, immunofluorescence, immunoprecipitation, and alkaline phosphatase anti-alkaline phosphatase assay. The MAbs were grouped according to their cross-reactions. Seven HIV-1-specific MAbs reacted exclusively with HIV-1, and five showed cross-reactivity with HIV-2 and simian immunodeficiency virus of macaques in ELISA. Four of the 15 MAbs against HIV-2 reacted only with the HIV-2 protein p26. Six showed cross-reactivity with HIV-1, and five showed a broad reaction with all three viruses. Overlapping 30-amino-acid-long peptides derived from the p24 protein sequence of HIV-1 were used in an epitope-mapping system. Three different immunogenic regions (A, B, and C) could be defined. Specific regions where anti-HIV-1 and -HIV-2 MAbs cross-reacted were mapped with shorter oligopeptides.
 ...
PMID:Characterization of murine monoclonal antibodies directed against the core proteins of human immunodeficiency virus types 1 and 2. 171 63

Monoclonal antibodies (termed as APP.1 and related to subclass IgG1) against seal alkaline phosphatase, have been obtained. APP.1 did not influence the enzymatic activity of alkaline phosphatase. The dissociation constant for the APP.1 interaction with Greenland seal alkaline phosphatase was equal to 8.5 x 10(-10) M. It was found that APP.1 interact with intestinal isoenzymes of common and fur seal, calf and deer alkaline phosphatases. An APP.1 complex with seal alkaline phosphatase was obtained and successfully applied in immunoenzymatic analysis. The use of this complex made it possible to diminish the limit of detectability of antibodies against peptide fragments of HIV-1 and HIV-2 proteins. Moreover, this complex allowed the identification of cytokeratin-8 and vimentin in human kidney slices and embryonic fibroblast-like cells, respectively.
 ...
PMID:[Preparation and use of monoclonal antibodies against seal alkaline phosphatase]. 172 98

Chemiluminescent detection of polymerase chain reaction (PCR-)amplified DNA was used as a quantitative method for detecting HIV-1. For this purpose, biotinylated dUMP was directly incorporated into the amplified DNA during the PCR reaction. Biotinylation was visualized in an enzymatic reaction using avidine-conjugated alkaline phosphatase and its chemiluminescent 1,2-dioxetane substrate AMPPD, which decomposes upon dephosphorylation and emits light. Light emission was either detected with X-ray films or quantified with a single-photon counting camera connected to a computer imaging system. The specificity of the method was shown by hybridization with a biotinylated or radiolabelled HIV-1-specific oligonucleotide probe. Besides being quantitative, this method represented a non-hazardous, rapid and sensitive technique for the detection of HIV-1 DNA.
 ...
PMID:Incorporation of biotinylated nucleotides for the quantification of PCR-amplified HIV-1 DNA by chemiluminescence. 176 43

The efficiency of enhanced chemiluminescence based on a novel generation substrate for alkaline phosphatase, adamantyl-1,2-dioxetane phosphate, was compared with that of 32P-labelled probe for visualization of human immunodeficiency virus type 1 (HTV-1)-specific DNA-DNA hybrids. The probe used for nonisotopic detection was digoxigenin labelled and targeted by anti-digoxigenin antibody Fab-fragments conjugated to alkaline phosphatase. The dot-blot hybridization analysis performed on a dilution series of HIV-1 proviral DNA demonstrated a lower sensitivity limit of 0.5 pg with the nonisotopic method. However, one order of magnitude less DNA could still be detected by a random-primed 32P-labelled probe. The ability of nonradioactive and radioactive probes to detect 590-bp gag gene-specific target sequences generated by the polymerase chain reaction (PCR)-mediated amplification of HIV-1 DNA was also compared. Analysis of 20 samples from individuals at increased risk for HIV infection by using the two assayed systems produced virtually equivalent signal images on corresponding specimens. Furthermore, complete concordance in the performance was found when HIV-1 proviral DNA was investigated by PCR in additional 50 samples of human blood mononuclear cells.
 ...
PMID:Enhanced chemiluminescence-based hybridization analysis for PCR-mediated HIV-1 DNA detection offers an alternative to 32P-labelled probes. 178 79

