Human-Immune-System (HIS) humanized mouse model (DRAGA: HLA-A2.HLA-DR4.Rag1KO.IL-2RγcKO.NOD) for COVID-19

Teodor D. Brumeanu*, Pooja Vir, Ahmad Faisal Karim, Swagata Kar, Dalia Benetiene, Megan Lok, Jack Greenhouse, Tammy Putmon-Taylor, Christopher Kitajewski, Kevin K. Chung, Kathleen P. Pratt, Sofia A. Casares*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


We report a Human Immune System (HIS)-humanized mouse model (“DRAGA”: HLA-A2.HLA-DR4.Rag1KO.IL-2 RγcKO.NOD) for COVID-19 research. DRAGA mice express transgenically HLA-class I and class-II molecules in the mouse thymus to promote human T cell development and human B cell Ig-class switching. When infused with human hematopoietic stem cells from cord blood reconstitute a functional human immune system, as well as human epi/endothelial cells in lung and upper respiratory airways expressing the human ACE2 receptor for SARS-CoV-2. The DRAGA mice were able to sustain SARS-CoV-2 infection for at least 25 days. Infected mice showed replicating virus in the lungs, deteriorating clinical condition, and human-like lung immunopathology including human lymphocyte infiltrates, microthrombi and pulmonary sequelae. Among the intra-alveolar and peri-bronchiolar lymphocyte infiltrates, human lung-resident (CD103+) CD8+ and CD4+ T cells were sequestered in epithelial (CD326+) lung niches and secreted granzyme B and perforin, suggesting anti-viral cytotoxic activity. Infected mice also mounted human IgG antibody responses to SARS-CoV-2 viral proteins. Hence, HIS-DRAGA mice showed unique advantages as a surrogate in vivo human model for studying SARS-CoV-2 immunopathological mechanisms and testing the safety and efficacy of candidate vaccines and therapeutics.

Original languageEnglish
Article number2048622
JournalHuman Vaccines and Immunotherapeutics
Issue number5
StatePublished - 2022
Externally publishedYes


  • COVID-19
  • DRAGA mice
  • Human immune system
  • SARS-CoV-2
  • human antibodies
  • human lung-resident CD8 T cells
  • humanized mice
  • lung immunopathology


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