Pharmacology For Immunity – Immune Dysfunction

week 1, pt. 1

Immune Dysfunction

• Overactive immune response

• Suppressed immune response

Overactive Immune Response

• Loss of immune tolerance - the immune system attacks the body’s own tissues

• Immune system responds when it should not - triggers activation against self or harmless stimuli

• Persistent activation of immune cells - immune cells stay “on” longer than needed

• Ongoing cytokine release - chemical signals amplify the immune response

• Excessive or prolonged inflammation → leads to collateral damage to healthy tissues & organs

What Drives Overactive Immunity?

• T-cells remain activated → self-reactive T-cells are not properly turned off

• B-cells may produce autoantibodies → B-cells generate antibodies that target the body’s own tissue

• Cytokines amplify & sustain inflammation → inflammatory cytokines promote & prolong immune activation

• Immune cells recruit more immune cells → chemokines & cytokines attract additional immune cells to the site

• Inflammation becomes self-perpetuating → a cycle of activation, inflammation, and the tissue damage perpetuated

Autoimmune Disease

T-cell activation → initiates response

B-cells/antibodies → drive tissue damage

Cytokines → amplify inflammation

Proliferation → expand immune response

Immune trafficking → direct cells to tissues

Transplant Rejection

• Immune system recognizes donor organ as foreign

• Activates an immune response against the graft

Driven by:

• T-cell activation

• Cytokines

• Proliferation

Result:

→ inflammation + tissue damage = graft dysfunction

Suppressed Immune System

• Decreased immune cell activity = fewer activated to respond to threats

• Reduced antibody & cytokine signalling = weaker immune communication

• Weaker recognition of pathogens

• Impaired immune function (e.g., killing infected cells, phagocytosis, & memory response)

• Reduced control of pathogens