PATHOMA Acute inflammation 10/30 Flashcards
In acute what 2 presence in tissue?
edema and neutrophils
Acute infl arises in response to?
Infection (to eliminate pathogen) or tissue necrosis (to clear necrotic debris)
whats the point of acute infl in infection?
to eliminate pathogen
whats the point of acute infl in tissue necrosis?
to clear necrotic debris
response and specificity in acute?
IMMEDIATE response with LIMITED specificy
type of immunity in acute?
innate immunity
Mediators of acute infl? 5 groups
Toll like receptors (TLRs); Arachidonic acid (AA) metabolites; Mast cells; Complement; Hageman factors.
- where are present TLRs?
present on cells on the innate immune system (eg. macrophages and dendritic cells)
and ALSO ON ADAPTIVE IMMUNITY (eg lymphocytes).
- What does activate TLRs?
Activated by pathogen-associated molecular patterns (PAMPs) that are commonly shared by microbes
- example of PAMPs?
lipopolysacharide
- what is co-receptor for TLR4 on macrophages?
CD14
- PAMPs and TLRs interaction example?
CD14 on macrophages recognizes LPS (a PAMP) on the outer membrane of gram negative bacteria.
- TLR activation results in what?
upregulation of NF-kappaB.
- what does NF-kappaB?
its a nuclear transcription factor that activates immune response genes leading to production of multiple immune mediators.
- why TLR plays important role also in chronic inflammation?
TLR are present on ADAPTIVE IMMUNITY (eg lymphocytes) cells and, hence, play important role in mediating chronic inflammation.
- Arachidonic acid (AA) is released from the ….?
phospholipid cell membrane by phospholipase A2.
- AA is released by?
Arachidonic acid (AA) is released from the phospholipid cell membrane by phospholipase A2.
- once AA is released from the phospholipid cell membrane by phospholipase A2, whats next?
acted upon by cyclooxygenase or 5-lipoxygenase
- If AA is acted upon by cyclooxygenase, what is produced?
prostaglandins (PG).
- What PG mediate vasodilation and incr. permeability?
PGI2, PGD2, PGE2
- what PG mediates pain and fever?
PGE2
- PGE2 does what?
mediate vasodilation and incr. permeability
mediates pain and fever
- What does PGI2, PGD2?
mediate vasodilation and incr. permeability
- If AA is acted upon by 5-lipoxygenase, what is produced?
leukotrienes (LT)
- What LT attracts and activates neutrophils?
LTB4
- What LT mediate vasoconstriction, bronchospasm and increased vascular permeability?
LTC4, LTD4, LTE4
- what are slow reacting substances for anaphylaxis?
LTC4, LTD4, LTE4
- what does LTB4?
attracts and activates neutrophils
- What does LTC4, LTD4, LTE4?
mediate vasoconstriction, bronchospasm and increased vascular permeability + they are slow reacting substances for anaphylaxis
- mast cells are distributed in what tissue?
connective tissue
- what activates mast cells?
- Tissue trauma;
- Complement proteins C3a and C5a or
- cross-linking of cell-surface IgE by antigen
- IMMEDIATE response of mast cell once they are activated?
release of preformed histamine granules, which mediate VASODILATION of arterioles and increased vascular permeability
- release of preformed histamine granules from mast cells results in?
release of preformed histamine granules, which mediate vasodilation of arterioles and increased vascular permeability
- DELAYED response of mast cell involves what?
production of arachidonic acid metabolites, particularly leukotrienes.
- What is complement?
proinflammatory serum proteins that ,,complement” inflammation
- Complement proteins circulate in what form?
inactive precursors
- What activates complement? classical pathway
C1 binds IgG or IgM that bound to antigen
- What activates complement? alternative pathway
microbial products directly activate complement
- What activates complement? mannose-binding lectin (MBL) pathway
MBL binds to mannose on m/os and activates complement
- All complement cascade pathways result in production of what?
C3 convertase
- What mediates C3 convertase?
C3 to C3a and C3b
- Due to activity of convertase eventually is produced what?
C5 convertase (C5 –> C5a and C5b)
- What does C5b?
C5b complexes with C6-C9 to form MAC
- What are anaphylatoxins?
C3a and C5a
- What does anaphylatoxins?
trigger mast cell degranulation, resulting in histamine-mediated vasodilation and increased vascular permeability.
- What other function has C5a?
chemotactic for neutrophils
- what does C3b?
opsonin for phagocytosis
- What does MAC?
lyses microbes by creating a hole in the cell membrane
- What is Hageman factor?
Factor XII
- How is caller factor XII?
Hageman factor
- where is produced Hageman factor (factor XII)?
is inactive proinflammatory protein produced in liver
- when is activated factor XII?
activated upon exposure to subendothelial or tissue collagen.
- activated factor XII leads to activation of what?
- Coagulation and fibrinolytic systems;
- Complement;
- Kinin system
- what does Kinin system?
Kinin cleaves high-molecular-weight kininogen (HMWK) to bradykinin, which mediates vasodilation and increased vascular permeability (similar to histamine), as well as pain.