Enhancement by recombinant human interleukin 2 of host resistance to Toxoplasma gondii infection in pregnant mice.
The lymphokine production by pregnant mice infected with a lethal dose of Toxoplasma gondii was evaluated in comparison with that by virgin mice infected with a sublethal dose of this protozoan parasite. Splenocytes taken from mice before and on the day after infection produced considerable amounts of IL-2 in response to concanavalin A (Con A) stimulation, but the titers rapidly declined in both pregnant and virgin mice as infection progressed. A trace amount or undetectable level of IL-2 was produced by splenocytes from acutely infected mice when stimulated with Toxoplasma lysate antigen (TLA). In contrast to the kinetics of IL-2 production, the levels of IFN-gamma produced by splenocytes cultured with Con A or TLA increased steadily in the later stage of infection in both pregnant and virgin mice. Thus, the response to Con A or TLA of splenocytes to produce IL-2 and IFN-gamma differed strikingly in acute toxoplasmosis in mice. The administration of rHuIL-2 resulted in a significant decrease in the mortality of pregnant mice infected with a lethal dose of Toxoplasma. The combination of rHuIL-2 and rMuIFN-gamma increased the survival rate slightly but not significantly compared with pregnant mice receiving either rHuIL-2 or rMuIFN-gamma. Moreover, exogenously administered rHuIL-2 enhanced the production of both IFN-alpha and IFN-gamma in the bloodstreams of pregnant mice, in accordance with the decreased mortality. These results indicate that IL-2 may play a significant role in modulating the host defense against Toxoplasma infection in pregnant mice.
Shirahata
T
T
Department of Veterinary Microbiology, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido, Japan.
Muroya
N
N
Ohta
C
C
Goto
H
H
Nakane
A
A
D000208:Acute Disease; D000818:Animals; D005260:Female; D007113:Immunity, Innate; D007371:Interferon-gamma / Q000096:biosynthesis / Q000627:therapeutic use; D007376:Interleukin-2 / Q000096:biosynthesis / Q000627:therapeutic use*; D051379:Mice; D008813:Mice, Inbred ICR; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic / Q000188:drug therapy*; D011270:Pregnancy, Animal; D011994:Recombinant Proteins / Q000627:therapeutic use; D013154:Spleen / Q000378:metabolism; D014122:Toxoplasma / Q000472:pathogenicity*; D014124:Toxoplasmosis, Animal / Q000188:drug therapy* / Q000401:mortality
D007376:Interleukin-2; D011994:Recombinant Proteins; D007371:Interferon-gamma