RESUMEN
Highly active antiretroviral treatment (HAART), i.e. the combination of three or more drugs against human immunodeficiency virus type 1 (HIV-1), has greatly improved the clinical outcome of HIV-1-infected individuals. However, HAART is unable to reconstitute HIV-specific immunity and eradicate the virus. Several observations in primate models and in humans support the notion that cell-mediated immunity can control viral replication and slow disease progression. Thus, besides drugs, an immunotherapy that induces long-lasting HIV-specific T-cell responses could play a role in the treatment of HIV/AIDS. To induce such immune responses, DermaVir Patch has been developed. DermaVir consists of an HIV-1 antigen-encoding plasmid DNA that is chemically formulated in a nanoparticle. DermaVir is administered under a patch after a skin preparation that supports the delivery of the nanoparticle to Langerhans cells (LC). Epidermal LC trap and transport the nanomedicine to draining lymph nodes. While in transit, LC mature into dendritic cells (DC), which can efficiently present the DNA-encoded antigens to naïve T-cells for the induction of cellular immunity. Pre-clinical studies and Phase I clinical testing of DermaVir in HIV-1-infected individuals have demonstrated the safety and tolerability of DermaVir Patch. To further modulate cellular immunity, molecular adjuvants might be added into the nanoparticle. DermaVir Patch represents a new nanomedicine platform for immunotherapy of HIV/AIDS. In this review, the antiviral activity of DermaVir-induced cellular immunity is discussed. Furthermore, the action of some cytokines currently being tested as adjuvants are highlighted and the adjuvant effect of cytokine plasmid DNA included in the DermaVir nanoparticle is reviewed.
Asunto(s)
Vacunas contra el SIDA/uso terapéutico , Fármacos Anti-VIH/uso terapéutico , Terapia Antirretroviral Altamente Activa/métodos , Infecciones por VIH/tratamiento farmacológico , Células de Langerhans/metabolismo , Nanopartículas/química , Replicación Viral/efectos de los fármacos , Vacunas contra el SIDA/inmunología , Animales , Fármacos Anti-VIH/inmunología , Antígenos Virales/genética , Antígenos Virales/inmunología , Ensayos Clínicos Fase I como Asunto , Células Dendríticas/inmunología , Evaluación Preclínica de Medicamentos , Infecciones por VIH/inmunología , VIH-1/efectos de los fármacos , VIH-1/inmunología , Humanos , Inmunidad Celular , Inmunoterapia , Células de Langerhans/inmunología , Linfocitos T/inmunología , Vacunas de ADN/administración & dosificación , Vacunas de ADN/genética , Vacunas de ADN/metabolismo , Replicación Viral/inmunologíaRESUMEN
The aim of this study was to evaluate the immunological responses induced by DNA plasmids containing HIV regulatory genes administered in combination in HIV-1-infected patients with pretreatment with highly active antiretroviral treatment (HAART). The study is a double-blind, randomized, and placebo-controlled study, including 15 asymptomatic HIV-1-infected patients on stable HAART for at least 6 months and with plasma HIV RNA levels below 50 copies/ml. Ten patients received a combination of rev, tat, and nef intramuscularly (im) at weeks 0, 4, and 16 at increasing doses giving totals of 300 (100 x 3), 900 (300 x 3), and 1800 (600 x 3) micrograms DNA. Five patients received saline in the same amounts im. Antigen-specific cytotoxic T lymphocyte (CTL) levels were preserved or increased and new T lymphocyte proliferative responses were induced in the group immunized with the HIV DNA genes. No increase in antibody levels was noted. Despite a 10-fold higher vaccine dose, patients on HAART did not respond better to vaccination compared to non-HAART patients included in a previous study where the genes were administered separately. Combining the regulatory genes rev, tat, and nef in increasing doses may reduce the anticipated augmentation of HIV-specific T cell proliferative and CTL responses. Viral suppression did not seem to further improve the initial vaccine responses of patients with comparable CD4 levels.
