Carriers of the fragile X mental retardation 1 (FMR1) premutation allele present with increased levels of cytokine IL-10.

BACKGROUND: Fragile X-associated tremor/ataxia syndrome (FXTAS) is an inherited late-onset neurodegenerative disorder, characterized both by neurological and cognitive deficits. It is caused by the expansion of CGG repeats (55 to 200 repeats) in the noncoding region of the fragile X mental retardation 1 (FMR1) gene. Abnormal immunological patterns are often associated with neurodegenerative disorders and implicated in their etiology. We therefore investigated the immune status of FXTAS patients, which had not been assessed prior to this study. METHOD: Peripheral blood mononuclear cells (PBMCs) were collected from 15 asymptomatic FMR1 premutation carriers and 20 age-matched controls. Concentrations of three cytokines (IL-6, IL-8, IL-10) were measured in PBMC supernatants using ELISA assays. RESULTS: We found a significant increase in the concentration of the major anti-inflammatory cytokine IL-10 in supernatants of PBMCs derived from premutation carriers, when compared with controls (P = 0.019). This increase correlated significantly with the number of CGG repeats (P = 0.002). CONCLUSIONS: Elevated IL-10 levels were observed in all premutation carriers, before appearance of the classical neurological symptoms; therefore, IL-10 may be one of the early biomarkers of FXTAS.

Humoral response to the influenza A H1N1/09 monovalent AS03-adjuvanted vaccine in immunocompromised patients.

BACKGROUND: Few data are available regarding the immunogenicity and safety of the pandemic influenza vaccine in immunocompromised patients. We evaluated the humoral response to the influenza A H1N1/09 vaccine in solid-organ transplant (SOT) recipients, in patients with human immunodeficiency virus (HIV) infection, and in healthy individuals. METHODS: Patients scheduled to receive the pandemic influenza vaccine were invited to participate. All participants received the influenza A H1N1/09 AS03-adjuvanted vaccine containing 3.75 µg of hemagglutinin. SOT recipients and HIV-infected patients received 2 doses at 3-week intervals, whereas control subjects received 1 dose. Blood samples were taken at day 0, day 21, and day 49 after vaccination. Antibody responses were measured with the hemagglutination inhibition assay (HIA) and a microneutralization assay. RESULTS: Twenty-nine SOT recipients, 30 HIV-infected patients, and 30 healthy individuals were included in the study. Seroconversion measured by HIA was observed in 15 (52%) of 29 SOT recipients both at day 21 and day 49; in 23 (77%) of 30 at day 21 and 26 (87%) of 30 at day 49 in HIV-infected patients, and in 20 (67%) of 30 at day 21 and in 23 (77%) of 30 at day 49 in control subjects (P = .12 at day 21 and P = .009 at day 49, between groups). Geometric means of antibody titers were not significantly different between groups at day 21 or at day 49. CONCLUSIONS: Influenza A H1N1/09 vaccine elicited a similar antibody response in HIV-infected individuals and in control subjects, whereas SOT recipients had an overall lower response. A second dose of the vaccine only moderately improved vaccine immunogenicity in HIV-infected patients.

Thymic selection generates a large T cell pool recognizing a self-peptide in humans.

The low frequency of self-peptide-specific T cells in the human preimmune repertoire has so far precluded their direct evaluation. Here, we report an unexpected high frequency of T cells specific for the self-antigen Melan-A/MART-1 in CD8 single-positive thymocytes from human histocompatibility leukocyte antigen-A2 healthy individuals, which is maintained in the peripheral blood of newborns and adults. Postthymic replicative history of Melan-A/MART-1-specific CD8 T cells was independently assessed by quantifying T cell receptor excision circles and telomere length ex vivo. We provide direct evidence that the large T cell pool specific for the self-antigen Melan-A/MART-1 is mostly generated by thymic output of a high number of precursors. This represents the only known naive self-peptide-specific T cell repertoire directly accessible in humans.

Treatment of primary HIV-1 infection with cyclosporin A coupled with highly active antiretroviral therapy.

Primary HIV-1 infection causes extensive immune activation, during which CD4(+) T cell activation supports massive HIV-1 production. We tested the safety and the immune-modulating effects of combining cyclosporin A (CsA) treatment with highly active antiretroviral therapy (HAART) during primary HIV-1 infection. Nine adults with primary HIV-1 infection were treated with CsA along with HAART. At week 8, all patients discontinued CsA but maintained HAART. Viral replication was suppressed to a comparable extent in the CsA + HAART cohort and in 29 control patients whose primary infection was treated with HAART alone. CsA restored normal CD4(+) T cell levels, both in terms of percentage and absolute numbers. The increase in CD4(+) T cells was apparent within a week and persisted throughout the study period. CsA was not detrimental to virus-specific CD8(+) or CD4(+) T cell responses. At week 48, the proportion of IFN-gamma-secreting CD4(+) and CD4(+)CCR7(-) T cells was significantly higher in the CsA + HAART cohort than in the HAART-alone cohort. In conclusion, rapid shutdown of T cell activation in the early phases of primary HIV-1 infection can have long-term beneficial effects and establish a more favorable immunologic set-point. Appropriate, immune-based therapeutic interventions may represent a valuable complement to HAART for treating HIV infection.

