The story of kuru, as classically told in biology textbooks, is a tragic one. The Fore population in Papua New Guinea ate the brains of their tribe members as an act of mourning, a ritual that allowed a misshapen protein to spread through the population. This caused the disease kuru, which killed as much as 10 percent of the population in the mid-twentieth century.
No one “developed” a resistance to it as a result of eating a brain. They already had it, and the ones who did not died. This is part of how evolution works – sometimes it’s the benefit of a random mutation, and a lot of death.
I suggest starting with chilled monkey brains before attempting human ones: