Immune System and Immunity Flashcards
Immune system is also referred to as the ________.
Lymphatic system
Network of cells, tissues and organs that provides the body mechanisms to resist infection and
disease
Immune system
Lymphoid organs are classified as __________.
Primary or Secondary
Primary lymphoid organs
bone marrow
thymus
secondary lymphoid organs
spleen lymph nodes mucosal-associated lymphoid tissues (MALT) ------------ cutaneous-associated lymphoid tissue (CALT) adenoids lymphatic vessels Peyer's patches tonsils
responsible for B lymph maturation
bone marrow
responsible for T lymph maturation
thymus
provide a location where contact with foreign antigens can occur
secondary lymphoid organs
2 glands located at the back of the nasal passage
adenoids
where are adenoids located
back of the nasal passage
channels throughout the body that carry the lymphocytes to the lymphoid organs and into your circulation
lymphatic vessels
lymphoid tissue in the small intestine
Peyer’s patches
where are peyer’s patches located
small intestine
2 oval masses at the back of the throat which contributes to the immune system
tonsils
filters antigen in the blood
spleen
study of a host’s reactions when foreign substances are introduced into the body
Immunology
foreign substances that induce host response
antigens
the condition of being resistant to infection
immunity
first successful invented vaccine
smallpox
who developed first smallpox vaccine
Edward Jenner (late 1700s)
via injection of cowpox (from disease affecting cows; more harmless substance)
father of immunology
Louis Pasteur
the process of making a pathogen less virulent which can take place via heat, aging or chemical means
attenuation
rabies vaccine was developed by
Louis Pasteur
who discovered phagocytosis
Elie Metchnikoff (observed under a microscope that foreign objects introduced into transparent starfish larvae became surrounded by motile, amoeboid-like cells that attempted to destroy penetrating objects
process of cells eating other cells
phagocytosis
who demonstrated that diphtheria tetanus toxins could be neutralized by noncellular portion of the blood of animals previously exposed to the mciroorganisms
Emil von Behring
type of immunity where the noncellular elements in the blood were believed to be responsible for protection from microorganisms.
humoral immunity
showed that the immune response involved both cellular and humoral elements
Almroth Wright
who observed that certain humoral, or circulating, factors called opsonins acted to coat bacteria so that they became more susceptible to ingestion by phagocytic cells.
Almroth Wright
A substance in the blood that increases as a response to an acute conditions such as infection, injury, tissue destruction, some cancers, burns, surgery, or trauma
are inflammation markers that exhibit significant changes in serum concentration during inflammation
acute phase reactant (APR)
serum proteins produced by certain lymphocytes when exposed to a foreign substance and they react
specifically with that foreign substance
antibodies
acute phase reactants are part of (innate/adaptive) immune response
innate
two branches of immunity
innate
adaptive
branch of immunity wherein the individual’s ability to resist infection by means of normally present
body functions.
innate immunity
type of resistance that is characterized by specificity for each individual pathogen, or microbial agent, and the ability to remember a prior exposure
adaptive immunity
what branch of immunity?
no prior exposure is required
innate
what branch of immunity?
response lacks memory and specificity
innate
what branch of immunity?
subject to influence by factors such as nutrition, age, fatigue, stress and genetic determinants
innate
what branch of immunity?
ability to remember prior exposure
adaptive
what branch of immunity?
memory and specificity result in increased response to pathogen upon repeated exposure
adaptive
T/F:
innate and adaptive immunity operate in combination and are dependent upon one another for maximal effectiveness
TRUE
Cells of Innate Immune System
Leukocytes (neutrophils, eosinophils, basophils, monocytes)
Tissue cells (mast cells, macrophages, dendritic cells)
T/F:
White blood cells (WBCs), or leukocytes, in the peripheral blood play a key role in both innate and adaptive immunity.
