There is increasing evidence that opiates accelerate the pathogenesis and progression of acquired immunodeficiency syndrome (AIDS), as well as the incidence of human immunodeficiency virus (HIV) encephalitis (HIVE), a condition characterized by inflammation, leukocyte infiltration, and microglial activation. The mechanisms, by which the HIV-1 transactivating protein Tat and opioids exacerbate microglial activation, however, are not fully understood. In the current study, we explored the effects of morphine and HIV-1 Tat1–72 on the activation of mouse BV-2 microglial cells and primary mouse microglia. Both morphine and Tat exposure caused up-regulation of the chemokine receptor CCR5, an effect blocked by the opioid receptor antagonist naltrexone. Morphine in combination with Tat also induced morphological changes in the BV-2 microglia from a quiescent to an activated morphology, with a dramatic increase in the expression of the microglial activation marker CD11b, as compared with cells exposed to either agent alone. In addition, the mRNA expression of inducible nitric oxide synthase (iNOS), CD40 ligand, Interferon-gamma-inducible protein 10 (IP-10), and the proinflammatory cytokines tumor necrosis factor alpha (TNFα), interleukin (IL)-1fβ, and IL-6, which were elevated with Tat alone, were dramatically enhanced with Tat in the presence of morphine. In summary, these findings shed light on the cooperative effects of morphine and HIV-1 Tat on both microglial activation and HIV coreceptor up-regulation, effects that could result in exacerbated neuropathogenesis.

Despite the advent of antiretroviral therapy, complications of HIV-1 infection with concurrent drug abuse are an emerging problem. Opiates are well-known to modulate immune responses by preventing the development of cell-mediated immune responses. Their effect on the pathogenesis of HIV-1 infection however, remains controversial. Using the Simian Immunodeficiency Virus/macaque model of HIV pathogenesis, we sought to explore the impact of morphine on disease progression and pathogenesis. Sixteen Rhesus macaques were divided into 2 groups; 4 were administered saline and twelve others morphine routinely. Both groups of animals were then inoculated with SIVmacR71/17E and followed longitudinally for disease pathogenesis. The morphine group (M+V) exhibited a trend towards higher mortality rates and retardation in weight gain compared to the virus alone group. Interestingly, a subset of M+V animals succumbed to disease within weeks post-infection. These rapid progressors also exhibited a higher incidence of other end-organ pathologies. Despite the higher numbers of circulating CD4+ and CD8+T cells in the M+V group, CD4:CD8 ratios between the groups remained unchanged. Plasma and CSF viral load in the M+V group was at least a log higher than the control group. Similarly there was a trend toward increased virus build-up in the brains of M+V animals compared with controls. A novel finding of this study was the increased influx of infected monocyte/macrophages in the brains of M+V animals.

Lung diseases such as chronic obstructive pulmonary disease (COPD), asthma, and lung infections are major causes of morbidity and mortality among HIV-infected patients even in the era of antiretroviral therapy (ART). Many of these diseases are strongly associated with smoking and smoking is more common among HIV-infected than uninfected people; however, HIV is an independent risk factor for chronic bronchitis, COPD, and asthma. The mechanism by which HIV promotes these diseases is unclear. Excessive airway mucus formation is a characteristic of these diseases and contributes to airway obstruction and lung infections. HIV gp120 plays a critical role in several HIV-related pathologies and we investigated whether HIV gp120 promoted airway mucus formation in normal human bronchial epithelial (NHBE) cells. We found that NHBE cells expressed the HIV-coreceptor CXCR4 but not CCR5 and produced mucus in response to CXCR4-tropic gp120. The gp120-induced mucus formation was blocked by the inhibitors of CXCR4, α7-nicotinic acetylcholine receptor (α7-nAChR), and γ-aminobutyric acid (GABA)AR but not the antagonists of CCR5 and epithelial growth factor receptor (EGFR). These results identify two distinct pathways (α7-nAChR-GABAAR and EGFR) for airway mucus formation and demonstrate for the first time that HIV-gp120 induces and regulates mucus formation in the airway epithelial cells through the CXCR4-α7-nAChR-GABAAR pathway. Interestingly, lung sections from HIV ± ART and simian immunodeficiency virus (SIV) ± ART have significantly more mucus and gp120-immunoreactivity than control lung sections from humans and macaques, respectively. Thus, even after ART, lungs from HIV-infected patients contain significant amounts of gp120 and mucus that may contribute to the higher incidence of obstructive pulmonary diseases in this population.

