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W Heneine

Publications and source records attributed to W Heneine.

At least 55 records · Page 3Linked to original sources
PubMed1998

Evidence of Nef truncation in human immunodeficiency virus type 2 infection.

Human immunodeficiency virus (HIV)-2 differs from HIV-1 in its relative lower transmissibility and pathogenicity. To understand the virologic basis of these differences, the nef gene from HIV-2-seropositive persons was analyzed because of its importance for disease progression in the genetically related simian immunodeficiency virus (SIV[MAC]). Proviral nef sequences from 60 HIV-2-infected persons were amplified from peripheral blood lymphocytes, and nef open-reading frames were screened by a transcription and translation assay for the presence of full-length (32- to 36-kDa) or truncated (<32 kDa) Nef proteins. Overall, 6 (10%) of 60 persons had truncated Nef proteins; of these, 5 were among the 36 asymptomatic subjects (13.9%) and only 1 was among the 24 symptomatic subjects (4.2%) (P =.23). The results of this study document the presence of defective nef genes in HIV-2 infections with a prevalence higher than that previously seen in HIV-1-infected cohorts of long-term nonprogressors or patients with AIDS.

Amino Acid Sequence↗
PubMed1998

Measurement of human immunodeficiency virus type 1 plasma virus load based on reverse transcriptase (RT) activity: evidence of variabilities in levels of virion-associated RT.

Virus load based on levels of functional reverse transcriptase (RT) was measured in plasma from 50 human immunodeficiency virus (HIV) type 1-infected persons, in 87 samples from 10 HIV-1 seroconversion panels, and in 100 uninfected persons by use of Amp-RT, an ultrasensitive RT assay. Of the 50 clinical samples, 38 (76%) were Amp-RT positive, while all uninfected controls were negative. Pearson's correlation coefficient of RNA and RT levels was .73 for all samples, .86 for seroconversion samples, and .49 for clinical samples. Calculated ratios of RT activity to virion RNA varied widely during both early and late stages of infection. Mean RT:RNA ratios in 8 seroconversion panels and in 12 (34.3%) of 35 individual clinical samples were significantly lower than the ratio for a reference virus. However, ratios were stable in individual seroconversions over time. These data demonstrate that RT activity can be used to quantitate plasma virus load and provide evidence of different levels of virion-associated RT among HIV-1-infected persons.

Acquired Immunodeficiency Syndrome↗
PubMed1997

The tax gene sequences form two divergent monophyletic lineages corresponding to types I and II of simian and human T-cell leukemia/lymphotropic viruses.

Evolutionary associations of human and simian T-cell leukemia/lymphotropic viruses I and II (HTLV-I/II and STLV-I/II) are inferred from phylogenetic analysis of tax gene sequences. Samples studied consisted of a geographically diverse assemblage of viral strains obtained from 10 human subjects and 20 individuals representing 12 species of nonhuman primates. Sequence analyses identified distinct substitutions, which distinguished between viral types I and II, irrespective of host species. Phylogenetic reconstruction of nucleotide sequences strongly supported two major evolutionary groups corresponding to viral types I and II. With the type I lineage, clusters were composed of strains from multiple host species. A genetically diverse, monophyletic lineage consisting of eight new viral strains from several species of Asian macaques was identified. The second lineage consisted of a monophyletic assemblage of HTLV-II/STLV-II strains from Africa and the New World, including an isolate from a pygmy chimp (Pan paniscus) as an early divergence within the lineage. High levels of genetic variation among strains from Asian STLV-I macaque suggest the virus arose in Asia. Evidence of the origin of the type II virus is less clear, but diversity among HTLV-II variants from a single isolated population of Mbati villagers is suggestive but not proof of an African origin.

Amino Acid Sequence↗
PubMed1996

Highly sensitive and specific polymerase chain reaction assays for detection of baboon and pig cells following xenotransplantation in humans.

