The influence of proline isomerization on potency and stability of anti-HIV antibody 10E8.

Monoclonal antibody (mAb) 10E8 recognizes a highly conserved epitope on HIV and is capable of neutralizing > 95% of circulating viral isolates making it one of the most promising Abs against HIV. Solution instability and biochemical heterogeneity of 10E8 has hampered its development for clinical use. We identify the source of 10E8 heterogeneity being linked to cis/trans isomerization at two prolines within the YPP motif in the CRD3 loop that exists as two predominant conformers that interconvert on a slow timescale.

Quantifying the contribution of Fc-mediated effector functions to the antiviral activity of anti-HIV-1 IgG1 antibodies in vivo.

In combating viral infections, the Fab portion of an antibody could mediate virus neutralization, whereas Fc engagement of Fc-γ receptors (FcγRs) could mediate an array of effector functions. Evidence abounds that effector functions are important in controlling infections by influenza, Ebola, or HIV-1 in animal models. However, the relative contribution of virus neutralization versus effector functions to the overall antiviral activity of an antibody remains unknown.

Engineering multi-specific antibodies against HIV-1.

As increasing numbers of broadly neutralizing monoclonal antibodies (mAbs) against HIV-1 enter clinical trials, it is becoming evident that combinations of mAbs are necessary to block infection by the diverse array of globally circulating HIV-1 strains and to limit the emergence of resistant viruses. Multi-specific antibodies, in which two or more HIV-1 entry-targeting moieties are engineered into a single molecule, have expanded rapidly in recent years and offer an attractive solution that can improve neutralization breadth and erect a higher barrier against viral resistance. In some unique cases, multi-specific HIV-1 antibodies have demonstrated vastly improved antiviral potency due to increased avidity or enhanced spatiotemporal functional activity.

In Vivo Production of Monoclonal Antibodies by Gene Transfer via Electroporation Protects against Lethal Influenza and Ebola Infections.

Monoclonal antibodies (mAbs) have wide clinical utility, but global access is limited by high costs and impracticalities associated with repeated passive administration. Here, we describe an optimized electroporation-based DNA gene transfer platform technology that can be utilized for production of functional mAbs in vivo, with the potential to reduce costs and administration burdens. We demonstrate that multiple mAbs can be simultaneously expressed at protective concentrations for a protracted period of time using DNA doses and electroporation conditions that are feasible clinically.

Distinct HIV-1 Neutralization Potency Profiles of Ibalizumab-Based Bispecific Antibodies.

Background: Preexposure prophylaxis using antiretroviral agents has been shown to effectively prevent human immunodeficiency virus type 1 (HIV-1) acquisition in high-risk populations. However, the efficacy of these regimens is highly variable, which is thought to be largely due to the varying degrees of adherence to a daily intervention in the populations. Passive immunization using broadly neutralizing antibodies (bNAbs) against HIV-1, with their relatively long half-life and favorable safety profile, could provide an alternative to daily preexposure prophylaxis.

Engineered Bispecific Antibodies with Exquisite HIV-1-Neutralizing Activity.

While the search for an efficacious HIV-1 vaccine remains elusive, emergence of a new generation of virus-neutralizing monoclonal antibodies (mAbs) has re-ignited the field of passive immunization for HIV-1 prevention. However, the plasticity of HIV-1 demands additional improvements to these mAbs to better ensure their clinical utility. Here, we report engineered bispecific antibodies that are the most potent and broad HIV-neutralizing antibodies to date.

Optimization of the Solubility of HIV-1-Neutralizing Antibody 10E8 through Somatic Variation and Structure-Based Design.

Unlabelled: Extraordinary antibodies capable of near pan-neutralization of HIV-1 have been identified. One of the broadest is antibody 10E8, which recognizes the membrane-proximal external region (MPER) of the HIV-1 envelope and neutralizes >95% of circulating HIV-1 strains. If delivered passively, 10E8 might serve to prevent or treat HIV-1 infection.

Colocalization of a CD1d-Binding Glycolipid with a Radiation-Attenuated Sporozoite Vaccine in Lymph Node-Resident Dendritic Cells for a Robust Adjuvant Effect.

