lecture 37 - immune insufficiency & over activity Flashcards
What are the 2 main cause of immune system insufficiency?
Genetic or induced by viruses.
What is severe combined immunodeficiency?
A genetic condition in which affected individuals lack T cells and B cells, so have limited adaptive immunity
What is the mode of inheritance of SCID (severe combined immunodeficiency)?
X linked recessive
How does HIV target the immune system?
It targets CD4 T cells of the adaptive immune system
How does HIV destroy T cells?
By binding to CD4 receptors on T cells, which allows them to enter and destroy them.
What are the effects on the destruction of CD4 T cells by HIV virus?
Loss of humoral (B cell and antibody) and cytoxic responses, so overall suppressed immunity.
How is autoimmune disease usually prevented?
The thymus identifies and deletes auto reactive T cells and bone marrow removes auto reactive B cells.
What is rheumatoid arthritis?
An autoimmune condition, in which auto reactive T and B cells attack self-antigens produced in joints
What is type 1 diabetes, in terms of auto immunology?
Auto-reactive lymphocytes attack beta cells of the pancreas, meaning sufficient insulin cannot be secreted.
What is the name for an antigen that causes an allergic reaction?
Allergen
What are the range of outcomes for an allergic reaction?
Hayfever to systemic anaphylaxis.
What is the process of an allergic reaction?
Dendritic cells present peptides from allergens to helper T cells, which activate B cells to secrete IgE. Secreted IgE binds to mast cell receptors, triggering degranulation and the release of histamine and other inflammatory mediators.
