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Biomedical subjects

J R Fiore

Publications and source records attributed to J R Fiore.

At least 37 records · Page 2Linked to original sources
PubMed1999

Phenotypic patterns of HIV-1 clonal populations during highly active antiretroviral therapy (HAART).

Several studies have demonstrated that during HIV-1 infection many different viral clones may co-exist in the same individual. These clones may differ regarding their biological phenotype and may influence both the natural history of infection and the clinical response to antiretroviral therapy. The aim of the present study was to investigate the influences of combination therapies including protease inhibitors (HAART) on the phenotypical pattern of HIV-1 biological clones in peripheral blood mononuclear cells. Viral isolation and biological characterisation of bulk isolates and clonal viral isolates were performed on two AIDS patients, before and after three months of antiretroviral therapy. A decrease of viral load in plasma specimens in association with a change of clonal composition during antiretroviral therapy was observed in both patients during treatment. Before therapy both of the patients had a syncytium inducing (SI) bulk isolate and the majority of the biological clones were characterised as SI. After treatment, the bulk isolates were still SI in both cases, but the majority of biological clones were characterised as non-syncytium inducing (NSI). These results suggest that HIV clonal composition and relative phenotypic pattern undergo different changes not only during the natural course of HIV infection but also while patients are on antiretroviral combination therapy.

Anti-HIV Agents↗
PubMed1998

Neurological disorders during HIV-1 infection correlate with viral load in cerebrospinal fluid but not with virus phenotype.

OBJECTIVES: To verify the compartmentalization of HIV-1 within the central nervous system (CNS) and to define whether viral phenotype of HIV-1 isolates from cerebrospinal fluid (CSF) samples and CSF viral load correlate with the presence and type of neurological disorders. METHODS: A total of 33 HIV-1-infected patients with and without neurological disorders were included in the study. HIV-1 isolation from paired CSF and peripheral blood mononuclear cell (PBMC) samples was attempted by a standard cocultivation technique; the biological phenotype of HIV-1 isolates was assessed by the MT-2 cell assay. CSF and plasma HIV-RNA levels were measured by a quantitative reverse transcripase-polymerase chain reaction. RESULTS: The rate of HIV-1 isolation from CSF and PBMC was 66% (22 isolates) and 85% (28 isolates), respectively. Seventeen out of 22 (77%) CSF HIV-1 isolates were characterized as non-syncytium-inducing, and 15 out of 28 (68%) isolates from PBMC were typed as syncytium-inducing (SI). The presence of SI isolates in CSF was limited to patients with HIV-1-, cytomegalovirus- or JC virus-related disorders and was often associated with high levels of HIV-1 RNA in the CSF. DISCUSSION: Our results demonstrate a correlation between high levels of HIV RNA in CSF and the presence of neurological disorders thus indicating a possible role for HIV-1 RNA in the CSF as a biological marker of neurological disease. The finding of viruses with a different phenotype in paired CSF and PBMC indicates that HIV-1 may evolve differently in the brain and in the blood. This suggests compartmentalization of HIV-1 within the CNS.

CD4 Lymphocyte Count↗
PubMed1998

Measurement of viral sequences in cerebrospinal fluid of AIDS patients with cerebral white-matter lesions using polymerase chain reaction.

OBJECTIVES: To optimize the use of polymerase chain reaction (PCR) on cerebrospinal fluid (CSF) for the evaluation of central nervous system (CNS) white-matter lesions that along with clinical findings and magnetic resonance imaging (MRI) can allow a definite diagnosis to be made; also to evaluate treatment with zidovudine plus foscarnet. DESIGN AND METHODS: Fifteen AIDS patients with uncertain CNS white-matter lesions were identified. HIV-1 RNA, cytomegalovirus (CMV) and JC virus (JCV) DNA were measured in a total of 29 CSF samples. The results were correlated with clinical and MRI findings and treatment with zidovudine plus foscarnet was evaluated. RESULTS: Four and five out of 15 patients with CMV DNA > or = 1 : 625 and JCV DNA > or = 10(3) copies/microl detected in the CSF were diagnosed with CMV and progressive multifocal leukoencephalopathy (PML), respectively. Six patients who were CMV/JCV-negative with the highest levels of HIV RNA (median, 6.87 log10 copies/ml) in CSF were considered as having HIV-1 encephalitis. Neurological symptoms were non-supportive for diagnosis as was MRI in 11 out of 15 patients. Nine patients completed a 21-day course of zidovudine plus foscarnet. HIV RNA decreased irrespective of neurological diagnosis. All three HIV-1 encephalitis patients and two out of three patients with CMV leukoencephalopathy improved. In these two latter patients, relief of clinical symptoms coincided with decreased CMV DNA. JCV DNA remained unchanged and all three PML patients deteriorated. CONCLUSIONS: Measurement of CSF viral sequences supports the diagnosis of CNS white-matter lesions in AIDS patients. While effective therapy for PML remains elusive, treatment including zidovudine plus foscarnet may be a promising option for HIV-1 and CMV-related manifestations.