Pig and baboon xenotransplants in humans require assays that discriminate source from human cells to investigate engraftment and identify true infection of recipients with xenogeneic endogenous retroviruses. We developed two polymerase chain reaction assays that target a porcine-specific sequence in the beta-globin gene and a baboon-specific sequence in the mitochondrial cytochrome oxidase subunit II gene. The sensitivity and specificity of both assays were evaluated on DNA lysates from baboon, pig, and human peripheral blood lymphocytes. Both assays detected single cells in backgrounds of human DNA. Additionally, both assays were highly specific and yielded negative results in reactions containing only human DNA. The two assays reliably detected peripheral blood lymphocyte samples from 14 baboons and 16 pigs. The baboon- and pig-specific target sequences are gender independent and nonpolymorphic and allow universal applicability. The high sensitivity and specificity is of particular importance in assessing low-level engraftment in human xenotransplant chimeras.

Animals↗
PubMed1996

Male-to-female transmission of human T-cell lymphotropic virus types I and II: association with viral load. The Retrovirus Epidemiology Donor Study Group.

SUMMARY: Risk factors for male-to-female sexual transmission of human T-lymphotropic virus types I and II (HTLV-I/II) were investigated among HTLV-seropositive volunteer blood donors and their long-term (> or = 6 month) sex partners. Direction of transmission in concordantly seropositive pairs was assessed by analyzing risk factors for HTLV infection. Donors and their partners were also questioned regarding sexual behaviors during their relationships; HTLV antibody titers and viral load were determined for specimens from male partners. Among 31 couples in whom HTLV-infected men likely transmitted infection to their partners (11 HTLV-I and 20 HTLV-II) and 25 male-positive, female-negative couples (8 HTLV-I and 17 HTLV-II), HTLV transmitter men had been in their relationships longer (mean 225 months vs. 122 months) and had higher viral loads (geometric mean 257,549 vs. 2,945 copies/300,000 cells for HTLV-I; 5,541 vs. 118 copies/300,000 cells for HTLV-II) than non-transmitters (P = 0.018 and P = 0.001 for duration of relationship and viral load, respectively, logistic regression analysis). Transmitter men also tended to have higher antibody titers against various env and whole virus proteins than non-transmitters. The identification of high viral load and duration of relationship as risk factors provides a biologically plausible framework in which to assess risk of sexual transmission of the HTLVs.

Adult↗
PubMed1996

Endemicity and phylogeny of the human T cell lymphotropic virus type II subtype A from the Kayapo Indians of Brazil: evidence for limited regional dissemination.

Long terminal repeat (LTR)-based restriction fragment length polymorphism (RFLP) analysis of human T cell lymphotropic virus type II (HTLV-II) from 17 seropositive Kayapo Indians from Brazil showed that all 17 samples contained a unique HTLV-IIa subtype (A-II). Additional RFLP screening demonstrated the presence of this subtype in two of three Brazilian blood donors and a Mexican prostitute and her child. In contrast, 129 samples from blood donors and intravenous drug users (IDUs) from the United States, two Pueblo Indian samples, five samples from Norwegian IDUs, and two samples from blood donors from Denmark were all found to be a different HTLV-IIa subtype (A-III). Phylogenetic analysis of two Kayapo and one Mexican LTR sequences showed that they cluster with a subtype A-II sequence from a Brazilian blood donor and with sequences from two prostitutes from Ghana and Cameroon. These results demonstrate that infection with the A-II subtype is endemic among the Kayapo Amerindians, has disseminated to non-Indian populations in Brazil, and is also present in Mexico. Furthermore, the A-II subtype does not appear to represent an origin for the HTLV-IIa infection in urban areas of the United States and Europe. This study provides evidence that HTLV-IIa may be a Paleo-Indian subtype as previously suggested for HTLV-IIb.

Base Sequence↗
PubMed1996

Highly sensitive qualitative and quantitative detection of reverse transcriptase activity: optimization, validation, and comparative analysis with other detection systems.