TRUE
Blood cells arise from ________.
hematopoietic stem cell (HSC)
precursor cells from HSC which would form WBCs
common myeloid precursor
common lymphoid precursor
cells from the common myeloid precursor
WBCs that participate in phagocytosis
cells from the common lymphoid precursor
lymphocytes
where are mature lymphocytes found
peripheral blood
tissues
blood cell formation and development is called
hematopoiesis
T/F:
Phagocytic cells function exclusively for innate immunity
FALSE
Phagocytic cells are
key to innate immunity, but they are also important in processing antigens for the adaptive response.
neutrophil is also termed as ____________.
polymorphonuclear neutrophilic (PMN) leukocyte
neutrophils represent what percentage of the total peripheral WBCs in adults
50%-75%
neutrophils measure _________ um.
10-15 um
which WBCs consist of a nucleus that has between two to five lobes
neutrophils
segs refer to what WBCs
neutrophils
segmented neutrophils
neutrophils contain a large number of neutral staining granules when stained. what types of granules are seen?
2/3 specific granules
1/3 azurophilic granules
neutrophilic granules which contain antimicrobial products such as myeloperoxidase,
lysozyme, elastase, proteinase-3, cathepsin G, and defensins, which are small proteins that have antibacterial activity
Azurophilic granules
primary granules of the neutrophils are referred to as:
azurophilic granules
secondary granules of the neutrophils are referred to as:
specific granules
neutrophilic granules which contain lysozyme, lactoferrin, collagenase, gelatinase, and respiratory
burst components
specific granules
specific granules contain:
lactoferrin lysozymes collagenase gelatinase respiratory burst components
azurophilic granules contain:
myeloperoxidase lysozymes elastase proteinase-3 cathepsin G defensins
WBC whose main function is phagocytosis, which result in destruction of foreign particles
neutrophils
neutrophils may circulate freely for how many hours
6-8 hrs
this pool allows neutrophils to move from circulating blood to tissues
margination (marginating pool)
the process of cells moving from the circulating blood to the tissues (movement through blood vessel walls)
diapedesis
chemical messengers that cause cells to migrate in particular direction
chemotaxins
T/F:
Once in the tissues, neutrophils have a life span of up to several days.
TRUE
T/F:
Normally, the influx of neutrophils from the bone
marrow equals the output from the blood to the tissues to maintain a steady state.
TRUE
In the case of acute infection, an increase of neutrophils in the circulating blood can occur almost immediately.
TRUE
Demonstrate hematopoiesis
CMP
- eosinophils/basophils
- neutro/monocyte/dendritic
- RBC/platelets
CLP
- T/NK progenitors (T cells, NK cells)
- B-cell progenitor (B cells, dendritic*)
eosinophils measure _________um.
approx. 12-15 um
eosinophils make up _______% of circulating WBCs in a nonallergic person
1%-3%
WBC which increases in an
allergic reaction or in response to certain parasitic infections.
eosinophils
WBC which has a bilobed or ellipsoidal nucleus and is often centrally located
eosinophil
which WBC take acidic dye and the cytoplasm is filled with large orange to reddish orange granules
eosinophils
WBCs with spherical and evenly distributed granules throughout the cells
eosinophils
eosinophil granules contain:
catalase lysozyme cytokines growth factors cationic proteins
WBC capable of phagocytosis but much less efficient than neutrophils
eosinophils
why are eosinophils less efficient in phagocytosis as compared to neutrophils
eosinophils are present in smaller numbers and they lack digestive enzymes
eosinophils are able to neutralize which cells
basophils
mast cells
WBC which use cationic proteins to damage cell membranes and kill
larger parasites that cannot be phagocytized
eosinophils
most important role of eosinophils
regulation of immune response (e.g, regulation of mast cell function)
least numerous of WBCs found in peripheral blood
basophils
basophils make up ________ of all circulating WBCs.
<1%
smallest granulocyte
basophils
T/F:
basophils are slightly larger than RBCs
TRUE
WBC which contain coarse, densely staining deep-bluish-purple granules that often obscure nucleus
basophils
eosinophil granules are ___________ in color.
reddish orange
basophil granules are _________ in color.
deep blue/purple
basophil granules contain:
histamine
cytokines
growth factors
heparin
WBC which regulate T helper cell responses and stimulate B cells to produce IgE antibody
basophils
basophils are involved in production of which immunoglobulin
IgE
T/F:
Basophils have a short life span of only a few hours in the bloodstream and are then pulled out and destroyed by macrophages in the spleen
TRUE
largest cells in the peripheral blood
monocytes
monocytes measure __________ um.
