Which of the following comparisons of the innate and adaptive immune systems is FALSE?

Question

A. The innate immune system is more likely to recognize normal self, and therefore cause autoimmunity, than is the adaptive immune system.
B. Receptors used for recognition in innate immunity are encoded in the germline, whereas those of the adaptive immune system are encoded by genes generated via somatic recombination of germline receptor gene loci.
C. The innate and adaptive immune systems share some of the same effector mechanisms.
D. Both the innate and adaptive immune systems can recognize nonmicrobial substances.
E. The innate immune system does not have memory but the adaptive immune system does.

Answer 1

ANS: A. Innate immune system receptors are encoded by germline genes that have evolved to recognize microbial structures or molecules produced by stressed self, and therefore there is little chance of innate immune responses to normal self. Because the specificities of adaptive immune system receptors (Ig or T cell receptor molecules) are randomly generated by somatic recombination and junctional-diversity mechanisms, there is a greater chance that the adaptive immune system receptors may recognize normal self molecules, leading to autoimmunity. Mechanisms of tolerance minimize this possibility, but these mechanisms can fail. The adaptive immune system receptors can recognize nonmicrobial structures. Although most innate immune system receptors recognize microbial structures, some Toll-like receptors and activating receptors of natural killer cells do recognize nonmicrobial self proteins expressed by stressed, damaged, or infected cells. Memory is a unique property of the adaptive and not the innate immune system.