HIV DNA vaccines are potent inducers of cell-mediated immune (CMI) response in mice but elicit poor HIV-specific IFN-γ-producing T cells in monkeys and humans. In this study, we performed kinetic analyses on splenocytes of BALB/c mice that were immunized by a single injection with a unique DNA vaccine. Using IFN-γ-ELISPOT and multiparametric FACS analysis, we characterized the induced CMI response. We found that the response was detectable for at least 63 wk. ELISPOT detection of IFN-γ-producing T cells showed a profile with two waves separated by a long period of minimal response. Multiparametric FACS analysis showed two populations of CD3+CD8+ T cells that were specific for all HIV Ags. These cells had similar robust proliferation abilities and contained granzyme B. However, only a few produced IFN-γ. Both IFN-γ-producing and non-IFN-γ-producing HIV-specific CD8+ T cells were detected in the early stage (week (W)1 and W2 postimmunization (PI)), in the prolonged intermediate period of minimal response (W4-W26 PI), and in the final late phase of increased response (W30-W63 PI). Our longitudinal characterization showed that both subsets of cells underwent expansion, contraction, and memory generation/maintenance phases throughout the lifespan of the animal. Altogether, these findings bring insight to the heterogeneity of the immune T cell response induced by a single immunization with this DNA and strengthen the concept that used of the IFN-γ-ELISPOT assay alone may be insufficient to detect critical T cell responses to candidate HIV vaccines.

Virol 79:3419-3428, 2005). To make this DNA safer, we deleted two more genes, the integrase gene and vif, along with the 3 long terminal repeat. We also replaced the gag, pro, and nef genes (SIVmac239 origin) with those of human immunodeficiency virus (HIV) type 1 strain SF2. The resultant construct, designated ⌬4SHIV KU2 DNA, was used in this study to evaluate gene expression and immunogenicity in BALB/c mice. DNA-transfected human embryonic kidney epithelial cells (HEK 293) produced all of the major viral proteins and released p24 in the supernatant for 12 days. Inoculation of the vaccine DNA into the gastrocnemius muscles resulted in intense mononuclear cell infiltration at the inoculated sites and the production of viral p24 in myocytes, in infiltrating mononuclear cells, and in cells in the spleen and draining lymph nodes between 3 and 10 days postinoculation. Expression of p24 in the muscle cells peaked at day 7 and became undetectable after day 12. The same 12-day period of expression of p24 was observed in mice that were given a second injection 4 weeks after the first. Evaluation of immune responses in BALB/c mice revealed that the DNA induced enzyme-linked immunospot and antigen-specific proliferative cell-mediated immunity responses. The responses were stronger in mice that were coinjected with a second plasmid expressing granulocyte-macrophage colony-stimulating factor. Since new waves of viral antigen production could be induced with each boosting injection of the vaccine DNA, this DNA could be a safe and efficient agent to induce long-term protection against HIV.An effective and safe vaccine against human immunodeficiency virus (HIV)/AIDS still remains elusive even after more than a decade of intense research. Although live vaccines are highly effective in preventing AIDS in macaques, they are not acceptable for use in humans because of concerns about reversion to pathogenicity by mutation or recombination. An alternative strategy using recombinant viral envelope glycoprotein was not effective in clinical trials. Further alternative strategies using viral DNA as a vaccine were therefore adopted. Initial clinical trials of certain of the DNA vaccines in humans have demonstrated only a limited degree of immunogenicity thus far (for a review, see reference 20), necessitating further improvement in DNA vaccine construction strategies. Attempts to improve the efficiency of DNA vaccines have been made either by optimization of HIV genes for codon usage in mammalian cells (4,7,18,44,45) or by modifying RNA structures through nucleotide changes facilitating high antigen expression in a Rev-independent manner (32). Other strategies tried to potentiate DNA vaccines by modulating and enhancing host immune response with the help of cytokine/chemokine adjuvants and T-cell costimulatory molecules (9,10,14,32) or by different enhancers/promoters such as cytomegalovirus (37) or ␤-actin or muscle-specific desmin promoter (13) to obtain high expression of one or two fused genes of HIV (26). The use of these DNA moie...