Safety and efficacy of the peptide-based therapeutic vaccine for HIV-1, Vacc-4x: a phase 2 randomised, double-blind, placebo-controlled trial.

BACKGROUND: Present combination antiretroviral therapy (cART) alone does not cure HIV infection and requires lifelong drug treatment. The potential role of HIV therapeutic vaccines as part of an HIV cure is under consideration. Our aim was to assess the efficacy, safety, and immunogenicity of Vacc-4x, a peptide-based HIV-1 therapeutic vaccine targeting conserved domains on p24(Gag), in adults infected with HIV-1. METHODS: Between July, 2008, and June, 2010, we did a multinational double-blind, randomised, phase 2 study comparing Vacc-4x with placebo. Participants were adults infected with HIV-1 who were aged 18-55 years and virologically suppressed on cART (viral load <50 copies per mL) with CD4 cell counts of 400 × 10(6) cells per L or greater. The trial was done at 18 sites in Germany, Italy, Spain, the UK, and the USA. Participants were randomly assigned (2:1) to Vacc-4x or placebo. Group allocation was masked from participants and investigators. Four primary immunisations, weekly for 4 weeks, containing Vacc-4x (or placebo) were given intradermally after administration of adjuvant. Booster immunisations were given at weeks 16 and 18. At week 28, cART was interrupted for up to 24 weeks. The coprimary endpoints were cART resumption and changes in CD4 counts during treatment interruption. Analyses were by modified intention to treat: all participants who received one intervention. Furthermore, safety, viral load, and immunogenicity (as measured by ELISPOT and proliferation assays) were assessed. The 52 week follow-up period was completed in June, 2011. For the coprimary endpoints the proportion of participants who met the criteria for cART resumption was analysed with a logistic regression model with the treatment effect being assessed in a model including country as a covariate. This study is registered with ClinicalTrials.gov, number NCT00659789. FINDINGS: 174 individuals were screened; because of slow recruitment, enrolment stopped with 136 of a planned 345 participants and 93 were randomly assigned to receive Vacc-4x and 43 to receive placebo. There were no differences between the two groups for the primary efficacy endpoints in those participants who stopped cART at week 28. Of the participants who resumed cART, 30 (34%) were in the Vacc-4x group and 11 (29%) in the placebo group, and percentage changes in CD4 counts were not significant (mean treatment difference -5·71, 95% CI -13·01 to 1·59). However, a significant difference in viral load was noted for the Vacc-4x group both at week 48 (median 23,100 copies per mL Vacc-4x vs 71,800 copies per mL placebo; p=0·025) and week 52 (median 19,550 copies per mL vs 51,000 copies per mL; p=0·041). One serious adverse event, exacerbation of multiple sclerosis, was reported as possibly related to study treatment. Vacc-4x was immunogenic, inducing proliferative responses in both CD4 and CD8 T-cell populations. INTERPRETATION: The proportion of participants resuming cART before end of study and change in CD4 counts during the treatment interruption showed no benefit of vaccination. Vacc-4x was safe, well tolerated, immunogenic, seemed to contribute to a viral-load setpoint reduction after cART interruption, and might be worth consideration in future HIV-cure investigative strategies. FUNDING: Norwegian Research Council GLOBVAC Program and Bionor Pharma ASA.

Indicators of therapeutic effect in FIT-06, a Phase II trial of a DNA vaccine, GTU(®)-Multi-HIVB, in untreated HIV-1 infected subjects.

BACKGROUND: Combination highly active antiretroviral therapy (HAART) has significantly decreased HIV-1 related morbidity and mortality globally transforming HIV into a controllable condition. HAART has a number of limitations though, including limited access in resource constrained countries, which have driven the search for simpler, affordable HIV-1 treatment modalities. Therapeutic HIV-1 vaccines aim to provide immunological support to slow disease progression and decrease transmission. We evaluated the safety, immunogenicity and clinical effect of a novel recombinant plasmid DNA therapeutic HIV-1 vaccine, GTU(®)-multi-HIVB, containing 6 different genes derived from an HIV-1 subtype B isolate. METHODS: 63 untreated, healthy, HIV-1 infected, adults between 18 and 40 years were enrolled in a single-blinded, placebo-controlled Phase II trial in South Africa. Subjects were HIV-1 subtype C infected, had never received antiretrovirals, with CD4 ≥ 350 cells/mm(3) and pHIV-RNA ≥ 50 copies/mL at screening. Subjects were allocated to vaccine or placebo groups in a 2:1 ratio either administered intradermally (ID) (0.5mg/dose) or intramuscularly (IM) (1mg/dose) at 0, 4 and 12 weeks boosted at 76 and 80 weeks with 1mg/dose (ID) and 2mg/dose (IM), respectively. Safety was assessed by adverse event monitoring and immunogenicity by HIV-1-specific CD4+ and CD8+ T-cells using intracellular cytokine staining (ICS), pHIV-RNA and CD4 counts. RESULTS: Vaccine was safe and well tolerated with no vaccine related serious adverse events. Significant declines in log pHIV-RNA (p=0.012) and increases in CD4+ T cell counts (p=0.066) were observed in the vaccine group compared to placebo, more pronounced after IM administration and in some HLA haplotypes (B*5703) maintained for 17 months after the final immunisation. CONCLUSIONS: The GTU(®)-multi-HIVB plasmid recombinant DNA therapeutic HIV-1 vaccine is safe, well tolerated and favourably affects pHIV-RNA and CD4 counts in untreated HIV-1 infected individuals after IM administration in subjects with HLA B*57, B*8101 and B*5801 haplotypes.