Asunto(s)
Vacunas contra el SIDA/inmunología , Infecciones por VIH/inmunología , Infecciones por VIH/terapia , VIH-1 , Vacunas de ADN/inmunología , Vacunas contra el SIDA/administración & dosificación , Fármacos Anti-VIH/uso terapéutico , Antígenos Virales/biosíntesis , Terapia Antirretroviral Altamente Activa , Método Doble Ciego , Genes Virales , VIH-1/genética , VIH-1/inmunología , Humanos , Vacunas de ADN/administración & dosificación , Carga ViralRESUMEN
Clinical and experimental studies of HIV-1 subcomponents were made in order to increase their immunogenicity. HIV subtype envelopes A, B and C have been compared and a detailed analysis made by peptides of the coreceptor-ligand interactions. We identified a direct interaction between HIV-1 envelope and a cellular receptor at the amino acid level. Both the viral subtype and its tropism appeared to influence inhibition of infection. Genetic immunization induced new cytotoxic responses while proteins appeared to efficiently boost previous responses. One HIV-1 subtype B antigen was strongly immunogenic in a human immunotherapeutic trial and permitted better survival at 2 years of the study in patients with poor prognosis.
Asunto(s)
Vacunas contra el SIDA/inmunología , Proteína gp120 de Envoltorio del VIH/metabolismo , Proteínas gp160 de Envoltorio del VIH/inmunología , VIH-1/clasificación , Fragmentos de Péptidos/metabolismo , Receptores CXCR4/metabolismo , Traslado Adoptivo , Secuencia de Aminoácidos , Animales , Presentación de Antígeno , Ensayos Clínicos como Asunto , Reacciones Cruzadas , Método Doble Ciego , Genes env , Anticuerpos Anti-VIH/biosíntesis , Anticuerpos Anti-VIH/inmunología , Proteína gp120 de Envoltorio del VIH/química , Proteína gp120 de Envoltorio del VIH/genética , Proteína gp120 de Envoltorio del VIH/inmunología , VIH-1/genética , VIH-1/inmunología , Humanos , Inmunidad Celular , Virus de la Leucemia Murina/genética , Virus de la Leucemia Murina/inmunología , Ratones , Ratones Endogámicos C57BL , Datos de Secuencia Molecular , Fragmentos de Péptidos/síntesis química , Fragmentos de Péptidos/química , Fragmentos de Péptidos/genética , Fragmentos de Péptidos/inmunología , Estudios Prospectivos , Unión Proteica , Estructura Terciaria de Proteína , Virus Reordenados/inmunología , Receptores CXCR4/química , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Relación Estructura-Actividad , Subgrupos de Linfocitos T/inmunología , VacunaciónRESUMEN
DNA plasmid immunization has the important advantage over traditional vaccines of making it possible to combine selected genes into one vaccine. The efficacy of a combination of DNA plasmids encoding the nef, rev, and tat HIV-1 regulatory genes in inducing cellular immune responses was analyzed in asymptomatic HIV-1-infected patients. Patients initially selected for having low or no detectable immune responses to Nef, Rev, or Tat antigens developed MHC class I-restricted cytolytic activities as well as enhanced bystander effects. The induction of memory cells against target cells infected with the whole HIV-1 genome was analyzed by using a pseudovirus HIV-1/murine leukemia virus (MuLV), and target cells infected with vaccinia virus carrying the respective gene. The most remarkable change observed after immunization with the gene combination was an increase in cytotoxic T lymphocyte (CTL) precursors to target cells infected with the whole HIV-1 genome. Infection by the pseudotype HIV-1/MuLV virus should result in a multitude of HIV-1 peptides presented on the target cell surface, representative of the in vivo situation. An in vitro assessment of the expression of the single and combined gene products showed that this was consistent with the induction of CTL responses in vivo. No clinical advantage or adverse effects were noted. Therapeutic effects of such immunization may become measurable by structured therapy interruption.
