Lecture 1: Properties and Overview of Immune Responses Flashcards
True or False:
All microbes can grow, reproduce, and infect humans.
True
True or False:
All pathogens do not necessarily fall into the extracellular or intracellular microbe classification.
False - ALL microbes are either have the extra- or intracellular classification
What is the immune system comprised of?
Immune Cells and Molecules that collectively mediate an immune response.
What is the definition of antigens (Ags)?
Ags are defined as substances (either microbial or nonmicrobial) which induce an immune response.
When is an antibody (Ab) produced by the immune system?
When the immune system detects an antigen.
Fill in the Blank:
An _____ (also called an antigenic determinant) is a portion of an Ag molecule to which an antibody binds.
epitope
What is the smallest epitope (antigenic determinant) to which an antibody can be made?
> 3-6 amino acids (AA)
> 5-6 sugar residues
True or False:
An Ag may contain a number of different epitopes to which individual responses (antibodies or T cells) are made.
True
Do all large molecules have multiple epitopes?
Yes
What are the principal components of innate immunity?
> physical and chemical barriers
> phagocytic cells (neutrophils, macrophages), dendritic cells, and natural killer (NK) cells and other innate lymphoid cells
> blood proteins, including the complement system and other mediators of inflammation
Does the innate immune system distinguish fine differences between microbes?
NO
What are the principal cells of the adaptive immune system?
> lymphocytes (B and T)
antigen-presenting cells
effector cells
What is humoral immunity?
Humoral immunity is mediated by molecules in the blood and mucosal secretions, called antibodies, which are produced by cells called B lymphocytes. Principle defense mechanism against extracellular microbes and their toxins because secreted antibodies can bind to these microbes and toxins and assist in their elimination.
What is cell-mediated immunity?
Cell-mediated immunity is mediated by T lymphocytes and is the defense against intracellular microbes (viruses and some bacteria) by promoting destructiong of microbes residing in phagocytes or by killing infected cells to eliminate reservoirs of infection.
Fill in the Blank:
In addition to inflammation, the innate immune system is a _____-_____ _____ of an immune response.
“decision-making stage”
*it “evaluates” the invader in the context of intracellular vs extracellular microbes and then provide the instructions to adaptive immunity.
In what two ways do cells communicate?
> direct cell-to-cell contact
> interactions involving cytokines and chemokines
What are the functions of cytokines?
> regulate growth and differentiation of all immune cells
> activate the effector functions of lymphocytes and phagocytes
True or False:
Each cytokine acts via a specific signaling receptor expressed on target cells.
True
What are chemokines?
Chemokines are a large subset of structurally related cytokines that regulate cell migration and movement (chemotaxis).
What are the cells of innate immunity?
> neutrophil > macrophage > eosinophil > basophil > mast cell > monocyte > dendritic cell > natural killer cell
What is the primary function of phagocytes of the innate immune system?
Primary function is to ingest and destroy microbes and get rid of damaged tissues (scavenger function).
What are the steps in functional responses of phagocytes?
> RECRUITMENT of the cells to the sites of infection
RECOGNITION of and activation by microbes
INGESTION of the microbes by the process of phagocytosis
DESTRUCTION of ingested microbes
Which circulating spherical white blood cell is the most abundant?
neutrophil (polymorphonuclear leukocytes)
Which cell type mediates the earliest phases of inflammatory reactions?
Neutrophils
Where hare neutrophils produced and which cytokine stimulates their production?
> bone marrow
> granulocyte colony-stimulating factor (G-CSF)
How many neutrophils does an adult human produce per day?
1 x 10^11 neutrophils/day
After neutrophils enter tissues, how many days do they function before they die?
1 - 2 days
Which 3 cell types play a roles in both the innate and adaptive immune responses?
> mast cells
basophils
eosinophils
