Js. Allen et al., CHARACTERIZATION OF THE EOSINOPHIL CHEMOKINE RANTES IN NASAL POLYPS, The Annals of otology, rhinology & laryngology, 107(5), 1998, pp. 416-420
Previous studies have demonstrated that the cytokine RANTES (Regulated
And Normal T cell Expressed and Secreted) has been shown to be a pote
nt mediator of eosinophil chemotaxis in vitro and of leukocyte recruit
ment. Because eosinophils are the hallmark cells in nasal polyposis, w
e hypothesize that RANTES is locally produced within the nasal polyp m
icroenvironment and is responsible for the eosinophil recruitment seen
in nasal polyposis. To begin to test this hypothesis, we evaluated na
sal polyps from 17 patients and 3 control specimens for distribution a
nd content of RANTES using immunohistochemical techniques and enzyme-l
inked immunosorbent assay technology. Our immunohistochemical studies
demonstrated that in nasal polyposis, RANTES antigen staining occurred
predominantly within eosinophils and epithelial cells. To quantify th
e relative levels of RANTES in normal and nasal polyp specimens, tissu
e homogenates were prepared, quantified, and normalized to protein lev
els. We detected RANTES in all 17 nasal polyp tissue homogenates (566
+/- 16 pg/mg total protein). The RANTES levels in nasal polyp homogena
tes were nearly 40-fold higher than the RANTES levels in normal tissue
(15.7 +/- 28.2 pg/mg total protein). Thus, it appears that increased
expression of RANTES by eosinophils and epithelial cells within the na
sal polyp microenvironment promotes eosinophil recruitment and activat
ion within nasal polyps. We hypothesize that RANTES induces increased
recruitment and activation of eosinophils, presumably contributing to
the increased tissue changes associated with nasal polyposis.