Intro to Adaptive Immunity Flashcards
What is adaptive immunity?
Resistance to infection produced by the adaptive immune response
Includes Cell-mediated immunity and Humoral immunity
What is Cell mediated immunity?
Directed against intracellular pathogens
Mediated by T-lymphoid cells activated by antigens
What is humoral immunity?
Mediated by antibodies generated by bone marrow derived by cells
Both intracellular and extracellular
What is the recombinase activating gene?
Products of this gene are responsible for somatic recombination of gene segments that encode antigen receptors
Acquired immunity relies on these receptors being diverse
What is acquired immunity characterized by?
Clonal distribution of antigen receptors
The acquisition of memory
What is clonal proliferation?
The multiplication of B and T lymphocytes after their activation by antigen
Result is a large number of lymphocytes directed agains a specific pathogen to eliminate it
What is a multi-valent response?
Immune response generated against multiple epitopes
Most adaptive immune responses are successful if multi-valent rather than univalent
What is antigenic drift?
Mechanism for variation in viruses that involves the accumulation of mutations within the genes that code for antibody-binding sites
How does the host adapt to antigenic drift?
Large numbers of T and B cell precursors that can possibly recognize the new antigen
What is antigenic shift?
Process by which two or more different strains of a virus, or strain of two or more different viruses, combine to form a new subtype having a mixture of the surface antigens of the original strains
What is antigenic modulation?
Intracellular pathogens can induce the host cell to down-regulate key molecules needed for recognition such as MHC class I
What are the two classes of T cell receptor?
alpha;beta - most of the T cells
gamma; delta - located in mucosa
