Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0001175 (AIDS)
 120,706 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human immunodeficiency virus (HIV-1) isolates from 8 Ethiopian and 8 Swedish AIDS patients, none of them treated with antiviral drugs, were compared for sensitivity to azido-deoxy-thymidine (AZT), dideoxy-inosine (ddI) and interferon-alpha. HIV was isolated from peripheral blood mononuclear class, identified by Western blot and nucleotide sequencing, and passaged 1-3 times. Sensitivity to the 3 drugs, expressed as ED50s relative to positive controls, was determined by culturing HIV in the presence of drugs in a range of concentrations and assaying the supernatant for p24 antigen and the virus pellet for reverse transcriptase (RT). Dose-dependent anti-HIV activity for AZT was seen in the 8 Ethiopian isolates, and ED50s for p24 antigen and RT activity were correlated. 1 Ethiopian HIV isolate was sensitive to ddI, and another, to interferon-alpha. 1 Swedish HIV was resistant to AZT, and on analysis had a mutation from threonine to tyrosine at position 215. There were no significant differences between ED50s for interferon in the Swedish and Ethiopian HIVs. Combined data for each drug showed correlation between the p24 antigen and RT activities of the Ethiopian and Swedish HIVs. Since there was no resistance observed in the Ethiopian HIV to AZT or ddI, low-dose treatment would probably slow progression of HIV infection in Ethiopians, if these drugs could be made available for clinical trials.
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PMID:Response of Ethiopian human immunodeficiency virus type 1 isolates to antiviral compounds. 128 93

Two antibodies, affinity-purified from human immunodeficiency virus-positive human plasma with synthetic peptides in the region gp41(566-596), were found to recognize oligomeric gp41 more strongly than the monomeric form in an immunoblot assay. In contrast, a murine anti-gp160 monoclonal antibody, which maps within this sequence to gp41(581-596), recognized only monomeric gp41 after disruption of the oligomer with sodium dodecyl sulfate. This monoclonal anti-gp160 antibody did not recognize chemically crosslinked oligomeric gp41 that had been treated with similar conditions used to disrupt the gp41 oligomer. These results indicate that this epitope is inaccessible to binding by this antibody when gp41 is oligomeric. Cyanogen bromide cleavage of gp41 resulted in a 17-kD fragment Thr-541-Met-631. A significant proportion of this fragment was oligomeric when derived from chemically crosslinked gp41. The region Ala-566-Gln-596, within the cyanogen bromide fragment, contains the oligomerization-sensitive epitopes as well as two lysine residues available for crosslinkage. This region is relatively conserved and has the propensity to form an amphipathic alpha-helix.
AIDS Res Hum Retroviruses 1992 Dec
PMID:Antibody epitopes sensitive to the state of human immunodeficiency virus type 1 gp41 oligomerization map to a putative alpha-helical region. 128 26

To investigate whether human immunodeficiency virus type 1 pol gene mutations are selected during prolonged 2',3'-dideoxycytidine (ddC) therapy, we used the polymerase chain reaction to amplify a portion of the reverse transcriptase segment of the pol gene from the peripheral blood mononuclear cell DNA of a patient with AIDS before and after an 80-week course of ddC therapy. The consensus sequence from the second sample contained a unique double mutation (ACT to GAT) in the codon for reverse transcriptase amino acid 69, causing substitution of aspartic acid (Asp) for the wild-type threonine (Thr). A mutation (ACA to ATA) also occurred in the codon for position 165, causing substitution of isoleucine (Ile) for Thr. The GAT (Asp) codon was introduced into the pol gene of a molecular clone of human immunodeficiency virus via site-directed mutagenesis. Following transfection, mutant and wild-type viruses were tested for susceptibility to ddC by a plaque reduction assay. The mutant virus was fivefold less susceptible to ddC than the wild type; cross-resistance to 3'-azido-3'-deoxythymidine or 2'3'-dideoxyinosine was not found. The Ile-165 mutation did not confer additional ddC resistance. The Asp-69 substitution may have contributed to the generation of resistant virus in this patient.
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PMID:Human immunodeficiency virus type 1 pol gene mutations which cause decreased susceptibility to 2',3'-dideoxycytidine. 131 43

