Heterogeneous Expression of Tumor Necrosis Factor-α Receptors I and II on Human Peripheral Eosinophils

Background: Expression of the tumor necrosis factor-α receptor by human eosinophils has not been determined. We examined the surface expression and mRNA for tumor necrosis factor-α receptors I and II (TNF-αRI and TNF-αRII) on peripheral eosinophils. Methods: Eosinophils were obtained from 17 asthma patients and 3 healthy volunteers. Flow cytometry was used to examine receptor expression, and the reverse transcriptase-polymerase chain reaction was used to examine receptor mRNA expression. Results: Flow cytometry revealed that 16 out of 20 subjects had eosinophils expressing TNF-αRI and 18 subjects had eosinophils expressing TNF-αRII. All eosinophils expressed at least one receptor. The mRNA for TNF-αRII was detected in all eosinophils examined, but the signals for TNF-αRI mRNA were only found in cells expressing this receptor. Conclusions: Human peripheral eosinophils show heterogeneous expression of TNF-αRI and TNF-αRII.