Term
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Definition
| 1st line of defense; one in which that component of immune system is designed to respond immediately; has ability to communicate with adaptive immune system in order to provide additional defense; (cells of the same lineage must all have the same receptors)- these are very tightly controlled mechanisms; all of these are available the second the body realizes something foreign is attacking |
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Term
| what are the 5 hallmarks of the innate immune system? |
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Definition
1) Epithelium provides barriers
2) Phagocytic cells
3) Neutrophils
4) Natural Killer cells
5) Complement system/components |
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Term
| Epithelium (provides barriers) |
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Definition
| this is a hallmark of innate immune system present in oral mucosa, respiratory mucosa, reproductive mucosa all have epithelial lining, have physical barriers to prevent penetration of infections |
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Term
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Definition
| This is a hallmark of innate immune system that includes cells that engulf foreign bodies very quickly, ex: (macrophages, neutrophils, and dendritic cells) |
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Term
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Definition
| This is a hallmark of innate immune system: can recognize tumor cells and can destroy them; these also fight against viral infectious agents (have many different receptors) |
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Term
| Complement system/components |
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Definition
| This is a hallmark of innate immune system that includes soluble proteins that are present in body fluids, when they are activated they develop characteristics that help them bind to membranes; then they can target membranes in a way that promotes elimination; gives rise to a number of proteins that lead to phagocytosis |
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Term
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Definition
| more commonly used word for antigen (abbreviated) |
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Term
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Definition
live for 6 hours,
are abundant and circulate in blood
can phagocytose and destroy bacteria
(undergo programmed cell death) |
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Term
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Definition
| term used to refer to substances that are foreign to the body that can trigger an immune response; once that immune system will respond to using specific receptors; even if you get a transplant, this transplant can be considered an antigen |
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Term
| When an antigen enters body, what happens? |
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Definition
| , the body has within it phagocytic cells that will recognize it, engulf it with phagocytosis, and within endosomes (part of plasma membrane that engulfs the object) and then it will be destroyed. (in a neutrophil, it will just die). But in macrophages, it will engulf the object and then express those proteins on its surface |
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Term
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Definition
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Term
| APC (antigen processing cell) |
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Definition
| cell that processes antigens and then expresses those proteins on its surface; in process of destroying them, it will then distribute them on membrane surface for the adaptive immune system |
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Term
| Typical antigens are substances that are present on: |
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Definition
| bacteria, viruses, fungi, or parasites, etc. |
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Term
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Definition
| substances that activate the immune response |
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Term
| When endosome engulfs antigen, what happens? |
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Definition
| the endosome then degrades its carbohydrates, proteins, and other things, and then the peptides of the antigen are then expressed on the membrane of the APC (crucial step of activation of adaptive immune system) |
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Term
| Transport of molecules of peptides from inside the cell to outside on membrane |
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Definition
| This synthesis of genes is made by the Major Histocompatibility Complex (MHC) which encodes 2 types of molecules (type 1 and type 2) – system of proteins that try to express the antigen’s peptides on the surface of the APC |
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Term
| Major Histocompatibility Complex (MHC) |
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Definition
| a large genomic region or gene family found in most vertebrates that encodes MHC molecules. MHC molecules play an important role in the immune system and autoimmunity. |
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Term
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Definition
these are specifically designed for activation of helper t cells ; There are cells in the body within inflammatory environment that can express these molecules; they must be careful to not upregulate genes that they don’t need; must regulate inflammation or else it will lead to autoimmune response
-these are aka Class II MHC molecules and are found on certain immune cells themselves, chiefly macrophages, B cells and dendritic cells, |
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Term
| class 1 versus class 2 MHC |
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Definition
Class I MHC molecules are found on all nucleated cells and present peptides to cytotoxic T cells. They present antigen fragments to cytotoxic T-cells via the CD8 receptor on the cytotoxic T-cells and also bind inhibitory receptors on NK cells.
Class II MHC molecules are found on certain immune cells themselves, chiefly macrophages, B cells and dendritic cells, collectively known as professional antigen-presenting cells (APCs). These APCs specialize in the uptake of pathogens and subsequent processing into peptide fragments within phagosomes. The Class II MHC molecules on APCs present these fragments to helper T cells, which stimulate an immune reaction from other cells |
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Term
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Definition
| Class I MHC molecules are found on all nucleated cells and present peptides to cytotoxic T cells. They present antigen fragments to cytotoxic T-cells via the CD8 receptor on the cytotoxic T-cells and also bind inhibitory receptors on NK cells. |
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Term
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Definition
| molecules are found on certain immune cells themselves, chiefly macrophages, B cells and dendritic cells, collectively known as professional antigen-presenting cells (APCs). These APCs specialize in the uptake of pathogens and subsequent processing into peptide fragments within phagosomes. The Class II MHC molecules on APCs present these fragments to helper T cells, which stimulate an immune reaction from other cells |
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Term
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Definition
| produce antibodies, also antigen-presenting cells |
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Term
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Definition
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Term
| Class 2 molecules will eventually meet up with: |
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Definition
endosomal molecules;
Eventually the endosome vesicle (breaking down antigen into smaller and smaller bits) will fuse with the vesicle that broke off of the ER
MHC- Brings things from inside cell to outside APC cell |
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Term
1) are there MHC molecules of different types?
