Immune complexed (IC) hepatitis C virus (HCV) in chronically and acutely HCV-infected patients.

In infected individuals, hepatitis C virus (HCV) exists in various forms of circulating particles which role in virus persistence and in HCV resistance to IFN therapy is still debated. Here, the proportion of HCV bound to immunoglobulin was determined in plasma of 107 chronically infected patients harbouring different HCV genotypes and, for comparison, of six patients with acute HCV infection. The results showed that, in spite of wide individual variability, chronically HCV-infected patients exhibited an extremely high proportion of immune complexed (IC) virus regardless of plasma HCV load and infecting genotype. Moreover, no significant association was found between baseline proportion of IC HCV and response to IFN treatment. Plasma samples collected within 2 weeks of treatment from 20 patients revealed a significant decline of mean IC HCV values relative to baseline that clearly paralleled the decay of total HCV load. In acutely infected patients, circulating HCV was not IC or IC at very low levels only in patients developing chronic HCV infection. Collectively, these findings strengthen the possibility that IC virus could play a critical role in the pathogenesis of HCV infection.

Markers of human papillomavirus infection and their correlation with cervical dysplasia in human immunodeficiency virus-positive women.

Human papillomavirus (HPV) genotypes and HPV DNA load were analysed in cervical smears from 76 human immunodeficiency virus (HIV)-positive and 54 HIV-negative women. The prevalence of genotypes was similar for all women, with the exception of HPV62, which was over-represented in HIV-positive samples. HIV-positive women showed a higher prevalence of multiple genotypes that correlated neither with CD4(+) T-cell counts nor with cervical dysplasia. No significant differences were observed in terms of total or single-type HPV DNA load. The HPV DNA load in both HIV-positive and HIV-negative women was significantly higher in squamous intra-epithelial lesions than in negative Pap smears.

Influence of GBV-C infection on the endogenous activation of the IFN system in HIV-1 co-infected patients.

BACKGROUND: GB virus C (GBV-C) co-infection is associated with a better prognosis in HIV-infected persons. Since interferon activation can be one of the possible mechanisms involved in GBV-C-driven protection against HIV, we compared the endogenous activation of the interferon system in PBMC from GBV-C-positive and -negative patients infected with HIV-1. METHODS: The expression of interferon related genes was analyzed in 20 GBV-C positive and 20 GBV-C-negative HIV-infected patients, comparable in terms of CD4 cell counts and HIV viral loads. The levels of mRNA for interferon-related genes (2-5-OAS, MxA, interferon AR-1 and PKR) in PBMC were measured by real time RT-PCR, using B-actin as internal control. RESULTS: The endogenous levels of all the Interferon-related genes in HIV/GBV-C co-infected patients were higher than in HIV mono-infected subjects. The difference was statistically significant for PKR mRNA. Direct positive correlation was found between PKR and all the other interferon-related genes, suggesting a coordinated activation of the interferon system. CONCLUSIONS: Enhanced activation of the interferon system occurs in GBV-C-positive, as compared to GBV-C-negative patients harbouring HIV-1. These data may be relevant to understand the GBV-C-driven protection against HIV, suggesting that the endogenous activation of the interferon system can contribute to the control of HIV replication.

Key questions in antiretroviral therapy: Italian Consensus Workshop (2005).

A panel of leading Italian specialists in infectious diseases, virologists and immunologists met in Rome in 2005 to review critical data and discuss recommendations for each of the key questions in antiretroviral therapy today: When to start treatment? How to start? When to switch? What to switch to? Whether to stop or not to stop treatment, and how? The method of a nominal group meeting was used and recommendations were graded for their strength and quality using a system based on the one adopted by the Infectious Diseases Society of America. Main conclusions are summarized and critically discussed in this consensus statement, as well as some of the most recent data supporting these recommendations are provided.

Secondary mutations in the protease region of human immunodeficiency virus and virologic failure in drug-naive patients treated with protease inhibitor-based therapy.

