Cross-Reactions between Mycobacteria

I. Crossed Immunoelectrophoresis of Soluble Antigens of Mycobacterium lepraemurium and Comparison with BCG


Institute for Experimental Medical Research, Ullevål Hospital, Oslo, Norway


Crossed immunoelectrophoresis (CIE) has been used to characterize the soluble antigens of Mycobacterium lepraemurium (Douglas strain) (MLM). The antigen was prepared by sonification of intact bacilli, purified as described. A pool of immunoglobulin isolated from hyperimmune rabbit antisera was used as antibody. By this procedure 42 antigens from MLM could be defined in a highly reproducible manner. An analysis of crossed line immunoelectrophoresis (CLIE) and CIE with intermediate gel as methods for studying antigenic cross-reactivity are presented. Based on this analysis both BCG antigen and BCG antibody were added separately to the intermediate gel of the MLM reference system to study the cross-reactivity between this mycobacterium and MLM. It was concluded that 23 out of the 42 MLM antigens defined in our reference system showed various degrees of cross-reactivity. However, most of these cross-reactions were weak. The method appears to be well suited for studying cross-reactions between mycobacteria, but similar studies using other mycobacteria are needed before it can be decided how closely MLM is related to BCG.