A broadly neutralizing macaque monoclonal antibody against the HIV-1 V3-Glycan patch.

A small fraction of HIV-1- infected humans develop broadly neutralizing antibodies (bNAbs) against HIV-1 that protect macaques from simian immunodeficiency HIV chimeric virus (SHIV). Similarly, a small number of macaques infected with SHIVs develop broadly neutralizing serologic activity, but less is known about the nature of simian antibodies. Here, we report on a monoclonal antibody, Ab1485, isolated from a macaque infected with SHIVAD8 that developed broadly neutralizing serologic activity targeting the V3-glycan region of HIV-1 Env. Ab1485 neutralizes 38.1% of HIV-1 isolates in a 42-pseudovirus panel with a geometric mean IC50 of 0.055 µg/mLl and SHIVAD8 with an IC50 of 0.028 µg/mLl. Ab1485 binds the V3-glycan epitope in a glycan-dependent manner. A 3.5 Å cryo-electron microscopy structure of Ab1485 in complex with a native-like SOSIP Env trimer showed conserved contacts with the N332gp120 glycan and gp120 GDIR peptide motif, but in a distinct Env-binding orientation relative to human V3/N332gp120 glycan-targeting bNAbs. Intravenous infusion of Ab1485 protected macaques from a high dose challenge with SHIVAD8. We conclude that macaques can develop bNAbs against the V3-glycan patch that resemble human V3-glycan bNAbs.

Isolation of single HIV-1 Envelope specific B cells and antibody cloning from immunized rhesus macaques.

Antibody cloning from single B cells is an essential tool for characterizing humoral immune responses and obtaining valuable therapeutic and analytical reagents. Antibody cloning from individuals with high serologic titers to HIV-1, Influenza, Malaria and ZIKV has led to new insights that inform vaccine design efforts. In contrast to humans and mice, less is known about antibody cloning from single B cells in macaques. Here, we describe a protocol to identify and purify single antigen-specific macaque B cells, and subsequently clone and produce macaque monoclonal antibodies. The sorting strategy requires the use of a combination of fluorochrome labeled antigens and omission of anti-IgG antibodies that can interfere with antigen binding and vice versa. Optimized methods for macaque antibody gene amplification, DNA preparation for antibody production and antibody screening by ELISA are also presented.

Plasma metabolite profiles, cellular cholesterol efflux, and non-traditional cardiovascular risk in patients with CKD.

BACKGROUND: Patients with chronic kidney disease (CKD) experience high rates of atherosclerotic cardiovascular disease and death that are not fully explained by traditional risk factors. In animal studies, defective cellular cholesterol efflux pathways which are mediated by the ATP binding cassette transporters ABCA1 and ABCG1 are associated with accelerated atherosclerosis. We hypothesized that cholesterol efflux in humans would vary in terms of cellular components, with potential implications for cardiovascular disease. METHODS: We recruited 120 CKD patients (eGFR<30mL/min/1.73m2) and 120 control subjects (eGFR ≥60mL/min/1.73m2) in order to measure cholesterol efflux using either patients' HDL and THP-1 macrophages or patients' monocytes and a flow cytometry based cholesterol efflux assay. We also measured cell-surface levels of the common ß subunit of the IL-3/GM-CSF receptor (IL-3Rß) which has been linked to defective cholesterol homeostasis and may promote monocytosis. In addition, we measured plasma inflammatory cytokines and plasma metabolite profiles. RESULTS: There was a strong positive correlation between cell-surface IL-3Rß levels and monocyte counts in CKD (P<0.001). ABCA1 mRNA was reduced in CKD vs. control monocytes (P<0.05), across various etiologies of CKD. Cholesterol efflux to apolipoprotein A1 was impaired in monocytes from CKD patients with diabetic nephropathy (P<0.05), but we found no evidence for a circulating HDL-mediated defect in cholesterol efflux in CKD. Profiling of plasma metabolites showed that medium-chain acylcarnitines were both independently associated with lower levels of cholesterol transporter mRNA in CKD monocytes at baseline (P<0.05), and with cardiovascular events in CKD patients after median 2.6years of follow-up. CONCLUSIONS: Cholesterol efflux in humans varies in terms of cellular components. We report a cellular defect in ABCA1-mediated cholesterol efflux in monocytes from CKD patients with diabetic nephropathy. Unlike several traditional risk factors for atherosclerotic cardiovascular disease, plasma metabolites inversely associated with endogenous cholesterol transporters predicted cardiovascular events in CKD patients. (Funded by the National Institute of Diabetes and Digestive and Kidney DiseasesK23DK097288 and others.).

A simple method for detecting up to five immunofluorescent parameters together with DNA staining for cell cycle or viability on a benchtop flow cytometer.

In this manuscript, we describe modifications to a commercial three-laser benchtop flow cytometer, as well as relevant biological methods, that allow analysis of up to five immunofluorescent parameters together with an ultraviolet (UV)-excitable DNA stain. This method allows expanded capacity for multiparameter immunophenotyping of complex mixed cell populations, together with accurate measurements of DNA content (cell cycle) or cell viability, on a stable, end-user operated platform.