Search tips
Search criteria

Results 1-8 (8)

Clipboard (0)

Select a Filter Below

Year of Publication
Document Types
1.  TREX1 knockdown induces an interferon response to HIV that delays viral infection in humanized mice 
Cell reports  2016;15(8):1715-1727.
Despite their antiviral effect, the in vivo effect of interferons on HIV transmission is difficult to predict, because interferons also activate and recruit HIV-susceptible cells to sites of infection. HIV does not normally induce Type I interferons in infected cells, but does if TREX1 is knocked down. Here we investigated the effect of topical TREX1 knockdown and local interferon production on HIV transmission in human cervicovaginal explants and humanized mice. In explants in which TREX1 was knocked down, HIV induced interferons, which blocked infection. In humanized mice, even though TREX1 knockdown increased infiltrating immune cells, it delayed viral replication for 3–4 weeks. Similarly intravaginal application of Type I interferons the day before HIV infection induced interferon responsive genes, reduced inflammation and decreased viral replication. However, intravenous interferon enhanced inflammation and infection. Thus, in models of human sexual transmission, a localized interferon response inhibits HIV transmission, but systemic interferons do not.
Graphical abstract
PMCID: PMC4881429  PMID: 27184854
2.  Visualizing lipid-formulated siRNA release from endosomes and target gene knockdown 
Nature biotechnology  2015;33(8):870-876.
A central hurdle in developing small interfering RNAs (siRNAs) as therapeutics is the inefficiency of their delivery across the plasma and endosomal membranes to the cytosol, where they interact with the RNA interference machinery. With the aim of improving endosomal release, a poorly understood and inefficient process, we studied the uptake and cytosolic release of siRNAs, formulated in lipoplexes or lipid nanoparticles, by live-cell imaging and correlated it with knockdown of a target GFP reporter. siRNA release occurred invariably from maturing endosomes within ~5–15 min of endocytosis. Cytosolic galectins immediately recognized the damaged endosome and targeted it for autophagy. However, inhibiting autophagy did not enhance cytosolic siRNA release. Gene knockdown occurred within a few hours of release and required <2,000 copies of cytosolic siRNAs. The ability to detect cytosolic release of siRNAs and understand how it is regulated will facilitate the development of rational strategies for improving the cytosolic delivery of candidate drugs.
PMCID: PMC4663660  PMID: 26192320
3.  Ex Vivo Cytosolic Delivery of Functional Macromolecules to Immune Cells 
PLoS ONE  2015;10(4):e0118803.
Intracellular delivery of biomolecules, such as proteins and siRNAs, into primary immune cells, especially resting lymphocytes, is a challenge. Here we describe the design and testing of microfluidic intracellular delivery systems that cause temporary membrane disruption by rapid mechanical deformation of human and mouse immune cells. Dextran, antibody and siRNA delivery performance is measured in multiple immune cell types and the approach’s potential to engineer cell function is demonstrated in HIV infection studies.
PMCID: PMC4395260  PMID: 25875117
4.  Distribution of Immune Cells in the Human Cervix and Implications for HIV Transmission 
Knowledge of the mucosal immune cell composition of the human female genital tract is important for understanding susceptibility to HIV-1.
Method of Study
We developed an optimized procedure for multicolor flow cytometry analysis of immune cells from human cervix to characterize all major immune cell subsets in the endocervix and ectocervix.
Half of tissue hematopoietic cells were CD14+, many of which were macrophages and about a third were CD11c+, most of which were CD103-CD11b+CX3CR1+DC-SIGN+ dendritic cells (DCs). The other dominant population were T cells, with more CD8 than CD4 cells. T cells (both CD8 and CD4) and B cells were more abundant in the ectocervix than endocervix of premenopausal women, however CD8+ T cell and B cell numbers declined in the ectocervix after menopause, while CD4 T cell counts remained higher. B, NK and conventional myeloid and plasmocytoid DCs each were a few percent of tissue hematopoietic cells. Although the ectocervix had more HIV-susceptible CD4+ T cells, polarized endocervical explants supported HIV-replication significantly better.
Due to their abundance in the genital tract CX3CR1+DC-SIGN+DCs might be important in HIV-transmission. Our data also suggests that the columnar epithelium of the upper genital tract might be a preferential site for HIV-transmission.
PMCID: PMC3943534  PMID: 24410939
endocervix; ectocervix; T cells; dendritic cells; menopause
5.  Inhibition of HIV transmission in human cervicovaginal explants and humanized mice using CD4 aptamer-siRNA chimeras 
The Journal of Clinical Investigation  2011;121(6):2401-2412.
The continued spread of the HIV epidemic underscores the need to interrupt transmission. One attractive strategy is a topical vaginal microbicide. Sexual transmission of herpes simplex virus type 2 (HSV-2) in mice can be inhibited by intravaginal siRNA application. To overcome the challenges of knocking down gene expression in immune cells susceptible to HIV infection, we used chimeric RNAs composed of an aptamer fused to an siRNA for targeted gene knockdown in cells bearing an aptamer-binding receptor. Here, we showed that CD4 aptamer-siRNA chimeras (CD4-AsiCs) specifically suppress gene expression in CD4+ T cells and macrophages in vitro, in polarized cervicovaginal tissue explants, and in the female genital tract of humanized mice. CD4-AsiCs do not activate lymphocytes or stimulate innate immunity. CD4-AsiCs that knock down HIV genes and/or CCR5 inhibited HIV infection in vitro and in tissue explants. When applied intravaginally to humanized mice, CD4-AsiCs protected against HIV vaginal transmission. Thus, CD4-AsiCs could be used as the active ingredient of a microbicide to prevent HIV sexual transmission.
