NEW YORK – Scottish bio-printing firm ArrayJet is looking to repurpose its protein array printing technology for studying SARS-CoV-2.
The Edinburgh-based company is collaborating with proteomics firm CDI Laboratories to print arrays containing synthetic SARS-CoV-2 proteins that can then be used to profile the immune responses of COVID-19 patients, said ArrayJet CEO Iain McWilliam.
ArrayJet uses inkjet printing technology to produce protein microarrays either on slides or microtiter plates for applications including glycomics, reverse phase protein array analysis, biomarker discovery, and antibody screening.
McWilliam said the company planned to use its ArrayPlex platform for the SARS-CoV-2 work. Originally developed for cancer immunotherapy research, the ArrayPlex system allows researchers to spot arrays with thousands of droplets containing SARS-CoV-2 proteins. They can then spot serum samples from COVID-19 patients or other subjects of interest on top of these protein droplets, allowing them to screen those samples for antibodies against SARS-CoV-2.
According to McWilliam, the platform is capable of screening 18,000 patient samples per instrument per day.
In its cancer immunotherapy work, "we are screening very large hybridoma antibody libraries against cancer biopsies," he said. "We have about 100 to 200 cancer biopsies, and we print those down on our chips first and then we overlay those [with antibodies of interest]. And in a typical week we will do about 5,000 to 10,000 antibodies against each of those biopsies in various numbers of replicates, so we get about two million datapoints" per week.
"Now, we're reapplying that same technology to screen libraries of patient sera against the library of viral proteins," he said.
McWilliam said the arrays could feature either bulk collections of SARS-CoV-2 proteins or the individual viral proteins spotted separately. He said that while large in vitro diagnostic companies would likely dominate the market for serology-based diagnostics, ArrayJet expects that its system might draw interest from public health labs and epidemiological labs or other researchers looking to do longer-term population scale work monitoring and tracking the development of the virus over time.
"If you are walking into the doctor's and asking for a test, I think there are other means that will be preferable," he said. "But I think this is going to be a long-term game, and I think there will be a requirement and an interest in having in-house capabilities to be able to monitor the situation closely and at very low cost, as well."
McWilliam added the company was in discussions with several large pharma firms to assess their interest in using the platform for COVID-19 vaccine work.
"They will be trialing different forms of attenuated virus or synthetic elements of the virus that are able to elicit an immune response, and they will be interested in trying to identify what kind of profiles people develop, how fast they develop against different sections of a viral proteome, and how long lasting they are," he said, noting that the high throughput of the ArrayPlex system would allow for frequent sampling of large patient cohorts over the course of a project.
ArrayJet is not producing SARS-CoV-2 protein arrays itself but is collaborating with CDI, which uses ArrayJet's technology for producing its own protein arrays, including its lead product, the HuProt array, which features 21,000 human proteins and isoforms accounting for roughly 81 percent of expressed human proteins as defined by the Human Protein Atlas.
McWilliam said the Baltimore, Maryland-based company has created a version of the HuProt array that includes a selection of SARS-CoV-2 proteins, which he said allows researchers to screen reagents like anti-SARS-CoV-2 antibodies for cross-reactivity with human proteins that could impact their performance in research or clinical assays.
The two companies are now hoping to develop collaborations with other companies and researcher centers to use the platform for screening patient samples.