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Department of Physics & Astronomy at the University of Utah

A New Way to Nip AIDS in the Bud

Protease might become a friend instead of foe in fighting HIV

University of Utah researchers Saveez Saffarian and Mourad Bendjennat conducted a study suggesting a possible future approach to fighting AIDS. Current drugs inhibit a protein named protease to prevent HIV from replicating and infecting news cells. In laboratory experiments, the Utah scientists found a way to use protease itself to destroy the virus instead of helping it spread. Photo credit: Shanti Deemyad, University of Utah

Jun 9, 2016 – When new AIDS virus particles bud from an infected cell, an enzyme named protease activates to help the viruses mature and infect more cells. That’s why modern AIDS drugs control the disease by inhibiting protease.

Now, University of Utah researchers found a way to turn protease into a double-edged sword: They showed that if they delay the budding of new HIV particles, protease itself will destroy the virus instead of helping it spread. They say that might lead, in about a decade, to new kinds of AIDS drugs with fewer side effects.

“We could use the power of the protease itself to destroy the virus,” says virologist Saveez Saffarian, an associate professor of physics and astronomy at the University of Utah and senior author of the study released today by PLOS Pathogens, an online journal published by the Public Library of Science.

So-called cocktails or mixtures of protease inhibitors emerged in the 1990s and turned acquired immune deficiency syndrome into a chronic, manageable disease for people who can afford the medicines. But side effects include fat redistribution in the body, diarrhea, nausea, rash, stomach pain, liver toxicity, headache, diabetes and fever.

“They have secondary effects that hurt patients,” says Mourad Bendjennat, a research assistant professor of physics and astronomy and the study’s first author. “And the virus becomes resistant to the inhibitors. That’s why they use cocktails.”

Bendjennat adds that by discovering the molecular mechanism in which protease interacts with HIV, “we are developing a new approach that we believe may be very efficient in treating the spread of HIV.”

However, he and Saffarian emphasize the research is basic, and that it will be a decade before more research might develop the approach into news AIDS treatments.

Figuring out the role of protease in HIV budding

Inside a cell infected by HIV, new virus particles are constructed largely with a protein named Gag. Protease enzymes are incorporated into new viral particles as they are built, and are thought to be activated after the new particles “bud” out of infected cell and then break off from it.

The particles start to bud from the host cell in a saclike container called a vesicle, the neck of which eventually separates from the outer membrane of the infected cell. “Once the particles are released, the proteases are activated and the particles transform into mature HIV, which is infectious,” Saffarian says.

“There is an internal mechanism that dictates activation of the protease, which is not well understood,” he adds. “We found that if we slow the budding process, the protease activates while the HIV particle is still connected to the outer membrane of host [infected] cell. As a result, it chews out all the proteins inside the budding HIV particle, and those essential enzymes and proteins leak back into the host cell. The particle continues to bud out and release from the cell, but it is not infectious anymore because it doesn’t have the enzymes it needs to mature.”

Budding HIV needs ESCRTs

This illustration shows how the AIDS-causing virus normally buds and releases from an infected cell (upper right to middle left) and how a new approach to fighting the virus could render release virus particles noninfectious (upper right, curing back to the left). The blue band in the illustration represents the surface of an infected cell. The process begins at the upper right as a new HIV particle begins to emerge or bud from an infected cell (first two light blue partial spheres), with viral envelope proteins protruding from the emerging virus particle. The budded particle is shown at the center, now with a cutaway view of the inside of the HIV, which includes Gag proteins (yellowish orange) and Pol proteins (blue), which include enzymes needed for the virus to replicate. At this point the virus is still attached to the cell. The last two HIV particles on the left represent the normal budding process, in which the HIV particle or “viron” is released from the cell, with an orange capsid protein inside the virus carrying the enzymes that make it infectious. University of Utah scientists have found that if they can delay the budding process – represented by the three HIV particles extending from the center to the middle right – they can render it noninfectious. In that case, the delay allows the enzymes inside the HIV particle to leak back into the host cell, so that when the virus finally is released, it lacks the enzymes in the capsid protein that makes it infectious. Photo credit: Saveez Saffarian, University of Utah

The scientists found they could slow HIV particles from budding out of cells by interfering with how they interact with proteins named ESCRTs (pronounced “escorts”), or “endosomal sorting complexes required for transport.”

