Eric Sandström

Cellular cytotoxic response induced by DNA vaccination in HIV-1-infected patients

BACKGROUND DNA vaccination is known to generate immune responses against HIV-1 in animal models. We aimed to assess the efficacy of DNA vaccination in induction of immune responses in HIV-1-infected human beings. METHODS Nine symptom-free HIV-1-infected patients were immunised with DNA constructs encoding the nef, rev, or tat regulatory genes of HIV-1. The patients were selected for having no or low antibody reactivities to these antigens. HIV-1-specific cytotoxic T-lymphocytes (CTLs), precursor frequencies, and antigen-specific proliferative responses were measured before, during, and after three immunisations over 6 months. FINDINGS Cellular immune reactivities against the HIV-1 regulatory proteins were absent or low before DNA immunisation. DNA vaccination induced detectable memory cells in all patients and specific cytotoxicity in eight patients. CTLs were MHC-class-I restricted and mainly of CD8+ origin. In three patients the cellular activity was transient, decreasing after an initial response. INTERPRETATION DNA immunisation with HIV-1 genes can induce specific cellular responses in human beings with no apparent side-effects. It is theoretically possible that HIV-1-specific cytotoxic responses to regulatory proteins could lead to infected cells being eliminated before they have released new viral particles. However, it is possible that the patients we selected responded less than would non-selected or non-infected individuals. The small number of patients presented here does not allow generalisation of our findings.

Broad Immunogenicity of a Multigene, Multiclade HIV-1 DNA Vaccine Boosted with Heterologous HIV-1 Recombinant Modified Vaccinia Virus Ankara

BACKGROUND A human immunodeficiency virus (HIV) vaccine that limits disease and transmission is urgently needed. This clinical trial evaluated the safety and immunogenicity of an HIV vaccine that combines a plasmid-DNA priming vaccine and a modified vaccinia virus Ankara (MVA) boosting vaccine. METHODS Forty healthy volunteers were injected with DNA plasmids containing gp160 of HIV-1 subtypes A, B, and C; rev B; p17/p24 gag A and B, and RTmut B by use of a needle-free injection system. The vaccine was administered intradermally or intramuscularly, with or without recombinant granulocyte macrophage colony-stimulating factor, and boosted with a heterologous MVA containing env, gag, and pol of CRF01A_E. Immune responses were monitored with HIV-specific interferon (IFN)-gamma and interleukin (IL)-2 ELISpot and lymphoproliferative assays (LPAs). RESULTS Vaccine-related adverse events were mild and tolerable. After receipt of the DNA priming vaccine, 11 (30%) of 37 vaccinees had HIV-specific IFN-gamma responses. After receipt of the MVA boosting vaccine, ELISpot assays showed that 34 (92%) of 37 vaccinees had HIV-specific IFN-gamma responses, 32 (86%) to Gag and 24 (65%) to Env. IFN-gamma production was detected in both the CD8(+) T cell compartment (5 of 9 selected vaccinees) and the CD4(+) T cell compartment (9 of 9). ELISpot results showed that 25 (68%) of 37 vaccinees had a positive IL-2 response and 35 (92%) of 38 had a positive LPA response. Of 38 subjects, a total of 37 (97%) were responders. One milligram of HIV-1 DNA administered intradermally was as effective as 4 mg administered intramuscularly in priming for the MVA boosting vaccine. CONCLUSION This HIV-DNA priming-MVA boosting approach is safe and highly immunogenic. TRIALS REGISTRATION International Standard Randomised Controlled Trial number: ISRCTN32604572 .