Asunto(s)
Vacunas contra el SIDA/genética , Vacunas contra el SIDA/inmunología , Antígenos VIH/genética , Infecciones por VIH/inmunología , Linfocitos T Citotóxicos/inmunología , Vacunas de ADN/genética , Vacunas de ADN/inmunología , Vacunas contra el SIDA/administración & dosificación , Vacunas contra el SIDA/uso terapéutico , Recuento de Linfocito CD4 , Islas de CpG/genética , Citotoxicidad Inmunológica , Expresión Génica , Productos del Gen nef/biosíntesis , Productos del Gen nef/genética , Productos del Gen nef/inmunología , Productos del Gen nef/uso terapéutico , Productos del Gen rev/biosíntesis , Productos del Gen rev/genética , Productos del Gen rev/inmunología , Productos del Gen rev/uso terapéutico , Productos del Gen tat/biosíntesis , Productos del Gen tat/genética , Productos del Gen tat/inmunología , Productos del Gen tat/uso terapéutico , Genes Virales/genética , Vectores Genéticos/administración & dosificación , Vectores Genéticos/genética , Antígenos VIH/biosíntesis , Antígenos VIH/inmunología , Infecciones por VIH/terapia , Infecciones por VIH/virología , VIH-1/genética , VIH-1/inmunología , Células HeLa , Antígenos de Histocompatibilidad Clase I/inmunología , Humanos , Virus de la Leucemia Murina/genética , Activación de Linfocitos , Plásmidos/genética , Linfocitos T Citotóxicos/citología , Vacunación , Vacunas de ADN/administración & dosificación , Vacunas de ADN/uso terapéutico , Virus Vaccinia/genética , Productos del Gen nef del Virus de la Inmunodeficiencia Humana , Productos del Gen rev del Virus de la Inmunodeficiencia Humana , Productos del Gen tat del Virus de la Inmunodeficiencia HumanaRESUMEN
By eliminating infected cells, virus-specific cytotoxic T-lymphocytes (CTL) play a central role in host protection. Many studies to date seem to support the concept that human immunodeficiency virus (HIV)-specific CTL responses contribute to the control of viral replication, and thus delay the onset of disease. The feasibility of improving the virus-specific T-cell immunity by immunizing during the asymptomatic phase of infection has been studied in man. DNA vaccination is a novel strategy, involving direct inoculation of genetic material that is capable of producing antigen intracellularly for presentation to CTL. Such DNA-based immunization has been shown in animal models to be effective for the induction of both cellular and humoral immune responses as well as for protection from infectious challenge. This article reviews the cell-mediated immune responses in natural HIV-1 infection and the induction by DNA vaccination in humans.
Asunto(s)
Vacunas contra el SIDA/inmunología , Infecciones por VIH/inmunología , VIH-1 , Linfocitos T Citotóxicos/inmunología , Vacunas de ADN/inmunología , Animales , Ensayos Clínicos como Asunto , Infecciones por VIH/prevención & control , VIH-1/genética , VIH-1/fisiología , Humanos , Inmunidad Celular/inmunología , Modelos AnimalesRESUMEN
The role of the maternal antibody response in relation to vertical human immunodeficiency virus type 1 (HIV-1) transmission was investigated in HIV-1-infected mothers from Argentina. Sera from 23 transmitting and 18 nontransmitting HIV-1-infected mothers were tested for the presence of antibodies to V3 loop gp120 peptides representing both Argentinian sequences and several well-characterized viral isolates from different geographic areas. Argentinian sera from transmitting mothers had significantly higher capacity to react with four of 14 V3 loop peptides tested than sera from nontransmitting mothers. Frequency of reactivity against the other peptides did not differ between the two maternal groups. Furthermore, no differences in antibody affinity were found between transmitting and nontransmitting mothers. Sera were also tested against overlapping peptides covering a neutralizing epitope of the HIV-1 MN gp41 (amino acids 648-677). Statistical analysis indicated that no correlation between anti-gp41 antibodies and vertical transmission exists. Although we used V3 loop peptides based on local HIV-1 sequences, our data showed that maternal antibodies to these peptides, as well as to gp41 peptides, are not correlated with protection against HIV-1 vertical transmission.