The role of mutations in protease (PR) and reverse-transcriptase (RT) of human immunodeficiency virus (HIV) in predicting virologic failure was assessed in 248 antiretroviral-naive HIV-positive patients who began a PR inhibitor-containing antiretroviral regimen. Genotypic testing was performed on plasma samples stored before the start of therapy. Twenty-seven patients (10.9%) had mutations in the RT, 5 (2%) carried primary mutations in the PR, and 131 (52.8%) showed only secondary PR mutations. Virologic failure at week 24 occurred in 62 (25.0%) of 248 patients. There was a statistically significant correlation between virologic failure and the number of PR mutations (P= .04, chi(2) test). Mutations at codons 10 and 36 of PR (present in 39.3% and 40.0% of patients in whom treatment failed, respectively) were identified by stepwise logistic regression as the strongest predictors of virologic failure (odds ratio, 2.20; 95% confidence interval, 1.30-3.75; P= .004). If confirmed in independent studies, this result may justify the increased use of HIV genotyping in drug-naive patients requiring antiretroviral therapy.

Changes in host cell molecules acquired by circulating HIV-1 in patients treated with highly active antiretroviral therapy and interleukin-2.

OBJECTIVE: To analyse cell membrane proteins (CMP) acquired by HIV-1 present in the plasma of asymptomatic patients, and their modifications after a cycle of highly active antiretroviral therapy (HAART) and interleukin (IL)-2. DESIGN AND METHODS: Plasma samples from eight drug-naive asymptomatic subjects underwent immobilized antibody capture (IAC) to detect CMP on the surface of circulating HIV-1. The CMP considered were lymphocyte subset markers (CD45RA, CD45RO), activation markers (HLA-DR), adhesion molecules (LFA-3), costimulatory proteins (B7-2), lymph-node homing receptors (CD62L) and pro-apoptosis molecules (FasL). This analysis was repeated after one cycle of HAART + IL-2, after virus rebound. RESULTS: LFA-3, followed by CD45RO and HLA-DR, are the most represented CMP on the surface of circulating virions in naive asymptomatic patients; CD45RA, CD62L, B7-2 and FasL are detected only occasionally. After rebound, a significant reduction of CD45RO and HLA-DR, but not of LFA-3, is observed on virions, whereas CD45RA and CD62L, as well as other molecules, are not affected, remaining almost undetectable. CONCLUSIONS: Assuming that CMP on HIV-1 reflect the cellular origin of virions, activated T cells expressing CD45RO, HLA-DR, and LFA-3 may be the main source of HIV-1 in asymptomatic patients. After a cycle of HAART + IL-2, followed by therapy interruption, CD45RA and CD62L are detected on virions rarely, indicating that even during virus rebound, expanded naive T cells do not become a major target of virus replication. Furthermore, the presence of HLA-DR on rebound HIV-1 is decreased, consistent with decreased activation of the HIV-producing cells. More extensive investigation may clarify the significance of these findings with respect to pathogenesis.

Decay of HIV type 1 DNA and development of drug-resistant mutants in patients with primary HIV type 1 infection receiving highly active antiretroviral therapy.

The present study was aimed at describing the effect of highly active antiretroviral therapy (HAART) in 10 patients with primary HIV infection (PHI). Clearance rates of HIV RNA and HIV DNA in peripheral blood as well as the preexistence and the emergence of drug-resistant strains of HIV were determined over 52 weeks of treatment. The data indicate that HAART is able to induce a suppression of plasma viral load together with a significant decrease, but not a suppression, of peripheral blood mononuclear cell-associated proviral DNA in PHI subjects. Analysis of drug-resistant strains revealed that three PHI patients, showing a complete virologic response, developed mutations in the pol gene, thus suggesting that a persistent residual virus replication exists despite a sustained suppression of plasma viremia.

Activation of signal transduction and apoptosis in healthy lymphomonocytes exposed to bystander HIV-1-infected cells.