A total of 188 open-pollinated families of Eucalyptus camaldulensis Dehnh. from 18 Australian natural provenances and 15 selected Indian families of the “Mysore Gum” land race were evaluated in three provenance- family trials at contrasting sites in southern India. At two years of age, the fastest growth was recorded at the driest site in Tamil Nadu, where E. camaldulensis provenances from Queensland were superior to those from Northern Territory and Western Australia, and the Indian land race. Provenance differences were less pronounced at the two higher-rainfall sites in Andhra Pradesh and Kerala. Interaction of provenance performance with site was significant. Within- provenance individual-tree heritabilities for height and diameter at breast height (dbh) were low at the three individual sites, ranging from 0.08 ± 0.05 to 0.19 ± 0.05 for height and 0.10 ± 0.05 to 0.19 ± 0.04 for dbh. Across-site heritabilities, 0.07 ± 0.02 for both height and dbh, were lower than those at individual sites. Phenotypically superior trees were selected from these trials and seven other plantings of E. camaldulensis and Eucalyptus tereticornis Smith in southern India and cloned from basal coppice. A total of 78 E. camaldulensis and 27 E. tereticornis selections, together with thirteen commercially planted Eucalyptus clones and five superior natural provenance seedlots, were tested in clonal trials at three sites in southern India, the different individual treatments being tested at from one to three sites. Three years after planting, most clones selected from E. camaldulensis trials and the commercial Eucalyptus clones were superior in volume production to E. tereticornis clones and seedling controls at a dry site in Tamil Nadu. A smaller number of clones, particularly those of E. camaldulensis, were also superior to seedling controls at an intermediate-rainfall site in Andhra Pradesh. At a third high-rainfall site in Kerala, seedling controls were superior to all but four of 46 clones tested. Significant clone-by-site interaction was observed for growth traits. At the dry site in Tamil Nadu, clones varied widely in their wood basic density from 450 to 700 kg m-3, and there was no significant correlation of clonal values for growth and wood density. The results confirm that clones are best selected and tested in environments similar to those where they will be deployed.

Simian/human immunodeficiency virus SHIV KU2 replicates with extremely high titers in macaques. In order to determine whether the DNA of the viral genome could be used as a vaccine if the DNA were rendered noninfectious, we deleted the reverse transcriptase gene from SHIV KU2 and inserted this DNA (⌬rtSHIV KU2 ) into a plasmid that was then used to test gene expression and immunogenicity. Transfection of Jurkat and human embryonic kidney epithelial (HEK 293) cells with the DNA resulted in production of all of the major viral proteins and their precursors and transient export of a large quantity of the Gag p27 into the supernatant fluid. As expected, no infectious virus was produced in these cultures. Four macaques were injected intradermally with 2 mg of the DNA at 0, 8, and 18 weeks. The animals developed neutralizing antibodies and low enzyme-linked immunospot assay (E-SPOT) titers against SHIV KU2 . These four animals and two unvaccinated control animals were then challenged with heterologous SHIV89.6P administered into their rectums. The two control animals developed viral RNA titers exceeding 10 6 copies/ml of plasma, and these titers were accompanied by the loss of CD4 ؉ T cells by 2 weeks after challenge. The two control animals died at weeks 8 and 16, respectively. All four of the immunized animals became infected with the challenge virus but developed lower titers of viral RNA in plasma than the control animals, and the titers decreased over time in three of the four macaques. The fourth animal remained viremic and died at week 47. Whereas the control animals failed to develop E-SPOT responses, all four of the immunized animals developed anamnestic E-SPOT responses after challenge. The animal that died developed the highest E-SPOT response and was the only one that produced neutralizing antibodies against the challenge virus. These results established that noninfectious DNA of pathogenic SHIV could be used as a vaccine to prevent AIDS, even though the immunological assays used did not predict the manner in which the challenge virus would replicate in the vaccinated animals.

CD8+ CTL responses are important for the control of HIV-1 infection. The immunodominant HLA-A2-restricted Gag epitope, SLYNTVATL (SL9), is considered to be a poor immunogen because reactivity to it is rare in acute infection despite its paradoxical dominance in patients with chronic infection. We have previously reported SL9 to be a help-independent epitope in that it primes highly activated CTLs ex vivo from CD8+ T cells of seronegative healthy donors. These CTLs produce sufficient cytokines for extended autocrine proliferation but are sensitive to activation-induced cell death, which may cause them to be eliminated by a proinflammatory cytokine storm. Here we identified an agonist variant of the SL9 peptide, p41 (SLYNTVAAL), by screening a large synthetic combinatorial nonapeptide library with ex vivo-primed SL9-specific T cells. p41 invariably immunized SL9-cross-reactive CTLs from other donors ex vivo and H-2Db β2m double knockout mice expressing a chimeric HLA-A*0201/H2-Db MHC class I molecule. Parallel human T cell cultures showed p41-specific CTLs to be less fastidious than SL9-CTLs in the level of costimulation required from APCs and the need for exogenous IL-2 to proliferate (help dependent). TCR sequencing revealed that the same clonotype can develop into either help-independent or help-dependent CTLs depending on the peptide used to activate the precursor CD8+ T cells. Although Ag-experienced SL9-T cells from two patients were also sensitive to IL-2-mediated cell death upon restimulation in vitro, the loss of SL9 T cells was minimized with p41. This study suggests that agonist sequences can replace aberrantly immunogenic native epitopes for the rational design of vaccines targeting HIV-1.