Path inflammation / FA immunology Flashcards
What is LPS?
PAMP present in cell wall of all gram neg bacteria that is recognized by CD14 on macs
What is NFKB?
Turned on when TLR is activating turning on acute inflammatory response
What does LTB4 doing?
Attract and activate neuts
4 things attracting and turning on macs?
- C5a
- LTB4
- IL8
- Bacterial products
Function of LTs?
- Vasoconstrict
- Bronchospasm
- Vascular perm
What are pericytes?
Contract to pull endothelial cells to allow extravasation form capillaries
- Activated by leukotrienes
What activates masts?
- Trauma
- C3/5
- IgE cross linking
* Causes dumpin of histamine = dilation and increased permeability
What do mast cells do after dumping histamine?
Several hours later dumb leukotrienes to keep acute response going
How is classical complement path activated?
“GM makes classic cars”
IgG / M bound to antigen turn on C1
What is C3b?
Opsonin for phagocytosis
What mediates pain?
- Bradykinin
2. PGE2
Who is fever caused?
- Macs release IL1 and TNF
- Increase COX in perivascular cells of hypothalamus
- Increased PGE2 raises temp set point
What upregulates P and E selectin?
P: histamine
E: IL1 / TNF
What is sialyl Lewis X?
What selectins bind on neuts to slow them down
What binds in adhesions?
Integrins on neuts to cellular adhesion molecules
What is leukocytes adhesion deficiency?
- AR defect in CD18 unit of integrins responsible for adhesion
1. Delayed umbilical separation
2. Increased neuts
3. Recurrent bacterial infx w/o puss
- Delayed umbilical separation
- Increased neuts
- Recurrent bacterial infx w/o puss
leukocytes adhesion deficiency
2 opsonins?
IgG
C3b
What is chediak hegashi?
- AR protein trafficking defect with impaired phagolysosome formation
- Defect in microtubules
1. Increased pyogenic infections
2. Albinism
3. Neutropenia: microtubule issues
4. Granules in leukocytes
5. Neuropathy: cant move nutrients to end of nerve
6. Defective primary hemostasis
- Increased pyogenic infections
- Albinism
- Neutropenia
- Granules in leukocytes
- Neuropathy
- Defective primary hemostasis
Chediak
Oxidative burst?
- O2 -> O2- (superoxide): via NADPH oxidase
- O2- -> H202: via superoxide dismutase
- H2O2 -> HOCL: via MPO
* HOCL kills microbe in phagolysosome
CGD?
NADPH oxidase deficiency: cant make O2-
**Catalase positive infx
Why catalase positive in GCG?
Catalase destroys the H2O2 bacteria is making preventing CGD cells from using it to make HOCL
Cat pos orgs?
Aureus Pseudomonas cepacia S marcescens Nocardia Aspergillus
Nitro blue test?
Turs blue if person can turn O2 -> O2-
Negative nitro blue test?
= CGD
MPO deficiency?
Candida infx with normal nitro blue as can make O2- but problem making HOCL
How do macs kill?
Mainly oxygen independent with enzymes in secondary granules
**Lysozyme
What do macs release for resolution?
IL10
TGF Beta
- Could release IL8 if want more neuts
What is TCR coupled with?
CD3 - allows to recognize antigens but only when present in MHC
2nd CD4 signal?
APC B7 binds CD28 on CD4 t cell
2 types of CD4s?
- TH1: help CD8s
2. Th2: help B cells
What does TH1 secrete?
- IL2: activates and grows CD8s
2. IFN gamma: activates macs
What do Th2s secrete?
- IL4 - Class switch to IgG / E
- IL5 - IgA, b cell maturation, Eosinophils
- IL10 - Stops Th1
- Macs also produce IL 10 to end acute inflammation
Second signal for CD8s?
IL2 from TH1 CD4
How does CD8 kill?
- Performing makes hole, granzyme enters, apoptosis occurs via caspase
- Fas ligand on CD8 binds FAS on target = apoptosis
How are Caspases activated?
- Cytochrome C from mitochondria
- Fas
- Granzyme `
What do naive B cells express?
IgM and IgD think, naive MD
How are naive B cells activated?
- Antigen binds IgM / D: becomes IgM plasma cell
2. B cells presents to CD4 in MHC2, CD40/40L provides second signal: T cell releases IL4/5 allowing isotype switching
Cell that defines granuloma?
Epithelioid histiocyte: Mac with pink cytoplasm
Do non caseating granulomas have necrosis?
No
DDx non caseating?
- Beryllium
- Crohns
- Sarcoid
- Foreign material
- Cat Scratch
Stellate shaped granuloma?
Cat Scratch: non caseating
DDx caseating? How do differentiate types?
- TB: AFB stain
2. Fungal: GMS stain
How is granuloma formed?
- Macs present to CD4 in MHCII
- Macs release IL2 - > TH1 differentiation
- TH1 secreted IFN-gamma -> giant cells and epithelioid histiocytes form macs
What does IL12 do?
Released by macs for TH differentiation
Digeorge?
- T cells deficient: lack of thymus - > viral / fungal
- HYPO Ca: no parathyroids
- Facial deformities
- Cardiac abnormalities
SCID? Causes?
Defective cell and Ig immunity
- Cytokine recept Defect
- Absent MHC II
- Adenosine deaminase deficiency: adenosine builds up and is toxic to lymphocytes
What does Adenosine deaminase deficient cuase?
SCID
X linked Agammaglobulinemia?
- Zero Ig from disordered B cell maturation
- Naive cannot become plasma
- Absent lymph nodes
- Only seen in boys
- Bruton tyrosine kinase deficiency
*Bruton tyrosine kinase deficiency
Agammaglobulinemia
Presentation of Agammaglobulinemia?
A 6 months infx with:
- Giardia
- Enterovirus
- Bacterial
* only in boys
A 6 month old boy infx with:
- Giardia
- Enterovirus
- Bacterial
Agammaglobulinemia
Disease common in IgA deficient?
Celiacs
Hyper IgM
- Second 40/40L signal cant be sent
- Cytokines for class switching cant be made
- Low IgA / E / G
- *Recurrent mucosal and pyogenic infx
Wiskott aldrich?
- Eczema
- Thrombocytopenia: petechia
- Recurrent infx
* WASP mutation
- Eczema
- Thrombocytopenia: petechia
- Recurrent infx
* WASP mutation
Wiskott aldrich
C5 - 9 Deficient?
Neisseria
C1 inhibitor deficient?
Edema of skin and mucosal surfaces especially around eyes
“C1 esterase”
Positive selection?
Can you bind MHC and antigen
- If not = death