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Flashcards in Immunophysiology Deck (163)
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91

Due to the size of Pentamer IgM, it causes a blockage in transplacental transfer of IgM, preventing...

Haemoblastosis fetalis

92

Monofunctional character of immunoglobulins is...

FAB dependent function

93

Polyfunctional character of immunoglobulins is a...

FC dependent function

94

Non-activated B-lymphocytes produce

IgM

becuase Cµ is next to VDJ

95

When is Monofunctional character of immunoglobulins activated?

Before antigen administration

96

When is polyfunctional character of immunoglobulins activated?

After antigen administration

97

Immunoglobulins are synthesised by...

B-lymphocytes

98

During the humoral immune response, B-lymphocytes with B-cell receptors (BCR) are called...

Recognising cells

As they bind to a specific antigen

99

Antigen binding to B-lymphocytes causes...

Cell differentiation:

B-lympocyte → Plasma cell

Plasma cell secretes antibodies

100

Primary antibody repertoire

A set of immunoglobulins produced by B-cells:

  • 10different antigen determinants
  • No antigen stimulus
  • B-cell recognises a single antigen

101

What is shown?

Model of clone selection theory

102

1

  • Lymphocyte clones mature
  • Specific for diverse antigens

103

2

  • Lymphocyte clones contact with antigens
  • Go to lymph organs
  • Antigens are selecting appropriate lymphocytes
  • Then activating antigen-specific clones

 

104

3

  • Clones converted to plasma cells​

Result: Antigen specific immune response

105

Clone selection theorises that B-lymphcytes specific to an antigen are...

Already present before infection

106

It can be deduced from the clone selection theory that...

Immunoglobulins against all antigens are produced, and are stored on the B-lymphocyte cell surface

107

What ensures genetic diversity of immunoglobulins?

Gene rearrangement

108

What is shown in the figure?

Gene structure of a mouse heavy chain locus

109

L=

Leader

First section of the proteins

110

V=

Variable region

of the heavy chain

111

D=

Diversity supporting region

112

J=

Joining region

113

C=

 

Constant region

 

114

What do the red numbers represent?

DNA section length

115

Describe immunoglobulin gene rearrangement

  • Segments join randomly
    • Can recognise millions of different antigens
  • Isotype switching
    • Antigen stimulus → H-chain changes

116

Which process is shown in the diagram?

Isotype switching

117

List the stages of gene rearrangement

  1. Somatic recombination D-J joining
  2. Somatic recombination V-D-J joining
  3. Deleted DNA collapses in nucleus

118

List the stages of isotype switching

  1. Linear deletion (proliferation/differentiation of B-cells)
  2. Transcription + Translation
  3. Final product

119

Switching of Immunoglobin class happens due to...

Alternative splicing

at an mRNA level

120

List the stages of Alternative splicing

  • Rearranged DNA → Transcription
  • Primary RNA transcript → Splicing
  • mRNA → Translation
  • M heavy chain/ IgM produced