Immunogenicity of 23-valent pneumococcal polysaccharide vaccine in HIV-infected pregnant women and kinetics of passively acquired antibodies in young infants

Whether gestational immunization of HIV-infected mothers with the 23-valent pneumococcal polysaccharide vaccine (PPV) confers maternal and infant early life, passive protection is not known. We evaluated safety, immunogenicity and placental transfer of antibodies in 44 HIV-infected women. Pneumococcal IgG antibodies against serotypes 1, 3, 5, 613, 9V, and 14 were measured in mothers (pre-vaccination and at delivery), and infants (at birth, 1, 2, 3, and 6 months). PPV was safe and immunogenic in mothers. Newborns received 46-72% of maternal antibody titers. Overall, infants had antibody levels lower than protective by 2 months of age. Alternative pneumococcal vaccination of HIV-infected pregnant women should be explored with the aim of prolonging passive protection in their infants. (C) 2009 Elsevier Ltd. All rights reserved.

Mucosal and systemic anti-GAG immunity induced by neonatal immunization with HIV LAMP/gag DNA vaccine in mice

Vaccines capable of inducing mucosal immunity in early postnatal life until adulthood, protecting early sexual initiation, should be considered as strategies to vaccination against HIV. The HIV-1 GAG protein as a chimera with the lysosome-associated membrane protein (LAMP/gag), encoded by a DNA vaccine, is targeted to the endosomal/lysosomal compartment that contains class II MHC molecules and has been shown to be immunogenic in adult mice. Assuming that one such strategy could help to overcome the immunological immaturity in the early postnatal period, we have evaluated the systemic and mucosal immunogenicity of LAMP/gag immunization in neonatal mice. Intranasal immunization with LAMP/gag vaccine induced higher levels of sIgA and IgG anti-GAG antibodies in intestinal washes than did the gag vaccine. The combination of ID injections and the IN protocol with the chimeric vaccine promoted the increase of Ab levels in sera. Both vaccines induced splenic IFN-gamma- secreting cells against GAG peptide pools, as well as in vivo cytotoxic T lymphocyte (CTL) function, and increased the percentage of CD8+ T cells to the immunodominant class I peptide in gut and spleen. However, only the chimeric vaccine was able to enhance Th1/Th2 cytokine secretion in response to class II GAG peptide and to enhance IL-4-secreting cells against GAG peptides and p24 protein stimuli. Long-lasting humoral and cellular responses were detected until adult age, following neonatal immunization with the chimeric vaccine. The LAMP/gag vaccination was able to induce potent GAG-specific T and B cell immune responses in early life which are essential to elicit sustained and long-lasting mucosal and systemic humoral response. (C) 2010 Elsevier GmbH. All rights reserved.

Immunization of neonatal mice with LAMP/p55 HIV gag DNA elicits robust immune responses that last to adulthood

Successful T cell priming in early postnatal life that can generate effective long-lasting responses until adulthood is critical in HIV vaccination strategies because it prevents early sexual initiation and breastfeeding transmission of HIV. A chimeric DNA vaccine encoding p55 HIV gag associated with lysosome-associated membrane protein 1 (LAMP-1; which drives the antigen to the MIIC compartment), has been used to enhance cellular and humoral antigen-specific responses in adult mice and macaques. Herein, we investigated LAMP-1/gag vaccine immunogenicity in the neonatal period in mice and its ability to generate long-lasting effects. Neonatal vaccination with chimeric LAMP/gag generated stronger Gag-specific immune responses, as measured by the breadth of the Gag peptide-specific IFN-gamma, proliferative responsiveness, cytokine production and antibody production, all of which revealed activation of CD4+ T cells as well as the generation of a more robust CTL response compared to gag vaccine alone. To induce long-lived T and B cell memory responses, it was necessary to immunize neonates with the chimeric IAMP/gag DNA vaccine. The LAMP/gag DNA vaccine strategy could be particularly useful for generating an anti-HIV immune response in the early postnatal period capable of inducing long-term immunological memory. (C) 2010 Elsevier Inc. All rights reserved.

