Elizabeth Severa

Department of Medicine, NYU Grossman School of Medicine, New York, New York, USA.

4 publications 2022 – 2025
MiceCell Line, TumorCD8-Positive T-LymphocytesCTLA-4 AntigenCytotoxicity, Immunologic

What does Elizabeth Severa research?

Elizabeth Severa studies the immune system's role in organ transplants and cancer therapies. She investigates how certain types of immune cells, called T cells, behave when a pig organ is transplanted into a human. Specifically, her research looks at how these T cells can cause the body to reject the organ, which is a significant challenge in organ transplantation. Additionally, Severa examines how different treatments for melanoma, a type of skin cancer, can help reprogram T cells to be more effective in attacking cancer cells. By tracking these immune responses, her research aims to develop better strategies for preventing organ rejection and improving cancer treatment outcomes.

Key findings

  • In a pig kidney transplant into a deceased human, dominant T cell clones targeting pig cells were identified, providing a potential early warning for organ rejection.
  • Specific donor-reactive T cells expanded in the blood during an episode of organ rejection, indicating they play a critical role in xenograft failure.
  • The combination therapy of anti-PD-1 and anti-CTLA-4 was shown to reprogram exhausted T cells in melanoma patients, an effect dependent on IL-21 signaling.
  • A new semi-automated system to train rats for vocalizations achieved similar results to manual training while reducing labor and measurement errors.

Frequently asked questions

Does Dr. Severa study organ rejection?
Yes, Dr. Severa studies how the immune system, particularly T cells, interacts with transplanted organs and contributes to rejection.
What types of cancer treatments has Dr. Severa researched?
Dr. Severa has researched combination immunotherapies for melanoma, specifically the effects of anti-PD-1 and anti-CTLA-4 therapies on T cell activity.
Is Dr. Severa's work relevant to patients needing organ transplants?
Yes, her findings on immune responses in organ transplants aim to improve the success rates of such procedures, making her work highly relevant for patients.
How does Dr. Severa's research improve cancer treatment?
Her research identifies how to better activate T cells in cancer therapies, potentially leading to more effective treatments for patients.
What is the significance of T cells in Dr. Severa's studies?
T cells are crucial in both organ rejection and cancer, as their behavior can determine whether an organ is accepted or if a tumor is effectively targeted.

Publications in plain English

Efficacy of CTLA-4 checkpoint therapy is dependent on IL-21 signaling to mediate cytotoxic reprogramming of PD-1CD8T cells.

2025

Nature immunology

Zhang Z, Langenbach M, Sagar S, Fetsch V, Stritzker J +23 more

Plain English
Researchers profiled T cells from melanoma patients treated with anti-PD-1 alone or combined with anti-CTLA-4 and found that only the combination therapy shifted exhausted T cells toward an active killing state. This reprogramming depended on IL-21 signaling, and blocking IL-21 in mice abolished the benefit of CTLA-4 blockade entirely. The work reveals a key molecular difference between these two checkpoint therapies and suggests that IL-21 pathway activity could predict or enhance responses to CTLA-4-based treatments.

PubMed

Donor-reactive T cells and innate immune cells promote pig-to-human decedent xenograft rejection.

2025

Research square

Fathi F, Suek N, Vermette B, Breen K, Saad YS +14 more

Plain English
This study tracked how donor-reactive immune cells behaved during a 61-day pig-to-human decedent kidney transplant. Specific T cell clones that attack pig tissue were detected expanding in blood and the organ, and innate immune cells also contributed to rejection. The findings clarify the combined immune barriers that must be overcome before pig-to-human transplants can succeed in living patients.

PubMed

Coordinated circulating and tissue-based T cell responses precede xenograft rejection.

2025

bioRxiv : the preprint server for biology

Novikova E, Severa E, Chen H, Doepke E, Chacon F +24 more

Plain English
Researchers transplanted a pig kidney-thymus combination into a deceased human and tracked the immune response over 61 days. T cells from the recipient infiltrated the organ and specific clones expanded in blood, tissue, and lymph nodes around rejection events. This reveals that T cell-driven rejection of pig organs in humans closely mirrors what happens with human-to-human transplants, informing how future immunosuppression strategies must be designed.

PubMed

Semi-Automated Training of Rat Ultrasonic Vocalizations.

2022

Frontiers in behavioral neuroscience

Johnson AM, Lenell C, Severa E, Rudisch DM, Morrison RA +1 more

Plain English
The paper describes a semi-automated system for training rats to vocalize on demand, replacing a labor-intensive manual process. Commercially available operant conditioning hardware is paired with an ultrasonic detector so that when a rat calls, it automatically receives a sugar pellet reward, producing the same increase in call rate as human-led training. Automating detection and reward delivery reduces staff time, human variability, and measurement error, making it easier to study voice and laryngeal function at scale.

PubMed

Publication data sourced from PubMed . Plain-English summaries generated by AI. Not medical advice.