EX1 Opsonization and Phagocytosis - Quan Flashcards
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
