Single-cell transcriptome profiling reveals cell type-specific variation and development in HLA expression of human...

Area of Science:

• Immunology
• Genetics
• Dermatology

Background:

• The skin, a major immunogenic organ, contains diverse immune cells and expresses human leukocyte antigen (HLA) molecules critical for immune response coordination.
• While HLA expression is studied in immune cells, its patterns across various skin cell types, including stromal cells, remain underexplored.

Purpose of the Study:

• To comprehensively map HLA gene expression profiles across diverse skin cell types using single-cell RNA sequencing.
• To investigate HLA expression dynamics during skin development and identify cell type-specific variations.
• To assess the immunogenicity of skin cell populations and explore hair follicle immune privilege.

Main Methods:

• Single-cell RNA sequencing (scRNA-seq) was performed on adult and fetal skin datasets, including hair follicles.
• Analysis of HLA gene expression variations across different skin cell populations in normal adult skin.
• Pseudotime trajectory analysis to examine HLA gene dynamics during vascular endothelial cell development.

Main Results:

• Significant variations in HLA expression were observed among different skin cell types.
• Classical HLA class I genes were expressed in all analyzed cell types, indicating potential immunogenicity.
• Dynamic, cell type-dependent HLA gene expression patterns were identified during fetal skin development.
• Hair follicles exhibited immune-privileged characteristics at the single-cell level.

Conclusions:

• This study provides a detailed single-cell transcriptomic map of HLA genes in the skin.
• The findings offer new insights into HLA molecule variability within the skin and its implications for immune responses.
• Understanding these HLA variations may inform strategies for allogeneic skin transplantation.