Microbiology Exam 3 Ch. 13-17

Bio144 Microbiology: Chapters 13-17

Immunodeficiency

Lack of a proper immune response, difficulties fighting off infections (usually opportunistic pathogens)

- CAN lead to cancer

Primary Immunodeficiency

GENETIC

- Rare, but more severe
SPUR: severe, persistent, uncommon, recurring infections

SPUR (primary immunodeficiency)

Severe, Persistent, Uncommon, Recurring infections

Secondary Immunodeficiency

ACQUIRED later in life
- more common

- Caused by aging, some drugs (immunosuppressants), some disorders (diabetes, malnutrition), some infections (HIV, measles)

Autoimmune Disorders (systemic vs localized)

Immune system is too strong, attacks body

- Diagnosed via antibodies and treated with immunosuppressants

Systemic Autoimmune Disorders

Attacks WHOLE body (ex. lupus attacks healthy tissue everywhere leading to array of symptoms)

Localized Autoimmune Disorders

Attacks specific tissue (ex. arthritis localized to a joint)

Autoinflammatory vs Autoimmune Disorders

Autoinflammatory disorders = innate immune system causing unprovoked inflammation
Autoimmune disorders = adaptive immune system (b/t cells) mistakenly attacking specific tissues

Hypersensitivity

An inappropriate adaptive immune response

• Body attacks harmless non-self OR self antigen (autoimmune)

• NOT CURABLE, only treated with immunosuppressants

• 4 types of hypersensitivities

Hygiene Hypothesis

Over cleanliness lowers microbiome diversity, decreases immune system training, —> leads to hypersensitivity

Type I Hypersensitivity

Allergy (most common), triggered by allergens

• Activation of IgE and mast cells

• *method of exposure determines the reaction

  • reaction: anaphylaxis (localized and systemic)

Anaphylaxis

An allergen in blood causes response everywhere

• treated with epinephrine to decrease muscle swelling

Type I hypersensitivity: primary exposure

First time exposed to allergen

B cells make IgE antibody = sensitization

Sensitization - Type I hypersensitivity

repreated exposure converts T_h2 into T_h1 cells (LESS IgE)
- at home remedy: eating localized honey

Type I hypersensitivity: secondary exposure

IgE on mast cells causes degranulation (histamine = big driver)

Type I Hypersensitivity: Treatments

• avoid allergen

• manage symptoms (ex. eye drops)

• anti-inflammatory drugs (ex. antihistamines)

• epinephrine

Type II Hypersensitivity

Binds to NON SOLUBLE antigen

- usually cytotoxic, not always

- activation of IgG and IgM

Cytotoxic Type II Hypersensitivity

Antibodies bind to target and induce KILLING via other immune pathways