12-22 um (average:18 um)
WBC with irregularly folded or horseshoe-shaped nucleus that occupies almost half of the cell’s entire volume
monocyte
WBC with abundant cytoplasm that stain dull grayish-blue
monocyte
Cytoplasm of monocyte are described to be __________ in appearance.
ground-glass (due to presence of fine dustlike granules
There are two types of granules found in a monocyte. Differentiate the two.
First type is similar to the lysosomes of neutrophils and contains peroxidase, acid phosphatase, arylsulfatase.
Second type contains B-glucoronidase, lysozyme and lipase with no alkaline phosphatase
Monocytes make up _________ of total circulating WBCs.
4%-10%
how long do monocytes stay in the peripheral blood
30 hours
what happens to monocytes after migration from peripheral blood
they migrate to tissues and become macrophages
macrophages arise from ___________.
monocytes
The transition from monocyte to macrophage in the tissues is characterized by
progressive cellular enlargement to between _____ um.
25-80 um
T/F:
Macrophages contain peroxidase
FALSE
Unlike monocytes, macrophages contain no peroxidase
Macrophages in the lung
alveolar macrophages
macrophages in the liver
Kupffer cells
Macrophages in the brain
microglial cells
macrophages in the bone
osteoclasts
macrophages in connective tissue
histiocytes
Macrophages may not be as efficient as neutrophils in phagocytosis because?
Macrophages have slower motility
How do macrophages progress through tissue
by means of amoeboid action; others are immobile
macrophage lifespan
months
T/F:
Macrophages play an important role in initiating and regulating both innate and adaptive immune responses
TRUE
Innate immune functions of macrophages
microbial killing anti-tumor activity intracellular parasite eradication phagocytosis secretion of cell mediators
adaptive immune functions of macrophages
presenting antigens to T and B cells
T/F:
Killing activity is enhanced when macrophages
become “activated” by contact with microorganisms or with
chemical messengers called cytokines, which are released by T lymphocytes during the immune response
TRUE
Which granulocytes do mast cells resemble?
basophils
lifespan of mast cells
9-18 months
T/F:
Mast cells are distributed throughout the body in a wide variety of tissues
TRUE
skin, CT, mucosal epithelial tissue of the respiratory, genitourinary, and digestive tract
What are some characteristics of mast cells
smaller than basophils
small round nucleus
presence of lots of granules
Mast cell granules contain:
acid phosphatase
alkaline phosphatase
protease
histamine
mast cell function
for allergic reactions
function as antigen-presenting cells
can both enhance and suppress adaptive immune response
cells that are covered with long membranous extensions that resemble nerve cell dendrites
dendritic cells
who discovered dendritic cells
Steinman and Cohn (1973)
T/F:
Progenitors in the bone marrow give rise to dendritic cell precursors that travel to lymphoid as well as nonlymphoid
tissue.
TRUE
considered the most effective APC and the most potent phagocytic cell
dendritic cell
key cell involved in the adaptive immune response
lymphocyte
lymphocytes make up ____________ of the total circulating WBCs
20%-40%
Typical small lymphocyte is similar in size to that of:
RBCs (7-10 um in diameter)
Which WBC has a large rounded nucleus that may be somewhat indented; the nuclear chromatin is dense and tends to stain a deep blue
lymphocyte
Which WBC has a sparse cytoplasm, containing a few organelles and no specific granules , and consists of a narrow ring surrounding the nucleus; cytoplasm stains a lighter blue
lymphocyte
Which WBC are unique because they arise from an HSC and then are further differentiated in the primary lymphoid organs
lymphocyte
3 major populations of lymphocytes based on specific functions and proteins on their cell surface
T cells
B cells
Natural Killer cells
How much of the 3 major lymphocytes are present in the peripheral blood of adults
10%-20% B cells
61%-80% T cells
10%-15% NK cells
T/F
Three types of lymphocyte cells are difficult to distinguish visually
TRUE
How to differentiate lymphocyte subpopulations?
by the proteins or antigens present on the cell surface
a surface marker that identifies a particular differentiation lineage recognized by a group of monoclonal antibodies.