We have cloned and sequenced the cDNA for cat CD4. The overall amino-acid sequence of cat CD4 is similar to that from the primate and rodent CD4 molecules, with a 58% identity between the cat and human sequences. Comparison to the crystal structure of human CD4 does, however, reveal unusual features in the second Ig-like domain, D2, of cat CD4. First, a reciprocal substitution between a tryptophan and a cysteine, this latter involved in an intrasheet disulfide bond of human D2, is predicted to generate an intrastrand disulfide bond, a feature rarely observed in an Ig-fold. Second, a large serine-threonine-rich insertion is found between the A and B beta strands of D2. This sequence is a potential O-linked glycosylation site, and should protrude in a region that appears flexible in human CD4. This unusual insertion could affect the interaction of cat CD4 with class II molecules, or with FIV, a feline homolog of HIV. The expression of cat CD4 in different environment, or of a mutated human CD4 carrying the cat insertion, should help in understanding the role of cat CD4 as a putative receptor for FIV, and the CD4/MHC class II interaction.
AIDS Res Hum Retroviruses 1992 Sep
PMID:Unusual amino acid sequence of the second Ig-like domain of the feline CD4 protein. 145 4

Two immunologically distinct glycoproteins, fractions C4 and C6, with a molecular weight of 28,000 and 28,500, respectively, estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, were isolated from seeds of Luffa cyclindrica using acetone precipitation, gel filtration on Sephadex G-75, and ion exchange chromatography on CM-Sepharose CL-6B. Fractions C4 and C6 correspond to luffin-a and luffin-b, respectively, according to the ion exchange chromatographic behavior and amino acid compositions. Fraction C6 and luffin-b were characterized by a lower content of threonine and a higher content of proline than fraction C4 and luffin-a. The 2 luffins, the protein from Luffa acutangula (luffaculin) and trichosanthin exhibited an overall similarity in amino acid composition. The proteins differed in the content of aspartic acid, threonine, proline, and alanine but were otherwise similar in amino acid composition. The ribosome inactivating proteins from Luffa cylindrica seeds also possessed abortifacient activity: they were capable of inducing mid term abortion in mice, inhibiting protein synthesis in a cell-free system, and suppressing thymidine uptake by human choriocarcinoma cells. The abortifacient activity of these proteins is possibly the result of their inhibitory effects on the biosynthetic activity of implanting embryos and endometrial cells. Trichosanthin inhibits the replication of human immunodeficiency virus (HIV) in acutely and chronically infected cells of lymphocyte and mononuclear phagocyte lineage with a potential in AIDS therapy. However, it is still unknown whether the proteins from Luffa cylindrica seeds also possess anti-HIV activity.
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PMID:Two proteins with ribosome-inactivating, cytotoxic and abortifacient activities from seeds of Luffa cylindrica roem (Cucurbitaceae). 150 59

Genetic diversity is a hallmark of the human immunodeficiency virus (HIV) genome, but the role of distinct HIV variants in the development of AIDS is unclear. Envelope (env) is the most highly variable gene in HIV as well as in other retroviruses. We have previously demonstrated that variation in simian immunodeficiency virus (SIV) env is primarily localized in two regions (V1 and V4) during progression to simian AIDS. To determine whether there is a common genotype that evolves as AIDS develops, a total of 160 SIV env genes isolated directly from the tissue DNAs of four macaques infected with cloned virus were compared. Common amino acid sequence changes were identified within V1, V4, and, in the late stages of disease, near V3. At several positions, the same amino acid change was seen frequently in the variant genomes from all four animals. As AIDS developed, the majority of viruses evolved an extended sequence in V1 that was rich in serine and threonine residues and shared similarity with proteins modified by O-linked glycosylation. Several of the predominant common sequence changes in V1 and V4 created new sites for N-linked glycosylation. Thus, common features of the SIV variants that evolve during progression to AIDS are motifs that potentially allow for structural and functional changes in the env protein as a result of carbohydrate addition.
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PMID:Alterations in potential sites for glycosylation predominate during evolution of the simian immunodeficiency virus envelope gene in macaques. 152 47

Tuftsin, Thr-Lys-Pro-Arg, is a natural immunomodulating peptide originally found as a phagocytosis-stimulating factor for polymorphonuclear leukocytes. The peptide is now known to elicit various other activities including antimicrobial, antiviral and antitumor effects in vivo. Preliminary human studies revealed antitumor and anti-AIDS activities. In view of this clinical potential, we performed studies on the stability of sterile saline solutions of tuftsin stored at 25 degrees C, 5 degrees C, -20 degrees C or -70 degrees C utilizing a phagocytosis assay and analytical HPLC. Tuftsin stored at -20 degrees C or -70 degrees C gradually lost its phagocytosis-stimulating activity; tuftsin stored at 25 degrees C or 5 degrees C lost its phagocytosis activity rather rapidly. By 6 months, tuftsin stored at 25 degrees C lost all activity, and by 12 months, it significantly inhibited phagocytosis. In contrast, HPLC analysis indicated very minor changes. While tuftsin stored at 25 degrees C lost almost all activity by 6 months, we detected appearance of only 1% impurities by HPLC. This study indicates that if its activity is to be preserved, solutions of tuftsin must be frozen for storage.
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PMID:Stability of sterile saline solutions of synthetic tuftsin, a naturally occurring immunomodulating peptide. 182 2

