Establishment of a human microbiome- and immune system-reconstituted dual-humanized mouse model

• Published in: Experimental Animals Vol. 72; no. 3; pp. 402 - 412
• Main Authors: Ka, Yuyo, Ito, Ryoji, Nozu, Ryoko, Tomiyama, Kayo, Ueno, Masami, Ogura, Tomoyuki, Takahashi, Riichi
• Format: Journal Article
• Language: English
• Published: Japan Japanese Association for Laboratory Animal Science 01.01.2023; Japan Science and Technology Agency
• Subjects: Animal models; CD3 antigen; CD34 antigen; CD34+ cells; Cell proliferation; fecal microbiota transplantation; Flow cytometry; germ-free; Germfree; Hematopoietic stem cells; Homeostasis; humanized mice; Immune system; Immunodeficiency; Immunology; In vivo methods and tests; Intestinal microflora; Lymphocytes; Lymphocytes T; Maintenance; Microbiomes; Microbiota; Microorganisms; NOD/Shi-scid-IL2rγnull (NOG) mice; Original; Stem cells; Therapeutic targets; germ-free; NOD/Shi-scid-IL2rγnull (NOG) mice; fecal microbiota transplantation; humanized mice; CD34+ cells
• ISSN: 1341-1357; 1881-7122
• DOI: 10.1538/expanim.23-0025

Humanized mice are widely used to study the human immune system in vivo and investigate therapeutic targets for various human diseases. Immunodeficient NOD/Shi-scid-IL2rγnull (NOG) mice transferred with human hematopoietic stem cells are a useful model for studying human immune systems and analyzing engrafted human immune cells. The gut microbiota plays a significant role in the development and function of immune cells and the maintenance of immune homeostasis; however, there is currently no available animal model that has been reconstituted with human gut microbiota and immune systems in vivo. In this study, we established a new model of CD34+ cell-transferred humanized germ-free NOG mice using an aseptic method. Flow cytometric analysis revealed that the germ-free humanized mice exhibited a lower level of human CD3+ T cells than the SPF humanized mice. Additionally, we found that the human CD3+ T cells slightly increased after transplanting human gut microbiota into the germ-free humanized mice, suggesting that the human microbiota supports T cell proliferation or maintenance in humanized mice colonized by the gut microbiota. Consequently, the dual-humanized mice may be useful for investigating the physiological role of the gut microbiota in human immunity in vivo and for application as a new humanized mouse model in cancer immunology.