Persistent activation of the immune system is one of the hallmarks of HIV-1 infection. In this study we analysed the induction of factors involved in cytokine signal transduction, such as STAT 1 proteins and IRF-1 mRNA, in normal peripheral blood mononuclear cells (PBMC) exposed to HIV-infected cells, and the induction of apoptosis. Western blot analyses and reverse transcriptase-polymerase chain reaction results indicate that both cells infected with a X4 strain and cells infected with a R5 strain are able to increase intracellular levels of STAT 1alpha and beta proteins as well as IRF-1 mRNA. This effect was prevented by neutralizing antibodies against interferon-alpha (IFN-alpha). HIV-1-infected cells dose-dependently induced apoptotic commitment in normal PBMC, as revealed by DNA fragmentation analysis, but this was not accompanied by an increase of caspase-3 activity, even if a slight up-regulation of IL-1beta-converting enzyme mRNA was detected. Apoptosis induction could be abrogated mainly by antibodies against tumour necrosis factor-alpha (TNF-alpha) and, to a lesser extent, by antibodies against IFN-gamma. All these findings suggest that uninfected PBMC can undergo activation of signal transduction and apoptosis after exposure to bystander HIV-infected cells, subsequent to the induction of cytokines such as IFNs and TNF-alpha.

Plasma viral load concentrations in women and men from different exposure categories and with known duration of HIV infection. I.CO.N.A. Study Group.

CONTEXT: According to recent studies, women have lower plasma HIV RNA concentrations than men. However, these studies did not take into account the duration of HIV infection. OBJECTIVES: To analyze the relationship between viral load and gender among individuals with known date of seroconversion. SETTING: Sixty infectious disease clinics in Italy. DESIGN: Cross-sectional analysis of data collected at enrollment in a cohort study. PARTICIPANTS: Injecting drug users and heterosexual contacts naive to antiretroviral therapy at enrollment (245 men; 170 women). MAIN OUTCOME MEASURES: Plasma HIV RNA concentrations, measured using quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) or signal amplification b-DNA assays before antiretroviral therapy. RESULTS: Plasma HIV RNA concentrations were similar by age and exposure category (p =.80 and p =.39, respectively). Median viral load among women was roughly half that of men (p =.002). The association between viral load and gender remained significant after fitting a two-way analysis of variance (p =.03) and after adjusting for CD4 count, modality of HIV transmission, and age at enrollment in a regression model. Viral load was 0.27 log10 copies/ml (95% confidence interval, 0.05-0.40; p =.01) lower in women (i.e., 50% lower in the raw scale). CONCLUSIONS: Plasma HIV RNA concentrations were found to be lower among women, even when considering the duration of HIV infection. Compared with men, it is possible women should be given highly aggressive antiretroviral therapy at lower HIV-RNA concentrations.

Cellular factors involved in the induction of resistance of HIV to antiretroviral agents.

Long-term treatment of HIV-1 infected patients with antiretroviral agents may result in failure of therapy due to the emergence of resistant virus mutants with decreased susceptibility to the therapeutic agents. Several authors have asked whether cellular factors, other than viral mutation may contribute to the declining efficiency of chemotherapy including nucleoside analogues and protease inhibitors (PI). Prolonged treatment with AZT may induce a defect of thymidine kinase activity in vitro and in vivo. Long-term treatment with other nucleoside analogues, such as d4T and 3TC, is also able to induce in host cells, a decreased sensitivity to the antiviral activity of these compounds. It is suggested that antiviral activity of PI could be modified by the expression of a protein P-gp that has been demonstrated to be able to bind PI and is involved in extrusion of anticancer agents.

The number of HIV DNA-infected mononuclear cells is reduced under HAART plus recombinant IL-2. IRHAN Study Group.

It is common opinion that, in addition to potent antiretroviral regimens which effectively reduce plasma viremia, new strategies should be developed to ensure the reduction of cell-associated HIV DNA load together with HIV RNA plasma levels. The present study explored whether the number of provirus-infected cells can be reduced by combined antiviral and immunomodulatory regimens. Thus, 14 naive patients (with CD4 > 400/microl and plasma HIV RNA copies > 5000/ml) were randomly assigned to receive highly active antiretroviral therapy (HAART) alone or HAART plus rIL-2. Plasma viremia (measured by a commercial RT-PCR assay) and the number of provirus-infected cells (measured by an endpoint cell dilution PCR assay) were monitored at the enrollment and after 12 weeks of treatment. The results indicate that while HAART and HAART plus rIL-2 are both able to significantly reduce plasma viremia after 12 weeks of treatment, a significant reduction of the number of provirus-infected cells can be achieved only by treatment with HAART plus rIL-2.

