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1.
Lancet ; 343(8904): 1001-5, 1994 Apr 23.
Article in English | MEDLINE | ID: mdl-7909048

ABSTRACT

Prospective cohort studies indicate that 13-45% of human immunodeficiency virus type 1 (HIV-1)-infected pregnant women transmit the virus to their infants. Although factors that influence perinatal transmission are not well understood, drug and immunotherapy trials to interrupt transmission are underway. The identification of women most at risk is essential for prevention, counselling, and medical intervention. We assessed 70 HIV-1-infected pregnant women enrolled in a prospective study of perinatal transmission in Brazzaville, Congo. The relations between maternal health status, antibody levels to selected HIV-1 structural antigens at delivery, and infant outcome were explored. Independent of clinical stage, higher maternal antibody titres to peptides corresponding to the V3 region of gp120 and the immunodominant domain of gp41 were correlated with a higher risk of perinatal transmission. In a logistic regression model, the predicted risk of transmission for symptom-free women whose antibody titres to V3 and gp41 were lowest was 0.02, whereas it was 0.88 for symptomatic women whose antibody titres to V3 and TMSP18 were highest. These associations may give new insight into the mechanisms of perinatal transmission and they may also provide a powerful means of identifying women who would most benefit from intervention trials to halt perinatal transmission.


Subject(s)
HIV Antibodies/immunology , HIV Infections/transmission , Pregnancy Complications, Infectious/immunology , Cohort Studies , Congo , Delivery, Obstetric , Enzyme-Linked Immunosorbent Assay , Female , HIV Envelope Protein gp120/immunology , HIV Envelope Protein gp41/immunology , HIV Infections/epidemiology , Humans , Infant, Newborn , Pregnancy , Pregnancy Complications, Infectious/epidemiology , Prospective Studies
2.
AIDS Res Hum Retroviruses ; 9(12): 1209-15, 1993 Dec.
Article in English | MEDLINE | ID: mdl-7511395

ABSTRACT

The principal neutralization determinant (PND) of the human immunodeficiency virus type 1 (HIV-1) is located within the variable V3 region of the external envelope protein gp120. Although it is recognized that V3 sequences induce antibody response with restricted neutralization activity in vitro, we observed that the V3 consensus sequences representing North American/European and African isolates were highly cross-reactive, binding 94 and 77%, respectively, of sera collected from HIV-1 individuals originating from various parts of the world. Even HIV-1-positive sera from some East African residents, infected by strains whose V3 loop sequences are undoubtedly distinct from the North American/European consensus V3 loop sequence, reacted better to the V3 North American/European consensus peptide than to African-specific V3 sequences. Results indicate that the V3 consensus sequences represent the best candidates for optimal cross-reactivity with a wide variety of strains. Furthermore, using immunoassays for antibodies to prototype-specific V3 sequences, it is shown that HIV-1 strains related to the MN group are prevalent in West Africa, indicating either a West African origin of the MN-related viruses or more probably an introduction of this group of viruses through European/North American contacts.


Subject(s)
HIV Envelope Protein gp120/immunology , HIV-1/immunology , Peptide Fragments/immunology , Africa/epidemiology , Amino Acid Sequence , Antigenic Variation/genetics , Consensus Sequence , Cross Reactions , Epitopes/genetics , Europe/epidemiology , HIV Antibodies/blood , HIV Envelope Protein gp120/genetics , HIV Infections/epidemiology , HIV Infections/immunology , HIV Infections/microbiology , HIV-1/genetics , HIV-1/isolation & purification , Humans , Molecular Sequence Data , Neutralization Tests , North America/epidemiology , Peptide Fragments/genetics
3.
J Gen Virol ; 74 ( Pt 11): 2473-8, 1993 Nov.
Article in English | MEDLINE | ID: mdl-8245865

ABSTRACT

Hepatitis delta antigen (HDAg), the only protein encoded by the hepatitis delta virus (HDV), binds specifically genomic and antigenomic strands of the HDV RNA. In a previous study, three recombinant HDAg subdomains were synthesized, covering residues 11 to 78, 79 to 163 and 164 to 212, and only the middle domain was shown to be responsible for the binding to HDV RNA. To investigate HDAg sequences involved in HDV RNA binding, we synthesized five peptides, 15 to 29 residues in length, and tested their ability to bind HDV RNA using a simple non-radioactive ELISA with digoxigenin-labelled HDV genomic or antigenomic RNA probes. The specificity of interactions was demonstrated by comparison with control peptides and non-HDV RNA probes, and with an inhibition assay using recombinant HDAg. The HDAg-binding domain found within the middle region (79 to 163) of HDAg was more finely mapped: it is located between residues 79 and 107. In addition, another domain (residues 2 to 27) of HDAg was also found to bind specifically to HDV RNA. These two peptides share sequence similarities at residues 2 to 10 and 97 to 107 with other RNA-binding domains.


