The grant money will support research and development of a series of CRISPR-Cas-based screening tests that would be used in homes and healthcare settings for blood-based early detection of HIV RNA with results within 30 minutes.
"Our goal is to develop a test kit that is not only highly advanced but also user-friendly, like a reliable alarm that detects potential issues before they escalate," Piyush Jain, assistant professor of chemical engineering at the University of Florida, said in a statement. "This research is crucial given the staggering global impact of HIV and the critical need for early detection."
Jain said in an interview that his team is working on a test that combines CRISPR-Cas12b with a reverse transcription loop-mediated isothermal amplification (RT-LAMP)-based assay and fluorescent reporter molecules that allow for visual or sensor-based detection.
According to the NIH, about 39,000 HIV infections are identified in the US each year, with the number worldwide growing to about 1.7 million people, of which 20 percent are unaware that they are infected.
The University of Florida said that during the early weeks of an HIV infection, an infected individual, who doesn't know they may be infected, can transmit the virus to an uninfected individual. However, promising early results from Jain's team suggest their test could help to identify infections during those early weeks with a platform that is affordable, accurate, user-friendly, rapid, equipment-free, and portable. In turn, that could reduce the number of infections resulting from individuals who are unaware of their HIV status.
Molecular early testing for HIV is already available at the point of care. In April, Cepheid secured prequalification status from the World Health Organization for its Xpert HIV-1 Qual XC test that allows the detection of infections from dried blood spot samples up to 10 days before seroconversion.
OraSure Technologies also already offers an HIV self-test, the OraQuick In-Home HIV Test, and the company secured in 2022 a federal contract for up to 1 million of those tests. That test is used to detect antibodies to HIV-1/2 in an oral swab sample with results in about 20 minutes. However, the company notes on its website that post-exposure HIV detection may take up to three months while antibodies to the virus are developed.
In a statement, OraSure spokesperson Amy Koch said, "As an innovator and advocate for HIV self-testing globally, we applaud all efforts to expand access to HIV testing. Our OraQuick HIV Self-Test, using a simple oral swab, remains the only HIV self-test approved in the US and is a valuable tool in the fight against the spread of HIV."
In the CRISPR space, a growing list of academic researchers and companies are pursuing diagnostics based on the technology. Sherlock Biosciences became an early leader in the field with the US Food and Drug Administration's 2020 Emergency Use Authorization of the company's CRISPR SARS-CoV-2 kit, and the firm has been planning to launch an assay design service that would help others develop CRISPR-based diagnostics. Mammoth Biosciences also secured in 2022 FDA EUA for its CRISPR-based COVID-19 assay.
Others such as Proof Diagnostics, and a team from Rice University and the University of Connecticut have also entered the fray with work on SARS-CoV-2 assays. Meanwhile, VedaBio said it has developed a CRISPR-based method of one-minute detection of nucleic acids, and a team from the Broad Institute, Harvard University, and Princeton University recently described their work on the development of four assays for the detection and differentiation of flu A/B and subtypes H1N1 and H3N2 with 100 percent concordance with quantitative RT-PCR assays.
The NIH awarded the funding to Jain's team through a funding opportunity for self-tests that could be used during the earliest phases of acute infection or during periods of viral rebound. The NIH is providing $1.3 million for those development activities over the next three years and another $1.5 million will become available for two years of clinical testing. According to information from the NIH's website, the $1.5 million is contingent on Jain's team achieving certain milestones.
The work by Jain's lab on the HIV test follows similar development of an assay that coupled CRISPR-Cas12b with a LAMP assay for the detection and differentiation of SARS-CoV-2 variants of concern. Jain coauthored a 2022 report in eBioMedicine on the team's progress toward developing a low-cost point-of-care assay that performed with 93 percent sensitivity, 99 percent specificity, and 97 percent overall accuracy in testing on 208 saliva samples, with results in 10-30 minutes.
The research team also reported last year in Cell Reports Medicine on the use of machine learning tools to engineer a Cas12b-based assay with Cas thermostability that allows enzymatic activity at higher temperatures that would allow more flexibility for pairing it with a LAMP assay.
The NIH reported that the researchers have been following up on those results with work on an assay and an automated microfluidic device that could be used for the visual detection of HIV RNA in plasma at a concentration of 1,000 copies per milliliter. After achieving those goals, the team will recruit 200 patients to perform the self-test and evaluate its performance in self-testing.
Jain said that the clinical studies will include evaluations on whether patients are comfortable with the testing process and surveys to assess whether people would want such a test considering the stigma attached to HIV testing.
The recently announced grant will support the development of multiple versions of the test, the first of which will use a heating phase to inactivate the virus and extract RNA ahead of the RT-LAMP assay and CRISPR-Cas12b-based detection in a palm-size testing instrument, Jain said. The team has developed a prototype of a palm-sized reusable reader that would be used with microfluidic paper-based test strips.
Because the test uses a heating step to inactivate the virus, the testing instrument could use either a USB cable or batteries to supply electricity, Jain said.
The researchers also hope that further refinements could lead to the development of a room temperature assay that could be used for visual detection.
Jain said that the test has so far performed with 100 percent accuracy in an initial study on frozen samples from 11 HIV-positive patients and 11 controls. While he said that the test matched with PCR results in a second study, he said that both methods failed to detect some HIV-positive samples and he suspects that the samples used in that study had been compromised during freeze and thaw cycles. With support from the NIH grant, he said that the team will collect more samples for further testing.
Jain noted that the research out of his 20-person lab could lead to the production of a handheld device that will use finger prick-collected samples on test strips that will be slightly larger than those used in glucose meters. The testing devices could cost about $20 each, and the microfluidic test strips could cost about $1 each.
As for regulatory pathways, Jain said that the test could be brought to market through the US Food and Drug Administration's de novo authorization because he knows of no FDA-approved predicate devices. He added that FDA officials have explained the requirements in previous discussions about the research team's SARS-CoV-2 test, including the data that a company needs to provide to show an individual can perform a self-test and interpret the results.
Jain said that his diagnostics spinout company, CasNx, has established a laboratory through the University of Florida's biotech incubator, and it may license the technologies that his lab developed for the HIV test for the development of a commercial assay. He has begun discussions with the university on licensing some testing technologies that were developed in his lab, though no agreements have been signed. He declined to provide further information about potential deals.
"We have built a number of different diagnostic platform technologies in the lab, and hopefully, if the HIV test … is also successful, then we can potentially also license it," he said.