In the mid-1950s, Frank Burnet, inspired by a suggestion made by Niels Jerne, formulated the clonal selection theory (CST) of immunity. On the basis of CST, Burnet developed a theory of how an immune response is triggered according to the self/nonself distinction: "self" constituents (constituents of the body) do not trigger destructive immune responses, while "nonself" entities (e.g., pathogens, an allograft) trigger a destructive immune response. The theory was later modified to reflect new discoveries regarding histocompatibility or the complex "two-signal" activation of T cells. The self/nonself theory of immunity and the self/nonself vocabulary have been criticized, but remain very influential. COUNT 5
QSN1 What medical scientist first proposed the clonal selection theory of immunology? ANS1 Frank Burnet QSN2 What triggers an immune response according to CST? ANS2 self/nonself distinction QSN3 In CST, what triggers a destructive immune response? ANS3 "nonself" entities (e.g., pathogens, an allograft) QSN4 What property of T cells caused modification of CST? ANS4 the complex "two-signal" activation QSN5 When was clonal selection theory first proposed? ANS5 In the mid-1950s