Asunto(s)
Anticuerpos Anti-VIH/inmunología , Proteína gp120 de Envoltorio del VIH/inmunología , Proteína gp41 de Envoltorio del VIH/inmunología , Infecciones por VIH/transmisión , VIH-1/inmunología , Fragmentos de Péptidos/inmunología , Complicaciones Infecciosas del Embarazo/inmunología , Adulto , Secuencia de Aminoácidos , Especificidad de Anticuerpos , Argentina/epidemiología , Femenino , Enfermedades Fetales/etiología , Enfermedades Fetales/inmunología , Anticuerpos Anti-VIH/sangre , Proteína p24 del Núcleo del VIH/sangre , Proteína gp120 de Envoltorio del VIH/química , Proteína gp41 de Envoltorio del VIH/química , Infecciones por VIH/congénito , Infecciones por VIH/embriología , Infecciones por VIH/epidemiología , Humanos , Recién Nacido , Intercambio Materno-Fetal , Datos de Secuencia Molecular , Fragmentos de Péptidos/química , Embarazo , Carga Viral , Viremia/inmunologíaRESUMEN
Intensive chemotherapy is capable of reducing the viral load in HIV-1-infected individuals while infected cells are still present. A special property of DNA immunization is to induce both new CTL and Ab responses. We evaluated the possibility of inducing new immune responses in already infected individuals by means of DNA constructs encoding the nef, rev, or tat regulatory HIV-1 genes. Significant changes in viral loads and CD4+ counts were observed in four patients who started highly active antiretroviral treatment (HAART) during the immunization study. The DNA immunization induced Ag-specific T cell proliferation, which persisted up to 9 mo after the last DNA injection, and cytolytic activities but did not, by itself, reduce viral load. Increased levels of CTL precursor cells were induced in all nine DNA-immunized patients. The profile of IFN-gamma secretion observed when human PBMC were transfected with the nef, rev, and tat DNA resembled that found in the CTL activity (nef > tat > rev). Ab responses that occurred after immunizations were of a low magnitude. In accordance with the high IL-6 production induced by the nef DNA plasmid, IgG titers were highest in patients immunized with nef DNA. The initiation of HAART appears to contribute to the induction of new HIV-specific CTL responses, but by itself did not cause obvious re-induction of these activities.
Asunto(s)
Vacunas contra el SIDA/inmunología , Fármacos Anti-VIH/uso terapéutico , Infecciones por VIH/inmunología , Infecciones por VIH/terapia , VIH-1/inmunología , Vacunas de ADN/inmunología , Anticuerpos Antivirales/biosíntesis , Antígenos Virales/biosíntesis , Recuento de Linfocito CD4/efectos de los fármacos , Terapia Combinada , Citocinas/biosíntesis , Pruebas Inmunológicas de Citotoxicidad , Quimioterapia Combinada , Epítopos de Linfocito T/análisis , Estudios de Seguimiento , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/patología , VIH-1/efectos de los fármacos , Humanos , Estudios Longitudinales , Activación de Linfocitos/efectos de los fármacos , Recuento de Linfocitos/efectos de los fármacos , Células Madre/efectos de los fármacos , Células Madre/inmunología , Células Madre/patología , Linfocitos T Citotóxicos/efectos de los fármacos , Linfocitos T Citotóxicos/inmunología , Linfocitos T Citotóxicos/patología , Carga ViralRESUMEN
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.
Asunto(s)
Vacunas contra el SIDA/inmunología , Citotoxicidad Inmunológica , Infecciones por VIH/inmunología , VIH-1 , Vacunación , Vacunas de ADN/inmunología , ADN Viral/inmunología , Genes Reguladores/inmunología , Genes Virales/inmunología , VIH-1/genética , VIH-1/inmunología , Humanos , Activación de Linfocitos , Linfocitos T Citotóxicos/inmunologíaRESUMEN
The clinical utility of the detection of anti-HIV-1 IgA antibodies using a modified commercial ELISA (EIA) test for the early diagnosis of perinatally acquired HIV-1 infection was evaluated. One hundred and seventeen sera were obtained from 86 infants born to HIV-1-infected mothers and tested for HIV IgA antibodies by an ELISA test (third generation) after removal of IgG with recombinant protein G. Infants were classified according to the Center for Disease Control and Prevention's (CDC) classification system after 15 months of age; 46 were classified as HIV-infected children and 40 as uninfected. HIV-IgA antibodies were detected in 53 of 64 serum samples from all infected children. No significant differences were observed in IgA detection among symptomatic or asymptomatic infected children. However, when analyzed by age a significant difference was observed in IgA detection when children who were over 6 months of age were compared with the younger group (Fisher exact test, p = 0.0000053). All 53 samples from 40 noninfected children were IgA-negative. Statistical analysis was assessed comparing IgA results with HIV infection status as the gold standard. Sensitivity (95%) and specificity (100%), positive predictive value (100%), and negative predictive value (94%) of IgA antibody determination were analyzed taking into account only one sample per child and only children older than 6 months. Positive likelihood ratio was 95.9% and negative likelihood ratio was 94%. Test efficiency was 97%. The detection of IgA HIV antibodies using EIA is an effective method for early diagnosis of HIV-infected infants in comparison with conventional IgG HIV antibody tests. It is a simple and inexpensive method that could be used in both developed and developing countries.