ESCRTs are involved in helping pinch off budding HIV particles – essentially cutting them from the infected host cell.

Saffarian says scientific dogma long has held “that messing up the interactions of the virus with ESCRTs results in budding HIV particles permanently getting stuck on the host cell membrane instead of releasing.” Bendjennat says several studies in recent years indicated that the particles do get released, casting some doubt on the long held dogma.

The new study’s significance “is about the molecular mechanism: When the ESCRT machinery is altered, there is production of viruslike particles that are noninfectious,” he says. “This study explains the molecular mechanism of that.”

“We found HIV still releases even when early ESCRT interactions are intentionally compromised, however, with a delay,” Saffarian says. “They are stuck for a while and then they release. And by being stuck for a while, they lose their internal enzymes due to early protease activation and lose their infectivity.”

Bendjennat says by delaying virus budding and speeding “when the protease gets activated, we are now capable of using it to make new released viruses noninfectious”

How the research was done

The experiments used human skin cells grown in tissue culture. It already was known that new HIV particles assemble the same way whether the infected host cell is a skin cell, certain other cells or the T-cell white blood cell infected by the virus to cause AIDS. The experiments involved both live HIV and so-called viruslike particles.

Bendjennat and Saffarian genetically engineered mutant Gag proteins. A single HIV particle is made of some 2,000 Gag proteins and 120 copies of proteins known as Gag-Pol, as well as genetic information in the form of RNA. Pol includes protease, reverse transcriptase and integrase – the proteins HIV uses to replicate.

The mutant Gag proteins were designed to interact abnormally with two different ESCRT proteins, named ALIX and Tsg101.

A new HIV particle normally takes five minutes to release from an infected cell.

When the researchers interfered with ALIX, release was delayed 75 minutes, reducing by half the infectivity of the new virus particle. When the scientists interfered with Tsg101, release was delayed 10 hours and new HIV particles were not infectious.

The scientists also showed that how fast an HIV particle releases from an infected cell depends on how much enzyme cargo it carries in the form of Pol proteins. By interfering with ESCRT proteins during virus-release experiments with viruslike particles made only of Gag protein but none of the normal Pol enzymes, the 75-minute delay shrank to only 20 minutes, and the 10-hour delay shrank to only 50 minutes.

“When the cargo is large, the virus particle needs more help from the ESCRTs to release on a timely fashion,” Saffarian says.

Because HIV carries a large cargo, it depends on ESCRTs to release from an infected cell, so ESCRTs are good targets for drugs to delay release and let HIV proteases leak back into the host cell, making new HIV particles noninfectious, he says.

Bendjennat says other researchers already are looking for drugs to block ESCRT proteins in a way that would prevent the “neck” of the budding HIV particle from pinching off or closing, thus keeping it connected to the infected cell. But he says the same ESCRTs are needed for cell survival, so such drugs would be toxic.

Instead, the new study suggests the right approach is to use low-potency ESCRT-inhibiting drugs that delay HIV release instead of blocking it, rendering it noninfectious with fewer toxic side effects, he adds.

The study was funded by the National Institutes of Health. Saffarian also is funded as an investigator with USTAR, the Utah Science Technology and Research economic development initiative.

Read Full Press Release Here.

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2016 Department Awards & Scholarships

Graduation and commencement exercises for the University of Utah took place on May 5-6, 2016. The Department of Physics & Astronomy congratulates all of its 2016 graduates and welcomes them to their alumni family.

The Department of Physics & Astronomy congratulates all its 2016 student award recipients on their hard work and accomplishments. Recipients were honored at the Physics & Astronomy Awards Ceremony on Friday, April 29 at 2:00 PM in 103 James Fletcher Building.

