Monocyte and macrophage markers for diagnostics of immunopathology

Abstract

Hidden sterile inflammations lead to the most dangerous diseases, including cardiovascular, type 2 diabetes and various malignant tumors. The key regulatory cells driving hidden inflammations are tissue macrophages that show certain inflammatory properties being, however incapable of inducing acute inflammation. We hypothesize that programming of blood monocytes by endogenous factors like high glucose, modified lipoproteins and others lead to the development of such tissue macrophages. Activation of monocytes by pathogenic factors leads to increased expression of intracellular and surface biomarkers, that can be used for diagnostics of hidden inflammations. The best studied marker of inflammatory monocytes is FcyRI – CD16. Association of CD16+ monocyte populations size with pathology was described for various inflammatory diseases. During their differentiation into macrophages, activated monocytes maintain their inflammatory properties acquired in the circulation. Upon additional stimulation by local factors this leads to the development of macrophages that are unable to react adequately to self and non-self-factors and promote local low-grade inflammation. As blood monocytes, these macrophages express various molecular markers that can be used in diagnostics. Our studies of monocytes and macrophages led to identification of several markers associated with inflammatory processes. These include stabilin-1, IL17RB, FOXQ1 and members of chitinase-like protein family YKL-40, YKL-39 и SI-CLP. In this review we discuss diagnostic potential of these markers.