Microbio Week 6 (Exam 2) Flashcards
Which of the following factors is the first to be secreted upon mast cell activation?
Leukotriene C4
Prostaglandin D2
Histamine
IL-5
Acid cationic factor
Histamine
What is stored into granules and released immediately when mast cells are activated and degranulate?
Histamine
Penicillin cannot elicit an immune response on its own, but can elicit an immune response if coupled to a carrier protein. It is then referred to as a:
Antigen
Immunogen
Antibody
Hapten
Immunoglobulin
Hapten
Small molecules that cannot elicit an immune response themselves, but can when coupled to a protein
Haptens
Which of the following causes of cancer has been responsible for the very large increase in oral cancers over the last 10+ years?
HIV infection
HPV infection
Exposure to radiation
Exposure to chemical carcinogens
P. gingivalis infection
HPV infection
T/F: Tumors can evade the immune response.
True
Despite its vital protective role against pathogens, the immune system is often responsible for __________ __________ and is involved in the ___________ of many diseases
tissue injury; pathogenesis
A set of undesirable reactions by the normal immune system that require a “pre-sensitized” (immune) state
Hypersensitivities
What are the 4 types of hypersensitivities based on the triggering mechanism?
Immediate - Type I
Antibody-mediated - Type II
Immune complex-mediated - Type III
Cell-mediated - Type IV
Which type of hypersensitivity?
Cross-linking of IgE antibodies bound to mast cells by antigen (allergen)
Immediate - Type I
Which type of hypersensitivity?
Binding of IgG or IgM antibodies to antigens present on cells or basement membranes
Antibody-mediated - Type II
Which type of hypersensitivity?
Deposition of immune complexes (Ag/Ab) in tissues
Immune complex-mediated - Type III
Which type of hypersensitivity?
T cell-directed mechanisms of tissue injury
Cell-mediated - Type IV
Which Type I phase - acute or late?
5-30 mins
Subsides within 60 mins
Vasodilation
Vascular leakage
Smooth muscle spasm
Type I acute phase
Which Type I phase - acute or late?
2-24 hours
No additional exposure
Eosinophils, neutrophils, basophils, monocytes, CD4+ T cells
Mucosal epithelial cell damage
Type I late phase
Which hypersensitivity?
- Rapid immune reaction (mins)
- Preformed antibodies (IgE) to allergen
- IgE binds FceRI on mast cells
- Allergen crosslinks bound IgE molecules + triggers release of histamine
- Acute (< 1 hr) + late (2 hr - days) phases
- Local or systemic (anaphylaxis)
Immediate - Type I hypersensitivity
Name the key immune elements of Immediate - Type I hypersensitivity (6)
CD4+ T cells
B cells
IgE antibodies
Th2 cytokines
Mast cells + mediators (acute phase)
Eosinophils + neutrophils (late phase)
What are the Th2 cytokines involved in Immediate - Type I hypersensitivity?
IL-4
IL-13
IL-5
What is the primary mediator of mast cells?
Histamine
What leads to the following:
Increased vascular permeability
Smooth muscle contraction (airways)
Increased mucous gland secretion
Produced by mast cells, basophils, platelets
Histamine