Collagen Organization Does Not Influence T-Cell Distribution in Stroma of Human Pancreatic Cancer

Abstract

The dominant intrastromal T-cell infiltration in pancreatic cancer is mainly caused by the contact guidance through the excessive desmoplastic reaction and could represent one of the obstacles to an effective immune response in this tumor type. This study analyzed the collagen organization in normal and malignant pancreatic tissues as well as its influence on T-cell distribution in pancreatic cancer. Human pancreatic tissue was analyzed using immunofluorescence staining and multiphoton and SHG microscopy supported by multistep image processing. The influence of collagen alignment on activated T-cells was studied using 3D matrices and time-lapse microscopy. It was found that the stroma of malignant and normal pancreatic tissues was characterized by complex individual organization. T-cells were heterogeneously distributed in pancreatic cancer and there was no relationship between T-cell distribution and collagen organization. There was a difference in the angular orientation of collagen alignment in the peritumoral and tumor-cell-distant stroma regions in the pancreatic ductal adenocarcinoma tissue, but there was no correlation in the T-cell densities between these regions. The grade of collagen alignment did not influence the directionality of T-cell migration in the 3D collagen matrix. It can be concluded that differences in collagen organization do not change the spatial orientation of T-cell migration or influence stromal T-cell distribution in human pancreatic cancer. The results of the present study do not support the rationale of remodeling of stroma collagen organization for improvement of T-cell–tumor cell contact in pancreatic ductal adenocarcinoma.

Matrix alignment and density modulate YAP-mediated T-cell immune suppression

“…Notably, studies tracking T-cell migration in vivo have highlighted how aligned fibers shape the migratory paths of T-cells within tumor microenvironments, guiding them along collagen fibers and leading to accumulation in the stroma [18,53,54]. Our findings corroborated well with a study using reconstituted collagen matrices with random, partially aligned, and aligned fibrils, which showed that collagen fibril alignment did not influence the directionality of T-cell migration [26]. However, another study reported that T-cell migration directionality is increased in aligned collagen matrices [13].…”

“…These matrices can be customized in terms of fibril microstructure, crosslinking density, and integration with other ECM molecules [25], enabling the simulation of both homeostatic and pathophysiological conditions. Recent initiatives have utilized 3D collagen matrices with aligned collagen fibrils to study T-cell migration [13, 26], adjustable collagen density to examine T-cell activity [11], and tunable viscoelasticity to modulate T-cell subtypes [27]. However, a comprehensive study to elucidate T-cell activation and functions, alongside a mechanistic exploration of T-cell mechanosensing in response to matrix alterations, is still needed.…”

The Trinity: Interplay among Cancer Cells, Fibroblasts, and Immune Cells in Pancreatic Cancer and Implication of CD8+ T Cell-Orientated Therapy

“…The correlation of the ECM and immune cells in clinical samples has also been investigated. Kamionka et al showed the collagen composition in pancreatic tumor tissues was not significantly linked with immune cell infiltration, suggesting collagen organization has a minor impact on T cell distribution [127].…”

Development and validation of image processing and analysis tools for the quantification of the tumor microenvironment in multiplex immunostained cancer tissues.

“….1] 𝑚 x ×𝑚 y , where values specify how cells should be oriented. In case the tumor and the stroma are present in the neighborhood's mask, 𝑀 𝑂𝑟𝑛𝑡𝑡𝑛 is initialized in reference to the location of the tumor so that cells are oriented forming a rim around the tumor border153 (Fig 4.4ab).Cell phenotype mask values in 𝑀 𝑃𝑛 , 𝑀 𝑃ℎ_𝐶𝑒𝑙𝑙𝑠 , and 𝑀 𝑃ℎ_𝑁𝑢𝑐 are updated iteratively by a constrained minimization of ℓ 𝑃 :…”