Posts

coronavirus

T-cells show promise to protect vulnerable patients from COVID-19 infection

coronavirus

Children’s National Hospital immunotherapy experts have found that T-cells taken from the blood of people who recovered from a COVID-19 infection can be successfully multiplied in the lab and maintain the ability to effectively target proteins that are key to the virus’s function.

Children’s National Hospital immunotherapy experts have found that T-cells taken from the blood of people who recovered from a COVID-19 infection can be successfully multiplied in the lab and maintain the ability to effectively target proteins that are key to the virus’s function. Their findings were published Oct. 26, 2020, in Blood.

“We found that many people who recover from COVID-19 have T-cells that recognize and target viral proteins of SARS-CoV-2, giving them immunity from the virus because those T-cells are primed to fight it,” says Michael Keller, M.D., a pediatric immunology specialist at Children’s National Hospital, who led the study. “This suggests that adoptive immunotherapy using convalescent T-cells to target these regions of the virus may be an effective way to protect vulnerable people, especially those with compromised immune systems due to cancer therapy or transplantation.”

Based on evidence from previous phase 1 clinical trials using virus-targeting T-cells “trained” to target viruses such as Epstein-Barr virus, the researchers in the Cellular Therapy Program at Children’s National hypothesized that the expanded group of COVID-19 virus-targeting T-cells could be infused into immunocompromised patients, helping them build an immune response before exposure to the virus and therefore protecting the patient from a serious or life-threatening infection.

“We know that patients who have immune deficiencies as a result of pre-existing conditions or following bone marrow or solid organ transplant are extremely vulnerable to viruses like SARS-CoV-2,” says Catherine Bollard, M.D., M.B.Ch.B., senior author of the study and director of the novel cell therapies program and the Center for Cancer and Immunology Research at Children’s National. “We’ve seen that these patients are unable to easily clear the virus on their own, and that can prevent or delay needed treatments to fight cancer or other diseases. This approach could serve as a viable option to protect or treat them, especially since their underlying conditions may make vaccines for SARS-CoV-2 unsafe or ineffective.”

The T-cells were predominantly grown from the peripheral blood of donors who were seropositive for SARS-CoV-2. The study also identified that SARS-CoV-2 directed T-cells have adapted to predominantly target specific parts of the viral proteins found on the cell membrane, revealing new ways that the immune system responds to COVID-19 infection.

Current vaccine research focuses on specific proteins found mainly on the “spikes” of the coronavirus SARS-CoV-2. The finding that T-cells are successfully targeting a membrane protein instead may add another avenue for vaccine developers to explore when creating new therapeutics to protect against the virus.

“This work provides a powerful example of how both scientific advances and collaborative relationships developed in response to a particular challenge can have broad and unexpected impacts on other areas of human health,” says Brad Jones, Ph.D., an associate professor of immunology in medicine in the Division of Infectious Diseases at Weill Cornell Medicine and co-author on the study, whose lab focuses on HIV cure research. “I began working with Dr. Bollard’s team several years ago out of our shared interest in translating her T-cell therapy approaches to HIV. This put us in a position to quickly team up to help develop the approach for COVID-19.”

The Cellular Therapy Program is now seeking approval from the U.S. Food and Drug Administration for a phase 1 trial that will track safety and effectiveness of using COVID-19-specific T-cells to boost the immune response in patients with compromised immune systems, particularly for patients after bone marrow transplant.

t-cells

Tailored T-cell therapies neutralize viruses that threaten kids with PID

t-cells

Tailored T-cells specially designed to combat a half dozen viruses are safe and may be effective in preventing and treating multiple viral infections, according to research led by Children’s National Hospital faculty.

Catherine Bollard, M.B.Ch.B., M.D., director of the Center for Cancer and Immunology Research at Children’s National and the study’s senior author, presented the teams’ findings Nov. 8, 2019, during a second-annual symposium jointly held by Children’s National and the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH). Children’s National and NIAID formed a research partnership in 2017 to develop and conduct collaborative clinical research studies focused on young children with allergic, immunologic, infectious and inflammatory diseases. Each year, they co-host a symposium to exchange their latest research findings.

