Dense Array of Spikes on HIV-1 Virion Particles.

HIV-1 is rare among viruses for having a low number of envelope glycoprotein (Env) spikes per virion, i.e., ∼7 to 14. This exceptional feature has been associated with avoidance of humoral immunity, i.e., B cell activation and antibody neutralization. Virus-like particles (VLPs) with increased density of Env are being pursued for vaccine development; however, these typically require protein engineering that alters Env structure. Here, we used instead a strategy that targets the producer cell. We employed fluorescence-activated cell sorting (FACS) to sort for cells that are recognized by trimer cross-reactive broadly neutralizing antibody (bnAb) and not by nonneutralizing antibodies. Following multiple iterations of FACS, cells and progeny virions were shown to display higher levels of antigenically correct Env in a manner that correlated between cells and cognate virions (P = 0.027). High-Env VLPs, or hVLPs, were shown to be monodisperse and to display more than a 10-fold increase in spikes per particle by electron microscopy (average, 127 spikes; range, 90 to 214 spikes). Sequencing revealed a partial truncation in the C-terminal tail of Env that had emerged in the sort; however, iterative rounds of "cell factory" selection were required for the high-Env phenotype. hVLPs showed greater infectivity than standard pseudovirions but largely similar neutralization sensitivity. Importantly, hVLPs also showed superior activation of Env-specific B cells. Hence, high-Env HIV-1 virions, obtained through selection of producer cells, represent an adaptable platform for vaccine design and should aid in the study of native Env.IMPORTANCE The paucity of spikes on HIV is a unique feature that has been associated with evasion of the immune system, while increasing spike density has been a goal of vaccine design. Increasing the density of Env by modifying it in various ways has met with limited success. Here, we focused instead on the producer cell. Cells that stably express HIV spikes were screened on the basis of high binding by bnAbs and low binding by nonneutralizing antibodies. Levels of spikes on cells correlated well with those on progeny virions. Importantly, high-Env virus-like particles (hVLPs) were produced with a manifest array of well-defined spikes, and these were shown to be superior in activating desirable B cells. Our study describes HIV particles that are densely coated with functional spikes, which should facilitate the study of HIV spikes and their development as immunogens.

Topical Tenofovir Disoproxil Fumarate Nanoparticles Prevent HIV-1 Vaginal Transmission in a Humanized Mouse Model.

Preexposure prophylaxis (PrEP) with 1% tenofovir (TFV) vaginal gel has failed in clinical trials. To improve TFV efficacy in vaginal gel, we formulated tenofovir disoproxil fumarate nanoparticles in a thermosensitive (TMS) gel (TDF-NP-TMS gel). TDF-NPs were fabricated using poly(lactic-co-glycolic acid) (PLGA) polymer and an ion-pairing agent by oil-in-water emulsification. The efficacy of TDF-NP-TMS gel was tested in humanized bone marrow-liver-thymus (hu-BLT) mice. Hu-BLT mice in the treatment group (Rx; n = 15) were administered TDF-NP-TMS gel intravaginally, having TDF at 0.1%, 0.5%, and 1% (wt/vol) concentrations, whereas the control (Ctr; n = 8) group received a blank TMS gel. All Rx mice (0.1% [n = 4], 0.5% [n = 6], and 1% [n = 5]) were vaginally challenged with two transmitted/founder (T/F) HIV-1 strains (2.5 × 10(5) 50% tissue culture infectious doses). Rx mice were challenged at 4 h (0.1%), 24 h (0.5%), and 7 days (1%) posttreatment (p.t.) and Ctr mice were challenged at 4 h p.t. Blood was drawn weekly for 4 weeks postinoculation (p.i.) for plasma viral load (pVL) using reverse transcription-quantitative PCR. Ctr mice had positive pVL within 2 weeks p.i. Rx mice challenged at 4 h and 24 h showed 100% protection and no detectable pVL throughout the 4 weeks of follow-up (P = 0.009; Mantel-Cox test). Mice challenged at 7 days were HIV-1 positive at 14 days p.i. Further, HIV-1 viral RNA (vRNA) in vaginal and spleen tissues of Rx group mice with negative pVL were examined using an in situ hybridization (ISH) technique. The detection of vRNA was negative in all Rx mice studied. The present studies elucidate TDF-NP-TMS gel as a long-acting, coitus-independent HIV-1 vaginal protection modality.

