Studying human immunology and immunopathology in humanized mice transplanted with human lymphoid tissues and immune cells

Analysis of the heterogeneity and complexity of murine extraorbital lacrimal gland via single-cell RNA sequencing

PURPOSE

The lacrimal gland is essential for maintaining ocular surface health and avoiding external damage by secreting an aqueous layer of the tear film. However, a healthy lacrimal gland's inventory of cell types and heterogeneity remains understudied.

METHODS

Here, 10X Genome-based single-cell RNA sequencing was used to generate an unbiased classification of cellular diversity in the extraorbital lacrimal gland (ELG) of C57BL/6J mice. From 43,850 high-quality cells, we produced an atlas of cell heterogeneity and defined cell types using classic marker genes. The possible functions of these cells were analyzed through bioinformatics analysis. Additionally, the CellChat was employed for a preliminary analysis of the cell-cell communication network in the ELG.

RESULTS

Over 37 subclasses of cells were identified, including seven types of glandular epithelial cells, three types of fibroblasts, ten types of myeloid-derived immune cells, at least eleven types of lymphoid-derived immune cells, and five types of vascular-associated cell subsets. The cell-cell communication network analysis revealed that fibroblasts and immune cells play a pivotal role in the dense intercellular communication network within the mouse ELG.

CONCLUSIONS

This study provides a comprehensive transcriptome atlas and related database of the mouse ELG.

Humanized mouse models in transplantation research

The interest in the use of humanized mouse models for research topics like Graft versus Host Disease (GvHD), allograft studies and other studies to the human immune system is growing. The design of these models is still improving and enables even more complicated studies to these topics. For researchers it can be difficult to choose the best option from the current pool of available models. The decision will depend on which hypothesis needs to be tested, in which field of interest, and therefore 'the best model' will differ from one to another. In this review, we provide a guide to the most common available humanized mouse models, with regards to different mouse strains, transplantation material, transplantation techniques, pre- and post-conditioning and references to advantages and disadvantages. Also, an evaluation of experiences with humanized mouse models in studies on GvHD and allograft rejection is provided.