New Delhi, Jul 6 (IANS): A first-of-its-kind mice model with a fully functional human immune system and a human-like gut microbiome has shown promise of mounting specific antibody responses.

To date, researchers have not developed a fully functional human immune system, but only those with a brief lifespan that do not mount efficient immune responses, making them unsuitable for the development of in vivo human immunotherapies, human disease modelling, or human vaccine development.

Developed by scientists at The University of Texas in the US, the new model will overcome limitations of currently available in vivo human models and is a breakthrough for biomedical research and promises new insight into immunotherapy development and disease modelling.

Detailed in the journal Nature Immunology, the new humanised mice, called TruHuX (for truly human, or THX), possess a fully developed and fully functional human immune system, including lymph nodes, germinal centres, thymus human epithelial cells, human T and B lymphocytes, memory B lymphocytes, and plasma cells making highly specific antibody and autoantibodies identical to those of humans.

THX mice mount mature neutralising antibody responses to Salmonella Typhimurium and SARS-CoV-2 virus Spike S1 RBD after vaccination with Salmonella flagellin and the Pfizer Covid-19 mRNA vaccine, respectively.

It is also amenable to developing full-fledged systemic lupus autoimmunity after an injection of pristane -- an oil that triggers an inflammatory response.

"THX mice provide a platform for human immune system studies, development of human vaccines, and testing of therapeutics," said Paolo Casali, Professor at the University of Texas School of Medicine in San Antonio, US.

They do this "by critically leveraging oestrogen activity to support human stem cell and human immune cell differentiation and antibody responses", he added.