A novel humanized mouse model to study the function of human cutaneous memory T cells in vivo in human skin

Abstract

Human skin contains a population of memory T cells that supports tissue homeostasis and provides protective immunity. The study of human memory T cells is often restricted to in vitro studies and to human PBMC serving as primary cell source. Because the tissue environment impacts the phenotype and function of memory T cells, it is crucial to study these cells within their tissue. Here we utilized immunodeficient NOD-scid IL2rγnull (NSG) mice that carried in vivo-generated engineered human skin (ES). ES was generated from human keratinocytes and fibroblasts and was initially devoid of skin-resident immune cells. Upon adoptive transfer of human PBMC, this reductionist system allowed us to study human T cell recruitment from a circulating pool of T cells into non-inflamed human skin in vivo. Circulating human memory T cells preferentially infiltrated ES and showed diverse functional profiles of T cells found in fresh human skin. The chemokine and cytokine microenvironment of ES closely resembled that of non-inflamed human skin. Upon entering the ES T cells assumed a resident memory T cell-like phenotype in the absence of infection, and a proportion of these cutaneous T cells can be locally activated upon injection of monocyte derived dendritic cells (moDCs) that presented Candida albicans. Interestingly, we found that CD69+ memory T cells produced higher levels of effector cytokines in response to Candida albicans, compared to CD69- T cells. Overall, this model has broad utility in many areas of human skin immunology research, including the study of immune-mediated skin diseases.

Humanized Mouse Model as a Novel Approach in the Assessment of Human Allogeneic Responses in Organ Transplantation

“…For humanization, we utilized the recipient's PBMCs since they are mature cells capable of providing a fast and robust model for allogeneic immune responses (23,24,65). The disadvantage of this model is the GVHD symptoms that can arise during humanization and engraftment of the recipient PBMCs, with maximum development at 6-8 weeks (16,22,66,67). Though, our entire experiment including the humanization and the challenge phase was completed within 26 days.…”

Staphylococcus aureus Host Tropism and Its Implications for Murine Infection Models

“…In addition, and similar to what has been previously published, the humanization of different parts of the mouse will provide information about the species specificity of S. aureus molecules and thus reveal factors essential for host adaptation, define their role in host tropism, and disclose their contribution to S. aureus’ fitness in a certain host. Inspired by publications like those of Klicznik et al and Dusséaux et al in which not only the immune system but also other tissues, such as the skin or the liver, were humanized, it is also conceivable to use such a concept to study more localized S. aureus infections, such as skin infections, or S. aureus -associated diseases such as atopic dermatitis [ 219 , 220 ].…”

EB (epidermolysis bullosa)‐House Austria: Pioneering work for the care of patients with rare diseases

“…Current research strategies of the EB House Austria include CRISPR/Cas9‐based technologies to correct COL7A1 and COL17A1 mutations and restore functional protein expression in keratinocytes [26]. Additional important research topics are the identification of extracellular vesicles with tumor‐specific transcripts and tumor‐specific miRNA molecules as both diagnostic markers (liquid biopsy) and as a therapeutic target for the highly aggressive EB squamous cell carcinoma [27,28], and the generation of a humanized mouse model as a clinically relevant platform for testing immunomodulatory therapeutic approaches and for analysis of gene therapy‐associated immune reactions [29].…”