Subject(s)
Antigens, Viral/chemistry , Hepatitis Delta Virus , RNA, Viral/metabolism , RNA-Binding Proteins/chemistry , Amino Acid Sequence , Antigens, Viral/metabolism , Binding Sites , Hepatitis Delta Virus/genetics , Hepatitis delta Antigens , Molecular Sequence Data , Peptide Fragments/metabolism , RNA-Binding Proteins/metabolism
4.
J Clin Microbiol ; 31(6): 1481-5, 1993 Jun.
Article in English | MEDLINE | ID: mdl-8314990

ABSTRACT

We describe enzyme immunoassays that use synthetic oligopeptides to discriminate serologically between human T-cell lymphotropic virus type I and II (HTLV-I and HTLV-II) infections. The peptides represented 20-amino acid segments between residues 111 and 130 (MA1) and residues 116 and 135 (MA2) of the p19 gag proteins of HTLV-I and HTLV-II, respectively. The assays were sensitive since 69 of 74 HTLV-positive sera were reactive to at least one of the two matrix (MA) peptides (sensitivity, 93.2%). By using the ratio of the optical density of MA1 to the optical density of MA2, which represents for every serum sample the ratio between the absorbance value obtained in the MA1 assay and the absorbance value obtained in the MA2 assay, 59 of the 69 reactive serum samples were clearly and easily typed as positive for either antibody to HTLV-I or antibody to HTLV-II. Eight of the 10 remaining reactive serum samples were analyzed further by an inhibition procedure, and their type specificities were then clearly identifiable. Therefore, the results indicate that all MA-reactive sera were serologically distinguished by our peptide assays.


Subject(s)
Gene Products, gag/genetics , HTLV-I Infections/diagnosis , HTLV-II Infections/diagnosis , Retroviridae Proteins, Oncogenic/genetics , Amino Acid Sequence , Evaluation Studies as Topic , Gene Products, gag/immunology , HTLV-I Antibodies/blood , HTLV-I Infections/immunology , HTLV-II Antibodies/blood , HTLV-II Infections/immunology , Human T-lymphotropic virus 1/genetics , Human T-lymphotropic virus 1/immunology , Human T-lymphotropic virus 2/genetics , Human T-lymphotropic virus 2/immunology , Humans , Immunoenzyme Techniques/statistics & numerical data , Molecular Sequence Data , Peptides/chemical synthesis , Peptides/chemistry , Peptides/immunology , Retroviridae Proteins, Oncogenic/immunology , Sensitivity and Specificity , gag Gene Products, Human Immunodeficiency Virus
5.
AIDS Res Hum Retroviruses ; 7(9): 767-71, 1991 Sep.
Article in English | MEDLINE | ID: mdl-1720632

ABSTRACT

In this study the presence of a highly immunogenic domain located at the C-terminus of the external glycoproteins (EGP) of human and simian immunodeficiency viruses (HIV-1, HIV-2, and SIVMAC) is shown using synthetic oligopeptides as antigens in enzyme immunoassays. This epitope is probably located within the last 13 and 15 residues of the EGP of HIV-1 and HIV-2, respectively. The C terminal epitope of the EGP of SIVMAC may involve residues located more upstream. Among the HIV-2/SIV serotype, we observed that the reactivity to the C-terminal epitope of gp120 was dependent of both species and geographical origin of the samples tested. It seems that this gp 120 C-terminal epitope could distinguish subtypes among the HIV-2/SIV serotype. Further studies, using site-directed enzyme immunoassays with synthetic peptides representing the C-terminus of the EGP derived from a wide variety of HIV2/SIV strains must be performed to confirm this observation. These kinds of assays may constitute important tools for use in seroepidemiological studies and broaden our understanding of the distribution and phylogenetic relationship of primate lentiviruses.


