In order to analyze the cellular mechanism of immunosuppression during acute infection by
Ascaris suum, cytokine and natural killer activities in
A. suum infected mice were investigated.
Ten days after infection with 10
3 or 10
4 embryonated
A. suum eggs, Concanavalin A induced interleukin 2 (IL-2) production by splenocytes were reduced. At the same time, NK activity of splenocytes and the levels of serum interferon induced by Poly I. Poly C were also reduced. On the other hand, culture supernatants of peritoneal adherent cells from
A. suum infected mice showed significantly high interleukin 1 activity which reached peak level on day 15 following lipopolysaccharide stimulation. Increase in the number of macrophages in the peritoneal cavity were also observed in this period. Furthermore, the culture supernatants of peritoneal adherent cells from 10-days
A. suum infected mice exhibited a suppressive effect on both IL-2 production by normal splenocytes and IL-2 activity assayed using CTLL-2 cells. Dialysis and molecular filtration studies indicated that the factor with molecular weight below 10, 000 related to the suppressive effect. But there was no significant increase of prostaglandin E
2 in the culture supernatants.
These results suggest that activated macrophages may play an important part in the immunosuppression by producing a soluble suppressive factor during acute infection by
A. suum.
抄録全体を表示