Self-Assembling Peptide Nanofibers Eliminated Established HPV Tumors in Mice by Boosting Anti-Cancer Immunity

HPV16 E744-62 peptide was chemically conjugated to the N-terminus of the self-assembling peptide Q11. The conjugates formed nanofibers and were used to immunize C57BL/6 mice in a TC-1 tumor graft model. Two strategies were tested: preventive (immunization before tumor challenge) and therapeutic (immunization after tumors were established at 2-3 mm or 5-6 mm). Immune responses were evaluated by measuring Th1/Th2 cells, CTLs, MDSCs, IFN-γ, TNF-α, and IL-4 in E7 peptide-stimulated splenocytes. Tumor growth and tumor-free survival were tracked.

Existing HPV vaccines (Gardasil, Cervarix) prevent infection but cannot treat existing HPV cancers. Therapeutic HPV vaccines have shown disappointing clinical results, largely because they fail to generate strong enough T-cell responses to overcome the tumor's immune-suppressive environment. This nanofiber approach addresses both problems: the self-assembling structure naturally enhances immune activation (no separate adjuvant needed), and the resulting immune response is strong enough to eliminate established tumors in a significant fraction of animals.

Self-assembling peptide nanofibers are an emerging platform for vaccine delivery that eliminates the need for traditional adjuvants, which can cause inflammation and side effects. The Q11 peptide system used here has been studied with multiple antigens and represents a modular vaccine platform — different disease targets can be attached to the same self-assembling backbone. For HPV-related cancers specifically, this addresses a major unmet need: while preventive vaccines exist, millions of people already infected with HPV have no effective immunotherapy options.

This is a mouse study using a transplanted tumor model (TC-1), which does not fully replicate human HPV-related cancers that develop over years within an immunosuppressive microenvironment. The TC-1 model is relatively immunogenic, which may overestimate vaccine efficacy. Sample sizes per group are not specified in the abstract. No human safety or efficacy data exist. The long-term durability of the immune response is only partially addressed (6-week re-challenge). Manufacturing and stability challenges for nanofiber vaccines are not discussed.