Micro Exam 2 Lecture 22

Front 1

Define hypersensitivity

Back 1

a. Undesirable reaction produced by the normal immune system when the adaptive immune response to an antigen occurs in an exaggerated form. (because it is adaptive, the individual has to have been exposed to it previously)

Front 2

Type 1 examples

Back 2

i. Ex. Injection of antigen in one pig, two weeks later, same injection again causing anaphylactic shock in few minutes. Another experiment injected a pig…two weeks later there was a serum transfer from the pig to a naïve pig which died in a few minutes because of shock. **Note: if we had transferred immune cells to the naïve pig, it would not have died**
ii. Rapid reaction in response to antigen
iii. Rxn mediated by serum-derived components (antibodies)
iv. Hypersensitivity is antigen-specific

Front 3

Type 1 mechanism

Back 3

echanism: ex.pollen 1. Primary antibody: IgE
2. Primary cellular component: mast cell and basophil
3. Amplifiers/modifiers: neutrophils, eosinophils, macrophages, lymphocytes

Initial intro to antigen causes antibody response: IgE synthesized. Antibody binds to the FceRI receptor on the mast cell. Allergen (antigen) binds to the IgE on the mast cell causing cell to degranulate and release pharmacological mediators that cause smooth muscle contraction, vasodilation, and edema.

Front 4

Type 1 Mast cells. what are the two type? what does this mean

Back 4

vi. Type 1 hyper. Depends on antigen dose, route, and mast cell localization.
a. CT mast cells which are throughout the body
i. When high dose of antigen is injected intravaneously, mast cell activates and releases toxin granular proteins, histamines, leading to anaphylaxis.
ii. When antigen is injected subcutaneously, can see local reaction with limited histamine release. See activation of mast cells in the skin.
b. Mucosal mast cells which are on the mucosal surface
i. Inhalation of low dose leads to Allergic rhinitis (upper airway) caused by increased mucus production and nasal imitation. Can cause asthma (lower airway) because of contraction of bronchial smooth muscle and increased mucus secretion
ii. Ingestion of high doses causes contraction of intestinal smooth muscle inducing vomiting. Outflow of fluid into gut causes diarrhea. Antigen diffuses into blood vessels and is widely disseminated causing hives or anaphylaxis

Front 5

2 components of type 1 (mediators

Back 5

1. Primary mediators
a. Released in immediate phase measured in Fev
b. These are preformed mediators: histamine, serotonin, proteases, chemotactic factors
2. Secondary mediators
a. Released in late phase measured in Fev.

Newly synthesized and takes about 10 hours, see a wider and higher inflammatory response: leukotrienes, prostaglandins, bradykinin, cytokines.

Front 6

Urticaria and angioedema:

Back 6

Type 1
1. Urticaria and angioedema: caused by viral infection, drug, food, latex- affects superficial or deeper layers of the skin, causes priuritic wheals with surrounding edema

Front 7

Allergic rhinitis

Back 7

type 1
affects upper respiratory tract causing sneezing, congestion, runny nose, and often accompanied by itchy or sore throat (laryngitis) and red itchy, watery eyes ( conjunctivitis)

Front 8

Food allergy

Back 8

type 1
swelling of the tongue and throat, vomiting, abdominal crumps, diarrhea, loss of consciousness, and even death

Front 9

Allergic asthma:

Back 9

type 1
affects lower respiratory tract causing bronchial constriction, mucus production, inflammation of the airways a. Includes 2 types of hypersensitivity reaction:
i. Type 1:
ii. Type 4 which related to T cells that use Th2 which releases cytokines

Front 10

Anaphylaxi

Back 10

Type 1
systemic (more than 1 organ involved), causes systemic vasodilation, vasopermeability, hypotension, abdominal effects, throat swelling, and asphyxiation