Subject(s)
HIV Envelope Protein gp120/immunology , HIV-1/immunology , HIV-2/immunology , Simian Immunodeficiency Virus/immunology , Amino Acid Sequence , Animals , Epitopes , HIV Antibodies , HIV Envelope Protein gp120/genetics , HIV Infections/immunology , HIV-1/genetics , HIV-2/genetics , Humans , Lentivirus/classification , Lentivirus/genetics , Lentivirus/immunology , Molecular Sequence Data , Peptides/genetics , Peptides/immunology , Primates , Simian Acquired Immunodeficiency Syndrome/immunology , Simian Immunodeficiency Virus/genetics
6.
J Clin Microbiol ; 29(7): 1387-91, 1991 Jul.
Article in English | MEDLINE | ID: mdl-1885733

ABSTRACT

In this study, enzyme immunoassays for detection of type-specific antibodies to human immunodeficiency viruses (HIV) were developed by using short peptides corresponding to sequences located within the immunodominant domain of the transmembrane glycoproteins of both HIV-1 and HIV-2-simian immunodeficiency virus (SIV). The assays were highly sensitive with currently available sera from various geographical areas. Furthermore, they appeared to be more specific in HIV serotyping than the Western blot (immunoblot) assay, since all of the sera were clearly discriminated as one or the other type. It was also shown that in contrast to HIV-1, the C-terminal cysteine residue (amino acid 620, SIV from captive macaques, Mm142 strain) of the HIV-2-SIV peptide is not necessary for recognition of the peptide by antibody to HIV-2.


Subject(s)
HIV Infections/microbiology , HIV-1/classification , HIV-2/classification , Amino Acid Sequence , Cross Reactions , HIV Antibodies/blood , HIV Antigens , HIV Infections/diagnosis , HIV Infections/immunology , HIV-1/immunology , HIV-1/isolation & purification , HIV-2/immunology , HIV-2/isolation & purification , Humans , Immunoenzyme Techniques , Molecular Sequence Data , Peptides/chemistry , Peptides/immunology , Sensitivity and Specificity , Serotyping , Simian Immunodeficiency Virus/immunology
7.
J Clin Microbiol ; 29(3): 488-92, 1991 Mar.
Article in English | MEDLINE | ID: mdl-1709947

ABSTRACT

A sequential inhibition enzyme-linked immunoassay (SIEIA) using a peroxidase-conjugated monoclonal antibody reacting to the sequence AAEWDRVHP of p24HIV-1 (amino acids 209 to 217 of p55) was developed in order to detect and determine the titer of antibody to this epitope in various populations of human immunodeficiency virus type 1 (HIV-1)-positive patients. There was a good correlation between SIEIA and a commercially available competition assay that uses recombinant p24 protein and polyclonal antibody to HIV-1 antigen, demonstrating the importance of the described epitope. Analysis of sera from French patients showed a decline of antibody to the AAEWDRVHP sequence associated with the progression of AIDS. No decrease was observed with serum samples from African patients. An immune response to the epitope was detected by SIEIA early in the course of seroconversion. Although our SIEIA uses a single p24 epitope, these data are in accordance with previously published studies in which antibodies to the whole p24 were analyzed. Sera reacting to p24 only (indeterminate profiles by Western blot [immunoblot]) did not bind to AAEWDRVHP. This epitope, which is conserved between HIV-1 and HIV-2/simian immunodeficiency virus, appears to be a major antigenic domain of p24. The area containing the sequence AAEWDRVHP and the corresponding monoclonal antibody may serve as a convenient alternative to whole purified p24 and polyclonal antibody in diagnostic and prognostic assays.


Subject(s)
Gene Products, gag/immunology , HIV Infections/immunology , HIV-1/immunology , Viral Core Proteins/immunology , Amino Acid Sequence , Enzyme-Linked Immunosorbent Assay , Epitopes/chemistry , Gene Products, gag/chemistry , HIV Antibodies/biosynthesis , HIV Antigens/chemistry , HIV Core Protein p24 , HIV Infections/diagnosis , Humans , Male , Molecular Sequence Data , Prognosis , Viral Core Proteins/chemistry
8.
J Virol Methods ; 29(1): 81-9, 1990 Jul.
Article in English | MEDLINE | ID: mdl-2211958

ABSTRACT

Human immunodeficiency virus (HIV) strains can be separated into two serotypes: HIV-1 and HIV-2. In the study reported herein, we developed and evaluated competitive enzyme-immunoassays (CEIA-1 for the detection of antibody to HIV-1, CEIA-2 for the detection of antibody to HIV-2) to discriminate serologically between HIV-1 and HIV-2 infections. In most of the cases, the serotyping of known reactive serum samples was done easily with the CEIAs, showing a similar specificity to the Western blot. Such competitive assays could represent alternative procedures for serotyping HIV infection and would limit the need for expensive Western blots, especially in economically poor countries.


