Traditional fluorescence microscopy is limited by the phenomenon of spectral overlap. Multiple fluorophores can have an overlap in their exciting wavelength ranges, making it impossible to separate signals. The spectral overlap limits to a handful the number of fluorophores that can be imaged at one point. A few techniques have pushed this limit. Mass-Spectrometry Imaging is using metal beads attached to antibodys to "image" up to 50 proteins at a time. A powerful laser burns a small piece of the sample (1 squared micrometer) and the volatile metal beads are recognized with a mass-spectrometer. Mass-spectrometry imaging is a very promising imaging technique to analyse the spatial organization of a tissue while having access to an unprecented number of proteins.
We use mass-spectrometry images to analyse the tumor micro-environment of 2 types of cancer: the small cell-line lung cancer (SCLC), and the Chronic Lymphocytic Leukemia (CLL). We investigate the infiltration of immune cells in the tumor, the changes of protein expressions in different compartments, and the effect of advanced cancer treatments.
From the analysis point of view, the detection and segmentation of cells is difficult due to the low resolution of mass-spectrometry images (1 squared micrometer) compared to traditional microscopy. I develop crafted methods to detect all relevant celltypes, with special care for rare cell types. I further compare the protein expressions and tissue architectures.
Keywords: MIBI-TOF, IMC, multiplex imaging, segmentation, tumor micro-environment
Article: vom Stein, A.F., Rebollido-Rios, R., Lukas, A., Koch, M., von Lom, A., Reinartz, S., Bachurski, D., Rose, F., Bozek, K., Abdallah, A.T., Kohlhas, V., Saggau, J., Zölzer, R., Zhao, Y., Bruns, C., Bröckelmann, P.J., Lohneis, P., Büttner, R., Häupl, B., Oellerich, T., Nguyen, P. & Hallek, M. LYN kinase programs stromal fibroblasts to facilitate leukemic survival via regulation of c-JUN and THBS1. Nat Commun 14, 1330 (2023).