ImmunoTargets and Therapy (Apr 2025)
Selective Deletion of HLA-B, and -C Class I Genes Promotes Immunocompatibility of Humanized Skin Graft Model
Abstract
Laura Cobos-Figueroa,1,2,* Laura Notario,1,* Carmen Mir,1 Carlos Molpeceres,2 Sara Lauzurica,2 Daniel López,1 Elena Lorente,1,* Pilar Lauzurica1,* 1Centro Nacional de Microbiología, Insituto de Salud Carlos III, Majadahonda, Madrid, Spain; 2Centro Láser, Universidad Politécnica de Madrid, Madrid, Madrid, Spain*These authors contributed equally to this workCorrespondence: Laura Notario, Centro Nacional de Microbiología, Insituto de Salud Carlos III, Ctra. de Pozuelo, 28, Majadahonda, Madrid, 28222, Spain, Tel +34 918223718, Email [email protected]: The treatment of extensive burns requires rapid allogeneic skin transplantation, but HLA diversity poses a significant challenge in finding histocompatible donor-recipient matches.Methods: In this study, we developed a humanized skin graft model using HLA class I transgenic mice to closely examine the HLA-mediated immune response in skin transplantation. Additionally, this model was used to analyse the response against a human lymphoblastoid cell line, JY, with HLA-B and -C genes knocked out by a single-step CRISPR-Cas9 strategy, retaining the most common HLA class I allele, HLA-A*02:01.Results: Mice expressing the HLA-A02:01 allele alone or in combination with HLA-B07:02 do not reject the skin of animals expressing only HLA-A02:01. However, skin from HLA-A02:01/B07:02 mice transplanted into HLA-A02:01 mice is rejected, triggering a strong specific CD8 T cell response mediated by the HLA-B*07:02 molecule. In these latter mice, unlike the parental JY cell line, the edited cells did not induce a CD8 T cell response in vitro, suggesting that the selective deletion of HLA-B and -C may contribute to improve skin graft compatibility.Conclusion: This genetic engineering approach, repeated without modification for the five HLA-A class I most common alleles known to be associated with HLA-B7 and -C7 in the same haplotype, would cover 83.4% of the world population. Our findings offer a scalable HLA-compatible skin graft model, potentially improving practices in burn units worldwide.Plain Language Summary: This study addresses a key challenge in treating severe burns: finding suitable skin donors. When someone needs a skin transplant, it is important to match certain proteins on their cells, called HLA proteins, to avoid rejection by the immune system. However, there is a lot of variety in HLA types among people, making it hard to find good matches. Here, we developed a mouse model that mimics human skin transplants. We used mice that carry human HLA proteins, allowing us to study how the immune system reacts to different skin grafts. We also used a gene-editing tool (CRISPR-Cas9) to modify cells and remove some HLA proteins, keeping only the most common one, HLA-A*02:01. The results shows that when mice lack some HLA proteins but retain compatible ones, the skin is not rejected. However when there are differences, the immune system attacks the graft. Importantly, removing certain HLA proteins (like HLA-B and -C), in cell lines, helps avoiding their rejection. This technique could potentially apply to most people worldwide (about 83.4%), offering a new way to make skin transplants more successful and easier to match. This could greatly benefit burn patients by speeding up treatment and reducing the risk of rejection.Keywords: transplant, allorejection, CRISPR, genetic engineering, histocompatibility