[THE MOLECULAR TECHNIQUES OF DIAGNOSTIC OF GINGIVITIS AND PERIODONTITIS IN HIV-INFECTED PATIENTS].

The examination was carried out in the Moscow clinical infectious hospital No 2 concerning 102 patients with verified diagnosis "AIDS-infection" and seropositive according results of detection of anti-HIV-antibodies in blood serum. The study was organized to analyze rate ofcolonization of gums with virulent anaerobic bacteria in HIV-infected (polymerase chain reaction) and antibodies to HIV in gingival fluid (enzyme-linked immunosorbent assay). It is established that in HIV-infected patients, in scrape from gingival sulcus dominate anaerobic bacteria P. gigngivalis and A. ctinomycetemcomitans and in case of periodontitis--P. gingivalis and T. forsythia. The received data permits recommending the test-system "Multident-5" for polymerase chain reaction diagnostic. The reagents kit "Calypte®HIV-1/2"--for enzyme-linked immunosorbent assay gingival fluid. The results of polymerase chain reaction and enzyme-linked immunosorbent assay have no impact of concomitant stomatological (periodontitis, gingivitis) and somatic pathology.

Endosomal trafficking of nanoformulated antiretroviral therapy facilitates drug particle carriage and HIV clearance.

UNLABELLED: Limitations of antiretroviral therapy (ART) include poor patient adherence, drug toxicities, viral resistance, and failure to penetrate viral reservoirs. Recent developments in nanoformulated ART (nanoART) could overcome such limitations. To this end, we now report a novel effect of nanoART that facilitates drug depots within intracellular compartments at or adjacent to the sites of the viral replication cycle. Poloxamer 407-coated nanocrystals containing the protease inhibitor atazanavir (ATV) were prepared by high-pressure homogenization. These drug particles readily accumulated in human monocyte-derived macrophages (MDM). NanoATV concentrations were ∼1,000 times higher in cells than those that could be achieved by the native drug. ATV particles in late and recycling endosome compartments were seen following pulldown by immunoaffinity chromatography with Rab-specific antibodies conjugated to magnetic beads. Confocal microscopy provided cross validation by immunofluorescent staining of the compartments. Mathematical modeling validated drug-endosomal interactions. Measures of reverse transcriptase activity and HIV-1 p24 levels in culture media and cells showed that such endosomal drug concentrations enhanced antiviral responses up to 1,000-fold. We conclude that late and recycling endosomes can serve as depots for nanoATV. The colocalization of nanoATV at endosomal sites of viral assembly and its slow release sped antiretroviral activities. Long-acting nanoART can serve as a drug carrier in both cells and subcellular compartments and, as such, can facilitate viral clearance. IMPORTANCE: The need for long-acting ART is significant and highlighted by limitations in drug access, toxicity, adherence, and reservoir penetrance. We propose that targeting nanoformulated drugs to infected tissues, cells, and subcellular sites of viral replication may improve clinical outcomes. Endosomes are sites for human immunodeficiency virus assembly, and increasing ART concentrations in such sites enhances viral clearance. The current work uncovers a new mechanism by which nanoART can enhance viral clearance over native drug formulations.

The cellular factors Vps18 and Mon2 are required for efficient production of infectious HIV-1 particles.

Like all viruses, HIV-1 requires cellular host factors for replication. The mechanisms for production of progeny virions involving these host factors, however, are not fully understood. To better understand these mechanisms, we used a yeast (Saccharomyces cerevisiae) genetic screen to identify mutant strains in which HIV-1 Gag targeting to the plasma membrane was aberrant. Of the 917 mutants identified, we selected 14 mutants whose missing genes had single orthologous counterparts in human and tested them for Gag-induced viruslike particle (VLP) release in yeast cells. We found that the Vps18 and Mon2 proteins were important for HIV-1 Gag-induced VLP release in yeast. In eukaryote cells, these host proteins are highly conserved and function in protein trafficking. Depletion of hVps18 or hMon2 reduced the efficient production of infectious HIV-1 virions in human cells. Our data suggest that these cellular factors play an important role in the efficient production of infectious HIV-1 virion particles.

Application and removal of polyanionic microbicide compounds enhances subsequent infection by HIV-1.

