L3 - up to Ab types

Question 1

what are the 3 NORMALLY palpable lymph nodes? What does a palpable pre-auricular node signify?

Answer 1

CIA: cervical, inguinal, axillary - (+) axillary used for staging in breast cancer

lymphadenopathy in pre-auricular - adenoviral infection OR chlamydial infection

Question 2

types of pulp in the spleen?

-What does each contain?

Answer 2

white pulp - PALS - B/T/NK cells - lymph cells that hang around main artery
red pulp - sinusoids/other cells to eliminate dead/dying cells - filtered thru OPEN CIRCULATORY system (thru a sea of macrophages in reticular fiber network)

Question 3

what affect does sickle cell have on the spleen? What’s the problem with that/what does the spleen REMOVE?

Answer 3

splenomegaly

• filters ENCAPSULATED bacteria only - haemophilus influenze and streptococcus pneumonia
• that’s the reason for immunization in children..adults will have already been exposed most likely

Question 4

lymphocytes recirculate and are bound to high-walled cuboidal endo cells in WHICH vessels?

Answer 4

post-capillary venules - specialized version: HEV: high endothelial venule

-guided there via ADDRESSINS (in the wall of the HEV) and bound by an integrin so lymphos can filter everything passing thru

Question 5

two most effective antibodies at activating complement?

Answer 5

IgG, IgM–> the MOST effective

Question 6

two portions of an antibody:

What does each do?

Answer 6

Fc: Carboxy (C-term) end; binds B cell
-[CCC]: Constant AA, C-terminus, binds Complement

Fab: Antigen-Binding fragment
-contains variable regions on light and heavy - HYPERvariable region binds epitope

Question 7

unique feature of IgA? How does it do this?

Answer 7

can CROSS epithelium i.e. can transcytose into lacrimal gland lumen to get out into tears WITHOUT degradation

-binds POLYMERIC Ig receptor,–> incorporated into endosomes –> liberated attached to portion of Ig receptor known as the SECRETORY component, which PROTECTS IgA from degradation!

Question 8

Functions of IgA:

location: mucosa, tears
- levels in closed eyes?

Answer 8

fx: antimicrobial! [O-PIAA]

• opsonizes
• prevent microbial attachment
• inactivate bacterial enzymes
• agglutinate
• antibody-dep cell-mediated cytotoxicity
• WEAK activator of complement.
• HIGH levels in closed-eyes

Question 9

What’s the prototypical antibody among the [GAMED] classes of antibodies?

-2 main fx?

Answer 9

IgG - prototypical monomer (can bind TWO antigens)

Functions:

1) activates COMPLEMENT (with IgM)
2) binds antigen Rs on MEMORY B cells - basis of IMMUNIZATIONS

Question 10

What’s the FIRST antibody sent out? What else is important to know?

Answer 10

IgM - PENTAMER (binds 10 antigens) - overwhelm them!

MOST effective at binding complement! (With IgG)

• dominant IG receptor on VIRGIN B cells
• IgM monomers are polymerized into pentamer and linked/stabilized by a J CHAIN (IgA has this two)

Question 11

IgD: main function - act as an ____ receptor

-also is an antigen receptor on ____ B cells (along w/ IgM)

Answer 11

antigen receptor

-virgin B cells

Question 12

IgE: associate w/ which 2 types of cells?

Answer 12

basophils, mast cells

• HYPERSENSITIVITY rxns
• protective against parasitic infections

Question 13

The immune repertoire is formed due to the high volume of different VARIABLE regions - what 3 things are responsible for creating these selective regions?

Answer 13

[MMR]

• Multiple genes
• somatic Mutation
• somatic Recombination

-allow for different HYPERvariable regions, which respond to epitopic antigens