Sebastian Atwood

Sara Augustine

Paul Bergeron

Mark Hayward

Julie Imig

Wen Jin

Gajadahar Joshi

Jihee Kim

Evan LaFalce

Ethan Lake

Dieu Nguyen

Deric Session

Caleb Webb

Takahiro Yamamoto

Yue Zhang


Congratulations to our 2016 graduates and scholarship recipients!
(* denotes Honors degree)

2016 Awards & ScholarshipsBaccalaureate DegreesMasters DegreesPh. D Degrees

Swigart Scholarship for Outstanding Graduate Students
Wen Jin
Gajadahar Joshi
Dieu Nguyen

Outstanding Graduate Students
Jihee Kim
Yue Zhang

Outstanding Postdoctoral Research
Evan LaFalce

Outstanding Graduate Teaching Assistants
Paul Bergeron
Takahiro Yamamoto

Paul Gilbert Outstanding Undergraduate Research
Trey Jensen

Martin Hiatt Outstanding Undergraduate Research
Cedric Wilson

Outstanding Undergraduate - Senior
Sebastian Atwood

Outstanding Undergraduate - Junior
Julie Imig

Outstanding Undergraduate - Sophomore
Sara Augustine

Tyler Soelberg Memorial Award
Mark Hayward

Thomas J. Parmley Scholarship
Ethan Lake
Deric Session

Walter W. Wada Scholarship
Caleb Webb

Departmental Scholarships
Teddy Anderson
Caroline Lewis
Deric Session
Alexis Wilson

Brian Barnes
Nathan Barney
Denton Beck
Timothy Birch
Jonathan Boyle
Lara Carbuhn
Remington Carlson
Masen Christensen*
Thomas H. Christensen
Markus Dabell
Kel Davis
David Deganne
Trent Eason
Steven Farrell
Joshua Gallagher
Josh Hanes*
Paul Harrie
Darrell Henderson
Jasmine Hinton
Pyone Pwint Wai Thi Hlaing (Teaching)
Grey Hugentobler
Trey Jensen*
Rebecca Klaus
Von, Le Von
Hamilton Lucas
Scott Malloy
Michael May
Zachary Millsap
Amir Orome
Julianna M. G. Pierson (Teaching)
Troy Raen
William Renz*
Paul Richardson
Haylie Romero
David Rosen
Philip Simon*
Jason Sorger
Richard Stefanussen
David Stephens
Clayton Sweeten
Trevor Taylor
Taylor Trujillo
Ryan Ulibarri
Cedric Wilson
Soren Wood
Kyle Jeong
Marzieh Kavand
Andrew Flinders
Pei-i Ku
Song-Haeng Lee
Robert Roundy
Xuefang Sui
Christopher Winterowd
Cheryl Zapata-Allegro
Yaxin Zhai
Zachary Zundel


A New Way To Get Electricity From Magnetism

'Inverse spin Hall effect' works in several organic semiconductors

Apr 18, 2016 – By showing that a phenomenon dubbed the “inverse spin Hall effect” works in several organic semiconductors – including carbon-60 buckyballs – University of Utah physicists changed magnetic “spin current” into electric current. The efficiency of this new power conversion method isn’t yet known, but it might find use in future electronic devices including batteries, solar cells and computers.

University of Utah physicists Z. Valy Vardeny and Christoph Boehme published a new study in Nature Materials demonstrating that a range of organic semiconductors can be used to convert a so-called magnetic spin current into electric current. They don’t yet know the efficiency of this power-conversion method, but say it has possible future uses in future solar cells, batteries and electronic devices like computers and cell phones. Photo credit: Lee J. Siegel, University of Utah

“This paper is the first to demonstrate the inverse spin Hall effect in a range of organic semiconductors with unprecedented sensitivity,” although a 2013 study by other researchers demonstrated it with less sensitivity in one such material, says Christoph Boehme, a senior author of the study published April 18 in the journal Nature Materials.

