MOD E2, Chp4-6 Flashcards
Where are CR2 and CD21 located? Fxn?
Located on B cells, receptors for complement.
EBV uses CR2 to get into the B cell
What contains the Fc receptor? What binds to Fcr?
FceR?
Fc Receptors: (phagocytes)
- Follicular dendritic
- NK cells
- Mast cells
- Macrophages
Fc is the main stem part of an Ab
IgG after it’s opsonized something
FeCR on Mast cells
For NK cells, what activates perforin/granzyme release and what inhibits it?
ACtivatino: NKG2D
Inhibiting: MHC1
NK cells, what activates them? What do NK cells release?
Activated by:
IL-2, 12, 15, IFN a & b
Secretes:
IFNy
What chromosome are MHC/HLA on?
Chromsome 6
What activates NFKb?
TLR’s
HIV uses this
What do the following sense? TLR? NOD? CLR? RIG? GPCR? MLR?
TLR -- bacteria NOD - Intracellular uric acid, nectroic cells, ion imbalance [uses inflammasome] CLR fungal RIG - viruses GPCR - n formylmethionine MLR - sugar
What does MHCI present? What part of the receptor binds to CD8? What genes?
MHCII same except CD4?
Intracellular viral or tumor proteins
A3 - CD8;
Genes: HLA-DP, DQ, DR
Present only on APCs,
Extracellular that’s been internalized
B2 binds CD4
Genes: HLA-DP, DQ, DR
How does a T cell become activated?
- MHC on APC binds to TCR on T cell
2. B7/CD80 on APC; CD28 on T cell
How does a B cell class switch?
B cell has CD40. T cell had CD40L. Once bound, T cell shoots out IFNy, IL4, IL5 to class switch
What uses ADCC?
Antibody dependent compliment cascade?
NK cells! They have Fc receptor for IgG, which opsonizes tumor or viral cells
What abs do what? IgG IgM Iga IgE IgD
IgG: opsonizes, C', crosses placenta IgM: C', but also on naive cells IgA: Mucosal IgE: parasites, allergens IgD: NKF
What is atopy?
atopy = prone to allergy bc you have high IgE, IL4, Th2
What is anergy?
Peripheral tolerance =
T cells latch onto self cells, but without the second signal of B7-CD28 (B7 is only on foreign) then it becomes anergic
What is the apoptosis mechanism in peripheral tolerance?
- T cell binds self cell, cell sticks out Bim, mitochondrial apoptosis
- Self cell sticks out FAS-L and apoptosis the T cell.
Ankylosing spondylitisl gene?
B27
There are genes that aren’t MHC that can cause autoimmune dx. What are they?
PTPN22 cause polymorphisms –> RA, DMI, Tyrosine kinase defects
NOD2 cause polymorphisms –> crohns
IL-2 or IL7 receptor defects –> MS
How do infection cause autoimmune diseases? (2 ways)
- infections upregulate expression of costimulators on APC so that T cells can get that 2nd signal
- Molecular mimicry
What is BAFF?
(B-cell Activating Factor)
Promotes survival and differentiation of B cells.
If there is a n abnormality, coudl be SLE or common variable immunodeficiency
Wha tis a n LE cell?
Lupus cell - any phagocytic leukocyte htat has engulfed the denatured nucleus of an injured cell.
Produced when a damaged cell reacts with ANAs.
A pt presents with edema, erythema, scaliness and follicular plugging on the face and scalp. They have malar rash and discoid rash, but lack renal involvement.
Chronic Discoid Lupus
On autopsy a pt presents with Libman sacks endocarditis. What other symptoms did the pt probably experience while alive?
With this disease, what are they at a huge increased risk for?
IM DAMN SHARP
Igs. Malar Rash Discoid Rash Mucositis Antinuclear Antibodies Serositis Hematologic Defects Arthritis Renal defects Photosensitivity
- rub on auscultation
- Pleuritis, Pleural effusion
- Splenomegaly,
- Pericarditis
SLE
MALT cell lymphoma
A pt has the HLA isotype DR6, what are they at risk for?
DR4?
Drug- induced SLE with procainamide
with drug hydralazine
A pt blood test shows anti- DNA topoisomerase I (SCI-70), what is the preliminary dx? What about anticentromere ab?
What is the characteristic presentation?
What is this pt at risk of?
SCI70 = Diffuse Sjogren Anticentromere = limited Scleroderma OR SCLERODERMA
CREST:
antiCentromere abs, Raynaud’s phenom, Esophageal, sclerodatyly, Telangiectasia
Risk of: - pulmonary hypertension and fibrosis (cause of death)
- Scleroderma Renal Crisis = malignant HTN