Clusters of differentiation (CD)
Panels of antibodies from different laboratories were used for analysis and antibodies reacting similarly with standard cell lines were said to define
Clusters of differentiation (CD)
How many CD designations are there?
more than 500
Identify surface marker (CD) present:
Thymocytes
CD3
Identify surface marker (CD) present:
T cells
CD3
Identify surface marker (CD) present:
T helper cells
CD4
Identify surface marker (CD) present:
Monocytes
CD4
Identify surface marker (CD) present:
Macrophages
CD4, CD16
Identify surface marker (CD) present:
Thymocyte subsets
CD8
Identify surface marker (CD) present:
cytotoxic T cells
CD8
Identify surface marker (CD) present:
NK cells
CD16, CD56
Identify surface marker (CD) present:
neutrophils
CD16
Identify surface marker (CD) present:
B cells
CD19, CD21
Identify surface marker (CD) present:
follicular dendritic cells
CD19, CD21
Identify surface marker (CD) present:
subsets of T cells
CD56
Identify surface marker (CD) described:
found on all T cells and is associated wit T-cell antigen receptor
CD3
Identify surface marker (CD) described:
identifies T helper cells; also found on most T regulatory cells
CD4
Identify surface marker (CD) described:
identifies cytotoxic T cells
CD8
Identify surface marker (CD) described:
low affinity Fc receptor for antibody
CD16
Identify surface marker (CD) described:
mediates phagocytosis
CD16
Identify surface marker (CD) described:
part of b-cell receptor; regulates B-cell development and activation
CD19
Identify surface marker (CD) described:
receptor for complement component C3d
CD21
Identify surface marker (CD) described:
part of B-cell receptor with CD19
CD21
Identify surface marker (CD) described:
no definitive function
CD56
What cell type/s have the following surface markers (Ag)?
CD3
thymocytes, T cells
What cell type/s have the following surface markers (Ag)?
CD4
T helper cells, macrophages, monocytes
What cell type/s have the following surface markers (Ag)?
CD8
Thymocyte subsets, cytotoxic T cells
What cell type/s have the following surface markers (Ag)?
CD16
macrophages, NK cells, neutrophils
What cell type/s have the following surface markers (Ag)?
CD19
B cells, follicular dendritic cells
What cell type/s have the following surface markers (Ag)?
CD21
B cells, follicular dendritic cells
What cell type/s have the following surface markers (Ag)?
CD56
NK cells, subsets of T cells
What is the molecular weight of the following CD (in KD)?
CD3
20-28
What is the molecular weight of the following CD (in KD)?
CD4
55
What is the molecular weight of the following CD (in KD)?
CD8
60-76
What is the molecular weight of the following CD (in KD)?
CD16
50-80
What is the molecular weight of the following CD (in KD)?
CD19
> 120
What is the molecular weight of the following CD (in KD)?
CD21
145
What is the molecular weight of the following CD (in KD)?
CD56
175-220
These are derived from a lymphoid precursor that differentiates to become either a T cell, B cell, or NK depending on exposure to different cytokines
B cells
B cells can be recognized by the presence of membrane-bound antibodies of two types. Name the two.
IgM
IgD
What are other surface proteins that may appear on the B cells?
CD19
CD21
MHC-II
B cells remain in the environment provided by ________.
bone marrow stromal cells
these are programmed to produce a unique antibody molecule
B lymphocytes
These go through a developmental process that prepares them for their role in antibody production and at the same time restricts the types of antigens to which any one cell can respond
B cell precursors
T cells are differentiated in the _____.
thymus
precursor of T cells
thymocytes
T cells express unique surface markers that allow them to recognize foreign antigens bound to cell membrane proteins called __________.