According to the NIH, more than 200 forms of primary immune deficiency diseases impact about 500,000 people in the U.S. These rare, genetic diseases so impair the person’s immune system that they experience repeated and sometimes rare infections that can be life threatening. After a hematopoietic stem cell transplantation, brand new stem cells can rebuild the person’s missing or impaired immune system. However, during the window in which the immune system rebuilds, patients can be vulnerable to a host of viral infections.

Because viral infections can be controlled by T-cells, the body’s infection-fighting white blood cells, the Children’s National first-in-humans Phase 1 dose escalation trial aimed to determine the safety of T-cells with antiviral activity against a half dozen opportunistic viruses: adenovirus, BK virus, cytomegalovirus (CMV), Epstein-Barr virus (EBV), Human Herpesvirus 6 and human parainfluenza-3 (HPIV3).

Eight patients received the hexa-valent, virus-specific T-cells after their stem cell transplants:

  • Three patients were treated for active CMV, and the T-cells resolved their viremia.
  • Two patients treated for active BK virus had complete symptom resolution, while one had hemorrhagic cystitis resolved but had fluctuating viral loads in their blood and urine.
  • Of two patients treated prophylactically, one developed EBV viremia that was treated with rituximab.

Two additional patients received the T-cell treatments under expanded access for emergency treatment, one for disseminated adenoviremia and the other for HPIV3 pneumonia. While these critically ill patients had partial clinical improvement, they were being treated with steroids which may have dampened their antiviral responses.

“These preliminary results show that hexaviral-specific, virus-specific T-cells are safe and may be effective in preventing and treating multiple viral infections,” says Michael Keller, M.D., a pediatric immunologist at Children’s National and the lead study author. “Of note, enzyme-linked immune absorbent spot assays showed evidence of antiviral T-cell activity by three months post infusion in three of four patients who could be evaluated and expansion was detectable in two patients.”

In addition to Drs. Bollard and Keller, additional study authors include Katherine Harris M.D.; Patrick J. Hanley Ph.D., assistant research professor in the Center for Cancer and Immunology; Allistair Abraham, M.D., a blood and marrow transplantation specialist; Blachy J. Dávila Saldaña, M.D., Division of Blood and Marrow Transplantation; Nan Zhang Ph.D.; Gelina Sani BS; Haili Lang MS; Richard Childs M.D.; and Richard Jones M.D.

###

Children’s National-NIAID 2019 symposium presentations

“Welcome and introduction”
H. Clifford Lane, M.D., director of NIAID’s Division of Clinical Research

“Lessons and benefits from collaboration between the NIH and a free-standing children’s hospital”
Marshall L. Summar, M.D., director, Rare Disease Institute, Children’s National

“The hereditary disorders of PropionylCoA and Cobalamin Metabolism – past, present and future”
Charles P. Venditti, M.D., Ph.D., National Human Genome Research Institute Collaboration

“The road(s) to genetic precision therapeutics in pediatric neuromuscular disease: opportunities and challenges”
Carsten G. Bönnemann, M.D., National Institute of Neurological Disorders and Stroke

“Genomic diagnostics in immunologic diseases”
Helen Su, M.D., Ph.D., National Institute of Allergy and Infectious Diseases

“Update on outcomes of gene therapy clinical trials for X-SCID and X-CGD and plans for future trials”
Harry Malech, M.D., National Institute of Allergy and Infectious Diseases

“Virus-specific T-cell therapies: broadening applicability for PID patients”
Catherine Bollard, M.D., Children’s National 

“Using genetic testing to guide therapeutic decisions in Primary Immune Deficiency Disease”
Vanessa Bundy, M.D., Ph.D., Children’s National 

Panel discussion moderated by Lisa M. Guay-Woodford, M.D.
Drs. Su, Malech, Bollard and Bundy
Morgan Similuk, S.C.M., NIAID
Maren Chamorro, Parent Advocate

“Underlying mechanisms of pediatric food allergy: focus on B cells
Adora Lin, M.D., Ph.D., Children’s National 

“Pediatric Lyme outcomes study – interim update”
Roberta L. DeBiasi, M.D., MS, Children’s National 

“Molecular drivers and opportunities in neuroimmune conditions of pediatric onset”
Elizabeth Wells, M.D., Children’s National 

###

Also read: Johan’s story
View: Safeguarding Johan’s future

Michael Keller

Virus-specific t-cells show promise before transplant in SCID patients

Michael Keller

“Today, we know that virus-specific T-cells can help protect patients from dangerous viruses after stem cell transplants,” says Michael Keller, M.D. “Through this research, we used the same therapy and approach, but applied it pre-transplant with the hope of providing the same benefit of protection against life-threatening viruses to patients who need it the most.”

