Adaptive Immunity Flashcards
In what group of organisms is adaptive immunity present?
In vertebrates. First known to exist in sharks.
What types of cells are responsible for the adaptive immune response?
B-lymphocytes and T-lymphocytes.
Is the adaptive immune response pathogen-specific?
Yes, the adaptive immune response differentiates between pathogens through recognition of specific protein/sugar/lipid residues on targets.
What is the logic behind Clonal Selection Theory?
- Each lymphocyte has a uniquely specific receptor.
- Interaction between foreign molecule and the lymphocytes receptor activates the lymphocyte.
- Differentiated effector cells derived from an activated lymphocyte will bear receptors with identical specificity to the parent.
- Lymphocytes bearing receptors for self molecules are immediately deleted to prevent auto-immunity
How does the adaptive immune system rely on the innate immune system to function?
Activation of T-lymphocytes requires phagocytosis and digestion of pathogen by cells of the innate response. Following digestion, specific molecules are presented by the phagocyte for the lymphocyte to recognize. Lymphocytes also require a second signal from the innate immune system for full activation.
What is the concept of humoral and cellular immunity based upon?
Categorization of the immune system according to the effector mechanisms.
What is humoral immunity?
Immunity mediated by soluble molecules, predominantly by antibodies and complement, in the body’s fluids.
What was Jules Bordet best known for in the context of immunology?
He demonstrated that there are two components in serum that facilitate humoral immunity. The first was heat stable and specific to the target organism, now known as antibodies. The second was heat-labile and conferred non-specific anti-microbial activity to serum, now known as complement.
How does humoral immunity confer protection?
Soluble proteins bind target pathogens to either neutralize or directly lyse them. This response can be enhanced by opsonization, where further molecules are recruited to lyse the pathogen.
What is complement?
A series of approximately 40 soluble proteins that activate and bind to microbial cell surfaces. Activation leads to a proteolytic cascade resulting in the generation of the Membrane Attack Complex (MAC) which inserts itself into the pathogen’s membrane, creating pores and lysing it.