Therapeutic immunisation with recombinant gp160 in HIV-1 infection: a randomised double-blind placebo-controlled trial

BACKGROUND The immune systems ability to scavenge and destroy detrimental HIV-1 products has an important effect on virion production and the course of infection. In earlier trials of therapeutic immunisation with envelope protein recombinant gp160 (rgp160) we observed a transient positive effect on CD4-lymphocyte counts. This randomised placebo-controlled study investigated whether our preliminary findings represented a potential for a more benign clinical course. METHODS 835 HIV-seropositive patients from 20 centres in Sweden, Norway, and Finland with CD4-cell counts above 200/microL were randomly assigned to receive 160 microg rgp160 or placebo (alum adjuvant alone) every 3 months for 3 years after an induction period, as well as optimum available treatment. Analyses were by intention to treat. FINDINGS 63 of 416 vaccine-group patients and 61 of 419 placebo-group patients reached a primary clinical endpoint (AIDS-defining event or death); the time to first clinical endpoint did not differ between the groups (p=0.864). Significantly fewer vaccine-group patients than placebo-group patients reached the primary immunological endpoint of a decrease of more than 30% from baseline CD4-cell count (157 vs 189, p=0.03). A higher proportion of the vaccine group had CD4-cell counts higher than baseline at 6 months (167 vs 133, p=0.014). HIV-1-specific T-cell immune reactivity was induced in all vaccine recipients studied. No severe adverse events associated with the vaccine were noted during the study. There were significantly fewer deaths among the vaccine recipients than among the placebo-group patients at 2 years, but not at the end of the study. INTERPRETATION Therapeutic immunisations with rgp160 have a modest effect on CD4-cell counts, but this treatment alone did not lead to clinical benefit when given in addition to best clinical practice at the time of the trial. Immunisation in conjunction with antiretroviral therapy was also effective, which strongly suggests that a combination with highly active therapy would improve the total effect.

Broad and potent immune responses to a low dose intradermal HIV-1 DNA boosted with HIV-1 recombinant MVA among healthy adults in Tanzania☆☆☆

BACKGROUND We conducted a phase I/II randomized placebo-controlled trial with the aim of exploring whether priming with a low intradermal dose of a multiclade, multigene HIV-1 DNA vaccine could improve the immunogenicity of the same vaccine given intramuscularly prior to boosting with a heterologous HIV-1 MVA among healthy adults in Dar es Salaam, Tanzania. METHODS Sixty HIV-uninfected volunteers were randomized to receive DNA plasmid vaccine 1mg intradermally (id), n=20, or 3.8mg intramuscularly (im), n=20, or placebo, n=20, using a needle-free injection device. DNA plasmids encoding HIV-1 genes gp160 subtype A, B, C; rev B; p17/p24 gag A, B and Rtmut B were given at weeks 0, 4 and 12. Recombinant MVA (10(8)pfu) expressing HIV-1 Env, Gag, Pol of CRF01_AE or placebo was administered im at month 9 and 21. RESULTS The vaccines were well tolerated. Two weeks after the third HIV-DNA injection, 22/38 (58%) vaccinees had IFN-γ ELISpot responses to Gag. Two weeks after the first HIV-MVA boost all 35 (100%) vaccinees responded to Gag and 31 (89%) to Env. Two to four weeks after the second HIV-MVA boost, 28/29 (97%) vaccinees had IFN-γ ELISpot responses, 27 (93%) to Gag and 23 (79%) to Env. The id-primed recipients had significantly higher responses to Env than im recipients. Intracellular cytokine staining for Gag-specific IFN-γ/IL-2 production showed both CD8(+) and CD4(+) T cell responses. All vaccinees had HIV-specific lymphoproliferative responses. All vaccinees reacted in diagnostic HIV serological tests and 26/29 (90%) had antibodies against gp160 after the second HIV-MVA boost. Furthermore, while all of 29 vaccinee sera were negative for neutralizing antibodies against clade B, C and CRF01_AE pseudoviruses in the TZM-bl neutralization assay, in a PBMC assay, the response rate ranged from 31% to 83% positives, depending upon the clade B or CRF01_AE virus tested. CONCLUSIONS This vaccine approach is safe and highly immunogenic. Low dose, id HIV-DNA priming elicited higher and broader cell-mediated immune responses to Env after HIV-MVA boost compared to a higher HIV-DNA priming dose given im. Three HIV-DNA priming immunizations followed by two HIV-MVA boosts efficiently induced Env-antibody responses.

