Transcriptome analysis in rhesus macaques infected with hepatitis E virus genotype 1/3 infections and genotype 1 re-infection.

Hepatitis E virus (HEV) genotype 1 (gt1) and gt3 infections have distinct epidemiologic characteristics and genotype-specific molecular mechanisms of pathogenesis are not well characterized. Previously, we showed differences in immune response-related gene expression profiles of HEV gt1 and gt3 infections using qPCR. We hypothesize that HEV gt1 and gt3 infections induce transcriptome modifications contributing to disease pathogenesis.

Feasibility of Hepatitis B Vaccination by Microneedle Patch: Cellular and Humoral Immunity Studies in Rhesus Macaques.

Background: This study evaluated dissolvable microneedle patch (dMNP) delivery of hepatitis B vaccine in rhesus macaques and provides evidence that dMNP delivery elicits seroprotective anti-HBs levels comparable with human seroprotection, potentially useful for hepatitis B birth dose vaccination in resource-constrained regions.

Methods: Sixteen macaques were each vaccinated twice; they were treated in 4 groups, with dMNP delivery of AFV at 24 ± 8 µg (n = 4) or 48 ± 14 µg (n = 4), intramuscular injection of AFV (10 µg; n = 4), or intramuscular injection of AAV (10 µg; n = 4). Levels of antibody to hepatitis B surface antigen (HBsAg) (anti-HBs) and HBsAg-specific T-cell responses were analyzed.

Analysis of IgG Anti-HEV Antibody Protective Levels During Hepatitis E Virus Reinfection in Experimentally Infected Rhesus Macaques.

Background: Secondary spread of hepatitis E virus (HEV) infection occurs often in endemic settings in developing countries. The host immune signatures contributing to protection against subsequent HEV reinfection are unknown.

Methods: Twelve seroconverted rhesus macaques were reinoculated with homologous HEV genotype 1 (gt1, Sar-55) and followed for 115 days.

Disparities in detection of antibodies against hepatitis E virus in US blood donor samples using commercial assays.

Background: Reported hepatitis E virus (HEV) antibody assay performance characteristics are variable. Using a subset of surplus US blood donation samples, we compared assays for detecting anti-HEV immunoglobulin M (Ig)M and IgG or total anti-HEV antibodies.

Study Design And Methods: Samples from 5040 random blood donations, all HEV-RNA negative, collected primarily in the midwestern United States in 2015 were tested for anti-HEV IgM and IgG or total anti-HEV using assays manufactured by Diagnostic Systems, Wantai, and MP Biomedicals.

Ionic derivatives of betulinic acid exhibit antiviral activity against herpes simplex virus type-2 (HSV-2), but not HIV-1 reverse transcriptase.

Betulinic acid (1) has been modified to ionic derivatives (2-5) to improve its water solubility and biological activities. The binding properties of these derivatives with respect to human serum albumin (HSA) was examined and found to be similar to current anti-HIV drugs. These compounds did not inhibit HIV reverse transcriptase, however, 1, 2 and 5 inhibited herpes simplex type 2 (HSV-2) replication at concentrations similar to those reported for acyclovir (IC50 ∼ 0.

Loss of Cell Surface CD47 Clustering Formation and Binding Avidity to SIRPα Facilitate Apoptotic Cell Clearance by Macrophages.

CD47, a self recognition marker expressed on tissue cells, interacts with immunoreceptor SIRPα expressed on the surface of macrophages to initiate inhibitory signaling that prevents macrophage phagocytosis of healthy host cells. Previous studies suggested that cells may lose surface CD47 during aging or apoptosis to enable phagocytic clearance. In the current study, we demonstrate that the level of cell surface CD47 is not decreased, but the distribution pattern of CD47 is altered, during apoptosis.

Exosome-associated hepatitis C virus in cell cultures and patient plasma.

