Sequential MALDI-HiPLEX-IHC and Untargeted Spatial Proteomics Mass Spectrometry Imaging to Detect Proteomic Alterations Associated with Tumour Infiltrating Lymphocytes

• DOI: 10.1021/acs.jproteome.4c00914
• Publication Date: 2025-01-04T03:58:29Z
• Authors: Greta Bindi; Nicole Monza; Glenda Santos de ...; Vanna Denti; Farnaz Fatahian; Seyed-Mohammad Ja...; Vincenzo L’Imperio; Fabio Pagni; Andrew Smith
• Keywords: Mass spectrometry imaging; MALDI imaging

MALDI-HiPLEX-IHC mass spectrometry imaging (MSI) represents a newly established workflow to map tens of antibodies linked photocleavable tags (PC-MTs), which report the distribution antigens in formalin-fixed paraffin-embedded (FFPE) tissue sections. While this highly multiplexed approach has previously been integrated with untargeted methods, possibility mapping target cell and performing bottom-up spatial proteomics on same section yet be explored. This proof-of-concept study presents novel combining analyze single FFPE section, using clinical clear renal carcinoma (ccRCC) as model. Workflow implementation highlighted need for an additional antigen retrieval step following antibody staining aid detachment enhance tryptic digestion. Moreover, enabled stratification histologically similar tumor cores grade based varying lymphocyte populations, particularly T regulatory cells. Finally, integration revealed proteomic alterations associated these infiltration patterns. These findings demonstrate potential characterize molecular environment tumor-infiltrating lymphocytes, offering insights into impact immune cells within microenvironment.