PeptiCHIP: A Microfluidic Platform for Tumor Antigen Landscape Identification.

Area of Science:

• Immunology
• Oncology
• Biotechnology
• Microfluidics

Background:

• Identifying human leukocyte antigen (HLA) class I ligands on tumor cells is crucial for developing T-cell based cancer therapies.
• Current methods for isolating tumor-specific peptides are often limited by sensitivity, requiring substantial sample input and time.
• Technical advancements are needed to reliably characterize tumor antigens for personalized cancer vaccines.

Purpose of the Study:

• To develop and fabricate a microfluidic-based chip (PeptiCHIP) for efficient identification and characterization of tumor-specific HLA class I ligands.
• To overcome limitations of existing immunopeptidomics workflows by improving antibody immobilization and sample handling.
• To enable personalized immunopeptidome analysis from limited clinical samples for tailored cancer therapeutic design.

Main Methods:

• Fabrication of a microfluidic chip (PeptiCHIP) utilizing streptavidin-biotin chemistry for robust pan-HLA antibody immobilization.
• Implementation of a microfluidic through-flow system for immune-affinity purification (IP) of HLA-I complexes on customized pillar arrays.
• Analysis of eluted HLA-I presented peptides using tandem mass spectrometry and subsequent in vitro validation.

Main Results:

• The PeptiCHIP system successfully purified HLA-I complexes from as few as 1 × 10^6 cells, a significant reduction from the 5 × 10^8 cells typically required.
• The microfluidic approach reduced antibody usage and isolation time compared to standard immunopeptidomics methods.
• The platform demonstrated specificity and robustness in identifying HLA-I ligands from both cell lines and patient-derived ex vivo cultures.

Conclusions:

• Microfluidics-based strategies offer a sensitive and efficient platform for immunopeptidomics.
• The PeptiCHIP technology facilitates personalized immunopeptidome analysis from individual tumor biopsies.
• This advancement holds significant potential for designing tailored cancer therapeutic vaccines and improving cancer treatment strategies.