TypeIinterferons(IFNs),includingIFN-α,areafamilyofcytokinesthathavepleiotropicfunctionsintheimmunesystem.
1Besidesitspotentantiviralactivity,IFN-αexertsavarietyofimmunomodulatoryeffects,includingpositiveandnegativeregulationofitsownproduction,regulationofIL-12andIFN-γproduction,promotionofnaturalkiller(NK)cellcytotoxicity,activationandmaturationofdendriticcells,andthepromotionofBcelldevelopmenttowardsplasmacells.
2,3IFN-αisexpressedpredominantlybyCD123
+CD11c
–CD303(
BDCA2)
+plasmacytoiddendriticcells,alsoreferredtoasnaturalIFN-producingcells.Thesecellsrepresentingapproximately0.4%ofthetotalPBMCs,produceupto1000-foldmoretypeIIFNsthananyothercelltype.However,
BIOLOGicallyrelevantlevelsofIFN-αarealsoproducedbyothercelltypes,e.g.,monocytesandmyeloiddendriticcells.
4TheIFN-αSecretionAssaycanbeusedforthedetectionofviableIFN-α–secretingleukocytesorthedetectionofIFN-α–secretingcellsforenumerationandphenotypicanalysis.Fur
Thermore,thestimulatoryorregulatoryfunctionsofcytokine-secretingmonocytesanddendriticcellscanbeanalysed.