EX1 Opsonization and Phagocytosis - Quan Flashcards
(23 cards)
The process of attaching opsonins, such as IgG or complement fragments, to microbial surfaces to target microbes for phagocytosis
opsonization
These are macromolecules attached to the surface of a microbe and can be recognized by receptors on neutrophils and macrophages
opsonins
Two primary types of opsonins are…
IgG and complement factor C3
Most microorganisms (will/will not) be phagocytosed (with/without) opsonins
will NOT
withOUT
Opsonins change the organisms surface form (hydrophilic/hydrophobic) to more (hydrophilic/hydrophobic)
hydrophillic
hydrophobic
Receptors for opsonins are…..
Fcγ on phagocytes
CR and leukocyte integrin Mac-1
The _____ region of IgG reacts with the organism
Fab
There are _____ classes of Fc (Fcγ) domains on PMNs
3
Fcγ RI (CD64) binds to ____ and _____ with (high/low/intermediate) affinity, it (is/is not) expressed on resting neutrophils, has ____ immunoglobulin-like binding domains, and expression is (up/down) regulated by IFN-γ, G-CSF, and infection
IgG1 and IgG3 high is not 3 up regulated
Fcγ RII (CD32) binds to multiple IgGs with (high/low/intermediate) affinity, it is ______ spanning with a cytoplasmic tail, _____ different genes code for RII, ______’s RII exhibits genetically determined structural polymorphisms
low
membrane
3
neutrophils
Fcγ RIII (CD16) binds to _____ and _____ with (high/low/intermediate) affinity, ____ genes code of RIII
RIIIB is a molecule with a ________ anchor and is found only on ______
RIIIA has _______ and _____ domains and is found on ______ and _______
IgG1 and IgG3 intermediate 2 glycophosphatidylinositol neutrophils transmembrane and cytoplasmic NK cells and macrophages
Fcγ R____ is the most important for phagocytosis of IgG coated microorganisms and is the sole class capable of binding _______ IgG2 complexes (IgG2 contains antibodies to bacterial capsular polysaccharides)
RII
human
Activation of the _______ cascade causes proteolytic cleavage of ________ factors creating potential _______ for receptors on _______ surfaces
complement
complement
ligands
neutrophil
These complement factors are chemotatic factors
C3a and C5a
These complement factors are the main complement derived opsonins
C3b and C3bi
CR1 (CD35) is a neutrophil complement ________, resides in ___ pools of receptors, it binds dimeric ______ with (strong/weak) binding
receptor
2
C3bi
weak
Complement R CR3 is a glycoprotein member of the ____ family, resides in ____ pools of receptors, and the whole molecule is termed the CD___ and CD___ complex
integrin
2
CD11 and CD18
_________ are the major phagocytic cells in the innate immune response, has _____ and ______ granules, and is (continually/periodically) circulating
neutrophils
primary and secondary
continually
________ circulate in the blood eventually moving into tissue where they differentiate into _________; of which ________ and produce _______
monocytes
macrophages
phagocytose
cytokines
4 factors thats can increase PMN numbers…
stress
injury
infection
increased cytokines
There are 2 primary mechanisms for destruction/killing of cells
oxidative and non-oxidative
The non-oxidative mechanism uses ______ and ______ granules and/or a ____ change
enzymes and cytoplasmic
pH
Name the 2 ways in which microbes can avoid phagocytosis
inhibiting/inactivating opsonization/phagocytosis
surviving intracellular killing