L8 Flashcards
What is SCID?
Severe combined immunodeficiency
LAck of functional T and B cells
X crhomosome linked disease (more common in males)
Females can be carriers
What is virus-induced immune suppression and examples
Measles and HIV which interfere with normal host immune system
Targets and kills CD4 T cells
Dec CD4 T cells unable to help for antibody and cytotoxic responses
What is HIV
Infections leads to loss of CD4 T cells
HIV impacts immunity to microbes and cancer
How are autoimmune diseases prevented?
By host mechanisms of immune tolerance
2 Immune tolerance and what is failure of immune tolerance leads to
Thymus: Deletes autoreactive T cells
Periphery: Mechanisms to silence autoreactive T and B cells
Failures: Failure of immune tolerance can lead to autoimmunity
Autoimmune disease features
Preventable by immune tolerance
Innate system can trigger autoimmunity or exacerbate it
Autoimmune attack is mediated by adaptive immune response
What occurs in Rheumatoid arthritis?
Autoreactive T and B cells attack self antigens in joints
What does HIV target?
CD4 cells which disable the production of B cells and Cytotoxic cells (Decrease cytotoxic and antibody response)
What causes autoimmune disease?
Random arrangement of B and T cells which occur from Adaptive arm
What is peripheral tolerance?
Screening of autoreactive B and T cells in body for deletion
What are allergens?
Antigens which trigger allergy
What are the two types of allergens and examples
Environmental: Animal, plant
Chemical: penicillin
What are the 2 outcomes of allergic reactions
Hay fever to systemic anaphylaxis
What occurs in Type 1 diabetes
Selective disease which attacks insulin beta cells while other islet cells may escape autoimmune attack
What is the effector response of Allergic Reactions
DC present peptides of allergens to helper T cells
Primed Helper T cells activate B cells to secrete IgE
IgE binds to mast cells receptors (FcR) triggering degranulation and release of histamine and other inflammatory mediators