An ultra-sensitive assay for reverse transcriptase (RT) activity called Amp-RT has been developed. An in vitro transcribed heteropolymeric RNA sequence was used as a template, and polymerase chain reaction (PCR) amplification with Southern-blot hybridization served as a detection system for the cDNA product of the reaction. Titration of Mg2+ and Mn2+ concentrations using the human immunodeficiency virus type 1 (HIV-1) and the human T lymphotropic virus type 1 (HTLV-I), respectively, showed optimal assay reactivity for both viruses at 2-20 mM of Mg2+. Analysis of density banded HIV-1 showed that the peak RT activity of the assay was associated with the fractions consistent with retrovirus particles. The sensitivity of Amp-RT was also compared with that of three conventional RT assays by using seven different retroviruses including HIV-1, simian immunodeficiency virus (SIV), caprine arthritis-encephalitis virus (CAEV), HTLV-I and HTLV-II, simian retrovirus type 2 (SRV-2), and gibbon ape leukemia virus (GALV). HTLV-I, HTLV-II, and GALV could not be detected by the three conventional RT assays. Amp-RT was able to detect all these viruses in 10(1)-10(3)-fold dilutions. Similarly, Amp-RT was found to be 10(3)-10(6)-fold more sensitive than the other RT assays in detecting HIV-1, SIV< or CAEV. Culture supernatants from uninfected cell lines were all Amp-RT negative. A quantitative Amp-RT assay was also developed by using recombinant HIV-1 RT and signal quantitation. The assay was found to have a 5 log linear range, and therefore, provides a useful tool for quantitating RT and retroviruses. Amp-RT offers a sensitive generic tool for the qualitative and quantitative detection of known and unknown retroviruses.

Animals↗
PubMed1996

Strategies for Diagnosis of Xenotransplant-associated Retroviral Infections.

The demand for tissue for human-to-human transplantation consistently exceeds the available supply, resulting in attempts to use organs or tissues from animals; a field known as xenotransplantation. A major concern in xenotransplantation is the risk of infection of human recipients with new xenogeneic infectious agents and subsequent transmission of these infections to the general population. Of particular importance are infections with retroviruses that persist in the host and may allow silent human-to-human transmission. Pigs and baboons are considered as sources for human xenotransplants and are known to be infected with a number of retroviruses. Adequate diagnosis of pig and baboon retrovirus infections is required for pretransplant screening of animal sources to minimize risks of transmission to recipients and also for monitoring post-transplant infections in the human recipients. Strategies for serologic, molecular, and virologic diagnosis are described. Examples of virus-specific methods for detection of known retroviruses are also shown. Emphasis is made on the need for baboon and pig cell-specific polymerase chain reaction assays that are necessary for interpretation of polymerase chain reaction results of endogenous retroviruses. Generic methods for detection of novel or variant retrovirus are described and include screening by Amp-RT, an ultrasensitive reverse transcriptase assay.

Journal Article↗
PubMed1996

The phylogeny and molecular epidemiology of human T-cell lymphotropic virus type II.

Phylogenetic analysis of long terminal repeat (LTR) sequences from 29 human T-cell lymphotropic virus type II (HTLV-II) strains from endemic and nonendemic populations led to the proposition of three HTLV-IIa phylogroups (A-I, A-II, and A-III) and four HTLV-IIb phylogroups (B-I, B-II, B-III, B-IV). B-I and B-II represented sequences from U.S. and European intravenous drug users, and B-IV included Amerindian sequences from the Guaymi and Wayuu. Interestingly, sequences from an African Pygmy and Seminole and Pueblo Indians and other non-India U.S. samples clustered together in B-III. Similarly, sequences from the Kayapo Indians from Brazil, a Brazilian blood donor, a Cameroonian, and a Ghanaian prostitute clustered together in A-II. Sequences from non-Indian U.S./European samples and a Pueblo Indian formed A-III. A restriction fragment length polymorphism (RFLP) assay was developed to identify rapidly the prevalence of the A and B phylogroups in 246 HTLV-II samples. The RFLP results suggest that A-III and B-II may represent cosmopolitan subtypes because of global distribution in urban areas. In contrast, B-IV and A-II infections were restricted primarily to Central and South America. The phylogenetic data suggest a possible Amerindian origin for B-III, A-II, and A-III infections in non-Indians and an evolution into A and B subtypes that preceded population migrations to the Americas.

Genetic Variation↗
PubMed1995

Relation between human T-lymphotropic virus type I and neurologic diseases in Panama: 1985-1990.