BACKGROUND: Continued efforts are being directed toward the development of microbicides that will be used to reduce or eliminate the risk of HIV-1 sexual transmission. Unfortunately, clinical trials involving polyanion-containing microbicide formulations, including Carraguard (λ-carrageenan [LC]) and Ushercell (cellulose sulfate [CS]) demonstrated that these products were ineffective and may have, in some circumstances, increased the risk of HIV-1 infection. These findings prompted reassessments of the in vitro activities of these agents to determine whether variables that can affect agent safety and efficacy had been overlooked during preclinical testing. One such variable is product retention and loss following topical application. RESULTS: In the present studies involving an HIV-1-susceptible cell line and primary human immune cells, product loss was mimicked by introducing and then removing polyanionic compounds prior to HIV-1 infection. In these in vitro "washout" experiments, LC and CS significantly enhanced HIV-1 infection, despite potent antiviral activity when introduced simultaneously with the virus. The presence and magnitude of this effect were dependent on compound identity and concentration; target cell; interval between compound removal and virus challenge; and coreceptor usage. Levels of enhancement (relative to controls) were considerable, exceeding a 200% increase (CS) in P4-R5 MAGI cells and a 300% increase (LC) in human peripheral blood mononuclear cells. CONCLUSIONS: These studies, which demonstrate significant increases in HIV-1 infection subsequent to application and removal of LC and CS, support plausible explanations for the failures of microbicides formulated from these compounds. Detailed studies are now underway to determine the mechanism responsible for this enhancement effect and to assess the potential contribution of this effect to the clinical failures of these agents.

Polymeric nanoparticles affect the intracellular delivery, antiretroviral activity and cytotoxicity of the microbicide drug candidate dapivirine.

PURPOSE: To assess the intracellular delivery, antiretroviral activity and cytotoxicity of poly(ε-caprolactone) (PCL) nanoparticles containing the antiretroviral drug dapivirine. METHODS: Dapivirine-loaded nanoparticles with different surface properties were produced using three surface modifiers: poloxamer 338 NF (PEO), sodium lauryl sulfate (SLS) and cetyl trimethylammonium bromide (CTAB). The ability of nanoparticles to promote intracellular drug delivery was assessed in different cell types relevant for vaginal HIV transmission/microbicide development. Also, antiretroviral activity of nanoparticles was determined in different cell models, as well as their cytotoxicity. RESULTS: Dapivirine-loaded nanoparticles were readily taken up by different cells, with particular kinetics depending on the cell type and nanoparticles, resulting in enhanced intracellular drug delivery in phagocytic cells. Different nanoparticles showed similar or improved antiviral activity compared to free drug. There was a correlation between increased antiviral activity and increased intracellular drug delivery, particularly when cell models were submitted to a single initial short-course treatment. PEO-PCL and SLS-PCL nanoparticles consistently showed higher selectivity index values than free drug, contrasting with high cytotoxicity of CTAB-PCL. CONCLUSIONS: These results provide evidence on the potential of PCL nanoparticles to affect in vitro toxicity and activity of dapivirine, depending on surface engineering. Thus, this formulation approach may be a promising strategy for the development of next generation microbicides.

Comparing the sub-gingival levels of Cytomegalovirus, Epstein-Barr virus, Porphyromonas gingivalis in human immunodeficiency virus-1 seropositive patients with and without antiretroviral therapy.

OBJECTIVES: The effect of antiretroviral therapy (ART) on the oral pathogenic microbes in human immunodeficiency virus-1 seropositive patients remains relatively unexplored. Thus, the present study assessed the effect of ART on the sub-gingival levels of 3 pathogenic microbes. MATERIALS AND METHODS: The study groups consisted of 60 human immunodeficiency virus-1 seropositive patients divided into 3 groups of 20 each. Group 1 had periodontitis and did not start with the ART. Group 2 had periodontitis and started with ART (Tenofovir Disoproxil Fumarate 300 mg + Lamivudine 300 mg + Efavirenz 600 mg) at least 6 months before the study. Group 3 with normal periodontium, and have not started ART. The sub-gingival loads of Cytomegalovirus, Epstein-Barr virus, and the Porphyromonas gingivalis levels were assessed, along with the CD4 counts. RESULTS: The cytomegalovirus load was highest in group 1, followed by groups 2, and 3 (p-value of 0.271). The Epstein-Barr load was highest for group 2, followed by group 3, and 1 (p-value of 0.022). The P.gingivalis load was highest in group 2, followed by groups 1 and 3, (p-value of 0.028). The Epstein-Barr and Cytomegalovirus counts were significantly higher (p-value < 0.02) when the CD4 counts were less than 500 cells/cu3. CONCLUSION: ART did not cause any significant reduction in the sub-gingival levels of any of the 3 examined microbes. Given the lack of any significant effect on the sub-gingival microbial loads by the ART, human immunodeficiency virus patients may require additional anti-microbial agents and regular mechanical plaque removal to maintain their periodontal status.