A CD1d-binding glycolipid, α-Galactosylceramide (αGalCer), activates invariant NK T cells and acts as an adjuvant. We previously identified a fluorinated phenyl ring-modified αGalCer analog, 7DW8-5, displaying nearly 100-fold stronger CD1d binding affinity. In the current study, 7DW8-5 was found to exert a more potent adjuvant effect than αGalCer for a vaccine based on radiation-attenuated sporozoites of a rodent malaria parasite, Plasmodium yoelii, also referred to as irradiated P.

Rational design and characterization of the novel, broad and potent bispecific HIV-1 neutralizing antibody iMabm36.

Background: Although broadly neutralizing monoclonal antibodies (bNAbs) have always been considered to be a potential therapeutic option for the prophylaxis and treatment of HIV infection, their lack of breadth against all HIV variants has been one of the limiting factors. To provide sufficient neutralization breadth and potency against diverse viruses, including neutralization escape mutants, strategies to combine different bNAbs have been explored recently.

Methods: We rationally designed and engineered a novel bispecific HIV-1-neutralizing antibody (bibNAb), iMabm36.

A glycolipid adjuvant, 7DW8-5, enhances CD8+ T cell responses induced by an adenovirus-vectored malaria vaccine in non-human primates.

A key strategy to a successful vaccine against malaria is to identify and develop new adjuvants that can enhance T-cell responses and improve protective immunity. Upon co-administration with a rodent malaria vaccine in mice, 7DW8-5, a recently identified novel analog of α-galactosylceramide (α-GalCer), enhances the level of malaria-specific protective immune responses more strongly than the parent compound. In this study, we sought to determine whether 7DW8-5 could provide a similar potent adjuvant effect on a candidate human malaria vaccine in the more relevant non-human primate (NHP) model, prior to committing to clinical development.

Clinical development of a novel CD1d-binding NKT cell ligand as a vaccine adjuvant.

Natural killer T (NKT) cells are known to play a role against certain microbial infections, including malaria and HIV, two major global infectious diseases. Strategies that can harness and amplify the immunotherapeutic potential of NKT cells can serve as powerful tools in the fight against such diseases. 7DW8-5, a novel glycolipid, may be one such tool.

Nuclear shape, growth and integrity in the closed mitosis of fission yeast depend on the Ran-GTPase system, the spindle pole body and the endoplasmic reticulum.

The double lipid bilayer of the nuclear envelope (NE) remains intact during closed mitosis. In the fission yeast Schizosaccharomyces pombe, the intranuclear mitotic spindle has envelope-embedded spindle pole bodies (SPB) at its ends. As the spindle elongates and the nucleus divides symmetrically, nuclear volume remains constant but nuclear area rapidly increases by 26%.

The cell-end factor pom1p inhibits mid1p in specification of the cell division plane in fission yeast.

Intrinsic spatial cues ensure the proper placement of the cell division plane. In the fission yeast Schizosaccharomyces pombe, the position of the nucleus helps to direct the medial positioning of contractile-ring assembly and subsequent cell division . An important factor in this process is mid1p (anillin-like protein), which is a peripheral-membrane protein that forms a broad cortical band of dots overlying the nucleus in interphase and recruits myosin in early mitosis .

Infectivity and replication capacity of drug-resistant human immunodeficiency virus type 1 variants isolated during primary infection.

It is believed that replication capacity is an important determinant of human immunodeficiency virus type 1 (HIV-1) pathogenicity and transmissibility. To explore this, we conducted a comprehensive analysis of the replication properties of nine drug-resistant and nine drug-susceptible viral isolates derived from patients with primary HIV-1 infection. Viral isolates were tested for single-cycle infectivity in the GHOST cell line.

Determining the antiviral activity of tenofovir disoproxil fumarate in treatment-naive chronically HIV-1-infected individuals.

Objective: To assess the efficacy of tenofovir disoproxil fumarate (TDF) monotherapy by following the initial rate of decline in plasma viral load, which is a measure of the efficacy of therapy in blocking viral replication.

Design: An open-label, single-site study of TDF monotherapy in 10 antiretroviral drug-naive chronically HIV-1-infected individuals.

Methods: Antiviral responses were assessed at baseline and during 21 days of monotherapy with TDF by measuring plasma HIV-1 RNA levels.