Cerebrospinal fluid levels of chemokines in HIV infected patients with and without opportunistic infection of the central nervous system

Chemokines are chemoattractant cytokines involved in the immune response of a wide variety of diseases. There are few studies assessing their role in opportunistic infections in HIV-infected patients. In this study, we measured CC and CXC chemokines in cerebrospinal fluid (CSF) samples obtained from 40 HIV-infected patients with or without opportunistic infections of the central nervous system (CNS). CSF samples were also analyzed for quantification of total protein, cell count and HIV-1 RNA. HIV+ patients with cryptococcal meningitis had higher levels of CCL2, CCL3, CCL5, CXCL9 and CXCL10 when compared to patients without opportunistic neurological infections. Furthermore, HIV+ patients with associated cryptococcal meningitis had higher levels of CCL3, CXCL9 and CXCL10 when compared to HIV+ patients with associated toxoplasmic encephalitis. CCL3 and CXCL9 levels were positively correlated with CSF HIV-1 RNA levels, CSF protein concentration, and CSF cell count. CXCL10 level was correlated with the CSF viral load and the CSF cell count and CCL5 level was correlated with the CSF cell count. In conclusion, the profile of chemokines in CSF of HIV patients may differ according to the modality of the presented opportunistic infection and according to other biological markers, such as viral load in CSF. These differences are probably related to different patterns of neuroinflammatory responses displayed by patients with different opportunistic neurological infections. (C) 2009 Elsevier B.V. All rights reserved.

Transcriptional Errors in Human Immunodeficiency Virus Type 1 Generate Targets for T-Cell Responses

We measured T-cell responses to human immunodeficiency virus type 1 (HIV-1) cryptic epitopes encoded by regions of the viral genome not normally translated into viral proteins. T-cell responses to cryptic epitopes and to regions normally spliced out of the HIV-1 viral proteins Rev and Tat were detected in HIV-1-infected subjects.

Relationship between serum and saliva antibodies to Candida and isolation of Candida species from the mucosa of HIV-infected individuals

Colonisation and infection by Candida species occur frequently in acquired immunodeficiency syndrome (AIDS), but their relationship to the humoral immunity against candidiasis is controversial. To evaluate the levels of antibodies to Candida in the serum and in the saliva of HIV-1-infected patients in relation to the presence of immunodeficiency, oral candidiasis and Candida colonisation, Candida was investigated in the urine and in the oral and anal mucosae of HIV-1-infected patients, AIDS patients and healthy controls. The levels of IgG, IgM and IgA antibodies to Candida were determined in the serum and in the saliva by immunoassay. Candida species were detected in 76% of the patients. Mucosal yeast colonisation and the levels of serum and saliva antibodies to Candida were similar between asymptomatic HIV-infected and non-infected patients. Mucosal colonisation was highest in AIDS patients, who also had higher serum IgA and saliva IgG antibodies. Antibody levels were similar in patients with and without candidiasis oral lesions. Asymptomatic HIV-infected individuals are similar to non-infected individuals with respect to mucosal colonisation as well as serum and saliva levels of antibodies to Candida. The higher mucosal colonisation and clinical candidiasis observed in the AIDS patients apparently stimulated a more intense humoral response to the yeast.

Haemophilus ducreyi detection by polymerase chain reaction in oesophageal lesions of HIV patients

HIV patients frequently have opportunistic oesophageal infections. We report Haemophilus ducreyi genetic material detected by polymerase chain reaction in biopsies of oesophageal lesions in three HIV-1-infected patients. This finding may be an indication of its aetiopathological role in oesophageal lesions of HIV patients.

Silencing of HTLV-1 gag and env genes by small interfering RNAs in HEK 293 cells

Since the discovery of RNAi technology, several functional genomic and disease therapy studies have been conducted using this technique in the field of oncology and virology. RNAi-based antiviral therapies are being studied for the treatment of retroviruses such as HIV-1. These studies include the silencing of regulatory, infectivity and structural genes. The HTLV-1 structural genes are responsible for the synthesis of proteins involved in the entry, assembly and release of particles during viral infection. To examine the possibility of silencing HTLV-1 genes gag and env by RNA interference technology, these genes were cloned into reporter plasmids. These vectors expressed the target mRNAs fused to EGFP reporter genes. Three small interference RNAs (siRNAs) corresponding to gag and three corresponding to env were designed to analyze the effect of silencing by RNAi technology. The plasmids and siRNAs were co-transfected into HEK 293 cells. The results demonstrated that the expression of the HTLV-1 gag and env genes decreased significantly in vitro. Thus, siRNAs can be used to inhibit HTLV-1 structural genes in transformed cells, which could provide a tool for clarifying the roles of HTLV-1 structural genes, as well as a therapy for this infection. (C) 2011 Elsevier B.V. All rights reserved.

