Immunology Flashcards
physical barriers, inflammation, the complement system and WBCs compose what?
the innate immune system
lymphocytes, T Cells, B cells, NK cells and antibodies are components of what?
the acquired immune system
what triggers the classical pathway of complement activation?
antibodies binding to the antigen
The C1 complex is composed of what? and releases what?
composed of antigen and antibody.
releases C2a and C4b fragments which combine to form C3
C3 is cleaved by what enzyme, becoming what?
cleaved by C3 convertase, becomes C3a and C3b
What action does C3b have?
C3b cleaves C5 into C5a and C5b
once C5b is present, what can be formed?
the membrane attack complex
the membrane attack complex is formed by which proteins?
C5b, C6, C7, C8, C9
Describe the 5 main steps of the complement pathway
- activation
- C3 convertase formation
- opsonization/phagocytosis
- inflammation
- membrane attack complex and lysis
what happens to neutrophils when there is endothelial damage?
chemical signals from endothelium help neutrophils become “sticky” and stop rolling along capillary wall
In the inflammatory response, mast cells from the tissue release what?
histamine
histamine release causes vasodilation, which allows what?
holes open between endothelial cells
Because of the histamine mediated openings between endothelial cells, what can enter the tissue?
fluid, leukocytes
When neutrophils squeeze through the endothelium, that is called what?
extravasation
“Never Let Monkeys Eat Bananas” describes the distribution of what?
WBCs in the blood.
Neutrophils (62%) Lymphocytes (30%) Monocytes (5%) Eosinophils (2.5%) Basophils (0.5%)
these cells have the following characteristics:
- Phagocytes and Granulocyte
- 1st responders/scouts
- active against bacteria
- Myeloblast derived
Neutrophil
what does an increase in band neutrophils indicate?
bone marrow creating more WBCs
An increase in band neutrophils is described as what in lab values?
leukocytosis with left shift
why are immature neutrophils called band neutrophils?
they do not have segmented nucleus yet
Luekocytosis with a left shift indicates what?
acute bacterial infection
what percent of bands indicates a left shift?
> 8%
Neutrophilia indicates what?
acute infection, nonspecific inflammation, metabolic issues
Neutropenia indicates what?
viral infection, bone marrow disease, chemo/radiation therapy, toxicity
This WBC has the following characteristics:
- Histamine and heparine granules
- Allergic and antigen response
basophils
This WBC has the following characteristics:
- target large parasites
- modulate allergic inflammatory response
- rare in blood
- found in mucous membranes of respiratory, digestive urinary tracts
eosinophils
This WBC has the following characteristics:
- releases histamine and heparin
- Present in mucosa
- important for allergy and anaphylaxis
mast cells
This WBC has the following characteristics:
- largest WBC
- found in spleen
- differentiate to become macrophage or dentritic cell
monocytes
what are the primary lymph organs?
bone marrow, thymus
what cell matures in the bone marrow?
b-cells
what cell matures in the thymus?
t-cells
what are the secondary lymph organs?
lymph nodes, spleen, tonsils, MALT
This organ removes old blood cells, synthesizes Abs, removes antigens via blood and lymph
spleen
this organ filters foreign molecules and cancer cells
lymph nodes
this organ filters bacteria and viruses. found in oral/nasal mucosa
tonsils/adenoids
This tissue type regulates mucosal immunity
MALT
This condition results in the following:
- modest leukophilia
- diminished response to live vaccines
- increased susceptibility to encapsulated bacteria
asplenia
what is the first line of defense against ingested or inhaled pathogens?
tonsils/adenoids
This tissue is populated by b cells, t-cells, plasma cells and macrophages.
it specializes in sampling antigens and delivering to lymphoid tissue
MALT
this type of adaptive immunity has the following characteristics:
- antibody mediated
- B-lymphocytes
- works by circulation of Abs
- Effective against extracellular pathogens
Humoral immunity
This type of adaptive immunity has the following characteristics:
- Cell mediated
- T-lymphocytes
- Direct cell-to-cell contact or secreted products
- Effective against intracellular pathogens, tumors, etc.
