Let us consider a situation in which the body is attacked by a microbe, and the microbe is captured by the immune system for recognition of surface antigens.
The surface antigen recognized mimics one of our self antigens.
It is stated in textbooks that this situation results in the immune system attacking the microbe along with the tissue containing the self antigen(auto-immunity).
(Reference: Robbins and Cotran pathologic basis of disease)
If a microbial antigen mimicks self antigen, why is the microbial antigen attacked instead of being ignored in the way that all our self antigens are ignored by our immune system?