- Information
- AI Chat
Lecture notes – The call vertebrates of cells
Biology (C100)
University of Salford
Recommended for you
Related documents
Preview text
Lecture notes – The call vertebrates of cells
Natural killer cells recruited to the site can recognize and kill virus-infected, altered, or stressed cells. However, in some situations these innate and inflammatory responses can be harmful, leading to local or systemic consequences that can cause tissue damage and occasionally death.
To prevent these potentially harmful responses, regulatory mechanisms have evolved that usually limit such adverse effects. Despite the multiple layers of the innate immune system, some pathogens may evade the innate defenses. On call in vertebrates is the adaptive immune system, which counters infection with a specific tailor-made response to the attacking pathogen.
Difference between Innate and adaptive immunity
Attribute Innate immunity Adaptive immunity
Response time Minutes/hours Days
Specificity Specific for molecules and molecular patterns associated with pathogens and molecules produced by dead/damaged cells Highly specific; discriminates between even minor differences in molecular structure of microbial or nonmicrobial molecules
Diversity A limited number of conserved, germ line encoded receptors Highly diverse; a very large number of receptors arising from genetic recombination of receptor genes in each individual
Memory responses Some (observed in invertebrate innate responses and mouse/human NK cells) Persistent memory, with faster response of greater magnitude on subsequent exposure
Self/nonself discrimination Perfect; no microbe-specific self/nonself patterns in host Very good; occasional failures of discrimination result in autoimmune disease
discrimination result in autoimmune disease Many antimicrobial peptides, proteins, and other mediators Antibodies and cytokines
Major cell typesPhagocytes (monocytes, macrophages, neutrophils), natural killer (NK) cells, other leukocytes, epithelial and endothelial cells T cells, B cells, antigen-presenting cells
This attack occurs in the form of B and T lymphocytes, which generate antibodies, and effector T cells that specifically recognize and neutralize or eliminate the invaders. While innate immunity is the most ancient form of defense, found in all multicellular plants and animals, adaptive immunity is a much more recent evolutionary invention, having arisen in vertebrates.
In these animals, adaptive immunity complements a well-developed system of innate immune mechanisms that share important features with those of our invertebrate ancestors. A large and growing body of research has revealed that as innate and adaptive immunity have co-evolved in vertebrates, a high degree of interaction and interdependence has arisen between the two systems.
Recognition by the innate immune system not only kicks off the adaptive immune response but also helps to ensure that the type of adaptive response generated will be effective for the invading pathogen.
Lecture notes – The call vertebrates of cells
Module: Biology (C100)
University: University of Salford