AIDS Dementia Complex↗
PubMed1998

[Maternal viral and gestational risk factors in vertical transmission of HIV-1 infection].

BACKGROUND: Several risk factors are related to vertical transfer of HIV-1 infection, but the influence of each one separately is controversial. Various risk factors have been evaluated altogether and separately, in order to find a single condition, that is, early in pregnancy predictive of fetal infection. METHODS: A prospective, observational study has been carried out during the period January 1992-January 1997, at the Centre for infectious diseases in pregnancy, University Hospital of Bari, a tertiary reference setting. Forty-four HIV-1 infected mothers have been recruited in early pregnancy, to be followed-up until delivery. Neonates have been evaluated in the Pediatric Department of the same hospital until 18 months of age. Maternal risk factors, such as age, infection in the partner, mode of acquisition of HIV-1, drug addition, life-style and risky behaviour as well as stage of disease, immunological status and antiviral treatment were considered. Obstetrical factors, too, (parity, preterm delivery, rupture of membranes, duration of labour and mode of delivery) were taken into account. Data were analyzed according to Fisher exact test and Draper and Smith multivariate analysis. RESULTS: Thirty cases (9 inadequate for follow-up, 4 ongoing pregnancies, 1 perinatal death before ascertainment of infection) were evaluated for final results. The overall transmission rate was 13.3%. Single factors significantly related to transmission were stage of disease (p < 0.01), mode of maternal infection (p < 0.03) and maternal HCV infection (p < 0.04). Multivariate analysis has shown the stage of disease to be the only positively-related risk-factor. CONCLUSIONS: The data identify a sub-group among HIV-1 infected women, where the more sustained rate of vertical transmission is associated with risky behaviour, as determined both by drug addiction and positivity for another sexually transmitted disease. Maternal compromise and immunological status are, however, the highest-risk conditions for delivering a HIV-1 infected baby.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Biological correlates of HIV-1 heterosexual transmission.

OBJECTIVES: To study the role of HIV-1 biological phenotype, viral load and neutralizing antibodies in male-to-female heterosexual transmission of HIV-1. METHODS: Seven transmitting and seven non-transmitting HIV-1-seropositive heterosexual male index cases were included in the present study. All couples had engaged in unprotected sex for a period of over 1 year. Transmission was defined by the seroconversion of the female sexual partner. Virus isolates were tested in MT-2 cells for replication and syncytia induction. HIV-1 RNA plasma load was measured by the branched DNA technique. Serum neutralizing activity to primary HIV-1 isolates was tested by using peripheral blood mononuclear cells (PBMC) as target cells. RESULTS: Non-transmitting index cases had a lower HIV-1 RNA concentration in plasma than transmitting index cases. Non-transmitting index cases also tended to have serum neutralizing activity with broad specificity and to have viruses with low replicative capacity, as characterized by 50% infectious dose titres in PBMC and by the lack of MT-2 tropism. CONCLUSIONS: The results indicate that plasma viral-RNA load is a marker for transmission. Moreover, an interplay between the host immune response and viral replication may modulate the level of viral load and thereby influence HIV-1 transmission.

Cell Line↗
PubMed1997

Augmented serum neutralizing activity against primary human immunodeficiency virus type 1 (HIV-1) isolates in two groups of HIV-1-infected long-term nonprogressors.

