Fan and Ma et al. developed a vacuum-treated autologous blood clot vaccine (BCV) consisting of tumor antigens, TLR9 agonist (CpG-ODN), and GM-CSF to induce anticancer immune responses. BCV recruited and activated proinflammatory immune cells to create an immune niche with increased cytokine and stimulatory molecule expression in vivo. In combination with anti-PD-1, BCV demonstrated prophylactic efficacy against B16-OVA, as well as antitumor immunity against established B16F10 and 4T1 tumors. This combination also inhibited postsurgical recurrence, with increases in IFN-γ+ and Ki67+ cytotoxic CD8+ T cells and NK cells.
Contributed by Shishir Pant
ABSTRACT: Cancer immunotherapy using cancer vaccines has shown great potential in the prevention and treatment of cancer. Here, we report an implantable autologous blood clot scaffold for enhanced cancer vaccination. It comprises a gel-like fibrin network formed by coagulation of blood to trap a large number of red blood cells. Upon implantation, the cross-linked RBCs in the blood clot can attract and recruit a great number of immune cells, leading to the formation of an "immune niche." Encapsulated with tumor-associated antigen and adjuvant, the blood clot vaccine (BCV) can induce a robust anticancer immune response. The BCV combined with immune checkpoint blockade effectively inhibits tumor growth in B16F10 and 4T1 tumor models. The proposed implantable blood clot cancer vaccine can be readily made by mixing the blood from patients with cancer with immunomodulating agents ex vivo, followed by reimplantation into the same patient for personalized cancer immunotherapy in future clinical translation.