Pre-vaccination transcriptomic profiles of immune responders to the MUC1 peptide vaccine for colon cancer prevention

Area of Science:

• Oncology
• Immunology
• Vaccinology

Background:

• Therapeutic cancer vaccines target tumor-specific self-antigens like MUC1.
• Clinical trials investigated MUC1 peptide vaccines for preventing colon cancer in high-risk individuals with premalignant adenomas.
• Immune responses varied, with distinct responders and non-responders identified.

Approach:

• Peripheral blood mononuclear cells (PBMCs) from MUC1 vaccine responders and non-responders were analyzed pre-vaccination and post-vaccination.
• Flow cytometry, phosflow, and gene expression analyses identified early immune response markers.
• Specific transcripts linked to antigen presentation and B-cell activation were investigated.

Key Points:

• MUC1 vaccine responders showed higher pre-vaccination CD4+ T-cell counts and increased CD40L and ICOS expression on T-cells post-vaccination.
• Early activation of iCOSL, PI3K/AKT/mTOR, and B-cell signaling pathways was observed in responders.
• Six transcripts associated with antigen presentation and B-cell activation predicted antibody response.

Conclusions:

• Early biomarkers can predict MUC1 vaccine response, indicating immune readiness for antigen presentation.
• Predictive models for vaccine response may enable personalized cancer vaccines for high-risk populations.
• Tailored vaccines based on immune fitness could enhance efficacy in cancer prevention.