High frequency irradiation generated in a common household microwave oven was used to establish an in situ hybridization technique for rapid detection of HIV sequences in infected cells. A biotin-labeled DNA probe was subsequently detected either by an alkaline phosphatase-based colorimetric reaction or by fluorescence. When compared to standard hybridization procedures with radioactive or nonradioactive probes, microwave energy-mediated hybridization results in equal sensitivity and diminished background. The main advantage of this method, however, is the drastic reduction in time, allowing completion of the whole procedure, from sample preparation to hybrid signal visualization, within one hour. In addition to HIV detection, the approach described can be applied for the diagnosis of other viral infections and may stimulate the development of nucleic acid hybridization techniques based on microwave irradiation.
 ...
PMID:Microwave irradiation-accelerated in situ hybridization technique for HIV detection. 180 May 26

We have constructed a single-chain Fv fragment representing the variable domain of the human monoclonal antibody 3D6, binding specifically to HIV-1 gp41. This gene was fused to the coding region of E. coli alkaline phosphatase (EcPhoA) and expressed in E. coli. The EcPhoA signal peptide was used to direct the recombinant fusion protein to the periplasmic space of the bacteria, from where it was purified by hydrophobic interaction chromatography and gel filtration followed by antigen-affinity chromatography using a synthetic HIV-1 peptide as ligand. The purified fusion protein was bifunctional, showing both phosphatase activity as well as antigen-binding specificity identical to that of the original antibody.
 ...
PMID:Cloning and expression of an HIV-1 specific single-chain Fv region fused to Escherichia coli alkaline phosphatase. 180 81

Epidermal cell suspensions obtained from 3 symptom-free HIV-positive individuals were cultured and marked with monoclonal antibodies for the HIV proteins p15, p24 and gp120 in the alkaline phosphatase anti-alkaline phosphatase staining technique. For 2 individuals, cells were positive after 3 days in culture, and for the third, after 4 days. Supernatant from one of the cultures infected allogeneic peripheral blood mononuclear cells. We conclude that epidermal Langerhans cells from symptom-free HIV-positive individuals are latent-infected and are able to produce and release HIV.
 ...
PMID:Latent infection of epidermal Langerhans cells in HIV-positive individuals. 189 35

Cryostat-sections of biopsies from HIV-infected patients or HIV/SIV-infected experimental animals pose a biohazard risk to laboratory workers. The objective of this study was to select a procedure that appropriately fixes cryo-sections and reduces the risk of HIV-1 infectivity. This inactivation procedure should preserve antigen binding capacity of host-produced antibodies and the antigenic structure of epitopes present in these tissues, while retaining sufficient morphologic detail. We tested the effect of seven different established fixation-inactivation procedures for HIV-1 on the detection of specific antibodies and membrane markers, compared to acetone fixation as a reference. Frozen sections of spleens from mice immunized with trinitrophenyl (TNP)-Ficoll were incubated with TNP-alkaline phosphatase to detect specific antibody-forming cells and follicular immune complexes containing TNP-specific antibodies. In addition, sections were stained with monoclonal antibodies directed against IgM (187-1), T-cells (anti Thy-1), and marginal metallophilic macrophages (MOMA-1). Five procedures proved useful as they gave results similar to regular acetone fixation. In contrast, two procedures with a methanol-containing fixative obscured both antigen binding sites and membrane antigens. Subsequently, these five selected procedures were tested on glass slide preparations of HIV-1 infected cell lines, expressing HIV-1 determinants defined by monoclonal antibodies. Finally, the procedures were tested on sections of an HIV-1 infected human lymph node, for detection of HIV-specific B-cells.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Fixation of cryo-sections under HIV-1 inactivating conditions: integrity of antigen binding sites and cell surface antigens. 191 74


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>