Development of a potent Zika virus vaccine using self-amplifying messenger RNA.

Zika virus (ZIKV) is the cause of a pandemic associated with microcephaly in newborns and Guillain-Barre syndrome in adults. Currently, there are no available treatments or vaccines for ZIKV, and the development of a safe and effective vaccine is a high priority for many global health organizations. We describe the development of ZIKV vaccine candidates using the self-amplifying messenger RNA (SAM) platform technology delivered by cationic nanoemulsion (CNE) that allows bedside mixing and is particularly useful for rapid responses to pandemic outbreaks.

Establishment and maintenance of a PBMC repository for functional cellular studies in support of clinical vaccine trials.

A large repository of cryopreserved peripheral blood mononuclear cells (PBMCs) samples was created to provide laboratories testing the specimens from human immunodeficiency virus-1 (HIV-1) vaccine clinical trials the material for assay development, optimization, and validation. One hundred thirty-one PBMC samples were collected using leukapheresis procedure between 2007 and 2013 by the Comprehensive T cell Vaccine Immune Monitoring Consortium core repository. The donors included 83 human immunodeficiency virus-1 (HIV-1) seronegative and 32 HIV-1 seropositive subjects.

HLA class II restriction of HIV-1 clade-specific neutralizing antibody responses in ethnic Thai recipients of the RV144 prime-boost vaccine combination of ALVAC-HIV and AIDSVAX(®) B/E.

Immune responses to vaccines may be influenced or associated with allelic variants of host genes such as those encoding human leucocyte antigens (HLA). We have molecularly determined the HLA class II DR and DQ gene, allele and haploype profiles in HIV-1 negative ethnic Thai recipients of an HIV-1 prime boost vaccine regimen, designed to induce neutralizing antibody (NAb) responses to HIV-1 CRF01_AE. Non-response to vaccine associated with DRB1*11 (3/32 responders vs.

Equivalence of ELISpot assays demonstrated between major HIV network laboratories.

Background: The Comprehensive T Cell Vaccine Immune Monitoring Consortium (CTC-VIMC) was created to provide standardized immunogenicity monitoring services for HIV vaccine trials. The ex vivo interferon-gamma (IFN-γ) ELISpot is used extensively as a primary immunogenicity assay to assess T cell-based vaccine candidates in trials for infectious diseases and cancer. Two independent, GCLP-accredited central laboratories of CTC-VIMC routinely use their own standard operating procedures (SOPs) for ELISpot within two major networks of HIV vaccine trials.

Soluble CD4 broadens neutralization of V3-directed monoclonal antibodies and guinea pig vaccine sera against HIV-1 subtype B and C reference viruses.

To better understand the limits of antigenic reactivity and epitope accessibility of the V3 domain of primary HIV-1 isolates, we evaluated three human anti-V3 monoclonal antibodies (mAbs) and selected guinea pig vaccine sera for neutralization against reference panels of subtype B and C pseudoviruses derived from early stage infections. The mAbs and vaccine sera potently neutralized several prototype viruses, but displayed substantially less neutralization of most reference strains. In the presence of soluble CD4 (sCD4), the breadth of V3-mediated neutralization was increased; up to 80% and 77% of the subtype B and C viruses respectively were sensitive to V3-mediated neutralization.

HIV-1 envelope pseudotyped viral vectors and infectious molecular clones expressing the same envelope glycoprotein have a similar neutralization phenotype, but culture in peripheral blood mononuclear cells is associated with decreased neutralization sensitivity.

Recombinant lentiviral vectors pseudotyped with heterologous HIV-1 envelope glycoproteins allow rapid and accurate measurement of antibody-mediated HIV-1 neutralization. However, the neutralization phenotypes of envelope pseudoviruses have not been directly compared to isogenic replication competent HIV-1. We produced pseudoviruses expressing three different HIV-1 envelope glycoproteins and subcloned the same three env genes into a replication competent NL4-3 molecular clone.

Multiclade human immunodeficiency virus type 1 envelope immunogens elicit broad cellular and humoral immunity in rhesus monkeys.

The development of a human immunodeficiency virus type 1 (HIV-1) vaccine that elicits potent cellular and humoral immune responses recognizing divergent strains of HIV-1 will be critical for combating the global AIDS epidemic. The present studies were initiated to examine the magnitude and breadth of envelope (Env)-specific T-lymphocyte and antibody responses generated by vaccines containing either a single or multiple genetically distant HIV-1 Env immunogens. Rhesus monkeys were immunized with DNA prime-recombinant adenovirus boost vaccines encoding a Gag-Pol-Nef polyprotein in combination with either a single Env or a mixture of clade-A, clade-B, and clade-C Envs.

Neutralizing antibodies elicited by immunization of monkeys with DNA plasmids and recombinant adenoviral vectors expressing human immunodeficiency virus type 1 proteins.

Immunization with recombinant serotype 5 adenoviral (rAd5) vectors or a combination of DNA plasmid priming and rAd5 boosting is known to elicit potent immune responses. However, little data exist regarding these immunization strategies and the development of anti-human immunodeficiency virus type 1 (HIV-1) neutralizing antibodies. We used DNA plasmids and rAd5 vectors encoding the HIV-1 89.

Structure and mechanistic analysis of the anti-human immunodeficiency virus type 1 antibody 2F5 in complex with its gp41 epitope.

The membrane-proximal region of the ectodomain of the gp41 envelope glycoprotein of human immunodeficiency virus type 1 (HIV-1) is the target of three of the five broadly neutralizing anti-HIV-1 antibodies thus far isolated. We have determined crystal structures of the antigen-binding fragment for one of these antibodies, 2F5, in complex with 7-mer, 11-mer, and 17-mer peptides of the gp41 membrane-proximal region, at 2.0-, 2.

Specific antibody responses to vaccination with bivalent CM235/SF2 gp120: detection of homologous and heterologous neutralizing antibody to subtype E (CRF01.AE) HIV type 1.

HIV-1 CRF.AE-01 (formerly subtype E) infection is highly prevalent in Southeast Asia. Despite success with public health measures, the development of an effective CRF01.

Cellular immunity elicited by human immunodeficiency virus type 1/ simian immunodeficiency virus DNA vaccination does not augment the sterile protection afforded by passive infusion of neutralizing antibodies.

High levels of infused anti-human immunodeficiency virus type 1 (HIV-1) neutralizing monoclonal antibodies (MAbs) can completely protect macaque monkeys against mucosal chimeric simian-human immunodeficiency virus (SHIV) infection. Antibody levels below the protective threshold do not prevent infection but can substantially reduce plasma viremia. To assess if HIV-1/SIV-specific cellular immunity could combine with antibodies to produce sterile protection, we studied the effect of a suboptimal infusion of anti-HIV-1 neutralizing antibodies in macaques with active cellular immunity induced by interleukin-2 (IL-2)-adjuvanted DNA immunization.