Minority report: hidden memory genomes in HIV-1 quasispecies and possible clinical implications.

The RNA viruses replicate as complex distributions of closely related genomes termed viral quasispecies. The behavior of the evolving quasispecies and its response to selective pressures such as antiviral treatment is influenced by the ensemble of mutants that compose the viral population. One such influence is the presence of minority subpopulations in the mutant spectra of viral quasispecies. Biologically relevant mutants have long been known to be present as minority components of replicating viral populations. However, experiments designed with specific mutants of the animal pathogen foot-and-mouth disease virus in cell culture explained the presence of a class of minority genomes termed memory genomes. They descend from those variants that were dominant at an earlier phase of quasispecies evolution, and arise as a consequence of quasispecies dynamics, when viral populations are subjected to discontinuous selective pressures. The presence of memory genomes has also been documented during intrahost evolution of HIV-1 in vivo. The analysis of sequential viral samples of different HIV-1-infected patients showed that two distinct types of memory can operate in retroviruses: a replicative memory analogous to that observed in foot-and-mouth disease virus, as well as a reservoir memory derived from the integrative phase of the retroviral lifecycle. Despite being hidden as minority components of the HIV-1 viral population (ranging from about 0.1 to 20% of the total number of genomes in the quasispecies analyzed), memory genomes can drive the evolution of the virus during HIV-1 infections under antiviral therapy. The limited availability of current experimental data on minority HIV-1 subpopulations in vivo implies that further studies are required in order to define the cutoffs of clinically relevant minority genomes. Nevertheless, it is already evident that such low-abundance genomes remain undetectable by traditional genotyping methods such as consensus sequencing or conventional hybridization techniques. Several experimental systems are currently available for the detection and characterization of minority components of the mutant spectra of viral quasispecies including HIV, hepatitis C virus and hepatitis B virus. Some of these biotechnological approaches could, in the near future, be taken over and exploited in the clinical setting as useful biosensors with which to improve the management of HIV-infected patients.

Factors contributing to salivary human immunodeficiency virus type-1 levels measured by a Poisson distribution-based PCR method.

Objective To elucidate the mechanism underlying secretion of human immunodeficiency virus type 1 (HIV-1) into the oral cavity, by examining the relationships between various oral and systemic factors and the viral load in saliva. Methods Plasma and saliva samples from HIV-1 infected patients were assayed using the COBAS® AmpliPrep/COBAS® TaqMan® HIV-1 Test, version 1.0 and a Poisson distribution-based polymerase chain reaction (PCR) method for quantifying HIV-1 RNA and DNA. Results Forty-four pairs of samples were obtained from 18 patients. Salivary viral load was approximately 10% of the plasma viral load, but higher than the plasma load in two patients. The salivary viral DNA load was < 1% of the total HIV-1 nucleic acid load except in one patient who had more viral DNA than RNA. Multiple regression analysis showed that salivary viral load was significantly correlated with plasma viral load (partial correlation coefficient, 0.90) and the community periodontal index (-0.63). Conclusions The present results suggest that excretion through salivary glands, but not occult bleeding, may be a major pathway of HIV-1 into the oral cavity.

Design and cellular kinetics of dansyl-labeled CADA derivatives with anti-HIV and CD4 receptor down-modulating activity.