The finding of endocrine gland lesions at pathological examination in AIDS and reports of several cases of endocrine disease in patients with this syndrome have prompted us to study endocrine functions in 63 patients (51 men, 12 women) with HIV-1 infection. According to the Center for Disease Control (CDC) classification system, 13 of these patients were stage CDC II, 27 stage CDC III and 23 stage CDC IV. We explored the adrenocortical function (ACTH, immediate tetracosactrin test) and the thyroid function (free T3 and T4 levels, TRH on TSH test) in all 63 patients. The hypothalamic-pituitary-gonadal axis (testosterone levels, LHRH test) and prolactin secretion (THR test) were explored in the 51 men. The results obtained showed early peripheral testicular insufficiency at stage CDC II and early pituitary gland abnormalities with hypersecretion of ACTH and prolactin also at stage CDC II. On the other hand, adrenocortical and pituitary abnormalities were not frequently found. The physiopathology of the endocrine abnormalities observed in HIV-1-infected patients remains unclear, but one may suspect that it involves interleukin-1 since this protein factor has recently been shown to stimulate the corticotropin-releasing hormone secretion and to act directly on the glycoprotein capsule of the virus (gp 120) whose structure is similar to that of some neurohormones.
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PMID:[Endocrine abnormalities in HIV infections]. 216 75

Acquired immunodeficiency syndrome (AIDS) is initiated by the attachment of the human immunodeficiency virus (HIV) to a surface glycoprotein CD4 present on T4 helper/inducer lymphocytes, monocytes/macrophages and other cells. A simple octapeptide (H-Ala-Ser-Thr-Thr-Thr-Asn-Tyr-Thr-OH, peptide T) seems to inhibit HIV infectivity and to activate human monocyte chemotaxis. In order to study in vitro metabolic stability and structure-activity relationships, peptide T and a number of analogues were prepared and tested on human monocytes by chemotactic assay. Peptide T and the shorter fragments T(3-8)-OH and T(4-8)-OH displayed potent bioactivity (maximal chemotactic activity in the range 10(-11)-10(-10) M). The C-terminal heptapeptide showed a reduction of potency, while further truncations at N-terminus of T(4-8)-OH abolished the biological action. In the octapeptide series, whereas the alpha-amino butyric acid (Abu) substitution for Thr4 was well tolerated, the same "slight" structural change at Thr5 or Thr8 was very detrimental. Finally, [D-Asn6]T(1-8)-OH analogue has low chemotactic activity. All these results indicate that i) the C-terminal pentapeptide is the minimum sequence required for bioactivity, ii) residues 5 to 8 appear to play a crucial biological role, iii) peptide T chemotaxis is mediated, at least in part, through the polar properties of Thr side chains at the critical positions 5 and 8, while the Thr4 does not interfere with biological characteristics of peptides.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Synthesis, metabolic stability and chemotactic activity of peptide T and its analogues. 232 89

Automated N-terminal microsequencing of immune affinity-purified acquired immunodeficiency syndrome retrovirus polypeptides from infected cells was used to locate the N termini of 64-, 51-, and 34-kilodalton (kDa) polypeptides within the pol open reading frame (ORF) of the proviral DNA. The 64- and 51-kDa proteins had identical N termini (Pro-Ile-Ser-Pro-IIe-Glu-Thr-Val-) positioned 156 residues from the beginning of the pol ORF. The N terminus of the 34-kDa pol gene product, Phe-Leu-Asp-Gly-Ile-Asp-Lys-, mapped 716 residues into the pol ORF. These polypeptides were absent in an RT-negative, CD4-negative, persistently infected cell line (8E5) carrying a single defective copy of a constitutively expressed, integrated proviral DNA.
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PMID:Structural characterization of reverse transcriptase and endonuclease polypeptides of the acquired immunodeficiency syndrome retrovirus. 243 Jan 11


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