Lecture 2 Flashcards
(23 cards)
What are general features of microbes?
- exposed mannose residues in carbohydrates
- unmethylated CpG sequences in DNA
What are the four major categories of microbes?
- bacteria
- fungi
- parasites
- viruses
Which is an example of an intracellular microbe?
-viral species
How can you distinguish bacteria from mammalian hosts?
-bacteria initiate protein synthesis with N-formyl methionine rather than unmodified methionine
cycle of virus replication
- attachment of virus
- penetration of host cell
- uncoating of viral particle
- transcription of viral genome
- viral protein synthesis
- replication of viral genome
- capsid assembly from protein subunits
- packaging of viral nucleic acids into capsids
- release of viral particles from cell
Which are the generative (central) lymphoid organs?
bone marrow and thymus
What are the leukocytes of innate immunity?
- monocytes
- granulocytes
- natural killer (NK) cells
- dendritic cells
What is the difference between affinity and avidity of target-receptor interaction?
- affinity-sum of attractive and repulsive forces
- avidity-strength of interaction between multiple target subunits and multiple receptor molecules
- avidity is orders of magnitude higher than affinity
antigens
-foreign and self components that bind to BCR and TCRs as well as soluble antibodies
(T/F) Lymphocytes expressing antigen receptors that can bind with high affinity to normal self-antigens under apoptosis
-true
Most innate immune cells pass through vasculature of peripheral lymphoid organs. What is different about B and T cells?
-they exit vasculature into extravascular space inspecting for antigens and if none found they exit lymphatic vessels and proceed to inspect other peripheral lymphoid tissues and back into blood circulation
inflammation
-accumulation of fluid (contain plasma proteins) and cells at sites of infection or tissue damage
Which antigen presenting cells present antigen samples to T lymphocytes and which present to B lymphocytes?
- dendritic cells, macrophages, and B cells present to T lymphocytes
- follicular dendritic cells present antigen samples to B lymphocytes
What are effector cells?
-lymphocytes differentiate into effector cells and are able to participate in elimination of invading microbe
clonal selection
-specific lymphocyte selected by antigen to proliferate and differentiate into clone of effector cells
What are the two general strategies used by immune system to kill microbial particles bound by target-specific receptors?
- intracellular killing by phagocytosis (by neutrophils, macrophages, monocytes)
- cytoxicity by extracellular killing of microbes or infected host cells by lysis of microbial particles or injection of toxic substances
What are two ways you can activate additional immune forces during infection?
- activation of complement system
- secretion of cytokines
(T/F) Cytokines exert paracrine effects
true
chemokines
subset of cytokines belonging to class of chemoattractants
Where is the manufacturing site for innate immune cells?
bone marrow
How do leukocytes communicate?
-noncovalent cell-cell interactions mediated by cell surface receptors
What is the difference between protozoa and worms (helminths)?
- protozoa-single cell eukaryotes
- worms-multicellular animals
What is the outcome for target-receptor binding for cell-associated receptor (PRR) and for soluble receptor (antibody)?
- Cell-associated receptor-signal transduction, cell activation, elimination of target
- Soluble receptor-neutralization of target