A new class of anti-retrovirals, cyclotriazadisulfonamide (CADA) and its derivatives, specifically down-regulate CD4, the main receptor of HIV, and prevent HIV infection in vitro. In this work, several CADA derivatives, chemically labeled with a fluorescent dansyl group, were evaluated for their biological features and cellular uptake kinetics. We identified a derivative KKD-016 with antiviral and CD4 down-modulating capabilities similar to those of the parental compound CADA. By using flow cytometry, we demonstrated that the dose-dependent cellular uptake of this derivative correlated with CD4 down-modulation. The uptake and activity of the dansyl-labeled compounds were not dependent on the level of expression of CD4 at the cell surface. Removal of the CADA compounds from the cell culture medium resulted in their release from the cells followed by a complete restoration of CD4 expression. The inability of several fluorescent CADA derivatives to down-modulate CD4 was not associated with their lower cellular uptake and was not reversed by facilitating their cell penetration by a surfactant. These results prove the successful integration of the dansyl fluorophore into the chemical structure of a CD4 down-modulating anti-HIV compound, and show the feasibility of tracking a receptor and its down-modulator simultaneously. These fluorescent CADA analogs with reversible CD4 down-regulating potency can now be applied in further studies on receptor modulation, and in the exploration of their potentials as preventive and therapeutic anti-HIV drugs.

DNA-MVA-protein vaccination of rhesus macaques induces HIV-specific immunity in mucosal-associated lymph nodes and functional antibodies.

Successful future HIV vaccines are expected to generate an effective cellular and humoral response against the virus in both the peripheral blood and mucosal compartments. We previously reported the development of DNA-C and MVA-C vaccines based on HIV-1 subtype C and demonstrated their immunogenicity when given in a DNA prime-MVA boost combination in a nonhuman primate model. In the current study, rhesus macaques previously vaccinated with a DNA-C and MVA-C vaccine regimen were re-vaccinated 3.5years later with MVA-C followed by a protein vaccine based on HIV-1 subtype C envelope formulated with MF59 adjuvant (gp140Env/MF59), and finally a concurrent boost with both vaccines. A single MVA-C re-vaccination elicited T cell responses in all animals similar to previous peak responses, with 4/7 demonstrating responses >1000 SFU/106 PBMC. In contrast to an Env/MF59-only vaccine, concurrent boosting with MVA-C and Env/MF59 induced HIV-specific cellular responses in multiple mucosal associated lymph nodes in 6/7 animals, with high magnitude responses in some animals. Both vaccine regimens induced high titer Env-specific antibodies with ADCC activity, as well as neutralization of Tier 1 viruses and modest Tier 2 neutralization. These data demonstrate the feasibility of inducing HIV-specific immunity in the blood and mucosal sites of viral entry by means of DNA and poxvirus-vectored vaccines, in combination with a HIV envelope-based protein vaccine.

Gene therapy with plasmids encoding IFN-ß or IFN-α14 confers long-term resistance to HIV-1 in humanized mice.

Because endogenous interferon type I (IFN-I) produced by HIV-1 infection might complicate the analysis of therapeutically administered IFN-I, we tested different humanized mouse models for induction of IFN-I during HIV-1 infection. While HIV-1 induced high levels of IFN-α in BLT mice, IFN-I was undetectable following infection in the Hu-PBL mouse model, in which only T cells expand. We therefore tested the effect of treatment with Pegylated IFN-2 (pegasys), in Hu-PBL mice. Pegasys prevented CD4 T cell depletion and reduced the viral load for 10 days, but the effect waned thereafter. We next expressed IFN-I subsets (IFN-α2, -α6, -α8, -α14, and -ß) in Hu-PBL mice by hydrodynamic injection of plasmids encoding them and 2 days later infected the mice with HIV-1. CD4 T cell depletion was prevented in all subtypes of IFN-I-expressing mice by day 10. However, at day 40 post-infection, protection was seen in IFN-ß- and IFN-α14-expressing mice, but not the others. The viral load followed an inverse pattern and was highest in control mice and lowest in IFN-ß- and IFN-α14-expressing mice until day 40 after infection. These results show that gene therapy with plasmids encoding IFN-ß and -α14, but not the commonly used -α2, confers long-term suppression of HIV-1 replication.

Characteristics and prospects for hepatitis C therapy of an HIV-HCV coinfected population followed at a reference HIV center.

