Locations of three repetitive sequence families found in BALB/c adult β-globin clones

Three different repeat sequences have been mapped within the cloned EcoRI fragments that Contain the adult β-globin genes from the BALB/c (Hd

Evaluation of protection induced by a dengue virus serotype 2 envelope domain III protein scaffold/DNA vaccine in non-human primates

AbstractWe describe the preclinical development of a dengue virus vaccine targeting the dengue virus serotype 2 (DENV2) envelope domain III (EDIII). This study provides proof-of-principle that a dengue EDIII protein scaffold/DNA vaccine can protect against dengue challenge. The dengue vaccine (EDIII-E2) is composed of both a protein particle and a DNA expression plasmid delivered simultaneously via intramuscular injection (protein) and gene gun (DNA) into rhesus macaques. The protein component can contain a maximum of 60 copies of EDIII presented on a multimeric scaffold of Geobacillus stearothermophilus E2 proteins. The DNA component is composed of the EDIII portion of the envelope gene cloned into an expression plasmid. The EDIII-E2 vaccine elicited robust antibody responses to DENV2, with neutralizing antibody responses detectable following the first boost and reaching titers of greater than 1:100,000 following the second and final boost. Vaccinated and naïve groups of macaques were challenged with DENV2. All vaccinated macaques were protected from detectable viremia by infectious assay, while naïve animals had detectable viremia for 2–7 days post-challenge. All naïve macaques had detectable viral RNA from day 2–10 post-challenge. In the EDIII-E2 group, three macaques were negative for viral RNA and three were found to have detectable viral RNA post challenge. Viremia onset was delayed and the duration was shortened relative to naïve controls. The presence of viral RNA post-challenge corresponded to a 10–30-fold boost in neutralization titers 28 days post challenge, whereas no boost was observed in the fully protected animals. Based on these results, we determine that pre-challenge 50% neutralization titers of >1:6000 correlated with sterilizing protection against DENV2 challenge in EDIII-E2 vaccinated macaques. Identification of the critical correlate of protection for the EDIII-E2 platform in the robust non-human primate model lays the groundwork for further development of a tetravalent EDIII-E2 dengue vaccine

Phagocytosis by an HIV antibody is associated with reduced viremia irrespective of enhanced complement lysis

Increasingly, antibodies are being used to treat and prevent viral infections. In the context of HIV, efficacy is primarily attributed to dose-dependent neutralization potency and to a lesser extent Fc-mediated effector functions. It remains unclear whether augmenting effector functions of broadly neutralizing antibodies (bNAbs) may improve their clinical potential. Here, we use bNAb 10E8v4 targeting the membrane external proximal region (MPER) to examine the role of antibody-mediated effector and complement (C’) activity when administered prophylactically against SHIV challenge in rhesus macaques. With sub-protective dosing, we find a 78–88% reduction in post-acute viremia that is associated with 10E8v4-mediated phagocytosis acting at the time of challenge. Neither plasma nor tissue viremic outcomes in vivo is improved with an Fc-modified variant of 10E8v4 enhanced for C’ functions as determined in vitro. These results suggest that effector functions inherent to unmodified 10E8v4 contribute to efficacy against SHIVSF162P3 in the absence of plasma neutralizing titers, while C’ functions are dispensable in this setting, informing design of bNAb modifications for improving protective efficacy

Recommendations for the design and use of standard virus panels to assess neutralizing antibody responses elicited by candidate Human Immunodeficiency Virus Type 1 vaccines.

Guest commentary.No abstract available

Hepatocytic expression of human sodium-taurocholate cotransporting polypeptide enables hepatitis B virus infection of macaques

Hepatitis B virus (HBV) is a major global health concern, and the development of curative therapeutics is urgently needed. Such efforts are impeded by the lack of a physiologically relevant, pre-clinical animal model of HBV infection. Here, we report that expression of the HBV entry receptor, human sodium-taurocholate cotransporting polypeptide (hNTCP), on macaque primary hepatocytes facilitates HBV infection in vitro, where all replicative intermediates including covalently closed circular DNA (cccDNA) are present. Furthermore, viral vector-mediated expression of hNTCP on hepatocytes in vivo renders rhesus macaques permissive to HBV infection. These in vivo macaque HBV infections are characterized by longitudinal HBV DNA in serum, and detection of HBV DNA, RNA, and HBV core antigen (HBcAg) in hepatocytes. Together, these results show that expressing hNTCP on macaque hepatocytes renders them susceptible to HBV infection, thereby establishing a physiologically relevant model of HBV infection to study immune clearance and test therapeutic and curative approaches

AminoTrack TM: Automating the Entry and Analysis of Mutations in Multiple Protein Sequences Using a Spreadsheet Format

AminoTrack TM is a web based tool designed to increase the efficiency with which sequence data is recorded for further analysis. The main purpose of AminoTrack TM is to streamline the process and reduce human error in the identification of mutations present in multiple sequences compared to a reference sequence. Aligned protein sequences are entered in the web submission form and comma delimited files are generated in a zip file for loading into a spreadsheet. These files can be imported into any spreadsheet program that recognizes comma delimited files such as Microsoft Excel or SPSS. The sequences are analyzed for mutations in amino acids, charge changes, and potential N-linked glycosylation sites (PNG). The data may be viewed in a spreadsheet in a columnar binary format of “0 ” and “1 ” with one amino acid position per column. Currently this program is being used to identify mutations in viral proteins as these proteins evolve during infection

Passive and active antibody studies in primates to inform HIV vaccines

Introduction: Prevention of infection remains the ultimate goal for HIV vaccination, and there is compelling evidence that antibodies directed to Envelope are necessary to block infection. Generating antibodies that are sufficiently broad, potent, and sustained to block infection by the diverse HIV-1 strains circulating worldwide remains an area of intense study. Areas covered: In this review, we have summarized progress from publications listed as PubMed citations in 2016–17 in the areas of passive antibody studies using human neutralizing monoclonal antibodies in nonhuman primates, HIV Envelope vaccine development and active vaccination studies to generate potent neutralizing antibodies. Expert commentary: Passive transfer studies in nonhuman primates using human neutralizing monoclonal antibodies have informed the potency, specificity, and cooperativity of antibodies needed to prevent infection, leading to clinical studies now testing potent antibodies for prevention of HIV. Progress in understanding the structure of Envelope has led to novel vaccine constructs, including mimetics, scaffolds and native-like proteins. As yet, no single approach ensures protection against the circulating global HIV-1 strains, but there is progress in understanding why, and intense research continues in these and other areas for a solution. We offer perspectives on how this knowledge may shape the design of future HIV vaccines

REVIEW Open Access

SIV infection of rhesus macaques of Chinese origin: a suitable model for HIV infection in human

The Infectious Molecular Clone and Pseudotyped Virus Models of Human Immunodeficiency Virus Type 1 Exhibit Significant Differences in Virion Composition with Only Moderate Differences in Infectivity and Inhibition Sensitivity ▿

Two frequently employed methods for generating well-characterized, genetically defined infectious human immunodeficiency virus type 1 in vitro include the use of infectious molecular clones (IMCs) and pseudoviruses (PVs) competent for single-round infection. We compared six matched pairs of IMCs and PVs. The relative amounts of Env incorporated and efficiency of cleavage differed substantially between the two systems. Altering the ratio of proviral genome and env expression plasmids can produce pseudovirions that are structurally more similar to the matched IMCs. Differences in Env incorporation and cleavage translated into moderate differences in assays infectivity and sensitivity to neutralizing antibodies and entry inhibitors