Evaluation of IGF-2/ApaI polymorphism in pregnant women infected with human immunodeficiency virus type 1 taking antiretroviral drugs

Objective: Studies carried Out to assess the effects of antiretroviral drugs (ARV) in HIV-1 infected pregnant women have demonstrated carbohydrate intolerance. Some reports also refer to the effect of disturbances in the expression of the insulin-like growth factor (IGF) system on pancreas beta-cell function in humans and IGF-2/ApaI polymorphisms have been associated with obesity and features of the metabolic syndromes. in the present study, we tested the association between IGF-2/ApaI genotype and hyperglycemia in HIV-1 infected pregnant women receiving ARV. Design: We studied IGF-2/ApaI polymorphism in 87 healthy pregnant women, 43 HIV-1 infected pregnant women taking ARV with hyperglycemia during pregnancy, and 43 HIV-1-negative pregnant women with gestational diabetes. Blood samples were obtained for DNA extraction, PCR and genotyping. Data were analyzed statistically by the Kolmogorov-Smirnov normality, ANOVA and chi-square tests. Results: There were no significant differences in genotype frequency among the three groups analyzed. Considering the HIV-1-infected pregnant women, there were no significant differences in genotype frequency between the zidovudine group and the triple antiretroviral treatment group. There were no significant differences in allele frequencies among the groups evaluated. Non-white pregnant women tended to present the GG genotypes compared to white pregnant women. Conclusion: These results contribute to a better understanding of metabolic glycemic disorders in HIV-1 infected pregnant women using ARV, showing that IGF-2/ApaI polymorphisms are not responsible as a single Causative factor of glycemic alterations. These data indicate that other variables should be studied in order to explain these glycemic abnormalities. (C) 2009 Elsevier Ltd. All rights reserved.

Oral manifestations after immune reconstitution in HIV patients on HAART

In order to verify possible association between immune reconstitution inflammatory syndrome (IRIS) and oral manifestations (OMs), we selected AIDS patients who had low CD4 count before the initiation of highly active antiretroviral therapy (HAART) and who returned three months later for therapy evaluation. The oral lesions observed three months after the initiation of HAART were evaluated and associated with the type of antiretroviral therapy (ART), CD4 count and HIV-RNA load levels (before and three months after HAART initiation). A total of 105 patients matched the selected criteria. Immune reconstitution (IR) was identified in 35.2%. Among these patients, the mean CD4 cell count rose from 105.97 to 330.29 and the mean viral load dropped from 168.005 (log 5.22) to 21.852 (log 4.33). There was no significant difference in age (P=0.78), sex (P=0.41) or previous history of ART (P=0.55) between IR and non-IR patients. In the IR group, the most common OM was. parotid enlargement (57.14%) (P=0.619), whereas in the non-IR group candidiasis (46.15%) was the most common OM. The results of our study suggest that the parotid gland enlargement found in the studied population might be an IRIS event, as it was found in patients with IR three months after the initiation of HAART.

RNA trafficking signals in human immunodeficiency virus type 1

Intracellular trafficking of retroviral RNAs is a potential mechanism to target viral gene expression to specific regions of infected cells. Here we show that the human immunodeficiency virus type 1 (HIV-1) genome contains two sequences similar to the hnRNP A2 response element (A2RE), a cis-acting RNA trafficking sequence that binds to the trans-acting trafficking factor, hnRNP A2, and mediates a specific RNA trafficking pathway characterized extensively in oligodendrocytes. The two HIV-1 sequences, designated A2RE-1, within the major homology region of the gag gene, and A2RE-2, in a region of overlap between the vpr and tat genes, both bind to hnRNP A2 in vitro and are necessary and sufficient for RNA transport in oligodendrocytes in vivo. A single base change (A8G) in either sequence reduces hnRNP A2 binding and, in the case of A2RE-2, inhibits RNA transport. A2RE-mediated RNA transport is microtubule and hnRNP A2 dependent. Differentially labelled gag and vpr RNAs, containing A2RE-1 and A2RE-2, respectively, coassemble into the same RNA trafficking granules and are cotransported to the periphery of the cell. tat RNA, although it contains A2RE-2, is not transported as efficiently as vpr RNA. An A2RE/hnRNP A2-mediated trafficking pathway for HIV RNA is proposed, and the role of RNA trafficking in targeting HIV gene expression is discussed.

