CD103⁺ cDC1 Dendritic Cell Vaccine Therapy for Osteosarcoma Lung Metastases

Area of Science:

• Immunology
• Oncology
• Vaccine Development

Background:

• Osteosarcoma (OS) is a primary bone cancer with a high propensity for metastasis.
• Current treatments for relapsed/metastatic OS have limited efficacy.
• There is a need for novel therapeutic strategies to improve outcomes for patients with advanced OS.

Purpose of the Study:

• To investigate the efficacy of a CD103+ dendritic cell vaccine (cDCV) derived from K7M3 OS cell lysates.
• To evaluate cDCV's ability to induce regression of primary tumors and established lung metastases.
• To assess the induction of a systemic immune response following cDCV therapy, including combination with anti-CTLA-4.

Main Methods:

• A bilateral tumor model in mice was used to assess cDCV therapy against primary tumors and systemic immunity.
• Intratibial injection of K7M3 cells followed by amputation and systemic cDCV treatment evaluated efficacy against established lung metastases.
• Immune cell profiling of tumors, tumor-draining lymph nodes (TdLNs), and spleen was performed.
• The combination therapy of cDCV with anti-CTLA-4 was also evaluated.

Main Results:

• Intratumor cDCV therapy inhibited both treated and untreated primary tumors, increasing T-cell infiltration.
• Systemic cDCV therapy post-amputation reduced the size and number of lung metastases and enhanced T-cell responses.
• Combination of cDCV with anti-CTLA-4 significantly improved efficacy against lung metastases.

Conclusions:

• Intratumor cDCV therapy generates a systemic immune response that controls primary tumor growth and metastasis.
• Systemic cDCV therapy is effective against established lung metastases in OS.
• Combination therapy with anti-CTLA-4 enhances cDCV efficacy, suggesting a potential novel therapeutic approach for relapsed/metastatic OS.