Raj. Warringa et al., UP-REGULATION OF FORMYL-PEPTIDE AND INTERLEUKIN-8-INDUCED EOSINOPHIL CHEMOTAXIS IN PATIENTS WITH ALLERGIC-ASTHMA, Journal of allergy and clinical immunology, 91(6), 1993, pp. 1198-1205
Background: The cytokine granulocyte-macrophage colony-stimulating fac
tors, interleukin-3 and interleukin-5, are important modulators of eos
inophilia and eosinophil function. In particular, eosinophil chemotaxi
s is very sensitive to cytokine priming. Methods: We evaluated chemota
ctic responses of eosinophils from Patients with allergic asthma. Thes
e cells exhibited a primed phenotype as deduced from enhanced response
s toward formyl-methionyl-leucyl-phenylalanine and platelet-activating
factor and a decreased responsiveness toward granulocyte-macrophage c
olony-stimulating factor. Bronchoprovocation of patients with allergic
asthma with allergen was performed as a possible means to enhance in
vivo priming. Results: Indeed, eosinophils isolated 3 hours after alle
rgen challenge exhibited a more pronounced primed phenotype, which was
reflected by an induction of responsiveness towards interleukin-& Eos
inophil responses induced by platelet-activating factor, formyl-methio
nyl-leucyl-phenylalanine, complement fragment C5a, interleukin-3, inte
rleukin-5, and granulocyte-macrophage colony-stimulating factor were n
ot significantly altered after allergen challenge. Conclusion: These d
ata provide further evidence that eosinophils are already primed in th
e peripheral blood of individuals with allergic asthma. This is most l
ikely due to the presence of circulating cytokines in the peripheral b
lood of those individuals. This in vivo priming results in selective u
pregulation and downregulation of responses toward various chemotaxins
, which may be released in the lungs during allergic inflammation.