Breaking News
August 19, 2018 - HPV Legislation Doesn’t Impact Teen Sexual Behaviors
August 19, 2018 - Exenatide treatment alleviated symptoms of depression in patients
August 19, 2018 - Tufts researchers win grant to study integration of genomic sequencing into neonatal care
August 19, 2018 - Novel finger-prick test can help prevent toxoplasmosis
August 19, 2018 - Cosmetic Procedures Boost Well-Being, Poll Shows
August 19, 2018 - Responsive parenting intervention results in lower BMIs through age three
August 19, 2018 - Anticancer drugs can help plants to battle infection
August 19, 2018 - Sunscreen from bathers releases significant quantities of polluting titanium dioxide into the sea
August 19, 2018 - Case Western Reserve gets three-year grant to enhance food systems in Cleveland neighborhoods
August 19, 2018 - Teenagers can thank their parents’ positive attitude for avoiding obesity
August 19, 2018 - Body mass index positively linked with blood pressure
August 19, 2018 - New tool fills gap in Small Molecules market
August 19, 2018 - Study compares survival outcomes in rural and urban cancer patients enrolled in clinical trials
August 19, 2018 - Researchers develop molecular matrix that delivers healing stem cells to injured elderly muscles
August 19, 2018 - Teva and Regeneron Announce Positive Topline Phase 3 Fasinumab Results in Patients with Chronic Pain from Osteoarthritis of the Knee or Hip
August 19, 2018 - New study pinpoints ways to improve quality of food and nutrition research
August 19, 2018 - Ology Bioservices wins $8.4 million worth agreement to manufacture anti-Ebola monoclonal antibody
August 19, 2018 - New CRISPR technology may help eliminate mutated gene sequence
August 19, 2018 - “Zombie gene” protects elephants from cancer finds study
August 19, 2018 - Study explores how many American cities protect the rights of employed breastfeeding mothers
August 19, 2018 - FDA Approves Lenvima (lenvatinib) for First-line Treatment of Unresectable Hepatocellular Carcinoma (HCC)
August 19, 2018 - Pain: Considering Complementary Approaches (eBook)
August 19, 2018 - Autoimmune response drives vision loss in glaucoma
August 19, 2018 - Tandem Diabetes Care introduces t:slim X2 Insulin Pump with Basal-IQ Technology in the US
August 19, 2018 - Innovative platform developed to destroy cancer cells
August 19, 2018 - Lowering pH inside tumor cells can slow down spread of cancer
August 19, 2018 - Biomarker predicts kidney cancer risk years before diagnosis
August 19, 2018 - Consequences of healthcare-associated infections go beyond patients’ physical health
August 19, 2018 - New drug- free, nanotechnology-based method detects and treats oral plaque
August 19, 2018 - Integration of Opioid, Infectious Disease Treatment Needed
August 19, 2018 - How eye disorders may have influenced the work of famous painters
August 18, 2018 - Blood biomarker could help predict kidney cancer up to five years prior to diagnosis
August 18, 2018 - Dartmouth scientists create more sustainable feed for aquaculture
August 18, 2018 - Immigrants Not a Burden on U.S. Health Care: Study
August 18, 2018 - Women who eat fast food take longer to become pregnant
August 18, 2018 - Most YouTube videos on plastic surgery are misleading marketing campaigns
August 18, 2018 - The essential guide to make your laboratory more sustainable
August 18, 2018 - Loyola Medicine offers scalp cooling treatment to reduce risk of chemotherapy hair loss
August 18, 2018 - Researchers describe promising strategy to remove melanoma’s most powerful defenses
August 18, 2018 - Women with polycystic ovary syndrome dissatisfied with medical care
August 18, 2018 - Research discoveries reveal insights behind neurological degeneration
