Immune 8

Question 1

Severe combines Immunodeficiency (SCID)

Answer 1

• X-chromosome linked disease, therefore more common in XY-males
• XX-females are “carriers
• patents lack T and B cells

Question 2

Virus induced immune suppression

Answer 2

• measles, HIV and many other viruses interfere with normal host immune system
• HIV targets and can kill CD4 T cells
• this leads to a diminished level of CD4 T cells unable to provide ‘help’ for antibody and cytotoxic responses

Question 3

Human immunodeficiency virus (HIV)

Answer 3

• HIV-receptor is CD4 molecule on CD4 molecule on CD4 T cells
• infection leads to loss of CD4 T cells
• CD4 T cells help both hum oral (b cell / antibody) and cytotoxic responses
• HIV infection impacts on immunity to microbes (fungi, bacterial and virus) and to cancer

Question 4

Autoimmune diseases

Answer 4

• normally presented by host mechanisms of immune tolerance
• although the innate system can trigger autoimmunity or exacerbate (make worse) autoimmunity
• autoimmune attach is medicated by the adaptive immune response

Question 5

Immune tolerance

Answer 5

• immune tolerance is critical to avoid autoimmunity
• the thymus acts to delete auto reactive T cells
• in the periphery there are other mechanisms to ensure that auto reactive T and B cells are silenced
• failures (sue to your genes or triggering infection) in immune tolerance can lead to autoimmunity

Question 6

Rheumatoid arthritis is a autoimmune disorder that primarily affects joints

Answer 6

• aoutoreactive T cells and B cells attack self antigens present in joints
• affects about 1% of population often later in life

Question 7

Diabetes type 1

Answer 7

• insulin beta-cells attacked. Other islet cells may escape autoimmune attack

Answer 8

• foreign antigens cause allergic reactions
• alleerngens are the antigens that trigger allergy
• are normally ‘ harmless’ environmental antigens: non-toxic plant, animal or other food materials
• synthtiec and naturally occurring chemicals can induce allergy (e.g penicillin)

Range of outcomes: from hay fever to systemic anaphaxis

Question 9

Allergic reactions: the effector response:

Answer 9

• DC present peptides from peanut proteins (allergens) to help T cells
• primed helper T cells activate B cells to secrete IgE
• secreted IgE binge to mast cell receptors (FcR)
• binding of peanut proteins to FcR on mast cells triggers mast cell degranulation and realise of histamine and other inflammatory mediatiors

Question 10

LEarn this - rewatch last part of this

Answer 10