Significant reduction in HIV-1 plasma viral load but not in proviral infected cells during sub-optimal antiretroviral therapy.

Attempts to eradicate HIV infection through highly active antiretroviral therapy (HAART) in the very early stages of the infection have failed due to the resumption of viral replication from unknown reservoirs. It has been postulated that antiretroviral therapy capable of suppressing viral replication, as shown by reduction of HIV-RNA copies in plasma and lymph nodes, should have less effect on the number of HIV-DNA carrying cells in the same districts. To test this hypothesis, plasma viremia and the proportion of provirally infected cells in peripheral blood and in lymph nodes were measured in patients at 3 and 6 months of treatment with zidovudine plus lamivudine. All patients showed a significant decrease in plasma viremia at 3 months that was maintained at 6 months (mean values of 1.6 +/- 0.6 log10 from baseline). Conversely the proportion of HIV-DNA carrying cells slightly declined at 3 months but remained substantially stable thereafter both in peripheral blood and in lymph nodes. Taken together these data suggest that this therapeutic regimen, although sub-optimal, is effective in significantly reducing the virus production by productively infected cells but does not seem to substantially affect the load of provirally infected cells.

Effects of the human CD38 glycoprotein on the early stages of the HIV-1 replication cycle.

CD38 displays lateral association with the HIV-1 receptor CD4. This association is potentiated by the HIV-1 envelope glycoprotein gp120. The aim of this work was to evaluate the CD38 role in T cell susceptibility to HIV-1 infection. Using laboratory X4 HIV-1 strains and X4 and X4/R5 primary isolates, we found that CD38 expression was negatively correlated to cell susceptibility to infection, evaluated as percentage of infected cells, release of HIV p24 in the supernatants, and cytopathogenicity. This correlation was at first suggested by results obtained in a panel of human CD4(+) T cell lines expressing different CD38 levels (MT-4, MT-2, C8166, CEMx174, Supt-1, and H9) and then demonstrated using CD38 transfectants of MT-4 cells (the line with the lowest CD38 expression). To address whether CD38 affected viral binding, we used mouse T cells that are non-permissive for productive infection. Gene transfection in mouse SR.D10.CD4(-).F1 T cells produced four lines expressing human CD4 and/or CD38. Ability of CD4(+)CD38(+)cells to bind HIV-1 or purified recombinant gp120 was significantly lower than that of CD4(+)CD38(-) cells. These data suggest that CD38 expression inhibits lymphocyte susceptibility to HIV infection, probably by inhibiting gp120/CD4-dependent viral binding to target cells.-Savarino, A., Bottarel, F., Calosso, L., Feito, M. J., Bensi, T., Bragardo, M., Rojo, J. M., Pugliese, A., Abbate, I., Capobianchi, M. R., Dianzani, F., Malavasi, F., and Dianzani, U. Effects of the human CD38 glycoprotein on the early stages of theHIV-1 replication cycle.

Further study on the specificity and incidence of neutralizing antibodies to interferon (IFN) in relapsing remitting multiple sclerosis patients treated with IFN beta-1a or IFN beta-1b.

The development of neutralizing antibodies (NAbs) to interferon (IFN) is a common phenomenon of IFN beta therapy for relapsing-remitting multiple sclerosis (RRMS) patients. Here we examine the specificity of NAbs developed during therapy for RRMS with recombinant interferon (rIFN) beta-1a or rIFN beta-1b, and study the effect of switching from rIFN beta-1a to rIFN beta-1b on the incidence and specificity of NAbs. The relative ability to neutralize rIFN beta-1a and beta-1b was assayed in sera positive for NAbs derived from RRMS patients treated with either rIFN beta-1a (N=9) or rIFN beta-1b (N=16), while the incidence and specificity of NAbs to IFN beta developed during therapy were studied in 50 RRMS patients who were treated for two years with rIFN beta-1a followed by a further year either switching to rIFN beta-1b (N=34) or continuing treatment with rIFN beta-1a (N=16). The results show that all positive sera, independent of the source, may recognize both forms of rIFN beta and that a further year of treatment does not significantly affect the incidence and specificity of the NAbs developed during the first two years of treatment even if treatment is switched to a different type of IFN beta. The data then suggests that it is unlikely that the administration of rIFN beta-1b to anti-rIFN beta-1a NAbs-positive patients can overcome the inhibitory effect exerted by the serum antibodies (and vice versa), and that a further period of treatment with IFN beta-1b in patients previously treated with rIFN beta-1a does not significantly change the pattern of antibody response to IFN beta.