Human T-cell lymphotropic virus type I (HTLV-I) is endemic in the Caribbean basin and in Japan. HTLV-II, a closely related virus, is endemic in several groups of native Americans, including Panamanian Guaymi. In Panama, a nationwide HTLV-I/II seroprevalence of 1-2% has been reported. We evaluated the frequency of HTLV-I/II infection in patients with neurologic diseases admitted to state tertiary hospitals in Panama City between 1985 and 1990. Nineteen of 322 patients with eligible diagnoses had antibodies to HTLV-I/II, 17 with HTLV-I and 2 with HTLV-II. HTLV-I was associated with spastic paraparesis (13 of 23, 56.5% versus 4 of 299, 1.3%, p < 0.001) and with cerebellar syndrome (2 of 13, 15.4%) and multiple sclerosis (2 of 54, 3.7%) (p < 0.05 for both diseases compared with subject with none of these diagnoses). The two HTLV-I infected patients with cerebellar syndrome later developed spastic paraparesis. HTLV-II infection was noted in one patient with cerebellar syndrome and one with amyotrophic lateral sclerosis. All patients with other diagnoses were seronegative. Among patients with spastic paraparesis, HTLV-I-infected patients were clinically indistinguishable from seronegative subjects. There is apparently an overlapping clinical spectrum of neurologic diseases associated with HTLV-I and HTLV-II infection.

Adolescent↗
PubMed1995

Molecular analysis of human T-cell lymphotropic virus type II from Wayuu Indians of Colombia demonstrates two subtypes of HTLV-IIb.

Studies of the genetic heterogeneity of human T-cell lymphotropic virus type II (HTLV-II) have revealed the presence of two genetic subtypes, termed HTLV-IIa and HTLV-IIb. The HTLV-IIb subtype encodes an immunodominant epitope present at the C-terminus of the extended Tax protein and, by using an LTR-based, restriction fragment-length polymorphism (RFLP) assay, can be further classified into IIb60-IIb5, with HTLV-IIb1 (Central Amerindian-like) and HTLV-IIb5 (North Amerindian-like) being characteristic subtypes for Native American Indians. To determine the antigenic and genetic heterogeneity among HTLV-II-infected South Amerindians, we used a Tax synthetic peptide immunoassay on serum, and RFLP and phylogenetic analysis on LTR sequences amplified from genomic DNA from four Wayuu Indians of Colombia. The Wayuu specimens displayed seroreactivity to the immunodominant epitope located in the extended Tax region, as predicted, and demonstrated genetic heterogeneity by the presence of both the IIB1 (Wyu1, Zuc31) and IIb5 (Wyu2, Zuc42) subtypes sequences within separate phylogroups represented by the Guaymi Indian (IIb1) and North Amerindian (IIb5) sequences, respectively. Sequence analysis showed that major LTR regulatory motifs and the cis-acting repressive elements in the LTR RNA secondary structure were relatively conserved in both Wayuu subtypes, but the predicted secondary structure of the rex response stem loop in the Wyu2 (IIb5) LTR sequence was 45 nucleotides (nt) and 95 nt longer than that observed in the Wyu1 (IIb1) and G12.1 (IIb1) LTR sequences, respectively. These results extend our knowledge of the genetic heterogeneity of HTLV-II in South Amerindians.

Amino Acid Sequence↗
PubMed1995

Mother-to-child transmission of human T-lymphotropic virus type II.