Hypofibrinolytic state in HIV-1-infected patients treated with protease inhibitor-containing highly active antiretroviral therapy

Summary: Decreased insulin sensitivity, hyperlipidemia, and body fat changes are considered as risk factors for coronary heart disease (CHD). A clustering of such factors (metabolic syndrome [MSDR]) exponentially increases the risk. Impaired fibrinolysis and increased coagulation are additional independent risk factors for CHD. We studied the effects of protease inhibitor (PI)‐containing highly active antiretroviral therapy (HAART) on metabolic and hemostatic parameters in 363 HIV‐infected individuals, of whom 266 were receiving PI‐containing HAART and 97 were treatment naive. The fasting plasma levels of insulin, glucose, triglycerides, cholesterol, high‐density lipoprotein cholesterol, low‐density lipoprotein cholesterol, plasminogen activator inhibitor type 1 (PAI‐1), and fibrinogen were evaluated together with the areas of visceral adipose tissue and the visceral adipose tissue/subcutaneous adipose tissue area ratio. The levels of insulin, triglycerides, cholesterol, and low‐density lipoprotein cholesterol; visceral adipose tissue area; low‐density lipoprotein/high‐density lipoprotein ratio; and visceral adipose tissue/subcutaneous adipose tissue area ratio were significantly increased in patients receiving PI‐containing HAART compared with treatment‐naive patients. The levels of PAI‐1 and fibrinogen were significantly higher in patients receiving PI‐containing HAART. PAI‐1 levels were higher in individuals with MSDR but also in patients without MSDR who were receiving PI‐containing HAART. PAI‐1 was independently correlated to use of PI‐containing HAART, triglyceride level, insulin level, and body mass index (p < .001). These findings suggest that patients receiving PI‐containing HAART have decreased fibrinolysis and increased coagulability, which may thus represent additional risk factors for cardiovascular disease in this patient group.

Recombinant Modified Vaccinia Ankara (MVA) effectively boosts DNA-primed HIV-specific immune responses in humans despite pre-existing vaccinia immunity

The presence of vector-specific immune responses may hamper the induction of responses to a foreign antigen encoded by the vector. We evaluated the impact of pre-existing immunity to vaccinia virus on the induction of HIV-specific responses after immunization of healthy volunteers with a HIV-1 DNA prime-MVA boost vaccine. Following three priming immunizations with HIV-1 DNA plasmids, the volunteers were boosted with a single injection of recombinant MVA encoding HIV-1 proteins. Pre-existing immunity to vaccinia virus did not reduce the proportion of individuals who responded to HIV-1, but did lower the magnitude of responses. Our results suggest that vaccinia-based vectors can be used to efficiently induce immune responses to vectored HIV-1 antigens, even in individuals with pre-existing immunity to vaccinia virus.

Serum lipid levels associated with increased risk for cardiovascular disease is associated with highly active antiretroviral therapy (HAART) in HIV-1 infection

