First Aid, Chapter 2 Cells Involved in Immune Responses, Epithelial Cells Flashcards
What is the mnemonic for layers of the epidermis?
Layers of the epidermis: Before Signing Get Legal Counsel
Stratum Basale
Stratum Spinosum
Stratum Granulosum Stratum Lucidum
Stratum Corneum
What general roles do epithelial cells play?
Epithelial cells form a type of tissue that lines the surface of structures throughout the body, serving in innate and acquired host defense as both a barrier and an effector (secretory) tissue.
What cross-linked protein is present in the layers of epithelial cells that make up the skin epidermis?
Layers of keratinized epithelial cells make up the skin epidermis and contain an extensively cross-linked protein called transglutaminase.
What are the adhesion molecules in epithelial cells?
Defined by the expression of certain adhesion molecules called e-cadherins.
How are epithelial cells attached to adjacent epithelial cells?
Attached to adjacent epithelial cells by tight junctions, intermediate junctions, and desmosomes (which contain e-cadherins).
How are epithelial cells attached to the extracellular matrix?
Attached to extracellular matrix via hemidesmosomes (which use integrins for adhesion instead of cadherins).
What proteins do epithelial cells contain that bind keratin fibers?
Contain filament-associated proteins, which bind keratin fibers called filaggrins.
Describe the passage of IgA from binding to epithelial cells to being secreted.
Oligomeric IgA binds to a polymeric immunoglobulin receptor on epithelial cells, is transported through the cell, and secreted, while still attached to part of the receptor called the secretory component.
What are the functions of epithelial cells?
- Forms primary barrier against pathogens.
- Secretes numerous mediators used in defense, including cytokines, chemokines, growth factors, mucous, and antimicrobials. -Removes potential pathogens via beating motion of cilia.
- Also functions in absorption and diffusion of liquids and gases.
Name examples of pathogens that exploit epithelial receptors to initiate function and which receptors they exploit.
o Rhinovirus/ICAM-1
o Influenza/Glycans
o Adenovirus/Integrins and CD80/CD86
What do epithelial cells produce in response to house dust mite inhalation? What does this attract?
Airway epithelial cells produce CCL2 and CCL20 in response to house dust mite inhalation, which attracts monocytes and immature DCs to the lung.
What cytokines do epithelial cells secrete to activate DCs and prime the Th2 response?
Produce thymic stromal lymphopoietin (TSLP), GM-CSF, IL-25 and IL-33, which share the propensity to activate DCs that prime Th2 and coordinate the subsequent immune response.
What cytokines are released from bronchial epithelial cells in response to allergen exposure?
IL-33 and other members of the IL-1 family of cytokines, such as IL1α, IL-1β and IL-36γ (IL-1F9), are released from bronchial epithelial cells in response to allergen exposure.
Suppression of which innate molecules in epithelial cells contributes to atopic dermatitis?
Suppression of β defensins and cathelicidin due to the expression of IL-4 and IL-13 may contribute in the pathogenesis of atopic dermatitis.
Which chemokines produced by keratinocytes are responsible for homing T cells to the skin? What are the corresponding receptors on the T cells?
Keratinocytes produce CCL17 (TARC) and CCL22 (MDC). Skinhoming T cells express cutaneous lymphocyte antigen (CLA) and CCR4 and CCR10.