Experts at Children’s National Health System have been successfully studying the use of virus-specific T-cells (VST) to help protect immunocompromised patients from life-threatening viruses after bone marrow transplants. Research published recently in the Biology of Blood and Marrow Transplantation presents promising new findings from testing the use of these same VSTs before transplant to help give patients with severe combined immunodeficiency (SCID) a better chance at long-term survival.

Babies born with SCID are highly susceptible to severe infections that are often fatal if not treated with immune-restoring treatments, like hematopoietic stem cell transplants (HSCT). However, undergoing an HSCT with an infection present has shown to lead to a decrease in survival at two years old for SCID patients when compared to those who start the HSCT infection-free. The study lead, Michael Keller, M.D., hypothesized that the success of HSCTs in SCID patients may be improved by controlling severe viral infections before the patient undergoes the transplant.

“Today, we know that virus-specific T-cells can help protect patients from dangerous viruses after stem cell transplants,” says Dr. Keller. “Through this research, we used the same therapy and approach, but applied it pre-transplant with the hope of providing the same benefit of protection against life-threatening viruses to patients who need it the most.”

Dr. Keller administered the VSTs from a healthy third-party donor in a five-month-old infant fighting adenovirus before undergoing a HSCT to cure him of SCID. Today, the baby is healthy and has a normal immune system. Ultimately, this research shows that the use of VSTs is likely safe in the pre-HSCT period in patients with SCID and may be an effective therapy for viral infections when they are resistant to antiviral therapy.

“I believe this VST therapy could make a real and lasting impact for patients with SCID,” said Dr. Keller. “It gives them a real chance at a long life.”

Training t-cells, essential players in the immune system, to fight a trio of viruses

Children's is the only U.S. pediatric hospital that manufactures specialized T-cells from native cord blood

What’s Known
Following treatment, patients with leukemia, lymphoma, and other cancers may receive a transplant in order to restore their body’s natural ability to fight infection and, sometimes, such transplants are a component of leukemia treatment. (Leukemia is the second most common blood cancer, after lymphoma, and its incidence rate has increased by 0.2 percent annually from 2002 to 2011.) A stem cell or cord blood transplant restores the body’s ability to produce infection-fighting white blood cells. After such transplants, however, patients can face heightened risk of developing a life-threatening infection with such viruses as adenovirus, cytomegalovirus, or Epstein-Barr virus.

What’s New
A head-to-head comparison of two strategies to thwart such viral infections shows that both approaches leverage the power of multivirus-specific, donor-derived T-cells (mCTL), which are highly skilled at recognizing foreign invaders. The research team, made up of nine scientists and clinicians affiliated with Children’s National Health System, grew personalized T-cells from peripheral blood (PB) of adult donors who were seropositive for CMV and also coaxed T-cells to grow from naïve cord blood (CB). PB-derived cells have long memories of past battles; naïve CB-derived cells need additional training to acquire such skills. From 35 to 384 days after their stem cell or cord blood transplant, 13 patients were infused with PB mCTL and 12 patients were infused with CB mCTL. Within four weeks, patients experienced up to a 160-fold increase in virus-specific T-cells, which coincided with their response to therapy. Overall response rate was 81 percent.

Questions for Future Research
Q: Could T-cells be personalized to attack other viruses that infect patients post-transplant, such as human parainfluenza virus and BK polyomavirus, providing the potential to target five viruses in a single infusion?
Q: Could the proteins that are used to train T-cells to attack certain viruses also be used to create a personalized approach to tumor suppression?

Source: “A Phase 1 Perspective: Multivirus-Specific T Cells From Both Cord Blood and Bone Marrow Transplant Donors.” Hanley, P., M. D. Keller, M. Martin Manso, C. Martinez, K. Leung, C.R. Cruz, C. Barese, S. McCormack, M. Luo, R.A. Krance, D. Jacobsohn, C. Rooney, H. Heslop, E.J. Shpall, and C. Bollard. Presented during the International Society for Cellular Therapy 2016 Annual Meeting, Singapore. May 26, 2016.