Scientists from ARUP, The Ohio State University, UC Davis, and Luminex presented data from xMAP®-based assays in our user group meeting
We always look forward to xMAP Connect user group meetings—not only do they give scientists a chance to share their experiences with xMAP® Technology, but they offer deep dives into the amazing research enabled by our multiplexing platform. At the most recent event in La Jolla, CA, several scientists spoke about the work they’ve been doing.
The Clinical Utilizy of Cytokine Testing
Thomas Martins from the ARUP Institute for Experimental and Clinical Pathology spoke about the clinical utility of cytokine testing. These proteins are important for most immune responses and can be measured to detect problems such as cytokine storm syndrome, which often occurs in patients with severe COVID-19.
Martins and his team have been working with xMAP Technology since the late 1990s and have offered xMAP-based testing through their reference laboratory since the early 2000s. Their cytokine assay, an xMAP-based 13-plex panel test, saw demand soar from an average of about 2,000 to 3,000 tests per month to about 40,000 tests per month early in the COVID-19 pandemic. Most customers were primarily interested in IL-6 data, since the sickest patients experienced 1,000-fold increases in their IL-6 levels, and so Martins and his team quickly developed a single-analyte test to meet demand. “As a test developer, we really like the flexibility of [xMAP Technology],” he said, calling it “a robust, versatile, and flexible platform.”
Bead-based Neutralization Antibody Assay
The xMAP platform is also popular for assessing response to vaccines, which was the focus of two xMAP Connect presentations. In one, Resmi Ravindran from the University of California, Davis, spoke about a bead-based neutralization antibody assay for assessing the efficacy of COVID-19 vaccines. Alternative tests, such as a whole virus neutralization test, take several days to run and require BSL-3 facilities.
The high-throughput xMAP-based test designed by Bio-Rad, however, takes just a few hours and can be run in any laboratory to detect SARS-CoV-2 neutralizing antibodies. In studies of human samples, Ravindran’s team was able to use the test to evaluate the efficacy of the Pfizer and Moderna mRNA vaccines. They have also performed studies in a number of animal models, finding high correlation between neutralizing and binding antibodies in some cases.
B-cell Epitope Peptide-based Cancer Vaccine
In another vaccine presentation, Linlin Guo and Jay Overholser from The Ohio State University Wexner Medical Center spoke about their efforts to develop and evaluate B cell epitope peptide-based cancer vaccines. The treatment is designed to boost B cell and T cell activity for a more effective immune response to cancer. They’ve worked on both a PD-1 vaccine and a PD-L1 vaccine, finding that combinations of treatments can be more effective than any treatment alone.
The vaccines are studied by immunizing mice and then challenging them with tumor cells. These preclinical studies have shown that vaccinated mice have significantly less tumor growth compared to controls, Guo said. The team is using an xMAP-based panel to study cytokine release and has been working with the xMAP INTELLIFLEX® System’s dual reporter capability to evaluate PD-1 and PD-L1 antibodies.
A Multiplex Test For Early-stage Bladder Cancer
We were also excited to hear from Charles Rosser, a research scientist and professor of biomedical sciences at Cedars-Sinai Medical Center in Los Angeles, about his work using xMAP Technology to support the development of Oncuria®, a multiplex test for early-stage bladder cancer. The assay is slated to launch soon as a laboratory-developed test, and Rosser said he expects it to lead to a “major shift” in the care of patients with bladder cancer.
A small clinical utility study for this new approach indicated that doctors would reduce the number of alternative tests ordered for these patients should they receive clear results from Rosser’s test.
Technical Considerations For Bead Coupling
xMAP Connect attendees also gained valuable time with our team’s technical experts. Stephen Angeloni, a Senior Field Application Scientist at Luminex, offered a deep dive into the technical considerations for bead coupling. Examples of molecules suitable for coupling include purified proteins or antigens, peptides, small molecules, and carbohydrates.
Angeloni recommended that users consult the xMAP® Cookbook for easy-to-follow protocols, lists of the reagents, and equipment needed. He also reviewed the coupling chemistry workflow, which involves repeated washing and incubation cycles, as well as the option to use microgram or picomolar coupling to generate the best signal. Finally, he walked through four Excel worksheet-based calculators to help xMAP users perform the coupling process correctly.
All presentations from xMAP Connect in La Jolla are now available for on-demand viewing in our xMAP Connect Virtual event platform on Labroots. Our next in-person xMAP Connect meeting will be taking place in Atlanta, GA on November 2, 2023. Stay tuned for more information. We hope to see you there!