In Silico Comparative Expression Analyses of Pattern Recognition Receptors in Human Eosinophil Cell Lines and Primary Eosinophils

Objective: Eosinophils are one of the least abundant leukocytes in blood circulation; however, they compensate for this sparsity by highly potent content of their granules. Their involvement in numerous pathological conditions including acute and chronic infections make them an interesting research area for the field of immunology. Eosinophils play critical roles in the maintenance of immune homeostasis through their effector and modulatory functions in shaping innate and adaptive responses. Although they are mainly known for their roles in parasitic infections, it has become increasingly clear that eosinophils function not only in fungal, bacterial and viral infections, but also in tissue repair and signaling pathways regulating mast cells, Th2 and B cells. Of all the mediators of innate immunity, pattern recognition receptors (PRRs) are of great importance in the context of the stimuli. Therefore, we analyzed and cross-checked mRNA expression profiles of membrane-bound and cytosolic PRRs by comparing EoL-1 and HL-60 human eosinophil like cell lines to human primary eosinophils in silico. Materials and Methods: Utilizing publicly available databases, we analyzed PRR repertoires of eosinophils to determine the most ideal cell line models for in vitro mechanistic studies, requiring high protein and mRNA yields. Results: Our findings revealed that toll-like receptors 2 and NOD-like receptor 3 (NLRP3) had higher basal expressions in both cell lines than human primary eosinophils as opposed to NLRP12, laboratory of genetics and physiology 2 (LGP2), Dectin-1, whose expressions were higher in primary eosinophils than in both cell lines. Conclusion: These data might attribute new physiological functions to these receptors of NLR, RIG-I like receptor and C-type lectin receptor families in eosinophil immunity.