Interleukin-5 mediates peritoneal eosinophilia induced by the F1 cell wall fraction of Histoplasma capsulatum.
An alkali-insoluble fraction 1 (F1), which contains mainly ss-glucan isolated from the cell wall of Histoplasma capsulatum, induces eosinophil recruitment into the peritoneal cavity of mice. The present study was carried out to determine the participation of interleukin-5 (IL-5) in this process. Inbred C57BL/6 male mice weighing 15-20 g were treated ip with 100 microg of anti-IL-5 monoclonal antibody (TRFK-5, N=7) or an isotype-matched antibody (N=7), followed by 300 microg F1 in 1 ml PBS ip 24 h later. Controls (N=5) received only 1 ml PBS. Two days later, cells from the peritoneal cavity were harvested by injection of 3 ml PBS and total cell counts were determined using diluting fluid in a Neubauer chamber. Differential counts were performed using Rosenfeld-stained cytospin preparations. The F1 injection induced significant (P<0.01) leukocyte recruitment into the peritoneal cavity (8.4 x 10(6) cells/ml) when compared with PBS alone (5.5 x 10(6) cells/ml). Moreover, F1 selectively (P<0.01) induced eosinophil recruitment (1 x 10(6) cells/ml) when compared to the control group (0.07 x 10(6) cells/ml). Treatment with TRFK-5 significantly (P<0.01) inhibited eosinophil recruitment (0.18 x 10(6) cells/ml) by F1 without affecting recruitment of mononuclear cells or neutrophils. We conclude that the F1 fraction of the cell wall of H. capsulatum induces peritoneal eosinophilia by an IL-5-dependent mechanism. Depletion of this cytokine does not have effect on the recruitment of other cell types induced by F1.
Sá-Nunes
A
A
Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil.
Medeiros
A I
AI
Faccioli
L H
LH
D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000276:immunology; D002452:Cell Count; D002465:Cell Movement; D002473:Cell Wall / Q000737:chemistry; D004802:Eosinophilia / Q000209:etiology; D004804:Eosinophils / Q000187:drug effects* / Q000502:physiology; D005936:Glucans / Q000302:isolation & purification / Q000494:pharmacology*; D006658:Histoplasma / Q000737:chemistry*; D015848:Interleukin-5 / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010529:Peritoneal Cavity / Q000166:cytology*
D000911:Antibodies, Monoclonal; D005936:Glucans; D015848:Interleukin-5