CD84 is a specific target for acute myeloid leukemia CAR-T cell therapy

Area of Science:

• Immunotherapy
• Hematologic Malignancies
• Cancer Target Identification

Background:

• Chimeric antigen receptor (CAR)-T cell therapy shows promise for hematologic cancers.
• Acute myeloid leukemia (AML) treatment is hindered by a lack of specific targets, leading to challenges in efficacy and toxicity.
• Identifying a selective antigen is critical for effective AML immunotherapy.

Purpose of the Study:

• To identify and validate a novel, highly selective target for CAR-T cell therapy in AML.
• To assess the therapeutic potential of CD84-directed CAR-T cells against AML.
• To evaluate the safety profile of targeting CD84 in preclinical AML models.

Main Methods:

• Identification of CD84 as a potential AML target based on its expression profile.
• Generation of CD84-directed CAR-T cells.
• In vitro and in vivo testing of CD84 CAR-T cells using AML cell lines and patient-derived xenograft (PDX) models.
• Assessment of CAR-T cell efficacy, leukemia burden, survival, antigen expression, and impact on normal hematopoietic stem/progenitor cells.

Main Results:

• CD84 is highly and stably expressed on AML blasts, especially in relapsed disease, but not on normal hematopoietic stem/progenitor cells.
• CD84-directed CAR-T cells demonstrated potent cytotoxicity against CD84+ AML cells, including those with low expression.
• In AML-PDX models, CAR-T treatment significantly reduced leukemia burden and doubled animal survival without CD84 downregulation.
• Treated CAR-T cells preserved the repopulation potential of normal hematopoietic stem/progenitor cells.

Conclusions:

• CD84 is a promising and selective target for AML immunotherapy.
• CD84-directed CAR-T cell therapy offers a potential new treatment strategy for aggressive and refractory AML.
• This approach may improve therapeutic precision and reduce off-tumor toxicity in AML treatment.