Immunology Flashcards
Hematopoiesis
production of the cellular components of blood
-two linages that can be followed, the lymphoid linage leads to plasma cells and the myeloid linage leads to erythrocytes and many types of myeloblasts (cells that then differentiate into other things)
immune system
an internal system that allows the body to defend it self through innate and and adaptive immunity
neutrophil
- innate cell
- a type of white blood cell
- phagocyte
- hyper segmented nucleus
- they are increased when there is a bacterial infection
- have granules containing attack molecules
macrophage
-innate cell
-phagocytes (a cell that protects the body by ingesting harmful, foreign particles)
-antigen presenting
-can form giant cells
derived from monocytes
-have a long life
monocytes
- innate cell
- these are involved in bone reabsorption
ex. osteoclasts, microglial cells
eosinophil
- innate cell
- defend against helminths (worms)
- involved in allergic reactions
- phagocytes
basophil
- innate cell
- release molecules –> allergic reactions
- contains granules (histamine and heparin (an anticoagulant)
dendritic cells
- innate cell
- antigen presenting cells
- present antigen on the cell surface to the T cells of the immune system. They act as messengers between the innate and the adaptive immune systems.
complement system
a cascade that occurs that enhances the immune systems ability of antibodies and phagocytic cells to clear microbes and damaged cells from an organism, promote inflammation, and attack the pathogen’s cell membrane.
(a series of proteins that get activated in the presence of something and when one gets activated, it automatically cleaves and activates another, all of which leads to an increased immune response)
how is the complement system activated?
-it is always present in the blood and is activated through pathways
-ends with the MAC
(there are three pathways and an endpoint)
MAC
- membrane attack complex
- they attack the membrane, create a pore and then go in and are able to destroy the cell
interferons
- molecules that boost the immune response
- alpha and beta against viruses
- cell recognizes something is wrong and releases interferons to go to other cells near it to tell them to make anti virus things to protect against the bad thing spreading to other cells
cytokines
- immune cell hormones
- messenger molecules that help illicit different responces
- they mediate inflammation, immunity and response
What are the important organs of the immune system
- bone marrow
- lymph nodes
- the spleen
- thymus
bone marrow
this is where b cells are activated
spleen
- the vacuum cleaner of the blood
- contains memory cells
why is it significant when the spleen needs to be removed?
- the spleen holds memory cells so without it, the patient is more at risk to disease and infection
- they will need continuous vaccines and typically will have an open prescription for penicillin because prone to infection
thymus
t cell activation
-where t cells mature
how does the immune system create host defense?
- through non-specific (innate) responses
- through specific (adaptive) responses
how does the immune system work to have immune surveillance?
-they use information gathering through antigens that it can sense
what is auto tolerance
this is the ability to tell self from foreign organism
what is the process of the immune response?
- recognition of material (foreign/ dangerous)
- early innate (non-specific) response
- later adaptive response (specific–> this is the body figuring out the best way to attack this thing)
- non specific augmentation of the response (this is making the response much larger)
- memory of response (allows for it to be quicker on later recognition
b cell
- made in the bone marrow and they produce and secrete antibodies to activate the immune system
- humoral (hormone) response
- these are plasma cells so they are long living
t cell
- made and selected for in the thymus
- the receptor is variable
- there are different types of t cells
CD4+ (helper t cell)
- these help the immune system
- Th2: activate the responses for asthma or allergies
- Treg: these help to regulate the immune system so that the body does not freak out and diminishes the response to minor things
CD8+ (cytotoxic t cell)
these are ones that tell a cancerous cell to go to programed cell death
memory t cell
can be kept in the spleen until specific antigen is present and it is not active until then
lymphocyte activation (t cell)
- antigen recognition (they will recognize a t cell)
- activation
- clonal expansion
- differentiation
- effecter functions (will be either a memory t cell or an effecter t cell)
Major histocompatibility complex (MHC)
- a genetic system that allows large proteins in immune system cells to identify compatible or foreign proteins.
- It allows the matching of potential organ or bone marrow donors with recipients.
- if things are foreign the different MHC types allow for an immediate response of the immune system again non-self antigens
type 1 MHC
- presentation of viral antigens (IC) and cancer
- these could be due to mutations (misfiled proteins or cancer)
type 2MHC
-presentation of bacterial antigens
human leukocyte antigens (HLA)
- a persons tissue type
- determined by type 1 and type 2 MHC
- this is tissue typing for transport medicine
- subtypes linked to certain disease (namely autoimmune)
what level of match is required for transplants between donor and recipient
- accepted mismatch level depends on the transplant type (solid organ vs stem cells)
- stem cells need 10/10 match to ensure the bone marrow will survive long term
- solid organs dont need exact
what are things to consider when looking at recipients?
- previous immunizations
- transplant/transfusion/ pregnancy history
- level of immunization
- donor specific antibodies
what is the level of mismatch for donor dependent on
blood type
what is looked at post transplant for a solid organ?
was it rejected? Donor specific antibodies?
-level of immunosuppression
what is looked at post transplant for a stem cell?
- check if the cells have started to produce platelets, RBCs, and leucocytes
- look at the blood cells and see how many are the old type and the donor type
what are antibodies that are produced by B cells
- IgG
-IgM
-IgA
-IgD
-IgE
Big GAME Day
-these are produced in response to selection and activiation
opsonization
this is when b cell antibodies coat an organism and white blood cells see it and eat it and get rid of it
what does it mean when the complement system is activated
this is when b cell antibodies cause a complement cascade to lead to MAC and then cell death
immunodeficiency types
- primary (inherited/primary mutations/dysfunctions[missing enzymes or cell types or non functioning component])
- secondary (acquired [after infection, malignancy, caused by medical treatment (radiation/drugs), aging/malnutrition)
what you ask your patient if suspecting immunodefficiency?
- repeated simple ear, nose, throat infections?
- often secondary system involved (skin, guts, meninges)
- moderate/ severe reactions to common infections
- rare/specific infectious agents
- family disposition
what work up would you do to check for immunodeficiency?
- need a specialist evaluation
- need to do immune profile:
- cell type/counts (RBC/WBC)
- antibody concentration/profile
- functionality of cell responses
- complement assessment
- genetics
what are treatment for immunodeficiency
- profylactic antibiotics
- vaccination
- isolation
- IV immunoglobulins (IVIG)
- interferons, growth factors (induce the production of WBC)
- symptomatic treatment
- stem cell transplant (immune system reboot)
four types of hypersensitivities
- Allergic, Anaphylaxis and Atopy
- antiBody
- immune Complex
- delayed (cell mediated hypersensitivity)
example of antiBody hypersensitivities
type 1 diabetes
example of immune complex hypersensitivities
some types of arthritis
what goes wrong with hypersensitivites?
- loss of self tolerance
- autoantibodies (may be involved)
- autoreactive cells (may be involved)
- certain HLA (MHC0 types more prone
- certain drugs may induce
- molecular mimicry (may be involved)
what workup is done for hypersensitivities
- blood/tissue/fluid samples
- acute phase reactants (ex. CRP) (these are inflammation markers that increase in times of disease)
treatment for hypersensitivity
- immunosuppressive (modulatory drugs)
- symptomatic treatment
- specific anti-antibodies
- IVIG
- stem cell transplant (rare but rising)
