Lars Pache Archives - Sanford Burnham Prebys

Tag: Lars Pache

Institute News

Our top 10 discoveries of 2020

AuthorMonica May
Date

December 14, 2020

notebook with Top 10 written at top of page

This year required dedication, patience and perseverance as we all adjusted to a new normal—and we’re proud that our scientists more than rose to the occasion.

Despite the challenges presented by staggered-shift work and remote communications, our researchers continued to produce scientific insights that lay the foundation for achieving cures.

Read on to learn more about our top 10 discoveries of the year—which includes progress in the fight against COVID-19, insights into treating deadly cancers, research that may help children born with a rare condition, and more.

  1. Nature study identifies 21 existing drugs that could treat COVID-19

    Sumit Chanda, PhD, and his team screened one of the world’s largest drug collections to find compounds that can stop the replication of SARS-CoV-2. This heroic effort was documented by the New York Times, the New York Times Magazine, TIME, NPR and additional outlets—and his team continues to work around the clock to advance these potential treatment options for COVID-19 patients.

  2. Fruit flies reveal new insights into space travel’s effect on the heart

    Wife-and-husband team Karen Ocorr, PhD, and Rolf Bodmer, PhD, shared insights that hold implications for NASA’s plan to build a moon colony by 2024 and send astronauts to Mars.

  3. Personalized drug screens could guide treatment for children with brain cancer

    Robert Wechsler-Reya, PhD, and Jessica Rusert, PhD, demonstrated the power of personalized drug screens for medulloblastoma, the most common malignant brain cancer in children.

  4. Preventing pancreatic cancer metastasis by keeping cells “sheltered in place”

    Cosimo Commisso, PhD, identified druggable targets that hold promise as treatments that stop pancreatic cancer’s deadly spread.

  5. Prebiotics help mice fight melanoma by activating anti-tumor immunity

    Ze’ev Ronai, PhD, showed that two prebiotics, mucin and inulin, slowed the growth of melanoma in mice by boosting the immune system’s ability to fight cancer.

  6. New test for rare disease identifies children who may benefit from a simple supplement

    Hudson Freeze, PhD, helped create a test that determines which children with CAD deficiency—a rare metabolic disease—are likely to benefit from receiving a nutritional supplement that has dramatically improved the lives of other children with the condition.

  7. Drug guides stem cells to desired location, improving their ability to heal

    Evan Snyder, MD, PhD, created the first drug that can lure stem cells to damaged tissue and improve treatment efficacy—a major advance for regenerative medicine.

  8. Scientists identify a new drug target for dry age-related macular degeneration (AMD)

    Francesca Marassi, PhD, showed that the blood protein vitronectin is a promising drug target for dry age-related macular degeneration (AMD), a leading cause of vision loss in Americans 60 years of age and older.

  9. Scientists uncover a novel approach to treating Duchenne muscular dystrophy

    Pier Lorenzo Puri, MD, PhD, collaborated with scientists at Fondazione Santa Lucia IRCCS and Università Cattolica del Sacro Cuore in Rome to show that pharmacological (drug) correction of the content of extracellular vesicles released within dystrophic muscles can restore their ability to regenerate muscle and prevent muscle scarring.

  10. New drug candidate reawakens sleeping HIV in the hopes of a functional cure

    Sumit Chanda, PhD, Nicholas Cosford, PhD, and Lars Pache, PhD, created a next-generation drug called Ciapavir (SBI-0953294) that is effective at reactivating dormant human immunodeficiency virus (HIV)—an approach called “shock and kill.”

Institute News

Researchers reawaken sleeping HIV in patient cells to eliminate the virus

Authorsgammon
Date

September 9, 2015

Header image

Researchers at Sanford Burnham Prebys Medical Discovery Institute (SBP) have identified a new class of drugs that may be used to purge pockets of dormant HIV from a patient’s body, eliminating the virus once and for all. Fortuitously, these agents are already being explored in clinical trials for treating cancer, which could speed up the route to approval for treating HIV.

Antiretroviral therapies have made it possible for people to live with AIDS for decades. However, small reservoirs of a patient’s cells hide the virus. That is, HIV’s genes live in the cells, but its genetic code is never read to make protein, and so the virus goes undetected by the immune system.

“If you take people off the antiretroviral therapies, some of these dormant cells reawaken to make more virus,” said lead author Lars Pache, PhD, a postdoctoral fellow in the lab of Sumit Chanda, PhD, director of the Immunity and Pathogenesis Program at SBP. “The key for a cure for HIV is to purge these cells that have dormant HIV.”

Reactivating latent HIV-infected cells so that they can be killed off once and for all is called ‘shock and kill.’ The approach has remained elusive so far, because drugs that reawaken the virus could also trigger massive immune system activation, which itself could be deadly, Chanda said.

The new study, published September 9 in the journal Cell Host & Microbe, “uses a class of drug called Smac mimetics to tap into a cell pathway that can be used to wake up the virus but, based on clinical studies and our data, doesn’t appear to activate the immune system,” Chanda added.

The study started with a broad search of genes within the host cells that help keep the virus silent. Chanda’s group identified 651 genes. They then created batches of cells in which each one of those genes was silenced, and they measured how much HIV the cells produced after they were exposed to the virus.

The scientists whittled the list of candidate genes down to 139, to 24, and then 12 using increasingly stringent criteria. The absence of one gene in particular, BIRC2, boosted the activity of HIV. Even better, Smac mimetics—already proven safe in early-stage clinical trials for cancer—works by inhibiting BIRC2 and related molecules.

“These experiments led us to develop a strategy of using Smac mimetics to reawaken dormant HIV so that we could then kill it with anti-viral therapy,” said Chanda.

Chanda’s colleague at SBP, Nicholas Cosford, PhD, professor in the Cell Death and Survival Networks Program, had recently described a potent BIRC2 inhibitor, SBI-0637142. “This drug is about 10-100 times more potent than the small molecules currently in clinic development, making it a promising candidate to tackle HIV latency,” says Chanda.

Part of the reason that HIV’s genes stay hidden in its host is that they cover themselves with tightly wound DNA. A class of drugs called histone deacetylase inhibitors, which unfurls the DNA, is used to treat a variety of conditions. Although most of these inhibitors haven’t worked well on their own to reactivate latent HIV, they might work well with Smac mimetics including SBI-0637142, Chanda’s group reasoned.

The key question was whether they could reactivate the virus in cells from HIV-infected patients undergoing antiretroviral therapy. They combined SBI-0637142 with a histone deacetylase inhibitor (panobinostat) and saw signs that the virus had reawakened without triggering immune cell death.

“We anticipated that we would see a synergy because the drugs work along parallel pathways. What we didn’t expect was the level of activation—the potency and efficacy with which we were able to reverse latency in patient samples,” Chanda said.

They saw similar results in patient cells treated with a combination of LCL161—a Smac mimetic that is already in phase 1 and 2 trials for treating cancer—and panobinostat. “This is a one-two punch for HIV,” said Chanda, adding that ultimately, a cocktail of drugs will be necessary to cure HIV.

The scientists hope to partner with a pharmaceutical company to develop these molecules for testing in animal models of HIV and then move them into the clinic if they meet the safety and efficacy criteria.

In addition to SBP, the study consortium included the University of Utah School of Medicine, The Salk Institute for Biological Studies, the Perelman School of Medicine at the University of Pennsylvania, the Icahn School of Medicine at Mount Sinai, the Paul-Ehrlich-Insitut, and the German Center for Infection Research.

This post was written by Kelly Chi, a freelance science writer.