Lecture 45: B Cells and Antibodies Flashcards Preview

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Flashcards in Lecture 45: B Cells and Antibodies Deck (19):
1

B Cells are important because they make _______.

- Antibodies

2

B Cells recognise whole (native) _____ _____ whereas T Cells recognise _____ / ___ Complexes.

- Protein Antigens
- Peptide / MHC Coomplexes

3

B cells are activated by (only secrete antibodies if):

- Recognition of antigen
- CD4+ Help

4

B Cells are _____ that develop in the ____ _____. They are the only cell that secretes ______. They express unique antigen receptors. Plasma cells are activated by __ Cells that secrete antibody. Memory B Cells provide '_____'.

- Bone marrow
- Antibodies
- B
- Memory

5

Mature B and T Cells tend to be sent to the ___ ____.

- Lymph node

6

Just like T Cells, B Cells express a unique __ ____ _______. This enables the recognition of a wide variety of antigens. BCR gene __________ is responsible for this.

- B Cell Receptor
- Rearrangement

7

In The B Cell receptor has 2 _______ regions, changing them changes the antibodies _______.

- Constant
- Functions

8

Three functions of antibody:

- Neutralisation
- Opsonisation
- Complement Activation`

9

(Antibody) Neutralisation:

- Ab binds to surface strustures on microbes, blocking their ability to attach to host cells
- Binds to toxins preventing them from

10

(Antibody) Opsonisation

- Bind to surface of pathogen
- Facilitates uptake by phagocytes
- Have two binding sites and can agglutinate bacteria, this increases the efficiency of uptake

11

Isotype Switching:

- IGA / IGM etc.

12

What's so important as IgG?

- It's the most abundant Ig class in blood.
- Opsonises / Neutralises
- Ig class that crosses placenta: provides 'passive immunity'.
- Targets virus / bacteris

13

IgA:

- Present in secretion such as tears, saliva, mucus, and breast milk
- Defence of mucous membranes, esp. gut
- Present in breast milk
- 'Passive Immunity'

14

IgE:

- Present in blood at low concentrations
- Immunity to multicellular parasites
- Allergic reactions
- e.g. Penicillin modifies cell proteins, IgE responses to penicillin-modified proteins can induce hives or anaphylactic shock

15

IgD:

- Expressed on naive B Cells
- Together with IgM, acts as antigen receptor (BCR)
- Specific function unknown

16

IgM:

- First Ig class produced after initial exposure to antigen.
- Expressed on naïve B cells
- Very effective inactivating Complement Function
- Targets extracellular bacteria
- Acts as antigen receptor (BCR)

17

Humoral immunity is:

- Antibody mediated immunity

18

The basic antibody unit is made up:

- 2 identical heavy chains, and 2 identical light chains

19

IgG + IgA are important for....

- Passive Immunity