cell-mediated
Where are B lymphocytes created, where do they mature, and where do you migrate to?
born in bone marrow
mature in bone-marrow
migrate to spleen, lymph nodes, MALT
Describe the steps to activate a b-lymphocyte
antigen binds to mature naive b lymphocyte receptor
b lymphocyte proliferates
clones differentiate to become plasma or memory cells
What do antigens bind to on b-cells to activate them?
b cell receptor (BCR)
What are the five types of immunoglobulin?
IgM IgG IgA IgE IgD
This immune globulin is:
- 1st responder produced by plasma cell
- Large
- does not cross placenta
- Activates the complement system
- Short half-life
- 5-10% of circulating Abs
IgM
This immunoglobulin has the following characteristics:
- Second antibody produced by plasma cells
- crosses placenta
- opsonizing activity
- most abundant Ab (75%)
- 21 day half life
- can activate complement
IgG
The presence of IgM indicates what?
acute infection
A titer is drawn to test immunity. The results are the following:
IgG: Reactive
IgM: non-reactive
IgG avidity: high avidity
What does this indicate?
past infection from the pathogen
A titer is drawn to test immunity. The results are the following:
IgG: Reactive
IgM: Reactive
IgG Avidity: low avidity
What does this indicate?
primary infection
A titer is drawn to test immunity. The results are the following:
IgG: reactive
IgM: Reactive
IgG avidity: high avidity
what does this indicate?
non-primary infection
Low risk for in-utero transmission
when a booster dose is given, does IgM respond in the same magnitude it did during primary vaccination?
yes
When a booster dose is given, does IgG respond in the same magnitude it did during primary vaccination?
No, much greater response
This immunoglobulin has the following characteristics:
- found in mucosal membranes
- found in secretions including breast milk
- weak opsonizer, doesn’t activate complement
IgA
This immunoglobulin has the following characteristics:
- produced in allergic response
- defends against helminths and parasaites
- binds mast cells
- mediates histamine release
- large role in Type I hypersensitivity
IgE
This immunoglobulin has the following characteristics:
- involved in B-cell activation
- not well understood
IgD
a newborn is positive for IgM Abs. what does this indicate?
in utero infection of the infant
Where do T-lymphocytes get created, and where are they matured?
created in bone marrow, mature in thymus
What is the 1st signal of t-cell activation
TCR binding to MHC-antigen complex of an antigen presenting cell
TCR binds APC
what is the second signal of t-cell activation?
T-Cell CD28 binds APC’s B7
This T-Cell…
is “the regulator”
prevents immune overactivity
distinguishes self vs non-self
doesn’t express surface receptors
doesn’t bind to MHC
Suppressor T-Cells
This T-Cell…
is “the veteran”
recognizes antigens from previous exposure
doesn’t express surface receptors
doesn’t bind MHC
memory t-cell
This T-Cell…
stimulates B-Cells and T-Cells to proliferate
Activates macrophages
Activates NK cells
Displays CD4
Binds MHC II
helper T-cell
this T-Cell…
directly kills virus infected cells
kills tumor cells
expresses CD8
binds MHC I
cytotoxic t cell
What type of cell has major histocompatibility complexes on surfaces which display antigen to TCRs?
antigen presenting cells
What cells have an MHC Class I?
surface of all nucleated cells
What cells have MHC class II?
surface of b-cells, dentritic cells, macrophages
The granulocytes are…
neutrophils
eosinophils
basophils
mast cells
the agranulocytes are
monocytes
lymphocytes
monocytes can differentiate to become…
dendritic cells
macrophages
neutrophils, eosinophils, basophils, mast cells, and monocytes originate from what cell?
myeloid progenitor
plasma B cells, memory B cells, t-cells, and NK cells originate from what cell?
lymphoid stem cell