Subject(s)
HIV Infections/diagnosis , HIV-1/isolation & purification , HIV-2/isolation & purification , Immunoenzyme Techniques , Antibodies, Viral/blood , Antibodies, Viral/immunology , Antigens, Viral/immunology , Blotting, Northern , Diagnosis, Differential , Enzyme-Linked Immunosorbent Assay , HIV Infections/microbiology , Humans
10.
J Clin Microbiol ; 26(5): 1000-4, 1988 May.
Article in English | MEDLINE | ID: mdl-2838498

ABSTRACT

The efficacies of nine enzyme-linked immunosorbent assays (EIA) for antibody to human immunodeficiency virus type 1 (HIV-1) and one EIA for antibody to HIV-2 in detecting antibody to HIV-2 were studied. The competitive EIAs for antibody to HIV-1 were less sensitive than the indirect EIAs. The overall prevalence of positive results was between 28 and 51% with the competitive EIAs and between 70 and 93% with the indirect EIAs. Most of the EIAs were less sensitive in detecting antibody to HIV-2 in sera from people with acquired immunodeficiency syndrome-like diseases than in sera from symptomless individuals. The results indicate that there is a high degree of cross-reactivity between HIV-1 and HIV-2 by EIA, indicating that serotype specificity must be determined by Western blot (immunoblot) with both sets of viral antigens. The results are relevant for discussing public health strategies, especially the screening of blood donors; competitive EIAs for antibody to HIV-1 are not sensitive enough to be used in areas where HIV-2 is prevalent (West Africa).


PIP: The efficacy of 10 enzyme immunoassays (EIAs) for antibody to human immunodeficiency virus type 1 (HIV-1) in detecting antibody to HIV-2 was evaluated in sera from 43 West African residents. 23 sera were from asymptomatic individuals belonging to high-risk groups (prostitutes, prisoners, patients with sexually transmitted diseases), while the remaining 20 serum samples were from persons with symptoms of acquired immunodeficiency syndrome (AIDS). The overall prevalence of positive results was 28-51% with the competitive EIAs and 70-93% with the indirect EIAs. Most of the EIAs were less sensitive in detecting antibody to HIV-2 in sera from people with AIDS-like disease compared with asymptomatic individuals. This study shows that commercial HIV-1 antibody test kits are not equally efficient in detecting HIV-2-antibody-positive sera. Cross-reacting HIV-2 antibodies seem not to have enough affinity to compete with the anti-HIV-1 conjugate. Given the high degree of cross-reactivity between HIV-1 and 2 by EIA, serotype specificity must be determined by Western blot with both sets of viral antigens. In areas such as the Ivory Coast where HIV-2 is prevalent, these findings must be taken into consideration in the screening of blood donors.


Subject(s)
Antibodies, Viral/analysis , Enzyme-Linked Immunosorbent Assay , HIV/immunology , Cote d'Ivoire , Cross Reactions , HIV Antibodies , Humans , Immunoassay , Reagent Kits, Diagnostic , Species Specificity
12.
J Virol Methods ; 17(1-2): 55-61, 1987 Aug.
Article in English | MEDLINE | ID: mdl-2444614

ABSTRACT

A category of viruses has been identified which is related to human immunodeficiency virus (HIV) but is more closely related to a group of simian retroviruses (STLV-III). These viruses named HTLV-IV, LAV-II, or SBL-6669, are prevalent in West-Africa. In this study, we analysed the cross-reactivity at the protein level between HTLV-IV and HIV (HTLV-IIIB). The results indicate that most people infected with HTLV-IV have antibodies that react to the major gag protein of HIV p 24. There is also a high degree of immunologic cross-reactivity between the pol gene products of HIV and HTLV-IV. Among these the endonuclease/integrase is more conserved than the reverse transcriptase. In contrast, the envelope glycoproteins that are the most frequently detected antigens by antibodies from exposed individuals are serotype specific. These data make the env gene products the most interesting antigens for serotype specific diagnosis of human retroviruses infections.


Subject(s)
Antigens, Viral/immunology , Deltaretrovirus/immunology , HIV/immunology , Retroviridae Proteins/immunology , Antibodies, Viral/analysis , Cross Reactions , DNA Nucleotidyltransferases/immunology , Endonucleases/immunology , HIV Antibodies , HIV Antigens , Humans , Immunoassay , Integrases , RNA-Directed DNA Polymerase/immunology , Viral Core Proteins/immunology
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