Immune mechanisms in mouse malaria(1):Period of survival correlates with immune deficient status, but not with antibody titres and immune complex levels

ABSTRACT

Poasmodium berghei NK 65 or Plasmodium yoelii (lethal strain)was inoculated into normal BALB/c mice, BALB/c nu/nu mice, neonatally thymectomized mice (NTx) and antithymocyte serum treated neonatally thymectomized mice (NTx + ATS). Periods of survival were compared to one another. The nu/nu, NTx and NTx + ATS mice survived significantly longer than normal BALB/c mice P. berghei infection, whereas no such difference was noticed after P. yoelii infection. Antimalarial antibodies and circulating immune complex (CIC) levels were measured in order to examine their correlation with the survival period. A significant difference in the state of equilibrium between antibodies and CICs was revealed. Most of the antibodies induced by P. yoelii formed CICs whereas a portion of the antibodies induced by P. berghei remained unbound. However, no correlation between mortality pattern and serological changes was found. Therefore it seems unlikely that antimalarial antibodies and CICs are harmful factors responsible for the earlier death of the immunocompetent mice.