PURPOSE: A cross-sectional study was performed during 2004 at a large HIV clinic in Spain to identify HIV-HCV coinfected individuals who might be candidates for HCV therapy. METHOD: Plasma HCV RNA levels were measured in 405 anti-HCV antibody positive patients. Spontaneous HCV clearance had occurred in 11.4%. Overall, 165 (40.1%) of HCV-HIV coinfected patients had already been exposed to interferon (IFN)-based therapies. Excluding those currently on treatment, the majority of them had either failed (64/142; 45.1%) or not completed therapy (25/142; 17.6%). Other 103 (25.4%) chronic HCV carriers refused treatment or were not considered as appropriate candidates, most often due to low CD4 counts or severe neuropsychiatric conditions. Treatment was deemed feasible and planned in the near future in 91 (22.5%) patients. Unfavorable HCV genotypes (1 and 4) were significantly more frequent in this group of individuals ready for HCV treatment compared to those who had cleared HCV in the past following IFN-based therapies. RESULTS: Spontaneous clearance of the HCV infection was low in HIV-coinfected patients. One third of our HIV-HCV coinfected population had already been exposed to HCV therapy, but only a minority had achieved sustained HCV clearance. Half of patients with active HCV replication never exposed to IFN were not considered as appropriate candidates for HCV therapy. CONCLUSION: More flexible criteria would considerably increase the number of patients to be treated with IFN-based therapy. The majority of patients ready to initiate HCV therapy have a poor therapeutic profile.

Experimental conditions that increase the production of HIV-1 by monocyte-derived macrophages: use of collagen matrix.

Monocyte-derived macrophages (MDMs) from healthy blood donors were isolated by adherence to tissue culture-treated plasticware. They were cultured in vitro in medium supplemented with human serum and recombinant GM-CSF, then infected with the macrophage-tropic prototype strain HIV-1-PAR. Virus production was quantitated at various times after infection by measuring reverse transcriptase concentration in cell-free tissue culture supernatant fluids, using a sensitive nonradioactive assay. Virus production was significantly increased by culturing MDMs on plasticware previously coated with collagen 1. The increase in virus production was dependent upon collagen 1 concentration, with maximal value being encountered after coating with 1.5 microg/cm2. These results indicate that the sensitivity of peripheral macrophages to HIV-1 infection might be influenced by contact-dependent interactions involving components of the extracellular matrix that take place during the process of monocyte extravasation and migration.

Human submandibular saliva specifically inhibits HIV type 1.

Studies from a number of laboratories have shown the presence of factor(s) in whole, parotid, and submandibular human saliva capable of inhibiting HIV-1 infectivity in vitro. Data from our laboratory suggested that the level of anti-HIV-1 activity is higher in submandibular than parotid or whole saliva. Previous results obtained with pooled submandibular saliva from seronegative individuals included a filtration step following saliva-virus interaction. In this article, we present data on the HIV-1 inhibitory activity of individual submandibular saliva samples collected from 15 donors. We show that although anti-HIV activity is quantitatively similar in most individuals (9 of 15), some (4 of 15) are much less active than others and some (2 of 15) lack inhibitory activity. We also show that for most individuals the level of anti-HIV inhibitor is similar with or without a filtration step. However, 2 of the 15 samples demonstrated activity only after filtration. The quantitative and qualitative anti-HIV activity of individual saliva samples appeared to reflect differences in the individual donors. We further show that the anti-HIV activity of submandibular saliva is demonstrated not only against laboratory strains of HIV-1 but is similarly active against three clinical HIV-1 isolates. In contrast, submandibular saliva had little effect on the infectivity of HIV-2 or SIV.

Evaluation of anti-AIDS drugs in conventional mice implanted with a permeable membrane device containing human T cells infected with HIV.

We now report the confirmation of the work of Hollingshead et al. (1995) on development of a cell based hollow fiber (HF) system for evaluating potential anti-AIDS drugs in vivo using conventional mice rather than SCID mice. CD4 +, CEM-SS cells infected with HIV/1, strain RF, at a multiplicity of infection of 0.1 were placed into HFs. The fibers were implanted into the peritoneal cavity of outbred Swiss mice. Using this model, the antiviral activity of azidothymidine (AZT) at doses of approximately 150, 75 and 37.5 mg/kg/day was evaluated by administering AZT to the mice in drinking water. Upon fiber removal on day 6, AZT treatment was shown to significantly increase CEM cell viability over the untreated, virus control group and significantly reduced the levels of HIV p24 and HIV RT activity.

Efficacy of glove combinations in reducing cell culture infection after glove puncture with needles contaminated with human immunodeficiency virus type 1.