OBJECTIVE: To determine the frequency of mother-to-child transmission of human T-lymphotropic virus type II (HTLV-II) and to explore its association with breast-feeding. DESIGN: Prospective study of children born to a cohort of HTLV-II-infected pregnant women and a cross-sectional study of older siblings of these children. METHODS: Maternal sera were screened with an HTLV-I enzyme immunoassay that detects antibody to both HTLV-I and HTLV-II. Confirmatory serologic testing and viral typing were performed by Western blot, radioimmunoprecipitation assay, enzyme immunoassay with HTLV type-specific proteins, and polymerase chain reaction (PCR) analysis of DNA from peripheral blood mononuclear cells. The presence of HTLV was evaluated in children by serial serologic and PCR testing. Molecular analysis of PCR products from infected mother-child pairs was performed by means of restriction fragment length polymorphism of HTLV-II long-terminal repeated sequences. RESULTS: Twenty-nine HTLV-II-infected women were identified, and these 29 women had 30 pregnancies during the study. Of 28 live infants born to infected women, 19 were examined and none was infected with HTLV-II. Sixteen older children less than 10 years of age who were born previously to the infected women were also examined; two were infected with HTLV-II. One infected child was breast fed for 2 months and the second was not breast fed. The viral patterns of restriction fragment length polymorphism in the two infected children were distinct, but the viral pattern in each child was identical to that of her mother's virus, suggesting mother-to-child transmission. Overall, among examined children, 1 of 7 breast-fed children (14%; 95% confidence interval: 0, 40) and 1 of 28 children who were not breast fed (3.6%; 95% confidence interval: 0, 10) were infected with HTLV-II. CONCLUSION: Mother-to-child transmission of HTLV-II occurs both with and without breast-feeding and at rates similar to those of HTLV-I. We believe that this is the first demonstration of mother-to-child transmission of HTLV-II in the absence of breast-feeding.

Blotting, Western↗
PubMed1995

Investigation of proviral load in individuals infected with human T-lymphotropic virus type II.

Human T-lymphotrophic virus type II (HTLV-II) has not yet been associated with any disease. Little is known about the proviral loads of HTLV-II in vivo and its relationship, if any, to lack of pathogenicity. We determined the HTLV-II proviral copy number in peripheral blood lymphocyte (PBL) samples from 49 HTLV-II-infected individuals, of whom 25 were coinfected with human immunodeficiency virus type 1 (HIV-1). The HTLV-II copy numbers were determined by polymerase chain reaction (PCR) amplification of end-point dilutions of PBL lysates, followed by hybridization to a 32P-labeled HTLV-II-specific probe. The proviral copy number for the 49 samples ranged from < 0.02 to 200 per 1000 PBLs; 6% had < 0.02, 16% had 0.02, 20% had 0.2, 18% had 2, 31% had 20, and 8% had 200 copies per 1000 PBLs. The distributions of HTLV-II copy numbers in the coinfected and singly infected subgroups were not significantly different (Wilcoxon rank sum, p = 0.24). In the coinfected subgroup, there was no significant correlation between the HTLV-II proviral load and the counts of CD4-positive lymphocytes or CD8-positive lymphocytes (Spearman Coefficient = 0.26, p = 0.20; = 0.091, p = 0.67, respectively). Our data demonstrate the presence of a wide range of viral loads in HTLV-II-infected individuals. The high viral loads (> or = 20 copies/1000 lymphocytes) detected in 39% of our samples suggest that the low pathogenicity of HTLV-II is not related to the presence of low viral loads in the infected subjects. Our data from the HIV-1 coinfected individuals show no apparent effect of HIV-1 on HTLV-II proviral loads.

Adult↗
PubMed1995

Detection of reverse transcriptase by a highly sensitive assay in sera from persons infected with human immunodeficiency virus type 1.

In an ultrasensitive assay for reverse transcriptase (RT), an in vitro-transcribed heteropolymeric RNA sequence was used as a template and polymerase chain reaction (PCR) amplification with Southern blot hybridization served as a detection system for the cDNA reaction product. The assay, called Amp-RT, detected 9 tested retroviruses in unconcentrated culture supernatants diluted 10(2)- to 10(5)-fold. A comparative analysis using human immunodeficiency virus type 1 (HIV-1) revealed that Amp-RT was 100,000 times more sensitive than the standard RT assay, 10,000 times more sensitive than p24 antigen capture and branched DNA assays, and 100 times more sensitive than RT-PCR or TCID50 assays. Analysis of serum specimens from 42 HIV-1-infected persons by Amp-RT showed that 36 samples (85.7%) were RT-positive. In contrast, 41 serum specimens from persons seronegative for HIV-1 and human T lymphotropic virus types I and II were all Amp-RT-negative.

Animals↗
PubMed1995

Molecular subtyping of human T-cell lymphotropic virus type 2 by single-strand conformation polymorphism analysis. Retrovirus Epidemiology Donor Study Group.