Asunto(s)
Anticuerpos Antivirales/sangre , Ensayo de Inmunoadsorción Enzimática/normas , Infecciones por VIH/diagnóstico , VIH-1/inmunología , Inmunoglobulina G/sangre , Transmisión Vertical de Enfermedad Infecciosa , Infecciones por VIH/inmunología , Infecciones por VIH/transmisión , Humanos , Lactante , Recién Nacido , Juego de Reactivos para Diagnóstico/normas , Reproducibilidad de los Resultados , Estudios Retrospectivos , Sensibilidad y EspecificidadRESUMEN
A highly conserved gp41 epitope (amino acid sequence ELDKWA) has been described to elicit antibodies neutralizing a broad variety of HIV-1 strains. We analyzed the antibody reactivity of HIV-1-infected individuals from Argentina and Sweden to overlapping synthetic peptides covering aa647-684 of HIV-1 MN gp41. An immunodominant antigenic determinant was discovered in the C-terminal region adjacent to the ELDKWA sequence. Most of the sera from both Argentina and Sweden reacted only with peptides representing this region. Two other patterns of reactivity were also observed: some sera reacted only with peptides spanning the central region of gp41, including the ELDKWA sequence; other sera reacted with both the central and C-terminal regions. Differences in reactivity were noted between Argentinian and Swedish sera in terms of peptides covering the central region. In addition, to determine the amino acids essential for antibody binding, seroreactivity against a set of substitution peptides covering the immunodominant epitope was studied. Results obtained indicated that carboxyl amino acids WNWFDI close to the ELDKWA sequence were the most important for antibody binding. Ability of sera, tested for peptide reactivity, to neutralize HIV-1 was also analyzed. High antibody reactivity to the central region was frequently found in sera with high neutralizing titers. This observation was not seen when seroreactivity to peptides spanning the C-terminal region was analyzed. These results suggest that the immunodominant epitope C terminal to the ELDKWA sequence is not involved in inducing neutralizing antibodies.
Asunto(s)
Anticuerpos Anti-VIH/inmunología , Proteína gp41 de Envoltorio del VIH/inmunología , Seropositividad para VIH/inmunología , VIH-1/inmunología , Epítopos Inmunodominantes , Secuencia de Aminoácidos , Mapeo Epitopo , Anticuerpos Anti-VIH/sangre , Humanos , Masculino , Datos de Secuencia Molecular , Pruebas de NeutralizaciónRESUMEN
The aim of this retrospective study, which included 103 children born to human immunodeficiency virus type 1 (HIV-1)- infected mothers, is to initiate a database on HIV-infected children, which has to date been unavailable in Argentina. All HIV-1 seropositive children admitted to the Pedro de Elizalde Children's Hospital in Buenos Aires from March 1, 1987, to December 31, 1992, were enrolled in this study. The number of patients enrolled dramatically increased each year during the period of study. Of the 60 infected children, 22 (36.66%) have died with a clinical diagnosis of HIV-1 infection; in 10 of those children HIV infection was also confirmed by P24 antigenemia and/or polymerase chain reaction (PCR): 20 qualified for the Centers for Disease Control and Prevention (CDC) P2D class (P2D1 = 7, P2D2 = 10, P2D3 = 3), 1 for P2C, and 1 for P2A, whose cause of death was pneumonia. The mean age of death was 14.8 months, 18 (82%) died before 18 months. When immunoglobulin G (IgG), IgM, and IgA levels were determined according to age and clinical status, significant differences (P < 0.005) were observed when both asymptomatic and symptomatic infected children (P1, P2) were compared with noninfected children (P3). A significant difference was also obtained between those children who qualified for P2 classification prior to 12 months of age who died early (at or prior to 25 months) and those who reached stage P2 after 12 months of age and have survived to date (X2 = 24.73, p < 0.0001; RR = 5.83, 2.52 < RR < 13.49).