Development of antibodies to interferon beta in patients: technical and biological aspects.

There are now several papers describing the development of antibodies to interferons (IFN) in patients undergoing IFN therapy. Moreover, there is increasing evidence to indicate that the development of antibodies to IFN may be associated with a failure of the beneficial effects of the therapy. This paper will review and discuss what is currently known about the technical, and biological aspects of antibodies to IFN, with particular reference to antibodies to IFN beta that develop during therapy. Three main considerations arise from the data. Firstly, a standardized quantitative assay to detect antibody to IFN must be agreed upon. Only when results can be compared, both qualitatively and quantitatively, will it be possible to monitor fully the ability of antibodies to cause a relapse during treatment. Secondly, sufficient data are now available to provide a rationale for monitoring the presence of anti-IFN antibodies in patients treated with IFN. This approach may allow a better understanding of the disease reactivation state observed in numerous patients treated with IFN. Finally, approaches aimed at limiting the immunogenicity of IFN preparations and/or strategies designed to circumvent antibody-mediated resistance to IFN treatment are required.

Antigenic characterization of recombinant, lymphoblastoid, and leukocyte IFN-alpha by monoclonal antibodies.

To gain more insight into similarities of different interferon-alpha (IFN-alpha) species, we evaluated neutralization and immunoactivity of a variety of IFN preparations with various monoclonal antibodies (IFN-alpha mAb). Nine IFN-alpha mAb obtained through immunization with recombinant IFN-alpha (rmAb), lymphoblastoid IFN-alpha (LY mAb), and leukocyte IFN-alpha (LE mAb) were tested. The IFN-alpha mAb were evaluated for their ability to neutralize the antiviral activity of 11 recombinant IFN-alpha subtypes, two recombinant IFN-alpha hybrids, and lymphoblastoid and leukocyte IFN-alpha preparations. The same IFN-alpha mAb were also used in immunoblotting, and some of them were used in immunoaffinity chromatography. The results of the neutralization assay reveal that the IFN-alpha mAb significantly differ in their ability to neutralize the individual IFN-alpha species. Interestingly, none of the IFN-alpha mAb was able to neutralize all the IFN-alpha species. In particular, rmAb were unable to neutralize LE-IFN-alpha or LY-IFN-alpha, whereas LE mAb and LY mAb efficiently neutralized rIFN-alpha2. In some cases, the epitopes to which IFN-alpha mAb are directed were identified through the use of synthetic fragments of IFN-alpha2 or by evaluating the selectivity in binding to IFN-alpha subtypes.

RANTES stimulates cell-mediated transmission of HIV-1 infection.

We wished to determine the effects of the beta-chemokine RANTES in an established system of cell-mediated transmission of HIV-1, that is, normal human umbilical vein endothelial cells (HUVEC) nonproductively infected with HIV-1, cocultivated with CD4+ T cells to rescue productive infection. The results indicate that the addition of RANTES to HUVEC, either before or after HIV-1 infection, stimulates HIV-1 rescue by CD4+ T cells. However, viral DNA is not increased in HUVEC, suggesting that the stimulation exerted by RANTES could be mediated by events following HUVEC infection. The mechanisms of increase seem to be related to the rescue phase, involving membrane interaction of abortively infected HUVEC with permissive T cells. In fact, a strong upregulation and polarization of intercellular adhesion molecule-1 (ICAM-1) is induced in HUVEC by RANTES, and antibodies against ICAM-1 inhibit HIV-1 rescue by T cells. These results indicate that RANTES, similarly to other inflammatory cytokines, may favor HIV-1 spreading and crossing of blood-tissue barriers by indirect mechanisms involving membrane interactions between nonproductively infected and permissive cells.