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Flashcards in Regulation of lymphocyte responses Deck (11)
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1

What is hypercytokinemia and sepsis?

When there is too much immune response
Too much cytokines in the blood
Sepsis – bacteria has crossed the mucosa and entered the blood stream

2

What are the two general principles of regulating the immune response?

Responses against pathogens decline as the infection is eliminated – this is driven by apoptosis of lymphocytes
Immunological tolerance to persistent antigens

3

Define Immunological Tolerance.

Specific unresponsiveness to an antigen that is induced by exposure of lymphocytes to the antigen

4

What are the two types of tolerance?

Central tolerance – destroy self-reactive B and T cells before they enter the circulation
Peripheral tolerance – destroy self-reactive B and T cells that do reach the circulation

5

What gene allows thymic expression of all the body's gene products?

AIRE – autoimmune regulator

6

What does this gene encode?

Specialised transcription factor – allows thymic expression of all the body’s gene products

7

What are the four main mechanisms of peripheral tolerance?

Anergy
Deletion
Ignorance
Regulation

8

Describe each of the four processes.

Anergy – the way in which the APC presents the antigen shuts down the T cell and makes it unresponsiveness (sort of like increasing the activation energy by denying it of costimulation)
Deletion – antigen-induced cell death (apoptosis of T cell)
Ignorance – in some immuneprivileged sites there aren’t any APCs for the T cells to bind with
Regulation – regulation of response by cytokines released by Treg

9

What cytokine is frequently involved in shutting down dendritic cells?

IL-10

10

What transcription factor do Tregs express that is key to its function?

FoxP3

11

What are the two types of Treg?

Natural Tregs (nTreg) – develop in the thymus
Inducible Tregs (iTreg) – when exposed to APCs they turn from T helper function to Treg function