“The inverse spin Hall effect is a remarkable phenomenon that turns so-called spin current into an electric current. The effect is so odd that nobody really knows what this will be used for eventually, but many technical applications are conceivable, including very odd new power-conversion schemes,” says Boehme, a physics professor.

His fellow senior author, distinguished professor Z. Valy Vardeny, says that by using pulses of microwaves, the inverse spin Hall effect and organic semiconductors to convert spin current into electricity, this new electromotive force generates electrical current in a way different than existing sources.

Coal, gas, hydroelectric, wind and nuclear plants all use dynamos to convert mechanical force into magnetic-field changes and then electricity. Chemical reactions power modern batteries and solar cells convert light to electrical current. Converting spin current into electrical current is another method.

Scientists already are developing such devices, such as a thermoelectric generator, using traditional inorganic semiconductors. Vardeny says organic semiconductors are promising because they are cheap, easily processed and environmentally friendly. He notes that both organic solar cells and organic LED (light-emitting diode) TV displays were developed even though silicon solar cells and nonorganic LEDs were widely used.

Vardeny and Boehme stressed that the efficiency at which organic semiconductors convert spin current to electric current remains unknown, so it is too early to predict the extent to which it might one day be used for new power conversion techniques in batteries, solar cells, computers, phones and other consumer electronics.

“I want to invoke a degree of caution,” Boehme says. “This is a power conversion effect that is new and mostly unstudied.”

Boehme notes that the experiments in the new study converted more spin current to electrical current than in the 2013 study, but Vardeny cautioned the effect still “would have to be scaled up many times to produce voltages equivalent to household batteries.”

The new study was funded by the National Science Foundation and the University of Utah-NSF Materials Research Science and Engineering Center. Study co-authors with Vardeny and Boehme were these University of Utah physicists: research assistant professors Dali Sun and Hans Malissa, postdoctoral researchers Kipp van Schooten and Chuang Zhang, and graduate students Marzieh Kavand and Matthew Groesbeck.

 Read Full Press Release Here.


Students Recognized for Stellar Research


Congratulations to Parker Holzer, Julie Imig, and Ethan Lake, all undergraduate students in the Department of Physics & Astronomy, whom were recognized at the 2016 Undergraduate Research Symposium for their excellent research work.

   Parker Holzer, for his poster presentation at Research on Capitol Hill, "Understanding Planet Harboring Stars in the Open Cluster M67".

   Julie Imig, for her poster presentation at Research on Capitol Hill, "Chemical Composition of Ultra-Faint Dwarf Galaxy Bootes I", plus the Outstanding Undergraduate Researcher Award for the Honors College

   Ethan Lake: Outstanding Undergraduate Researcher Award for the College of Science

From the Office of Undergraduate Research:

"The Office of Undergraduate Research hosted its 13th annual Undergraduate Research Symposium on Tuesday April 12, 2016 in the Olpin Union Building. The Undergraduate Research Symposium provides an opportunity for students to present their work in a scholarly setting to students, faculty and other members of the University of Utah community. Undergraduate students from all disciplines were invited to present their research and creative work."

Click here to learn more about the Undergraduate Research Symposium.


Commencement & Convocation Information 2016

From the Office of the Registrar


University Commencement ceremony will be held on Thursday, May 5, 2016 at 6:30pm in the Jon M Huntsman Center (Map). Candidates for graduation in the summer 2015, fall 2015, spring 2016, or summer 2016 terms may attend.

Commencement is open to the public and free to attend. No tickets or RSVP required. This year's commencement speaker is work-life thought leader, Anne-Marie Slaughter. The University of Utah Board of Trustees announced four individuals selected to receive honorary doctorate degrees at commencement. For more information, please visit the Commencement Ceremony page. Those who are unable to attend commencement will be able to watch the live stream or posted video via the website. For more information, please visit the Commencement Ceremony page."

For those of you attending or participating in graduation ceremonies this spring, here's some important information.