August 18, 2018 - Researchers win multi-million Euro award to conduct research into liver disease
August 18, 2018 - Survey highlights variations in practice of airway management in pediatric intensive care units
August 18, 2018 - UK students win sponsorship from Promega Corporation
August 18, 2018 - Janssen Reports Positive Topline Results for ATLAS Phase III Study of a Novel, Long Acting Injectable Two-Drug Regimen for the treatment of HIV-1
August 18, 2018 - PSD as a molecular platform for understanding synapse formation and plasticity
August 18, 2018 - Improved visual communication could help patients to make informed health-care decisions
August 18, 2018 - New algorithm helps identify and manage diabetic patients at increased fracture risk
August 18, 2018 - Microscopic insect odour detecting mechanisms discovered
August 18, 2018 - Researchers develop new approach to study how tuberculosis infects people
August 18, 2018 - FDA Approves Kalydeco (ivacaftor) for Cystic Fibrosis in Children Ages 12 to
August 18, 2018 - An ion channel differentiates newborn and mature neurons in the adult brain
August 18, 2018 - Conditions of first sexual encounter can be indicators of future HIV risk and gender-based violence
August 18, 2018 - Socio-economic position associated with pregnant women’s exposure to environmental hazards
August 18, 2018 - Study evaluates how students change their breakfast consumption when given extra time
August 18, 2018 - Chronic perinatal hypoxia linked to locomotor miscoordination, long-term cerebellar learning deficits
August 18, 2018 - Voters to settle dispute over ambulance employee break times
August 18, 2018 - AGA urges policymakers and stakeholders to improve affordability of drugs
August 18, 2018 - Increasing dietary protein may lower risk of diabetes in people with NAFLD
August 18, 2018 - New HIV therapy suppresses viral replication and increases immune cells in drug-resistant patients
August 18, 2018 - Broad Genetic Testing for NSCLC May Not Improve Survival
August 18, 2018 - Discovery opens door for synthetic opioids with less addictive qualities
August 18, 2018 - Transgenic rice plant extracts could help stop the spread of HIV
August 18, 2018 - Hologic’s Cynosure division partners with Porter Instrument to distribute nitrous oxide and oxygen system
August 18, 2018 - Two thyroid medications recalled by FDA
August 18, 2018 - Forecast Sees Abnormal Heat Worldwide Through 2022
August 18, 2018 - Childhood absence epilepsy – Genetics Home Reference
August 18, 2018 - Fearing hard Brexit, UK drugmakers stockpile to protect lives
August 18, 2018 - Discovery may help broaden the scope of defenses against HPV
August 18, 2018 - When they start thinking green, they see green
August 18, 2018 - Scientists introduce microfluidics-based chip for manipulation and analysis of single cells
August 18, 2018 - Researchers design new way to grow nose cells for treating spinal cord injuries
August 18, 2018 - New light shed on relationship between calorie-burning fat and muscle function
August 18, 2018 - Surgery Saturday Instagram series takes you inside Stanford’s OR
August 18, 2018 - Researchers uncover surprising new role for inhibition in the cerebellum
August 18, 2018 - Children have better nutrition when they live near forests, global study shows
August 18, 2018 - OHSU professor conducts clinical trial with artificial pancreas using Xeris’ liquid glucagon
August 18, 2018 - HSS takes young patients with physical challenges on a surfing trip
August 18, 2018 - Study shows electronic health records leave doctors and patients unsatisfied
August 18, 2018 - Study uncovers mechanism that affects multiplication of dengue virus lineage
Researchers report technical advances in production of HIV vaccines