Neutralizing activity against primary human immunodeficiency virus type 1 (HIV-1) isolates from 17 persons who were long-term disease nonprogressors (LTNPs) and 13 persons who were fast progressors (FPs) was compared. Sera from LTNPs showed higher neutralizing activity both in titer and in host spectrum than did sera from FPs. However, LTNP sera had limited neutralizing activity against HIV-1 subtypes from different geographic areas. Sera collected 6 years earlier from both groups had limited neutralizing activity, indicating that early responses are not predictive for disease progression. LTNPs had very low virus loads, as reflected by only one positive isolation, which was an MT-2-negative phenotype. Virus was isolated from all FPs, and the isolates showed a phenotype switch from MT-2 negative to MT-2 positive. Development of high-titer, broadly cross-reactive neutralizing antibodies is associated with control of virus replication and low virus load in HIV-1-infected LTNPs.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Coreceptor usage of primary human immunodeficiency virus type 1 isolates varies according to biological phenotype.

The biological phenotype of primary human immunodeficiency virus type 1 (HIV-1) isolates varies according to the severity of the HIV infection. Here we show that the two previously described groups of rapid/high, syncytium-inducing (SI) and slow/low, non-syncytium-inducing (NSI) isolates are distinguished by their ability to utilize different chemokine receptors for entry into target cells. Recent studies have identified the C-X-C chemokine receptor CXCR4 (also named fusin or Lestr) and the C-C chemokine receptor CCR5 as the principal entry cofactors for T-cell-line-tropic and non-T-cell-line-tropic HIV-1, respectively. Using U87.CD4 glioma cell lines, stably expressing the chemokine receptor CCR1, CCR2b, CCR3, CCR5, or CXCR4, we have tested chemokine receptor specificity for a panel of genetically diverse envelope glycoprotein genes cloned from primary HIV-1 isolates and have found that receptor usage was closely associated with the biological phenotype of the virus isolate but not the genetic subtype. We have also analyzed a panel of 36 well-characterized primary HIV-1 isolates for syncytium induction and replication in the same series of cell lines. Infection by slow/low viruses was restricted to cells expressing CCR5, whereas rapid/high viruses could use a variety of chemokine receptors. In addition to the regular use of CXCR4, many rapid/high viruses used CCR5 and some also used CCR3 and CCR2b. Progressive HIV-1 infection is characterized by the emergence of viruses resistant to inhibition by beta-chemokines, which corresponded to changes in coreceptor usage. The broadening of the host range may even enable the use of uncharacterized coreceptors, in that two isolates from immunodeficient patients infected the parental U87.CD4 cell line lacking any engineered coreceptor. Two primary isolates with multiple coreceptor usage were shown to consist of mixed populations, one with a narrow host range using CCR5 only and the other with a broad host range using CCR3, CCR5, or CXCR4, similar to the original population. The results show that all 36 primary HIV-1 isolates induce syncytia, provided that target cells carry the particular coreceptor required by the virus.

Acquired Immunodeficiency Syndrome↗
PubMed1997

The use of serum-free medium delays, but does not prevent, the cytotoxic effects of seminal plasma in lymphocyte cultures: implications for studies on HIV infection.

Evidence indicates that seminal plasma is cytotoxic when used in lymphocyte cultures. In fact, an amine oxidase which is normally present in Fetal Calf Serum (FCS) causes spermine oxidation and, finally, cytotoxic substances are released. This seminal quality might obviously hamper studies aiming to evaluate the role of semen in HIV sexual transmission, since lymphocytes are generally used as target or effector cells in virological or immunological studies on HIV. We evaluated the efficacy of FCS free-medium, heat inactivated seminal plasma and/or the washing-out of cultures after a three hour incubation period in preventing the cytotoxicity to lymphocytes. Results show that when cultures are carried out in the absence of FCS and/or after seminal plasma removal, cytotoxicity is not prevented, although delayed. This finding indicates that, along with still unrecognized additional factors, spermine oxidation is still an important factor for semen cytotoxicity, and this considerably hampers any immunological and virological study, requiring the use of lymphocytes, concerning seminal fluid.

Animals↗
PubMed1996

The role of HIV type 1 phenotype and genotype in long-term responders to zidovudine therapy.