The long-term effects of fat metabolism, storage and utilization in HIV-1 infected patients on highly active antiretroviral therapy (HAART) including a protease inhibitor are profound and cause increasing concern. The main importance of these lipid/metabolic disorders lies in their assumed contribution to an increased risk of coronary heart disease (CHD). In the general population increased levels of lipoprotein(a) [Lp(a)] constitute an independent risk factor for CHD by itself as well as in combination with increased levels of cholesterol and low density lipoprotein (LDL)-cholesterol, respectively. Two hundred and fifty-six patients with 27 ± 7 months HAART and 84 treatment-naive HIV-1 positive patients were screened for cardiovascular risk factors. The subjective perception of fat wasting and/or accumulation in different sites of the body, which was possible to evaluate in 235 patients on HAART and 73 treatment-naive patients, the levels of plasma triglycerides (TG), cholesterol, LDL and high-density lipoproteins (HDL)-cholesterol, LDL/HDL ratio and Lp(a) were measured. Of the patients on HAART, 42% (98/235) reported abnormal fat distribution as compared with 4% (3/73) of the treatment-naive patients (P < 0.0001). The levels of TG, cholesterol and LDL-cholesterol, but not HDL-cholesterol or Lp(a) were higher (P < 0.0001) in the HAART group as compared with the naive group. Very high Lp(a) levels (>700 mg/l) were more common among HAART patients as compared with naive, 14% (36/256) vs 2% (2/83); P = 0.0022. The Lp(a) levels correlated to the levels of LDL-cholesterol, but not to total cholesterol, HDL-cholesterol or TG, and did not differ between patients with and without subjective perception of abnormal fat distribution. A significant number of the HAART patients had very high levels of Lp(a) and various combinations of increased lipid values associated with considerably increased risk for CHD. The elevation of Lp(a) did not relate to any other clinical or laboratory parameter than to LDL-cholesterol.

Treatment history and baseline viral load, but not viral tropism or CCR-5 genotype, influence prolonged antiviral efficacy of highly active antiretroviral treatment

Background:The efficacy of highly active antiretroviral treatment (HAART) in HIV-1 disease may vary between nucleoside-naive and experienced patients as well as between patients with different viral phenotypes and in different stages of disease. Objective:To investigate variables of importance for successful long-term viral suppression by analysing virological, clinical and immunological characteristics at initiation of protease inhibitor treatment on suppression of HIV RNA over 1 year. Design:An open, non-randomized, observational clinical study. Setting:Venhälsan, Department of Dermatovenereology, Söder Hospital, Stockholm, Sweden. Patients:A total of 147 unselected advanced patients with known HIV-1 infection for a mean of 7 years, of whom 37% had AIDS and who started treatment with a protease inhibitor during 1996. Interventions:All patients received HAART with at least two nucleoside analogues in combination with either indinavir (81%) or ritonavir (19%). The majority (77%) had been previously treated with nucleoside analogues for a mean of 39 months. Measurements:CD4+ lymphocyte count, plasma HIV-1 RNA, viral phenotype and HIV-1 coreceptor CCR-5 genotype at baseline. Viral load and CD4+ lymphocyte count were determined every 3 months. Results:Patients were analysed on an intention-to-treat basis. The mean CD4+ lymphocyte count at baseline was 170 × 106/l and the median viral load was 68 600 copies/ml. Heterozygosity for the Δ32 deletion of the CCR-5 gene (Δ32/wt) was found in 27%. MT-2 positive virus (syncytium-inducing) was isolated in 46%. Logistic regression revealed that nucleoside analogue experience and baseline log10 HIV-1 RNA were the only factors independently related to plasma HIV-1 RNA levels below 500 copies/ml after 1 year of treatment, which was found in 69%. Conclusion:The virological outcome after 1 year of HAART was strongly correlated to prior treatment history and baseline viral load, whereas CD4+ lymphocyte count, CCR-5 genotype and viral biological phenotype had less influence. The long-term antiviral efficacy of HAART was lowest in individuals with previous nucleoside analogue treatment and a high baseline viral load. In these individuals an even more aggressive treatment should be considered.

The prevalence and incidence of HIV-1 infection and syphilis in a cohort of police officers in Dar es Salaam, Tanzania : a potential population for HIV vaccine trials

