Development of a Corneal Bioluminescence Mouse for Real-Time In Vivo Evaluation of Gene Therapies

Bifunctional chemokine-nanobody fusion protein enhances neutrophil recruitment to impede Acanthamoeba immune evasion

BACKGROUND

Acanthamoeba keratitis (AK) is a severe infectious disease that causes serious visual impairment and low quality of life. This study aims to investigate the immune landscape in AK, with the goal of improving treatment outcomes through immunotherapy.

METHODS

We conducted single-cell transcriptome sequencing on corneal tissues from nine patients (3 AK patients, 3 patients with fungal keratitis and 3 patients with bacterial keratitis). Bioinformatic analysis calculated the cell subsets and their proportions within different infectious keratitis. CellChat analysis elucidated the differential expression of chemokines in keratitis. After that, screening amebic nano-antibodies, synthesizing antibody-chemokine fusion proteins, and validated their affinity and chemotactic abilities in vitro and in vivo. And assessing of the therapeutic efficacy of antibody-chemokine fusion proteins.

FINDINGS

The UMAP plot demonstrated the 13 major cell clusters in infectious keratitis. Compared with non-AK group, the neutrophil proportion of AK group is markedly reduced. Cell communication indicated a diminished CXCL pathway in AK. Acanthamoeba-specific antibodies were obtained by screening a natural antibody library derived from alpacas. The amoeba-specific antibodies were conjugated with the CXCL1 chemokine, and this fusion protein exhibited robust binding affinity to Acanthamoeba and chemotactic capacity both in vitro and in vivo. Furthermore, in vivo animal investigations indicated that the fusion protein presented excellent therapeutic effect and could effectively eliminate the Acanthamoeba burden.

INTERPRETATION

This study revealed an immune evasion mechanism employed by Acanthamoeba and offered a therapeutic approach. It presents promising potential for enhancing the treatment of infectious diseases by targeting and overcoming challenges posed by immune evasion.

FUNDING

This work was funded by National Natural Science Foundation of China (grant number 82171017 and 82471041) and the Beijing Municipal Public Welfare Development and Reform Pilot Project for Medical Research Institutes (PWD&RPP-MRI, JYY2023-6).

Gene therapy in the anterior eye segment

This review provides comprehensive information about the advances in gene therapy in the anterior segment of the eye including cornea, conjunctiva, lacrimal gland, and trabecular meshwork. We discuss gene delivery systems including viral and non-viral vectors as well as gene editing techniques, mainly CRISPR-Cas9, and epigenetic treatments including antisense and siRNA therapeutics. We also provide a detailed analysis of various anterior segment diseases where gene therapy has been tested with corresponding outcomes. Disease conditions include corneal and conjunctival fibrosis and scarring, corneal epithelial wound healing, corneal graft survival, corneal neovascularization, genetic corneal dystrophies, herpetic keratitis, glaucoma, dry eye disease, and other ocular surface diseases. Although most of the analyzed results on the use and validity of gene therapy at the ocular surface have been obtained in vitro or using animal models, we also discuss the available human studies. Gene therapy approaches are currently considered very promising as emerging future treatments of various diseases, and this field is rapidly expanding.