chapter 17 pt. 2 (go over HS type ll specific examples)

Hypersensitivity Type 2 starts with specific IgG antibody binding to ________ ________

cell-surface antigens

The most common example of a Type II hypersensitivity reaction arises from
what?

improper blood transfusions

Hypersensitivity Type 3 is initiated when IgG antibody binds to _______ antigen

soluble

Hypersensitivity Type 3

When antigen overwhelms the immune cells like macrophages and there is too much to clear, some antigen may be left to free-float and circulate in the blood and can embed where?

vessel walls

Antigens that have embed into vessel walls are dangerous, why?

they can bind to complement factor C1 of the classical pathway and this causes damage to nearby tissues, joints, etc

the only type of hypersensitivity that is triggered by antigen-specific T cells

Type 4

Hypersensitivity Type 4 is also called what?

delayed-type hypersensitivity

Hypersensitivity Type 4 develops in two stages

stage 1 - ??

stage 2 - ??

sensitization and second exposure

Hypersensitivity Type 4 stage 1 involves the process and presentation of ….

antigens on cutaneous dendritic cells

During stage 1 of Hypersensitivity Type 4 the APC travel where and why?

to the lymph nodes to present to naive t cells, this produces activated t cells and memory t cells to that specific antigen

Hypersensitivity Type 4

Stage 2 - second exposure

Memory TH1 cells can bind antigen presented on class II on APC’s which
trigger the release of ________ __________

inflammatory cytokines

Hypersensitivity Type 4

Stage 2 - second exposure

inflammatory cytokines bring in ________, ______, and _____ _____ cells to release inflammatory mediated that do damage to healthy,
uninfected bystander cells in the area

macrophages, PMNs, natural killer

have a genetic basis and usually manifest in early childhood

Primary immunodeficiencies

can be acquired at any age as a consequence of certain infections (like HIV), the use of immunosuppressive drugs, or radiation therapy

Secondary immunodeficiencies

Develop when immune cells lose “self-tolerance” and begin attacking and harming human cells

Autoimmune Disorders

• B and T cells learn not to react with self-antigens

• T cells that bind too strongly to self-antigens are deleted in the thymus

• B cells undergo apoptosis in bone marrow if the B cell is exposed to high doses of its BCR-matched self-antigen

Self-tolerance

Some _________ can trigger these loss of self-tolerance effects, but a lot of causes autoimmune disorders are very poorly understood, or understood at all

infections