Quantitative Multiplex Immunohistochemistry Reveals Myeloid-Inflamed Tumor-Immune Complexity Associated with Poor Prognosis

Here, we describe a multiplexed immunohistochemical platform with computational image processing workflows, including image cytometry, enabling simultaneous evaluation of 12 biomarkers in one formalin-fixed paraffin-embedded tissue section. To validate this platform, we used tissue microarrays containing 38 archival head and neck squamous cell carcinomas and revealed differential immune profiles based on lymphoid and myeloid cell densities, correlating with human papilloma virus status and prognosis. Based on these results, we investigated 24 pancreatic ductal adenocarcinomas from patients who received neoadjuvant GVAX vaccination and revealed that response to therapy correlated with degree of mono-myelocytic cell density and percentages of CD8+ T cells expressing T cell exhaustion markers. These data highlight the utility of in situ immune monitoring for patient stratification and provide digital image processing pipelines to the community for examining immune complexity in precious tissue sections, where phenotype and tissue architecture are preserved to improve biomarker discovery and assessment. [Display omitted] •Multiplex IHC and computational image analysis phenotypes tumor-immune complexity•In situ leukocyte density correlates with subclassification and prognosis in HNSCC•Immune complexity stratifies response to vaccination therapy in PDAC•CD8+ T cell and PD-L1 status correlate with outcomes of vaccinated PDAC patients Tsujikawa et al. develop a multiplex immunohistochemistry and image cytometry platform to reveal immune-based metrics for patient stratification and response monitoring. In HNSCC and PDAC, prognosis correlates with mono-myelocytic cell density. In PDAC, percentages of PD-1, Eomes, Ki67, and granzyme B in CD8+ T cells correlate with response to vaccine therapy.