Development of a novel lymphocyte engineering approach for treatment of vitiligo

点击翻译按钮获取中文摘要

Project Summary: Vitiligo is a common skin depigmentation disorder with an estimated prevalence of 1~4% of the population worldwide. Vitiligo is phenotypically characterized by non-scaly, white macules with distinct sharp margins distributed unilaterally on the patients’ skin, caused by systematic destruction of skin melanocytes. It has a significant impact on the patients’ life both biologically and psychologically. Although multiple mechanisms may jointly contribute to the development of vitiligo, there is a growing consensus that autoimmune response plays a key role in this process. Mounting evidence suggest that self-reactive CD8+ T cells are both necessary and sufficient for destruction of functional melanocytes in vitiligo lesions. The treatment of vitiligo remains one of the most difficult challenges for dermatologists. Approximately 40% of patients have relapse of the disease within the first year after the treatment. Cell and gene therapy provide a promising therapeutic approach for a variety of otherwise terminal or disabling diseases. Adoptive transfer of engineered lymphocytes, such as chimeric antigen receptor (CAR) T cells has shown tremendous success in treatment of hematologic malignancies. CAR T cells have been engineered to target activated myofibroblasts for cardiac fibrosis and autoantibody-producing B cells for potential treatment of pemphigus vulgaris. However, treatment with CAR T is associated with severe and sometimes lethal increases in systemic cytokine toxicity. In this regard, natural killer (NK) cells are powerful innate immune effectors cells. NK cells do not attack healthy self-tissues, nor do they induce the inflammatory cytokine storm as T cells, enabling their potential application as a safer adoptive cell therapy for many human diseases beyond cancer. The objective of this exploratory proposal will be to examine the intriguing possibility of CAR NK cell engineering for treatment of vitiligo. Specifically, we plan to test a β2-microglobulin-based CAR design in conjunction with exogenous expression of different melanocyte antigens in engineered NK cells. We posit that overexpression of the self- antigen with a fusion of degron signal domain can lead to efficient antigen presentation through the engineered MHC I complex containing CAR- β2-microglobulin, which can lead to recognition and destruction of self-reactive CD8+ T cells. Our study will define a novel paradigm for vitiligo treatment and lay the essential groundwork for treatment of other autoimmune disease involving self-reactive T cells with CAR-NK platform.