Introduction to inflammation, Autoimmune disease, NSAIDS and RA pathophysiology

Question 1

Define Autoimmunity
and describe how is it caused?

Answer 1

• Immune response against self antigens
• Caused by body’s failure to distinguish self and no-self antigens

Question 2

what is the difference between central and peripheral tolerance ?

Answer 2

• Central tolerance – deletion of lymphocytes specific for self antigens in generative organs

Peripheral Tolerance - deletion or anergy of lymphocytes that recognise self antigen in peripheral tissue

Question 3

Describe the process of T cell devlopment in central tolerance

Answer 3

• Immature T cells presented to self antigen on APC
• In the the THYMUS , immature T lymphocytes exposed to the MHC & self antigen complex and co-stimulatory receptors CD4/CD8 all of

immature T lymphocytes in the thymus are exposed to self antigens via antigen-presenting cells (APCs). The T cell is exposed to the MHC+ self antigen complex and co-stimulatory receptors, such as C4/CD8, are involved in the binding process.

depending on interaction type positive or negative selection occurs

Question 4

Describe the importance of binding type in T cell devlopment in central tolerance

Answer 4

The strength of ther bonding between the immature T cell and the T reg cell ( MHC - SElf antigen complex|) determines selection

STrong interaction - negative selection ( apoptosis)

Intermediate - positive selection

Weak - positive selection

No interaction - Apoptosis

Question 5

Describe the process of B cell development in central tolerance

Answer 5

• Immature B cells in BONE MARROW exposed to self antigens
• B cell binds to B cell receptor which has the self antigen attached to it
• Depending on how the B cell receptor binds to it there are three outcomes
• High avidity: The B cell undergoes receptor editing, where a new light chain is expressed to test avidity again.

If the avidity is still high, apoptosis occurs.

• Low avidity: The B cell reduces receptor expression and becomes anergic, meaning it is unresponsive to the antigen.

Question 6

Describe the normal process of T cell activation

Answer 6

APC activate CD4+ T cells by cytokine releasing IL-2

• CD4+ bind to IL-2
• CD4+ T cell proliferation
• some differentiate into effector cells activate macrophages and B cells
• others become memory T cells.

Question 7

Describe the process of T cell development in peripheral tolerance

Answer 7

Immature T cell bind to T ceel- self antigen complex but T reg come to stop activate the cell

• Depending on the reaction either of the following would occur:

1. = Anergy within the cell so without co stimulatory signals, T cell is unresponsive
2. Suppression of cell activation by T reg cells
3. Deletion - apoptosis of cell

Question 8

Describe the process of B cell in peripheral tolerance

Answer 8

BCR binds to self antigen no T cell activation but no T cell activation no release of cytokines

Types of outcomes

• Anergy of cell - ( B cell binds to self antigen however no T cell activation)
• APOPTOSIS - If cell binds to the self antigen
• REGULATION - activation is suppressed or regulated by inhibitory receptors

Question 9

Describe postulated mechanisms of autoimmunity

Question 10

Describe the different mechanisms of autoimmune damage

Question 11

Describe the Common Autoimmune Diseases, differentiating between organ and systemic

Question 12

Describe the organ-specific autoimmunity in diabetes type 1

Question 13

Describe the two conventional drugs types used in autoimmune diseases