Introduction to the Immune System Flashcards
Define immunity
Ability to respond to foreign substances regardless of the physiologic or pathologic consequence of such a reaction
Define adaptive immunity
Response of antigen-specific lymphocytes to antigen includes memory
Define innate immunity
Protection against antigens that relies on mechanisms that exist before exposure
What is a cluster of differentiation (CD)?
Cell surface molecule expressed on various cell types designated by a CD number. It is used to define cell type, receptors, etc. Recognized by monoclonal antibodies (mAbs)
Define cytokines. Give types of cytokines.
Bioactive protein molecules that mediate immune responses.
Interleukins (IL), tumor necrosis factor (TNF), interferon (IFN)-α, β, and γ, transforming growth factor (TGF)- β, and CSF
What are chemokines?
Chemotactic cytokines. They say “come here.”
Define antigen (Ag)
Define immunogen
Define tolerogen
Not all […] are […]
Ag: A molecule or part of a molecule that is recognized by the immune system.
Immunogen: An Ag that evokes a specific immune response.
Tolerogen: An Ag that induces immunologic tolerance.
Not all Ags are immunogens!!
endogenous Ag vs. Exogenous Ag
Compare autoAgs to alloAgs
Endogenous Ag is the body’s own cellular components or intracellular pathogens (e.g., viruses, intracellular bacteria and parasites). They can further be classified into:
AutoAgs: self-Ag
or
AlloAgs: Tissue specific Ag which is present in one individual of a species, but not in others (e.g., ABO blood groups)
Exogenous Ag enters the body or system and freely circulates in the body fluids until trapped by APCs
List the two branches of the adaptive immune system and examples of artificial and natural immunity from each of those branches
Two branches are passive and active.
Passive artificial: an intravenous injection of Abs
Passive natural: Mom passes Abs to baby through breast milk or through placenta
Active artificial: A vaccine
Active natural: Infection or exposure to pathogen
What are some characteristics of the innate immune system?
Responds rapidly
It is not Ag specific
No immunologic memory
Stimulates the adaptive immune system
What are the 3 different types of phagocytes in the innate immune system?
Neutrophils
Monocytes/macrophages
Dendritic cells
What are the 2 major functions of macrophages?
M1 classical macrophages are induced by innate immunity and play a role in inflammation
M2 alternative macrophages are induced by IL-4 and IL-13 and play a role in tissue repair and control of inflammation
What are the 2 major functions of dendritic cells?
Initiate inflammatory response
Initiate adaptive immune response
What is neutrophil leukocytosis?
Its when neutrophils are released from the bone marrow in greater numbers in response to an infection. Also called a left shift
What type of WBC is first to arrive at the site of an infection?
Neutrophil
What cell type is pus largely composed of, and what CD’s are characteristic of that same cell?
Neutrophils are what pus is largely composed of
CD15+ and CD16b+
List 3 functions of monocytes/macrophages
Garbage collectors when at rest
APCs when activated
Vicious killers when hyper-activated
What cell-surface marker is characteristic of monocytes/macrophages?
What does it bind?
CD14 (TLR4), which recognizes and binds to LPS