PMCID: PMC3104760  PMID: 21576818
6.  Structural details and composition of Trichomonas vaginalis lipophosphoglycan in relevance to the epithelial immune function 
Glycoconjugate journal  2008;26(1):3-17.
Trichomonas vaginalis causes the most common non-viral sexually transmitted infection linked to increased risk of premature birth, cervical cancer and HIV. This study defines molecular domains of the parasite surface glycol-conjugate lipophosphoglycan (LPG) with distinct functions in the host immunoinflammatory response. The ceramide phospho-inositol glycan core (CPI-GC) released by mild acid had Mr of ~8,700 Da determined by MALDI-TOF MS. Rha, GlcN, Gal and Xyl and small amounts of GalN and Glc were found in CPI-GC. N-acetyllactosamine repeats were identified by endo-β-galactosidase treatment followed by MALDI-MS and MS/MS and capLC/ESI-MS/MS analyses. Mild acid hydrolysis led to products rich in internal deoxyhexose residues. The CPI-GC induced chemokine production, NF-κB and extracellular signal-regulated kinase (ERK)1/2 activation in human cervicovaginal epithelial cells, but neither the released saccharide components nor the lipid-devoid LPG showed these activities. These results suggest a dominant role for CPI-GC in the pathogenic epithelial response to trichomoniasis.
PMCID: PMC2637367  PMID: 18604640
Trichomonad LPG; Mass spectrometry; Cytokines; NF-κB; ERK; Vaginal mucosal immunity
7.  Biocompatibility of Solid-Dosage Forms of Anti-Human Immunodeficiency Virus Type 1 Microbicides with the Human Cervicovaginal Mucosa Modeled Ex Vivo▿  
Antimicrobial Agents and Chemotherapy  2006;50(12):4005-4010.
Topical anti-human immunodeficiency virus (HIV) microbicides are being sought to reduce the spread of HIV type 1 (HIV-1) during sexual intercourse. The success of this strategy depends upon the selection of formulations compatible with the natural vaginal mucosal barrier. This study applied ex vivo-modeled human cervicovaginal epithelium to evaluate experimental solid-dosage forms of the anti-HIV-1 microbicide cellulose acetate 1,2-benzenedicarboxylate (CAP) and over-the-counter (OTC) vaginal products for their impact on inflammatory mediators regarded as potential HIV-1-enhancing risk factors. We assessed product-induced imbalances between interleukin-1α (IL-1α) and IL-1β and the natural IL-1 receptor antagonist (IL-1RA) and changes in levels of IL-6, tumor necrosis factor alpha, IL-8, gamma interferon inducible protein 10 (IP-10), and macrophage inflammatory protein 3α (MIP-3α), known to recruit and activate monocytes, dendritic cells, and T cells to the inflamed mucosa. CAP film and gel formulation, similarly to the hydroxyethylcellulose universal vaginal placebo gel and the OTC K-Y moisturizing gel, were nontoxic and caused no significant changes in any inflammatory biomarker. In contrast, OTC vaginal cleansing and contraceptive films containing octoxynol-9 or nonoxynol-9 (N-9) demonstrated similar levels of toxicity but distinct immunoinflammatory profiles. IL-1α, IL-1β, IL-8, and IP-10 were increased after treatment with both OTC vaginal cleansing and contraceptive films; however, MIP-3α was significantly elevated by the N-9-based film only (P < 0.01). Although both films increased extracellular IL-1RA, the cleansing film only significantly elevated the IL-1RA/IL-1 ratio (P < 0.001). The N-9-based film decreased intracellular IL-1RA (P < 0.05), which has anti-inflammatory intracrine functions. This study identifies immunoinflammatory biomarkers that can discriminate between formulations better than toxicity assays and should be clinically validated in relevance to the risk of HIV-1 acquisition.
PMCID: PMC1693981  PMID: 17030562
8.  Trichomonas vaginalis Lipophosphoglycan Triggers a Selective Upregulation of Cytokines by Human Female Reproductive Tract Epithelial Cells  
Infection and Immunity  2006;74(10):5773-5779.
Trichomonas vaginalis is one of the most common nonviral sexually transmitted human infections and, worldwide, has been linked to increased incidence of human immunodeficiency virus type 1 transmission, preterm delivery, low birth weight, cervical cancer, and vaginitis. The molecular pathways that are important in initiating host inflammatory and immune responses to T. vaginalis are poorly understood. Here we report interactions of human cervicovaginal epithelial cells with the most abundant cell surface glycoconjugate of the parasite, the T. vaginalis lipophosphoglycan (LPG). Purified LPG mediated the adhesion of parasites to human vaginal epithelial cells in a dose-dependent manner. Furthermore, T. vaginalis LPG (but not LPG from Tritrichomonas foetus, the causative agent of bovine trichomoniasis) induced a selective upregulation of chemotactic cytokines by human endocervical, ectocervical, and vaginal epithelial cells, which do not express Toll-like receptor 4/MD2. The T. vaginalis LPG triggered interleukin 8 (IL-8), which promotes the adhesion and transmigration of neutrophils across the endothelium, and macrophage inflammatory protein 3α, which is a chemoattractant for immune cells and is essential for dendritic cell maturation. These effects were dose dependent and sustained in the absence of cytotoxicity and IL-1β release and utilized, at least in part, a signaling pathway independent from the Toll-like/IL-1 receptor adaptor protein MyD88.
PMCID: PMC1594934  PMID: 16988255

Results 1-8 (8)