CD11b+ splenic myeloid cells in carcinoma patients
Authors: Andryukhova E.S. ,   Tomsk National Research Medical Center of the Russian Academy of Sciences, Cancer Research Institute, Tomsk, Tashireva L.A. , Vtorushin S.V. , Afanasyev S.G. , Avgustinovich A.V. , Zavyalova M.V. , Perelmuter V.M. ,   Tomsk National Research Medical Center of the Russian Academy of Sciences, Cancer Research Institute, Tomsk,   Tomsk National Research Medical Center of the Russian Academy of Sciences, Cancer Research Institute, Tomsk,   Siberian State Medical University, Tomsk,   Tomsk National Research Medical Center of the Russian Academy of Sciences, Cancer Research Institute, Tomsk,   Tomsk National Research Medical Center of the Russian Academy of Sciences, Cancer Research Institute, Tomsk,   Tomsk National Research Medical Center of the Russian Academy of Sciences, Cancer Research Institute, Tomsk,   Siberian State Medical University, Tomsk,   Tomsk National Research Medical Center of the Russian Academy of Sciences, Cancer Research Institute, Tomsk
Published: July 2024

Introduction. Splenic myeloid cells include monocytes and myeloid suppressor cells, which are deposited in the spleen and recruited to the sites of chronic inflammation, reparative tissues, and tumor microenvironment. In vivo experiments are mainly used to study the influence of the splenic system on the development and progression of the malignant neoplasm. The characteristics of myeloid elements with a common marker (CD11b) that are located in different splenic morphological and functional zones and their relation to metastases are still poorly studied. We aimed to compare the number and phenotypic features of CD11b+ myeloid cells considering their location in different splenic structural and functional areas in cohorts of patients with and without a malignant neoplasm, as well as depending on hematogenous and lymphogenous metastases in patients with carcinomas of various locations. Materials and methods. To estimate the number of CD11b+ cells with different variants of CD45, CD34, and CD90 expression, we applied the TSA technique. The number of cells of each phenotype per 1 mm2 of follicular, marginal, and red pulp areas was calculated in both groups. The association of cell number with lymphogenic and distant metastases was investigated in the group of patients with malignant neoplasms. Results. The CD11b+ myeloid cell population is heterogeneous and represented by cells at different stages of monocyte/MDSC differentiation, whose numbers predominate in the red pulp. The following changes are associated with carcinomas: a 17-fold increase in the number of promonocytes in the red pulp, a 2-fold decrease in the number of myelopoiesis progenitors in the marginal zone, and a reduction in the quantity of immature monocytoid cells/monoblasts in the marginal zone and the red pulp (5- and 12.5-fold, respectively). The number of CD11b+ myeloid cells with such phenotypes decreased even more in the cases with lymphogenic metastases. No association was found with distant metastases. Conclusion. The number of CD11b+ splenic myeloid cells is associated with carcinomas and lymphogenic metastases. Keywords: spleen, myeloid cells, CD11b, carcinomas, metastasis