2) are there different APC cells? |
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Definition
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Term
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Definition
| type of immunity that contains helper t cells, express CD4 (marker of helper t cells); CD4 can be expressed on different types of helper t cells as well; has capacity to recognize antigen peptides |
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Term
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Definition
| this is expressed on t-cell, that expresses peptide made by MHC |
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Term
| CD4 cells recognize antigen in form of......? |
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Definition
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Term
| what type of immunity contains clonal receptors? |
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Definition
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Term
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Definition
This is a signal for lymphoid cells (gene segments rearranged arbitrarily to create immunoglobulin producdts, t cells see some specific type of antigen (ex. for t cells it is the processed antigen peptides made by MHC from APC cells)
(ex. for b cells that make antibodies, it can be native antigens, antibodies can bind directly to intact bacteria (but t cells can't do this because they absolutely need processed antigen made by MHC from APC cells)) |
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Term
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Definition
this is a signal that comes in from the APC (so innate and adaptive immunity can communicate with one another)
for lymphocytes, it could be a native antigen, lymphocytes need more than 1 signal to be activated; comes in form of membrane associated events (in addition to t cell receptor) for receptor and from some soluble events in form of cytokines |
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Term
| in terms of signal 1 and signal 2, in the shortest way possible describe the function of both |
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Definition
1) recognition
2) verification/ additional activation step |
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Term
| which signal is made up of co-activation events that give rise to clonal amplification of t cells? |
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Definition
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Term
| once you get through signal 1 and signal 2, what will happen? |
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Definition
| you will get very rapid cell division |
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Term
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Definition
how adaptive immune system operates; upon activation of lymphoid cells (for signal 1 and 2) you get activation of cell division; amplify cell type that is desired for that particular infection, now war can be waged against the pathogen
-as long as infection persists, this will continue |
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Term
| As soon as pathogen is eliminated in the body, the cells that are activated go through |
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Definition
apoptosis
and no new cells are made because there is no more signal 1 being made |
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Term
signal 1 can also be called:
signal 2 can also be called: |
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Definition
1) antigen
2) co-activation |
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Term
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Definition
deals with soluble phases of immune response
B cell can probably see native form of antigen
If antigen is eliminated, the system contracts, and then t cells and b cells undergo apoptosis and if same antigen goes into body at later date, those antigens will be there to fight off the infection
T cells can help b cells (membrane immunoglobin (antibodies)) can bind to antigen and get signal from helper t cell, and enter plasma cell and then secretes immunoglobin
Immunoglobulin is used interchangeably with the word antibody (proteins globular in nature) |
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Term
| where do plasma cells go? |
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Definition
| some migrate to bone marrow and these survive for a very long time, however most stay in circulation and don’t exist for as long of a time |
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Term
| T helper cells also help cytotoxic t cell to deliver immune response against: |
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Definition
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Term
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Definition
| this is the process by which T helper cells help cytotoxic t cell to deliver immune response against intraceullular infection; lets say ordinary cell gets infected by virus, virus is inside cell MHC class 1 molecules deliver viral peptides to membrane surface of that infected cell, MHC class 1 molecules with bound viral peptide will then be recognized, becomes a target cell and then it undergoes apoptosis and kills itself with virus inside |
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Term
| cytotoxic t cells have what type of receptor? |
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Definition
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Term
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Definition
| made by GI tract, helps mucosa barrier; type of epithelial barrier |
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Term
| for an epithelial barrier, depending on the ______ of the barrier, you will be at either great risk or no risk at all to infection |
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Definition
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Term
| are epithelial cells innocent bystanders to infection? |
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Definition
| NO! they make a shield against infection; they are an integral part of innate immunity |
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Term
| some phagocytic cells have the capacity to process antigens and can then activate what type of immunity? |
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Definition
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Term
| What are the 3 main adaptive immunity hallmarks? |
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Definition
1) inducible
2) specificity
3) Memory |
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Term
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Definition
| the ability to decide when to undergo rapid amplification |
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Term
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Definition
| a hallmark of adaptive immunity; i. Of phagocytic cells; each clone of lymphoid cells has a unique receptor for antigen |
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Term
| Gene rearrangement phenomenon |
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Definition
| part of the specificity hallmark of adaptive immunity in which there are encoded polypeptides either on t cells or on immunoglobin on b cells |
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Term
| Pattern-recognition receptors (PRR's)- |
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Definition
| these are found on neutrophils, macrophages, dendritic cells; unique microbial patterns on infectious organism are signaled |
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Term
| Pathogen-associated molecular patterns (PaMPs) |
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Definition
| ligands on pathogen with which receptors are interacting |
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Term
| Toll-like receptors (TLRs) |
