Mechanisms of eosinophilia in BALB/c-nu/+ and congenitally athymic BALB/c-nu/nu mice infected with Toxocara canis.
We studied the mechanism of eosinophilia in BALB/c-nu/+ (nu/+) and BALB/c-nu/nu (nu/nu) mice infected with Toxocara canis. Eosinophilia with two peaks on days 11 and 21 of infection was observed in infected nu/+ mice, and with a peak on day 11 in nu/nu mice. Interleukin-5 (IL-5) mRNA was expressed on day 5 of infection in the lung and spleen of nu/+ mice and in the lung of nu/nu mice, but not in the spleen of nu/nu mice. Large numbers of eosinophils and lymphocytes infiltrated the lung of both mice 1 week after infection. The number of larvae in the lung was the largest on day 5. Anti-IL-5 monoclonal antibody (mAb) treatment completely inhibited eosinophilia of both mice, with no change of larval distribution. Administration of anti-CD4 or anti-CD3 mAb markedly reduced the second peak of eosinophilia on day 21 of infection in nu/+ mice, and slightly reduced the first peak of eosinophilia on day 11 in both mice. Anti-CD8 mAb had no effect on the eosinophilia. These results suggest that eosinophilia in both mice is caused by IL-5, and that IL-5 is produced by cells other than CD4+ T cells, in addition to CD4+ T cells.
Kusama
Y
Y
First Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto, Japan.
Takamoto
M
M
Kasahara
T
T
Takatsu
K
K
Nariuchi
H
H
Sugane
K
K
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D015703:Antigens, CD / Q000276:immunology; D015152:Blotting, Northern; D001921:Brain / Q000469:parasitology; D004802:Eosinophilia / Q000276:immunology*; D015848:Interleukin-5 / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D008168:Lung / Q000276:immunology / Q000469:parasitology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D018482:Muscle, Skeletal / Q000469:parasitology; D012333:RNA, Messenger / Q000235:genetics; D017166:Toxocara canis / Q000302:isolation & purification; D014120:Toxocariasis / Q000276:immunology*
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D015848:Interleukin-5; D012333:RNA, Messenger