Hepatitis C virus (HCV) infects its target cells in the form of cell-free viruses and through cell-cell contact. Here we report that HCV is associated with exosomes. Using highly purified exosomes and transmission electron microscopic imaging, we demonstrated that HCV occurred in both exosome-free and exosome-associated forms.

'Clustering' SIRPα into the plasma membrane lipid microdomains is required for activated monocytes and macrophages to mediate effective cell surface interactions with CD47.

SIRPα, an ITIMs-containing signaling receptor, negatively regulates leukocyte responses through extracellular interactions with CD47. However, the dynamics of SIRPα-CD47 interactions on the cell surface and the governing mechanisms remain unclear. Here we report that while the purified SIRPα binds to CD47 and that SIRPα is expressed on monocytes and monocytic THP-1 or U937, these SIRPα are ineffective to mediate cell binding to immobilized CD47.

CD47 deficiency does not impede polymorphonuclear neutrophil transmigration but attenuates granulopoiesis at the postacute stage of colitis.

Previous studies have suggested that CD47, an essential cell-surface protein, plays an important role in polymorphonuclear neutrophil (PMN) transmigration across tissue cells and extracellular matrix. In the current study, the role of CD47 in PMN transmigration and infiltration into tissues was further evaluated by investigating the function of CD47(-/-) PMN and inflammatory conditions induced in CD47(-/-) mice. Using in vitro time-course assays, we found that CD47(-/-) PMN exhibited no impediment, but slightly enhanced response to and transmigration toward, the chemoattractant fMLF.

Deletion of specific immune-modulatory genes from modified vaccinia virus Ankara-based HIV vaccines engenders improved immunogenicity in rhesus macaques.

Modified vaccinia virus Ankara (MVA) is a safe, attenuated orthopoxvirus that is being developed as a vaccine vector but has demonstrated limited immunogenicity in several early-phase clinical trials. Our objective was to rationally improve the immunogenicity of MVA-based HIV/AIDS vaccines via the targeted deletion of specific poxvirus immune-modulatory genes. Vaccines expressing codon-optimized HIV subtype C consensus Env and Gag antigens were generated from MVA vector backbones that (i) harbor simultaneous deletions of four viral immune-modulatory genes, encoding an interleukin-18 (IL-18) binding protein, an IL-1β receptor, a dominant negative Toll/IL-1 signaling adapter, and CC-chemokine binding protein (MVAΔ4-HIV); (ii) harbor a deletion of an additional (fifth) viral gene, encoding uracil-DNA glycosylase (MVAΔ5-HIV); or (iii) represent the parental MVA backbone as a control (MVA-HIV).

Advances in methods for the production, purification, and characterization of HIV-1 Gag-Env pseudovirion vaccines.

HIV pseudovirion or virus-like particle vaccines represent a promising approach for eliciting humoral and cellular immune responses. Pseudovirions present the envelope glycoprotein complex in its authentic trimeric form, and thus have the potential to generate neutralizing antibodies against relevant virion-associated epitopes that may be lacking in protein subunit vaccines. The development of pseudovirion particles as a viable vaccine approach for progression to clinical testing has been limited by a number of factors, including shedding of particle-associated gp120, practical limitations to large-scale production and purification, and the generation of antibodies against cellular proteins incorporated on the particle surface that confound the analysis of HIV-specific neutralizing antibody responses.

Direct comparison of antigen production and induction of apoptosis by canarypox virus- and modified vaccinia virus ankara-human immunodeficiency virus vaccine vectors.

Recombinant poxvirus vectors are undergoing intensive evaluation as vaccine candidates for a variety of infectious pathogens. Avipoxviruses, such as canarypox virus, are replication deficient in mammalian cells by virtue of a poorly understood species-specific restriction. Highly attenuated vaccinia virus strains such as modified vaccinia virus Ankara (MVA) are similarly unable to complete replication in most mammalian cells but have an abortive-late phenotype, in that the block to replication occurs post-virus-specific DNA replication.