MHC molecules
Route of thymocytes
BM -> Bloodstream -> Thymus
Its role is to produce cytokines
T cells
These stimulate B cells to produce antibodies that will assist in killing tumor cells or infected target cells and help regulate innate and adaptive immune response
Cytokines
Three main subtypes of T cells according to their functions:
helper
cytolytic
regulatory
Name the three subtypes of T cells and their surface markers.
CD4: helper/regulatory
CD8+: cytolytic (cytotoxic T cells)
ratio of CD4+ to CD8+ cells in peripheral blood
2:1
T cell subtypes can be identified by the presence of what surface markers
CD3, CD4, CD8
A small percentage of lymphocytes do not express the markers of either T cells or B cells. What are these?
NK cells
These cells can kill target cells without prior exposure to them
NK cells
Where do NK cells develop?
bone marrow
These cells contain kidney-shaped nuclei with condensed chromatin and prominent nucleoli
NK cells
NK cells measure ____________.
15 um in diameter
third population cells/ large granular lymphocytes
NK cells
Where are NK cells found?
liver
spleen
peripheral blood
NK cells make up ___________ of the circulating lymphoid pool
10%-15%
T/F:
There are specific surface markers that are unique to NK cells
FALSE
There are NO specific surface markers that are unique to NK cells, but they express a specific combination of antigens that can be used for ID.
Ag combination for NK cells
CD16
CD56
this surface marker is a receptor for the nonspecific end of antibodies
CD16
What surface marker helps NK cells to make contact with and lyse any cell coated with antibodies
CD16
T/F:
NK cells are capable of recognizing any foreign cell and
represent the first line of defense against virally
infected cells and tumor cells
TRUE
T/F:
Since NK cells are part of the innate immune system, they cannot develop memory to specific antigens
FALSE
NK cells also have the capability to develop memory to specific antigens in a similar manner to T cells
half-life time of NK cells
> /=7-10 days
NK cells play an important role in __________ the innate and adaptive immune response against pathogens
transitional cell bridging
considered one of the largest tissues in the body and fills the core of all long flat bones
bone marrow
main source of HSC
bone marrow
Why are B cells named as such?
They were originally found in birds in an organ called the bursa of Fabricius
bursa of Fabricius is similar to what organ in humans
appendix
Immature T cells appear in the fetus as early as __________ in the gestational period
8 weeks
a small, flat, bilobed organ found in the thorax or chest cavity, right below the thyroid gland and overlying the heart
thymus
thymus weight by puberty
30-40g
T/F:
Thymus gradually shrinks in size as you age
TRUE
Each love of the thymus is divided into smaller lobules filled with what type of cells
epithelial cells
play a role in differentiation process
How long does the maturation of T cells take place
3 weeks
as cells filter through the thymic cortex to the medulla
This part of the thymus contain most of the mature T lymphocytes. This is also where these mature lymphocytes are released
medulla
largest lymphatic vessel in the body
thoracic duct
T/F:
Lymphocytes spend most of their life span in solid tissue, entering the circulation only periodically to from from one secondary organ to another
TRUE
majority of circulating lymphocytes
T cells
this collects most of the body’s lymph fluid and empties it into the left subclavian vein
thoracic duct
where does the thoracic duct empty the collected lymph fluid of the body?
left subclavian vein
T cells or B cells?
a. effector cells that serve as regulatory role
b. produce antibodies
a. T
b. B
T/F:
It is in the secondary organs that contact with foreign antigens is most likely to take place
TRUE
the process of multiplication of lymphocytes
lymphopoiesis
where does lymphopoiesis occur?
secondary lymphoid tissue
T/F:
Lymphopoiesis is strictly independent from antigenic stimulation
FALSE
Lymphopoiesis is dependent on antigenic stimulation
T/F:
Lymphocyte formation is antigen-independent.
TRUE
T/F:
Most naive or resting lymphocytes die within a few days after leaving the primary lymphoid organs unless activated by the presence of a specific foreign antigen.
TRUE