Costimulatory ligand 4-1BBL (CD137L) as an efficient adjuvant for human antiviral cytotoxic T cell responses.

Effective adjuvants capable of inducing strong cytotoxic T cell responses in humans are lacking. In this study, we tested 4-1BBL as an adjuvant for activation of human memory antiviral CD8 T cell responses ex vivo. A recombinant replication-defective 4-1BBL adenovirus was used to convert autologous monocytes into efficient antigen-presenting cells after overnight incubation, bypassing the need to generate dendritic cells. Together with viral peptides, 4-1BBL led to robust memory responses of human Epstein-Barr virus- and influenza virus-specific cytotoxic T cells, with expansion of peptide-specific CD8 effector cells; up-regulation of Bcl-x(L), granzyme A, and perforin; enhanced cytotoxic activity; and increased cytokine production. The response was significant even at a 100-fold lower peptide dose, compared with responses obtained with control adenovirus. Adenovirus-delivered B7.1 also expanded and activated virus-specific CD8 T cells, but 4-1BBL was more effective in driving the T cells toward a more fully differentiated CD27(-) effector state. Thus, 4-1BBL is a promising adjuvant for human memory CD8 T cells and will likely be most effective in the boost phase of a prime-boost strategy.

Distribution and functional analysis of memory antiviral CD8 T cell responses in HIV-1 and cytomegalovirus infections.

In the present study, we have investigated the anatomic distribution and the function of different populations of HIV-1- and cytomegalovirus (CMV)-specific memory CD8 T cells. The different populations of virus-specific memory CD8 T cells were distinguished on the basis of the expression of CD45RA and CCR7, and the composition of HIV-1- and CMV-specific memory CD8 T cell pools were compared in subjects with chronic HIV-1 and CMV co-infection. The distribution of HIV-1-specific CD8 T cells was similar between blood and lymph node. However, CMV-specific CD8 T cells were accumulated predominantly in the blood away from the lymphoid tissue. The majority (>70%) of HIV-1- and CMV-specific CD8 T cells in both blood and lymph node had a phenotype, e.g. CCR7-, typical of effector T cells. HIV-1-specific memory CD8 T cells were mostly (>80%) pre-terminally differentiated cells, e.g. CD45RA-CCR7-, in both blood and lymph node while 30-50% of CMV-specific CD8 T cells were terminally differentiated, e.g. CD45RA+CCR7-. Therefore, consistently with studies in mice, antigen-specific effector memory CD8 T cells accumulate predominantly in the target organ of the pathogen in humans, and the differences in the composition of HIV-1- and CMV-specific CD8 T cell pools were also present in the lymphoid tissue. A substantial proportion (30-40%) of virus-specific CD8+CCR7+ T cells produced IFN-gamma. Thus, indicating that the expression of CCR7 does not provide a clear-cut separation of memory CD8 T cells with distinct functional capacities. Taken together, these results provide further advances in the characterization of human memory CD8 T cells.

Analysis of HIV-1- and CMV-specific memory CD4 T-cell responses during primary and chronic infection.

CD4 T-cell-specific memory antiviral responses to human immunodeficiency virus type 1 (HIV-1) and cytomegalovirus (CMV) were investigated in 16 patients with documented primary HIV-1 infection (4 of the 16 subjects also had primary CMV infection) and compared with those observed in patients with chronic HIV-1 and CMV coinfection. Virus-specific memory CD4 T cells were characterized on the basis of the expression of the chemokine receptor CCR7. HIV-1- and CMV-specific interferon-gamma-secreting CD4 T cells were detected in patients with primary and chronic HIV-1 and CMV coinfection and were mostly contained in the cell population lacking expression of CCR7. The magnitude of the primary CMV-specific CD4 T-cell response was significantly greater than that of chronic CMV infection, whereas there were no differences between primary and chronic HIV-1-specific CD4 T-cell responses. A substantial proportion of CD4(+)CCR7(-) T cells were infected with HIV-1. These results advance the characterization of antiviral memory CD4 T-cell response and the delineation of the potential mechanisms that likely prevent the generation of a robust CD4 T-cell immune response during primary infection.