Hymenolepis muris-sylvaticae and H. microstoma: immunological cross-reaction in mice.

A primary infection with Hymenolepis microstoma strongly protects against cross-infection with H. muris-sylvaticae and also against secondary infection with H. microstoma in NMRI mice, resulting in an accelerated loss of worms and a weight reduction of the remaining worms. A primary infection with H. muris-sylvaticae causes an accelerated rejection of secondary infection with H. muris-sylvaticae but it has no effect on cross-infection with H. microstoma, neither with regard to worm recovery nor with regard to worm biomass. Determinations by enzyme-linked immunosorbent assay of antibody concentrations in the mouse sera revealed that: (1) the antibody response evoked by H. microstoma infection is much greater than by H. muris-sylvaticae infection; (2) a cross-infection with H. muris-sylvaticae boosts the antibody response evoked by H. microstoma infection; (3) H. microstoma antigen can be used to measure antibody concentration against both H. microstoma and H. muris-sylvaticae; and (4) although H. muris-sylvaticae is rejected faster in a cross-infection (i.e., after a primary H. microstoma infection) than in a secondary infection (i.e., after a primary H. muris-sylvaticae infection), antibodies evoked by the primary H. microstoma infection show little cross-reaction with H. muris-sylvaticae antigen. This suggests that it is doubtful whether serum antibodies are the direct effectors in worm rejection.