Factors controlling IgM and IgG antibody responses to denatured trypanosome DNA.

Rabbits immunized with complexes of denatured calf thymus DNA and methylated bovine serum albumin (MBSA) produced only IgM antibodies to denatured DNA, confirming the results of previous studies. In contrast, both IgM and IgG antibodies were induced by MBSA complexes of Trypanosoma brucei DNA. A similar response was observed by Gruenewald and Stollar (1973) to T2 bacteriophage DNA, in which the normal base cytosine is replaced by hydroxymethylcytosine. T2 bacteriophage DNA is known to have a high adenine+thymine (A + T) content. It is suggested that the 7S antibody response to MBSA complexes of T. brucei DNA might be linked to the high A + T content in the DNA (especially kinetoplast DNA) of the subgenus Trypanozoon.