Molecular subtyping of human T-cell lymphotropic virus type 2 (HTLV-2) by the currently used method of restriction fragment length polymorphism analysis may not be sufficiently discriminatory for transmission studies because of the predominance of single restriction types in various HTLV-2-infected populations. The utility of single-strand conformations polymorphism (SSCP) analysis was evaluated as a tool to improve the sensitivity of the subtyping of HTLV-2. The assay was designed to target a highly variable region in the long terminal repeat and was shown to be able to detect single nucleotide changes in cloned HTLV-2 sequences. Analysis of 52 HTLV-2 samples, of which 32 were from 16 sex partner pairs (16 males, 16 females), showed nine different SSCP patterns. Identical SSCP results were obtained for each of the 16 couples, suggesting the presence of similar viral genotypes and, therefore, supporting the likelihood of sexual transmission of HTLV-2 in each of these couples. Furthermore, SSCP analysis of seven HTLV-2 samples of the same restriction type (b5) showed five different SSCP patterns. Nucleotide sequencing of two samples with distinct SSCP patterns confirmed the sequence differences. SSCP provides a facile and discriminatory tool for the differentiation of HTLV-2 strains, including those previously indistinguishable by restriction fragment length polymorphism.

Base Sequence↗
PubMed1995

Phylogenetic relationship and geographic distribution of multiple human T-cell lymphotropic virus type II subtypes.

The current env-based subtyping of human T-cell lymphotropic virus type II (HTLV-II) identifies only two heterogenetic groups, HTLV-IIa and HTLV-IIb. To better understand the genetic diversity and phylogeny of HTLV-II, we examined the most divergent genomic region of HTLV-II, the long terminal repeat, by using restriction fragment length polymorphism (RFLP) and sequence analysis. Long terminal repeat sequences were amplified from peripheral blood mononuclear cells by PCR and digested with seven restriction endonucleases that differentiated HTLV-II into five HTLV-IIa (IIa0 to IIa4) and six HTLV-IIb (IIb0 to IIb5) restriction types, with HTLV-IIa0 and HTLV-IIb0 being prototypes for the MoT and NRA isolates, respectively. We examined 169 HTLV-II-infected samples, including 123 from blood donors and intravenous drug users (IDU) from the Americas, 16 from IDU from Europe, and 30 from Amerindians. Of the 169 samples, 109 (64.5%) were categorized as HTLV-IIa and 60 (35.5%) were categorized as HTLV-IIb. The predominant restriction types seen among the U.S. blood donors and U.S. IDU were IIa0 (68.7%) and IIb4 (10.4%). Four Spanish and seven Italian samples were IIb4, while five Norwegian samples were IIa2. Twelve Guaymi and all ten Seminole samples were single restriction types (IIb1 and IIb5, respectively), whereas the two Navajo and six Pueblo samples had a mixture of restriction types IIa0, IIa4, and IIb5. Of the HTLV-IIb restriction types observed in the U.S. non-Indians, 42.8% appear to have originated from the North Amerindian (IIb5), while 57.2% were similar to the European IIb4 restriction type. Sequences of 15 selected HTLV-II samples were determined and phylogenetically compared with 7 previously published HTLV-II LTR sequences. The derived topologies revealed three HTLV-IIa phylogroups (A-I to A-III) and four HTLV-IIb phylogroups (B-I to B-IV). Furthermore, the HTLV-IIa phylogroups appear to have evolved from the HTLV-IIb phylogroups. In the HTLV-IIa cluster, a Navajo (A-I) and a Brazilian (A-II) sequence formed separate phylogroups, while the remaining IIa sequences formed a single phylogroup (A-III). The four HTLV-IIb phylogroups were represented predominantly by a New York IDU (B-I), European IDU (B-II), North Amerindian and NRA (B-III), and Central Guaymi Indian (B-IV) sequence(s). Comparison of the phylogenetic data with the RFLP results revealed that results of the two methods correlated completely, demonstrating the ability of the RFLP method to predict the phylogroup of HTLV-II-infected samples accurately and quickly. GENBANK/U10258

Base Sequence↗