Researchers report technical advances in production of HIV vaccines

image_pdfDownload PDFimage_print

Research on HIV over the past decade has led to many promising ideas for vaccines to prevent infection by the AIDS virus, but very few candidate vaccines have been tested in clinical trials. One reason for this is the technical difficulty of manufacturing vaccines based on the envelope proteins of the virus, according to Phil Berman, who led development of a major component of the only vaccine to have shown any efficacy against HIV in a clinical trial.

Berman, the Baskin Professor of Biomolecular Engineering at UC Santa Cruz, has now developed new methods for the production of HIV vaccines. His approach solves major technical problems which have bedeviled the field. Berman described the new methods, and the candidate vaccines his lab has produced, in a talk at a conference on HIV vaccines held last week in Canada (“Emerging Technologies in Vaccine Discovery and Development,” a joint meeting with “Progress and Pathways Toward an Effective HIV Vaccine,” January 28 to February 1 in Banff, Alberta, part of the Keystone Symposia Global Health Series).

“Dozens of interesting vaccine candidates have been described, but most have not been tested in humans because it has not previously been possible to manufacture them affordably and in a timely fashion,” Berman said. “The technology we developed should break the logjam in HIV vaccine development, because it tremendously shortens the time, improves the yield, and lowers the cost.”

Berman’s lab was able to use robotics to shorten the time required to produce stable cell lines, needed to make the proteins for a vaccine, while at the same time greatly increasing how much of the protein the cell lines can produce. The improved yield makes it possible to reduce the size of the bioreactor needed to make vaccine for large clinical trials–from 200- to 10,000-liter vessels to 50- or 100-liter vessels–resulting in tremendous savings in the equipment required and cost of materials. In addition, Berman’s lab was able to create cell lines that make HIV envelope proteins with the right kind of carbohydrate components (called glycans) needed for an effective immune response.

“The carbohydrates attached to the protein are really important, something no one realized until recently,” Berman said. “The conventional way of making these envelope protein vaccines incorporated the wrong kind of carbohydrates. We now know that destroyed many of the important antigenic sites recognized by protective antibodies.”

Cell lines derived from Chinese hamster ovary (CHO) cells are the industry standard used to produce complex recombinant proteins for therapeutic use. These cells are also useful for the production of HIV vaccines. The gene for the desired protein is transferred into CHO cells in a process called transfection, and tens of thousands of transfected cells are screened to find the few rare cells that produce large amounts of the protein. The best cell lines are grown in large batches, in a process similar to yeast fermentation for making beer, and the proteins are then isolated and purified.

Berman’s lab developed a new robotic method to isolate high-producing cell lines making HIV envelope proteins. This shortened the time required to produce stable cell lines from 18 to 24 months to just 2 or 3 months, while increasing yields by a factor of 100 to 200. Those improvements are in comparison with Berman’s previous experience creating the AIDSVAX vaccine, first at Genentech and then at VaxGen.

AIDSVAX was one component of an experimental vaccine regimen used in a large-scale clinical trial known as RV144, which showed 31 percent efficacy in preventing new HIV infections. The RV144 results showed that protection was correlated with antibodies to a certain segment of an HIV envelope protein called gp120. Other research, however, revealed that many of the most potent antibodies (broadly neutralizing antibodies capable of neutralizing many different strains of HIV) actually recognize the carbohydrate components (glycans) attached to gp120.

“We realized that the original AIDSVAX vaccine had the completely wrong type of carbohydrate, and that we might improve the level of protection if we could find a way to make it with the proper type of carbohydrate,” Berman said.

So he and graduate student Gabriel Byrne set out to create a cell line that can produce the unusual glycans found on HIV envelope proteins rather than the complex glycans CHO cells normally produce. This was made possible by the powerful new gene editing technology known as CRISPR/Cas9. Berman’s lab used CRISPR to create a new cell line they called MGAT CHO, which produces proteins lacking complex glycans containing sialic acid and enriched for the simple “high mannose” type found on HIV envelope proteins. An unexpected benefit of this new cell line was that it enabled a simpler, less expensive process for recovering and purifying the proteins.

“People used to think carbohydrates are not immunogenic, but HIV turns everything on its head, and it turns out that the most important antibodies are directed to this unusual carbohydrate,” Berman said. “We can now make vaccines with it for the first time, and we’ve created an improved version of the vaccine used in the RV144 trial. Our hope is that it will bring the efficacy up from 31 percent to greater than 50 percent, the level likely required for product registration.”

Berman’s lab currently has two cell lines he said are ready to start producing vaccines on a large scale. He is now looking for partners and funding to bring them into clinical trials. One vaccine is an improved version of AIDSVAX that incorporates the right kind of glycans. The other is made from a strain of the virus called Clade C that is widespread in Southern Africa and India and accounts for the majority of new HIV infections worldwide.

Researchers have continued to use the AIDSVAX vaccine in clinical studies because it has been so hard to make new HIV vaccines, Berman said, noting that there have been 14 such studies since the RV144 results were released in 2009. “They’re still using that same old vaccine we made in the early 1990s. Although the stability and safety of the product is testament to the quality of the vaccine we made, new vaccines are required that take advantage of all that we have learned since that time,” he said. “It just emphasizes the need to find a more efficient way to make an HIV vaccine.”

In addition to Berman’s talk, several other members of his lab presented details of their methods and findings at the conference. Berman said they expect to publish their findings in several papers later this year. This research was funded by major grants from the National Institute of Allergy and Infectious Diseases at the National Institutes of Health.

Tagged with:

About author

Related Articles