We performed a cross-sectional and partly retrospective virological evaluation of 31 long-term responders (LTRs) to zidovudine (ZDV) (persistent increase in the CD4+ cell counts without progression of HIV infection throughout a period of ZDV therapy > 3 years) and 17 well-matched controls who developed a marked immunological deterioration over a 24-month period of ZDV therapy. The biological phenotype of HIV-1 was assessed by testing the capacity of the isolates to replicate in the MT-2, HUT-78, C-8166, and U-937 T cell lines, and mutations at codons 215 and 41 of RT were checked in proviral DNA from uncultured PBMCs. Show/low non-syncytium-inducing (S/L-NSI) and rapid/high syncytium-inducing (R/H-SI) variants were detected in 25 (81%) and 2 (6%) LTRs, respectively. HIV-1 could not be isolated in the remaining four LTRs (13%). Conversely, 12 of 17 (71%) controls yielded R/H-SI variants. Conversion from the S/L-NSI to R/H to R/H-SI phenotype occurred in 5 controls but in none of the 18 LTRs tested. Mutant sequences in proviral DNA from control PBMCs were consistently detected (94%), while a wild-type sequence of the residues investigated was found in the majority of LTRs (77%). In our series, patients who received immunological and clinical benefits even after prolonged ZDV treatment had S/L-NSI viruses and a low risk to develop ZDV resistance. Conversely, subjects who demonstrated an immunological and clinical deterioration yielded R/H-SI variants or shifted from S/L-NSI to R/H-SI phenotypes and were at higher risk to develop mutations indicating ZDV resistance.

Acquired Immunodeficiency Syndrome↗
PubMed1996

HTLV-I and HTLV-II infections in subjects at risk for HIV-I infection from southeastern Italy (Apulia region).

To assess the prevalence of HTLV-I and HTLV-II infections in different groups at risk for HIV-I infection, a study on 867 subjects was carried out by means of serological and PCR analyses. Serum specimens were collected from 268 intravenous drug users (IVDU), 66 homosexual men, 248 subjects with sexually transmitted diseases (STD), 105 thalassemics and 180 hemophiliacs. Sera from 3 IVDU and a sample from an STD patient were confirmed as HTLV-II seropositive; a thalassemic patient was seropositive for HTLV-I; a homosexual man, though confirmed as HTLV-I/II-seroreactive, could not be typed by serological methods. No hemophiliac was found to be HTLV-I/II-reactive. All 3 HTLV-II-seroreactive IVDU and the HTLV-I-infected thalassemic were confirmed by PCR; an additional sample from an IVDU, indeterminate by Western blot, was confirmed to be positive for HTLV-II by PCR. Subtyping of HTLV-II samples indicated the presence of II/b subtype in all 4 cases. Up to now, the reservoir for HTLV-II infection in southeastern Italy is mainly represented by IVDU, while HTLV-I infection seems to be sporadic.

Blotting, Western↗
PubMed1995

P24 antigen detection, viral isolation, DNA-PCR and in vitro antibody production for the diagnosis of HIV-1 latent infection in heterosexual women at high risk for HIV-1 infection.

INTRODUCTION: The report of the existence of at-risk seronegative subjects, latently infected with HIV-1 and producing "in vitro" HIV-1 specific antibodies, prompted the authors to evaluate extensively twenty-five heterosexual HIV-1 seronegative women at high risk for HIV-1 infection. MATERIAL AND METHODS: The capability of peripheral blood mononuclear cells from such subjects to produce "in vitro" HIV-1 specific antibodies after pokeweed-mitogen stimulation, was studied. Silent HIV-1 infection was investigated by HIV-1 DNA PCR, viral isolation and serum p24 Ag detection at entry and after 6 and 12 months. RESULTS: Three seroconversions took place within 12 months, but no HIV-1 infections were found in the absence of detectable serum anti HIV-1 antibodies, even in subjects who apparently produced such antibodies in vitro. The antibodies produced in vitro by the seronegative women studied appeared of narrow specificity, reacting mainly with gp 160/120 envelope glycoproteins. CONCLUSIONS: A strong concordance was found between the serological status and the other markers for HIV-1 infection, suggesting that the phenomenon of HIV-1 "latent infection" is a very rare event, if it occurs at all. Seronegative women sexually exposed to the virus may produce in vitro anti HIV-1 antibodies of narrow specificity in the absence of other signs of infection and this phenomenon might be related to an anamnestic response to the virus.

Acquired Immunodeficiency Syndrome↗
PubMed1994

The biological phenotype of HIV-1 is usually retained during and after sexual transmission.

