Systemic delivery of AAV5, AAV8, and AAV9 packaging a C5-12-microdystrophin-FLAG expression cassette in non-human primates.

Safely achieving therapeutic expression levels with adeno-associated virus (AAV) gene therapy is a significant challenge for treating the large muscle mass in humans. Non-human primates (NHPs) provide a more accurate assessment of the feasibility of achieving an effective and safe dose than rodents. Here, we compared a single systemic administration of AAV5, AAV8, or AAV9 in NHPs, each packaging the C5-12-microdystrophin-FLAG expression cassette.

Quantification of surrogate monoclonal antibodies in mouse serum using LC-MS/MS.

Surrogate monoclonal antibodies (mAbs) used in preclinical studies can be challenging to quantify due to lack of suitable immunoaffinity reagents or unavailability of the mAb protein sequence. Generic immunoaffinity reagents were evaluated to develop sensitive LC-MS/MS assays. Peptides of unknown sequence can be used for selective LC-MS quantification.

A peptide immunoaffinity LC-MS/MS strategy for quantifying the GPCR protein, S1PR1 in human colon biopsies.

S1PR1, a G protein-coupled receptor (GPCR) protein, is a therapeutic target for treatment of autoimmune diseases. As a potential biomarker for drug effect and patient stratification, it is of great significance to measure it in biological samples. However, due to the hydrophobic nature of S1PR1 and the difficulties in extraction and solubilization, as well as low expression levels, quantitative determination of S1PR1 remains challenging.

Immunoaffinity microflow liquid chromatography/tandem mass spectrometry for the quantitation of PD1 and PD-L1 in human tumor tissues.

Rationale: High tumor expression of programmed cell death protein (PD1) and programmed death-ligand 1 (PD-L1) is thought to be associated with positive clinical outcomes after treatment with anti-PD1 or anti-PD-L1 agents. Several sensitive methods based on immunohistochemistry, ligand binding assay (LBA), and liquid chromatography/mass spectrometry involving the measurement of PD1 and PD-L1 expression have been reported. Here, we expand on the characterization of different tumor types using a highly specific, sensitive, and robust immunoaffinity liquid chromatography/tandem mass spectrometry (IA-LC/MS/MS)-based method for the simultaneous quantitation of PD1 and PD-L1 in tumor tissues.

LC/MS/MS-based quantitation of pig and human S100A1 protein in cardiac tissues: Application to gene therapy.

The S100A1 protein is a target of interest for the treatment of heart failure as it has been previously reported to be depleted in failing cardiomyocytes. A gene therapy approach leading to increased expression levels of the protein directly in the heart could potentially lead to restoration of contractile function and improve overall cell survival. S100A1 is a relatively small soluble protein that is extremely well conserved across species with only a single amino acid difference between the sequences in human and pig, a commonly used pre-clinical model for evaluation of efficacy, biodistribution and safety for cardiac-directed gene therapy approaches.