OBJECTIVE: To study the effect of various latex and treated glove combinations in reducing the frequency of human immunodeficiency virus (HIV) infection of tissue culture cells after puncture by surgical needles contaminated with infectious human immunodeficiency virus type 1 (HIV-1). DESIGN: One, two, or three layers of sterile latex glove material, or two latex layers with intermediate cotton or Kevlar (with or without the virucidal compound nonoxynol-9) were used to cover 24-well cell culture dishes containing MT2 cells in cell culture medium. Surgical needles wet with cell culture medium containing HIV-1 (HTLV IIIA strain) were passed through the glove materials into the culture medium in the wells of the culture dishes. The culture medium in each well was then assayed biweekly for HIV-1 p24 antigen as a test for infection of cells in the well. RESULTS: The rate of HIV-1 infection of cell cultures after glove puncture was greater than 90% with a single latex surgical glove barrier, 23% to 60% with double or triple layers of latex gloves, less than 8% with an intermediate cotton glove impregnated with 4% nonoxynol-9, 6% with an intermediate Kevlar glove, and 0% with an intermediate Kevlar glove impregnated with nonoxynol-9. CONCLUSIONS: An intermediate glove of Kevlar or of Kevlar or cotton impregnated with virucidal compound nonoxynol-9 between standard latex gloves may improve surgical glove safety, compared with latex gloves alone with respect to needlestick transmission of HIV-1. The experimental model used may permit rapid investigation of other glove systems as barriers to the transfer of infectious agents through gloves by needlestick.

Can we get AIDS from mosquito bites?

Human immunodeficiency virus, or HIV, is a human retrovirus that infects lymphocytes and other cells bearing the CD4 surface marker. The virus is transmitted primarily by sexual and parental routes. There are two ways blood feeding arthropods can spread disease, mechanically, by simple transfer of virus between hosts by contaminated mouth parts, or, biologically, which would require virus replication in arthropod tissues (especially salivary glands). There are some important factors which have proven that AIDS is not transmitted by mosquito bite. These factors are: (1) AIDS virus can not replicate inside the mosquito, bed bug, flea, or other blood sucking insect and the lack of replication of HIV in arthropod cells due to lack of T4 antigen on cell surface, and (2) it is unlikely that HIV is transmitted by insects, given the low infectivity of HIV and the short survival of the virus in the mosquito. HIV appears to be much less easily transmitted probably due to lower titers of virus in body fluids. So, on the basis of experimental evidence and probability estimates, it has been concluded that the likelihood of mechanical or biological transmission of HIV by insects is virtually nonexistent.

A comparative proteomic analysis of the soluble immune factor environment of rectal and oral mucosa.

OBJECTIVE: Sexual transmission of HIV occurs across a mucosal surface, which contains many soluble immune factors important for HIV immunity. Although the composition of mucosal fluids in the vaginal and oral compartments has been studied extensively, the knowledge of the expression of these factors in the rectal mucosa has been understudied and is very limited. This has particular relevance given that the highest rates of HIV acquisition occur via the rectal tract. To further our understanding of rectal mucosa, this study uses a proteomics approach to characterize immune factor components of rectal fluid, using saliva as a comparison, and evaluates its antiviral activity against HIV. METHODS: Paired salivary fluid (n = 10) and rectal lavage fluid (n = 10) samples were collected from healthy, HIV seronegative individuals. Samples were analyzed by label-free tandem mass spectrometry to comprehensively identify and quantify mucosal immune protein abundance differences between saliva and rectal fluids. The HIV inhibitory capacity of these fluids was further assessed using a TZM-bl reporter cell line. RESULTS: Of the 315 proteins identified in rectal lavage fluid, 72 had known immune functions, many of which have described anti-HIV activity, including cathelicidin, serpins, cystatins and antileukoproteinase. The majority of immune factors were similarly expressed between fluids, with only 21 differentially abundant (p<0.05, multiple comparison corrected). Notably, rectal mucosa had a high abundance of mucosal immunoglobulins and antiproteases relative to saliva, Rectal lavage limited HIV infection by 40-50% in vitro (p<0.05), which is lower than the potent anti-HIV effect of oral mucosal fluid (70-80% inhibition, p<0.005). CONCLUSIONS: This study reveals that rectal mucosa contains many innate immune factors important for host immunity to HIV and can limit viral replication in vitro. This indicates an important role for this fluid as the first line of defense against HIV.