The biological phenotype of HIV-1 isolates from 21 subjects with primary HIV-1 infection was determined in primary lymphocytes and monocyte-derived macrophages as well as in three T-cell lines (MT-2, HUT78, and C8166). Seven isolates (33%) replicated on at least one cell line and were classified as rapid/high (n = 6) or intermediate (n = 1), while 14 isolates (67%) did not replicate in cell lines and were classified as slow/low. All isolates replicated in primary monocyte-derived macrophage cultures. Studies on 10 pairs consisting of index case and seroconverting sexual partner showed that the biological phenotype of HIV-1 was unchanged in nine transmissions, including 5 pairs where a rapid/high virus was transmitted. Most individuals (5 of 6) infected by a rapid/high virus retained this phenotype after seroconversion. These individuals also had significantly lower CD4 lymphocyte counts 1-3 years after infection. Thus, in contrast to what has been suggested by others, we found that HIV-1 variants with rapid/high phenotype were usually not suppressed, neither during sexual transmission nor after seroconversion in the new host. These findings have important implications for the understanding of HIV-1 transmission and pathogenesis as well as for vaccine design.

Cell Line↗
PubMed1993

Detection of human T lymphotropic virus type II/b in human immunodeficiency virus type 1-coinfected persons in southeastern Italy.

A preliminary screening of 511 persons at risk for AIDS living in southeastern Italy disclosed 20 cases of seroreactivity to human T lymphotropic viruses (HTLV). To verify and type the HTLV infection among these subjects, confirmatory serologic tests, polymerase chain reaction (PCR), and virus culture were done. No evidence of HTLV-I infection was found. HTLV-II infection was confirmed in 8 cases by HTLV-specific, synthetic peptide EIAs and PCR on uncultured cells; restriction analysis of the PCR-amplified env regions revealed the presence of HTLV-II/b strains in all 8 cases. Four sera were nontypeable by EIA. The finding of such indeterminate reactivities in a geographic area in which HTLV variants were previously described indicates the need for more extensive surveys among the healthy population. HTLV-II was isolated in 5 cases, and virus isolation was mostly dependent on the presence of an actively replicating human immunodeficiency virus type 1 in culture.

Base Sequence↗
PubMed1993

Correlation between seroreactivity to HIV-1 V3 loop peptides and male-to-female heterosexual transmission.

OBJECTIVE: To evaluate the correlation between seroreactivity to peptides corresponding to the V3 loop of the major envelope glycoprotein from different HIV-1 strains and the risk of heterosexual HIV-1 transmission. METHODS: Sera from 39 infected individuals (16 transmitters and 23 non-transmitters) were tested for reactivity against synthetic peptides representing sequences of the V3 loop apex from HIV-1 strains MN, SC, WMJ2, RF and IIIB. RESULTS: A skewed distribution in seroreactivity to RF and IIIB peptides was observed between the two groups: reactivity was more prevalent in sera from non-transmitting than from transmitting individuals. Reactivity to the MN, SC and WMJ2 peptides was very frequent and there were no differences between the two groups. CONCLUSION: These data suggest that antibodies reactive with a larger set of V3 apex peptides (i.e., cross-reactive antibodies) could play a role in the prevention of heterosexual transmission.

Amino Acid Sequence↗
PubMed1993

Preliminary data on the establishment of permanent cell lines continuously producing HIV-1: factors affecting the transmissibility and adaptability of "wild" HIV-1 isolates.

This study examines some technical aspects of the transmission to and permanent adaptability in continuous cell lines of wild HIV-1 isolates. Three cell systems (the lymphocytic cell lines Molt-3 and H-9 and the monocytoid cell line U-937) and two transmission protocols (cell to cell and cell-free) were used. Two different replicative behaviours were observed among isolates efficiently transmitted: a) transmissibility but not adaptability (consisting in a limited length of viral replication); aa) transmissibility and adaptability (consisting in a stable and long term virus production). The second type of replication was confined to viruses from patients with severe immunodeficiency. Technical and viral factors can affect the rate of transmissibility and adaptability: the modality of infection (cell to cell transmission appeared to be the most efficient) and the tropism of the virus (some viruses could infect only one T cell line).

Adaptation, Physiological↗