Human eosinophils elaborate the lymphocyte chemoattractants. IL-16 (lymphocyte chemoattractant factor) and RANTES.
Eosinophils and CD4+ lymphocytes are preferentially recruited into sites of allergic inflammation. A role for eosinophils in the recruitment of CD4+ lymphocytes has not been defined. We studied the capacity of human eosinophils to release chemoattractants for T lymphocytes. Supernatants of cultured eosinophils contained chemoattractant activity for lymphocytes, which was predominantly due to IL-16 (lymphocyte chemoattractant factor) and RANTES. With neutralizing Abs, eosinophil-derived lymphocyte chemotactic activity was diminished by a mean (+/- SEM) of 60 +/- 3% with polygonal anti-IL-16 Ab, 69 +/- 4% with anti-IL-16 mAb, 48 +/- 3% with anti-CD4 F(ab) (IL-16 receptor blockade), 40 +/- 4% with anti-RANTES mAb, and 88 +/- 5% with a combination of anti-IL-16 and anti-RANTES mAbs. IL-16 and RANTES were detectable in eosinophil-derived supernatants by ELISA. Eosinophils constitutively expressed mRNA transcripts for both IL-16 and RANTES detectable by reverse transcription-PCR and contained preformed IL-16 and RANTES demonstrable by ELISA of cell lysates and by immunocytochemistry of freshly isolated eosinophils. Thus, eosinophils are a source of two cytokines, IL-16 and RANTES, that are chemoattractants for lymphocytes as well as eosinophils. These data indicate that eosinophils could contribute cytokines to enhance the recruitment of additional populations of CD4+ lymphocytes and eosinophils.
Lim
K G
KG
Department of Medicine, Beth Isreal Hospital, Harvard Medical School, Boston, MA 02215, USA.
Wan
H C
HC
Bozza
P T
PT
Resnick
M B
MB
Wong
D T
DT
Cruikshank
W W
WW
Kornfeld
H
H
Center
D M
DM
Weller
P F
PF
D000911:Antibodies, Monoclonal; D001483:Base Sequence; D018946:Chemokine CCL5 / Q000096:biosynthesis* / Q000235:genetics; D002630:Chemotactic Factors / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D017931:DNA Primers / Q000235:genetics; D004804:Eosinophils / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D019410:Interleukin-16; D008214:Lymphocytes / Q000276:immunology*; D008222:Lymphokines / Q000096:biosynthesis* / Q000235:genetics; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
D000911:Antibodies, Monoclonal; D018946:Chemokine CCL5; D002630:Chemotactic Factors; D017931:DNA Primers; D019410:Interleukin-16; D008222:Lymphokines; D012333:RNA, Messenger