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Definition
| these are specific receptors found on outer membrane and intracellular membranes of phagocytic cells |
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Term
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Definition
this is a specific receptor on outer membrane of phagocytic cells that recognizes a structural bacteria called lipopolysaccharides (LPS) (aka endotoxin) (product found on certain types of bacteria); this receptor allows phagocytic cells to bind to a ligand to trigger phagocytosis
(first stage of phagocytosis is attachment of ligand to this receptor to initiate the phagocytic event) |
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Term
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Definition
| this is a receptor on out membrane of phagocytic cells that recognizes Flagellin (bacteria can move by using their flagella which is made up of flagellin ) ; this receptor recognizes this flagellin); this is a way to recognize bacteria and take it out of the body |
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Term
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Definition
| when bacteria make carbohydrates, they contain a terminal mannose, and our body can recognize these cells as foreign bc of that terminal mannose |
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Term
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Definition
this is a hallmark of adaptive immunity
-Lymphocytes will recognize antigen and then amplify rapidly
-Each has a specific receptor for antigen
-Remembers having encountered a certain antigen in its past (whereas innate immune system cannot do this)
-If you are exposed to the same antigen after having already seen it, the kinetics increase as well as the magnitude of the second response. (respond faster and greater)
-This is why vaccination is important to protect against damage (induce memory) |
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Term
| if the cell is expressing adaptive immunity to an antigen that has already been seen in the past, what happens to the 1) kinetics and 2) magnitude of second response |
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Definition
1) kinetics increase
2) magnitude of second respose is greater
(responds faster and greater than before) |
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Term
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Definition
| each time you see an infection, the binding affinity increases after each |
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Term
| clonal selection occurs for what two types of cells |
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Definition
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Term
| important aspect of humoral immunity |
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Definition
| certain antibodies activate the complement system |
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Term
| all cells in body that have a nucleus express what class of MHC? |
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Definition
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Term
| when you kill off a target cell, |
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Definition
you kill off virus at different stages inside that target cell as well as the target cell itself
(cell-mediated immunity) |
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Term
| do natural killer cells need MHC class 1 to recognize an infection? |
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Definition
| NO!! they do not need MHC class one. In fact, they actually prefer fighting infections in cells that don't have class one. |
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Term
| relationship of natural killer cells with t cells: |
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Definition
if t cell expresses MHC class 1, then natural killer cell is inhibited.
-certain viruses shut down MHC class 1 expression in cells that they infect, this is a major problem for cytotoxic cells but this is fine for natural killer cells bc they don't need MHC class 1 to function |
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Term
| three different types of activation for the complement system: |
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Definition
1) classical
2) mannose binding lectin pathway
3) alternative pathway |
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Term
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Definition
| part of the complement system; also part of the adaptive immune system; this requires activation by antibodies (products of b cells (lymphocytes)) |
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Term
| what are the 2 types of antibodies that give rise to classical activation? |
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Definition
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Term
| Mannose binding lectin pathway |
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Definition
| part of complement system; part of innate immune system; a pattern-recognition receptor (not dependent on cells/products of immune system) |
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Term
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Definition
| part of complement system; part of innate immune system; does not require a specific antibody to commence |
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Term
| the immune system is viewed as having ______ responses which mediate initial protection against infectious agents, and _______ responses, which provides more specific protection against infection. |
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Definition
1) innate responses
2) adaptive responses |
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Term
| Innate immune system is designed to recognize microbes based on their expression of chemical structures that are not found on human tissues. Interaction with these microbial ligands is mediated by ________. these receptors have evolved to recognize and react against a variety of microbes, including bacteria, viruses, and fungi |
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Definition
| pattern recognitiion receptors |
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Term
| a major role of innate immune system is to stimulate _________ |
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Definition
adaptive immune responses.
there is a great deal of 'cross talk' between the two types of immunity. |
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Term
| it is crucial to remember that adaptive immune responses are _________ |
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Definition
pre-programmed
antigen does not instruct the adaptive immune system |
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Term
| does an antigen instruct the adaptive immune system??? |
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Definition
| NO! Rather, if the ells of adaptive immune system (ex. lymphocytes) display an antigen receptor of the appropriate specificity, they are induced to proliferate and differentiate upon interaction with antigen, leading to expansion of reactive cells. this is known as clonal selection. |
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Term
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Definition
| type of adaptive immunity that refers to antibody and complement-mediated responses |
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Term
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Definition
| type of adaptive immunity that refers to t cell- and Natural Killer (NK) cell-mediated immune responses. |
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Term
| adaptive immunity is organized into 2 types of defense systems: |
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Definition
1) humoral immunity
2) cellular immunity |
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