• CD1a is a 49 kDa member of the immunoglobulin superfamily also known as T6 and R4. It is a type I membrane glycoprotein with structural similarities to MHC class I and is non-covalently associated with β2-microglobulin. CD1a plays a role in non-peptide glycolipid antigen presentation to CD1-restricted T cells. It is expressed on cortical double positive and single positive thymocytes, Langerhans cells, and dendritic cells. In addition to antigen presentation, CD1a has been implicated in thymic T cell development.
• The BAC-derived human genome region containing the whole sequence of human CD1A gene was inserted into Hipp11 locus in B-hCD1A mice.
• Human CD1A mRNA was exclusively detectable in homozygous B-hCD1A mice but not in wild-type mice.
• Human CD1A was exclusively detectable in homozygous B-hCD1A mice, but not in wild-type C57BL/6N mice.

Gene targeting strategy for B-hCD1A mice. The BAC-derived human genome region containing the whole sequence of human CD1A gene was inserted into Hipp11 locus in B-hCD1A mice.

Strain specific analysis of CD1A mRNA expression in wild-type C57BL/6N mice and B-hCD1A mice by RT-PCR. Skin RNA were isolated from wild-type C57BL/6N mice (+/+) and homozygous B-hCD1A mice (H/H), then cDNA libraries were synthesized by reverse transcription, followed by PCR with mouse or human CD1A primers. Human CD1A mRNA was exclusively detectable in homozygous B-hCD1A mice.

Strain specific CD1A expression analysis in wild-type C57BL/6N mice and homozygous humanized B-hCD1A mice by flow cytometry. Skin cells were collected from wild-type C57BL/6N mice (+/+) (female, 16-week-old, n=1) and homozygous B-hCD1A mice (H/H) (female, 16-week-old, n=1). Protein expression was analyzed with anti-human CD1A antibody (Biolegend, 336307) by flow cytometry. Human CD1A was exclusively detectable in homozygous B-hCD1A mice, but not in wild-type C57BL/6N mice.