(this is the one for the entire campus where the VIPs speak)
Thursday, May 5, 2016
Huntsman Center (Map)

  • 5:00 pm - Graduates assemble in the Parking Terrace west of the Huntsman Center dressed in cap and gown
  • 5:30 pm - Guests should be seated
  • 5:45 pm - Procession begins
  • 6:30 pm - Commencement ceremony begins


(this is the one where your name is called and you walk across the stage)
College of Science (Click here for other colleges' date, time and location)
Friday, May 6, 2016
Kingsbury Hall (Map) with overflow seating in JFB 101 and JFB 103 (Map)
More info

  • 7:15 am - Graduates assemble on the west side of Kingsbury Hall (see the link above for additional details)
  • 7:45 am - Guests should be seated -
    (saving seats is not allowed - tell your family and friends they all need to arrive at the same time - once Kingsbury is full, guests will be directed to JFB for overflow seating and may view it on closed circuit projected onto the large screens in the lecture halls)
  • 8:00 am - Convocation ceremony begins
  • 9:30 am - College of Science Reception on Presidents Circle


Convocation will also be streamed live online so forward these links to family and friends who want to view it, but can't attend:
On-demand streaming of the College of Science Convocation will be available here.
The live stream link will be available here.


Campus parking lots may be used at no charge during commencement and convocation ceremonies. Please see the commencement parking map for parking locations as well as shuttle and TRAX stops. Additionally, since campus parking is limited, we encourage the use of UTA TRAX on these days. The use of TRAX while on campus is free both days, but fare is still required for any off campus travel.

Shuttle Services

As campus parking is limited, graduates and their guests are encouraged to use the free campus shuttle service to travel between commencement events. Shuttles run throughout campus and are scheduled every 10 minutes. Track the current location of any campus shuttle using the Live Shuttle Tracker.

Accessible Parking

For a map to all accessible parking options on campus, visit the campus map and select the "Accessible" option from the Map Features drop-down menu.

Construction Alerts

For a map with notifications regarding all parking lots effected by campus construction, view the campus map and select the "Construction" option from the Map Features drop-down menu.

Commuter Services

For more information about transportation and parking options, visit the Commuter Services website.

To learn more, please visit the Commencement Ceremony Parking & Transportation page.


Frontiers of Science with Steven C. Wofsy

Thursday, April 7, 2016 @ 6:00 p.m. - Frontiers of Science with Steven C. Wofsy! "Greenhouse Gases: Current Trends and Implications" in room 220 of the Aline Wilmot Skaggs Building (ASB) on the U of U Campus!.


with Dr. Steven C. Wofsy,
Abbott Lawrence Rotch Professor of Atmospheric and Environmental Chemistry at Harvard University

Greenhouse Gases: Current Trends and Implications

Date & Time: Thursday, April 7, 2016 at 6:00pm

Location: 220 Aline Skaggs Building at the University of Utah
View Map

Concentrations of methane (CH4) and carbon dioxide (CO2) in the atmosphere have increased dramatically, starting in the 18th century, representing powerful drivers of global change and climate warming. In order assess future changes and design mitigation strategies, the emissions of these gases must be quantified, and the underlying biological, chemical, physical, and human processes must be understood. The relevant spatial scales span ecosystems, landscapes, regions, and continents, with temporal scales from seasonal to decadal, all very difficult to measure directly. This talk traces historical changes in atmospheric composition, showing the dramatic trends starting in the 1950s and continuing today. We then focus on the Arctic, a region with strong sensitivity to warming climate and vast stores of frozen or waterlogged organic carbon. We show recent results from the Carbon in the Arctic Reservoirs Vulnerability Experiment (CARVE) and other regional measurements that challenge conventional ideas about climate-carbon feedbacks in this region, emphasizing the key roles of processes that occur out of sight--under the surface, after the growing season. We conclude with a comparison between emissions of CH4 and CO2 due to human activities versus the natural world, showing the astonishing transition of the human component from modest perturbation to overwhelming dominance, in recent human memory.

Frontiers of Science is free and open to the public. Please arrive early, as seating and parking will be limited. Click here to learn more about the Frontiers of Science lecture series.


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