[Immunoglobulin-lipoprotein complexes during P. chabaudi infection].
Immunoglobulin-lipoprotein complexes have been investigated in the course of P. chabaudi acute infection of Swiss mice. Serum ultracentrifugation in a sucrose density gradient was used to demonstrate the presence of immunoglobulins in the enriched lipoprotein fraction of density lower than 1100. The levels of lipoprotein-bound immunoglobulins (Ig-Lp) were measured using the rate-nephelometric Immuno-Chemistry-System. IgM-Lp and IgG-Lp were significantly increased at day 9 and reached a peak at day 13 post-infection. From day 13 to day 16 they dramatically decreased. This kinetic effect was similar to that of non-specific circulating immune complexes detected by the [125I]Clq binding assay. A radioimmuno-precipitation-PEG-assay (RIPEGAssay) with [125I]Lp revealed the highest Lp precipitation with day 13 post-infection mouse sera compared to controls. Similar results were recorded when control sera were 8 times as concentrated in order to obtain Ig levels identical in both control and experimental sera. Part of the lipoprotein-bound immunoglobulins were demonstrated to be anti-Lp antibodies by the way of the RIPEGAssay using F(ab')2 fragments from infected mouse sera. Moreover, the [125I]Clq bound to the Ig-Lp complexes isolated from day 13 mouse sera. The present data suggest that the alteration of lipid metabolism which characterizes malaria infection could lead to the complexation of lipoproteins to immunoglobulins.
D000818:Animals; D000936:Antigen-Antibody Complex / Q000378:metabolism*; D007140:Immunoglobulin Fab Fragments / Q000378:metabolism; D007074:Immunoglobulin G / Q000378:metabolism; D007075:Immunoglobulin M / Q000378:metabolism; D007136:Immunoglobulins / Q000378:metabolism*; D007158:Immunologic Techniques; D008074:Lipoproteins / Q000378:metabolism*; D008288:Malaria / Q000276:immunology*; D011817:Rabbits
D000936:Antigen-Antibody Complex; D007140:Immunoglobulin Fab Fragments; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007136:Immunoglobulins; D008074:Lipoproteins
Complexes immunoglobulines-lipoproteines dans l'infection par Plasmodium chabaudi.