Gag-Pol supplied in trans is efficiently packaged and supports viral function in human immunodeficiency virus type 1

The intracellular trafficking and subsequent incorporation of Gag-Pol into human immunodeficiency virus type 1 (HIV-1) remains poorly defined. Gag-Pol is encoded by the same mRNA as Gag and is generated by ribosomal frameshifting. The multimerization of Gag and Gag-Pol is an essential step in the formation of infectious viral particles. In this study, we examined whether the interaction between Gag and Gag-Pol is initiated during protein translation in order to facilitate the trafficking and subsequent packaging of Gag-Pol into the virion. A conditional cotransfection system was developed in which virion formation required the coexpression of two HIV-1-based plasmids, one that produces both Gag and Gag-Pol and one that only produces Gag-Pol. The Gag-Pol proteins were either immunotagged with a His epitope or functionally tagged with a mutation (K65R) in reverse transcriptase that is associated with drug resistance. Gag-Pol packaging was assessed to determine whether the Gag-Pol incorporated into the virion was preferentially packaged from the plasmid that expressed both Gag and Gag-Pol or whether it could be packaged from either plasmid. Our data show that translation of Gag and Gag-Pol from the same mRNA is not critical for virion packaging of the Gag-Pol polyprotein or for viral function.

Inhibitors of human immunodeficiency virus type 1 reverse transcriptase target distinct phases of early reverse transcription

Early HIV-1 reverse transcription can be separated into initiation and elongation phases. Here we show, using PCR analysis of negative-strand strong-stop DNA [(-)ssDNA] synthesis in intact virus, that different reverse transcriptase (RT) inhibitors affect distinct phases of early natural endogenous reverse transcription (NERT), The effects of nevirapine on NERT were consistent with a mechanism of action including both specific and nonspecific binding events. The nonspecific component of this inhibition targeted the elongation reaction, whereas the specific effect seemed principally to be directed at very early events (initiation or the initiation-elongation switch), In contrast, foscarnet and the nucleoside analog ddATP inhibited both early and late (-)ssDNA synthesis in a similar manner. We also examined compounds that targeted other viral proteins and found that Ro24-7429 (a Tat antagonist) and rosmarinic acid (an integrase inhibitor) also directly inhibited RT, Our results indicate that NERT can be used to identify and evaluate compounds that directly target the reverse transcription complex.

Human immunodeficiency virus type 1 reverse transcription is stimulated by Tat from other lentiviruses

The tat gene is required by HIV-1 for efficient reverse transcription and this function of Tat can be distinguished from its role in transcription by RNA polymerase II using tat point mutations that abrogate each function independently The mechanism of Tat's role in reverse transcription, however, is not known, nor is it known whether this role is conserved among trans-activating factors in other retroviruses. Here we examine the abilities of heterologous viral trans-activating proteins from jembrana disease virus (jTat), HIV-2 (Tat2), and equine infectious anemia virus (eTat) to substitute for HIV-1 Tat (Tat1) and restore reverse transcription in HIV-1 carrying an inactivated tat gene. Natural endogenous reverse transcription assays showed that trans-activators from some retroviruses (Tat2 and jTat, but not eTat) could substitute for Tat1 in complementation of HIV-1 reverse transcription. Finally, we show that Y47 is critical for Tat1 to function in reverse transcription, but not HIV-1 gene expression. We mutated the homologous position in jTat to H62Y and found it did not improve its ability to stimulate reverse transcription, but an H62A mutation did inhibit jTat complementation. These data highlight the finding that the role of Tat in reverse transcription is not related to trans-activation and demonstrate that other tat genes conserve this function. (C) 2002 Elsevier Science (USA).

Worldwide molecular epidemiology of HIV

Human immunodeficiency virus (HIV) is the worldwide disseminated causative agent of acquired immunodeficiency syndrome (AIDS). HIV is a member of the Lentivirus genus of Retroviridae family and is grouped in two types named HIV-1 and HIV-2. These viruses have a notable ability to mutate and adapt to the new conditions of human environment. A large incidence of errors at the transcriptional level results in changes on the genetic bases during the reproductive cycle. The elevated genomic variability of HIV has carried important implications for the diagnosis, treatment and prevention as well as epidemiologic investigations. The present review describes important definitions and geographical distribution of subtypes, circulating recombinant forms and other genomic variations of HIV. The present study aimed at leading students of Biomedical Sciences and public health laboratory staff guidance to general and specific knowledge about the genomic variability of the HIV.