ObjectivesTo assess the suitability of a cohort of police officers in Dar es Salaam for HIV vaccine trials by determining the prevalence and incidence of HIV-1 infection, active syphilis and their associated factors. Design and settingAn open cohort study of police officers in Dar es Salaam, Tanzania. MethodsRecruitment of police officers began in 1994. A standardized questionnaire was completed at enrolment and subsequent visits. HIV antibodies were determined using two consecutive enzyme-linked immunosorbent assays. Samples repeatedly discordant on the two tests were tested by a Western blot assay. Treponema pallidum antibodies were first determined by Venereal Disease Research Laboratory (VDRL) test and reactive sera were confirmed by Treponema pallidum hemagglutination test. ResultsAt the end of 1996 a total of 2850 police officers had been recruited of whom 2733 (96%) consented to be tested for HIV. The overall HIV-1 seroprevalence at recruitment was 13.8% (378 of 2733). Females had a significantly higher HIV-1 seroprevalence, 18.0% (55 of 306), as compared to males, 13.3% (323 of 2427), P  < 0.05. From a total of 2215 married police officers, 585 (26.4%) responded to a question on extramarital sex within the previous 3 months of whom 36.2% (212 of 585) admitted to have had at least one extramarital sexual intercourse. Condoms were not used during these encounters by 178 of 212 (84.0%). As of 31st December 1998, among the 1524 males observed for 2553 person–years (PYAR), 50 had seroconverted and among 200 females observed for 357 PYAR, eight had seroconverted. The overall crude HIV-1 incidence was thus 19.9/1000 PYAR; 19.6 and 22.4/1000 PYAR for males and females, respectively. The overall prevalence and incidence of active syphilis were 3.1% (88 of 2850) and 8.6/1000 PYAR (26 of 3149), respectively. Males had a higher prevalence of active syphilis, 84 of 2525 (3.3%) than females, five of 325 (1.5%), P  = 0.09. ConclusionsThere was high risk sexual practice including low condom use in this cohort of police officers. The incidence and prevalence of HIV infection were high. Police officers in Dar es Salaam are therefore a potential population group for HIV vaccine evaluation.

Zidovudine twice daily in asymptomatic subjects with HIV infection, and a high risk of progression to AIDS : a randomized, double-blind placebo-controlled study

Objective:To evaluate the efficacy of zidovudine given twice daily in subjects with asymptomatic HIV-1 infection and a high risk of progression to AIDS. Design.Randomized, double-blind placebo-controlled trial. Setting.Multicentre study in five European countries and Australia. Patients.Asymptomatic subjects (n = 329) with CD4 cell counts between 200 and 400 x 106/l, or if > 400 x 106/l, subjects with HIV p24 antigenaemia (> 10pg/ml). Intervention.Patients were randomly assigned to receive zidovudine 500 mg or placebo twice daily for 104 weeks, following a 250mg four times daily dose regimen for the first 4 weeks. Main outcome measures.The primary end-point was the development of AIDS or severe AIDS-related complex (ARC). Before unblinding the study other end-points were defined: the development of Centers for Disease Control and Prevention (CDC) group IV disease (AIDS, severe ARC and other CDC stage IV disease) and the development of symptomatic HIV disease (AIDS, severe ARC, other CDC stage IV disease and minor HIV disease). Changes in CD4+ cell counts, p24 antigenaemia and toxicity were also reviewed. Results.Median treatment duration was 57 weeks for the placebo and 60 weeks for the zidovudine group, respectively. Progression to AIDS or severe ARC occurred in 17 placebo and 12 zidovudine recipients (log-rank p=0.26). However, in the first of the 2 study years the rate of progression to AIDS or severe ARC was significantly higher in the placebo than in the zidovudine group. Zidovudine delayed progression to symptomatic HIV disease (P=0.01); a trend in a delay in progression to CDC stage IV disease was observed (P=0.08). Zidovudine recipients maintained CD4+ cell counts at or above baseline levels for longer than placebo recipients (P=0.04). HIV p24-antigen levels decreased in the zidovudine group and returned to pretreatment levels by week 36. Substantial toxicity was not observed. Conclusions.Zidovudine twice daily is effective in delaying progression to symptomatic HIV disease in high-risk, asymptomatic HIV-infected subjects. Modified definitions of clinical end-points may be useful for evaluating Phase III trials in comparable patient groups in the light of changes in the definition of AIDS and the increasing use of primary prophylaxis against opportunistic infections.