Antibodies stored??

[rockyroad2009]

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HEy guys I got this question on a practice test and Had trouble answering it, where are antibodies stored in what region?

bone, liver, spleen, neutrophil

 

[klpennin]

HEy guys I got this question on a practice test and Had trouble answering it, where are antibodies stored in what region?

bone, liver, spleen, neutrophil

Well antibodies are made by plasma cells, but since thats not what it is asking I would say spleen bc thats where a lot of white blood cells "hang out"

 

[rockyroad2009]

yah that makes sense thanks! heres another que i came across


Which is true about t cell receptors?

MHC class 1 receptors are found on all cells
mhc class 2 receptors are not found on immune cells
upon an immune rxn the MHC receptors display proteins of the foreign body
none of the above
2 of the above

 

[funkymonkey]

yah that makes sense thanks! heres another que i came across


Which is true about cell receptors?

MHC class 1 receptors are found on all cells
mhc class 2 receptors are not found on immune cells
upon an immune rxn the MHC receptors display proteins of the foreign body
none of the above
2 of the above

hey hey from my immuno notes (Kuby, Immunology) this is what i have:

MHC (major histocompatibility complex) binds to fragments of the antigen and presents it to T cells (does so by degrading the antigen within the cell so it can present it); because T cells are "MHC restricted" meaing they must have a MHC to present the antigen.

the two classes are MHC1 and MHC2.

MHC1- are found on all nucleated cells. They present to cytotoxic t-cells by binding with CD8 molecule on the t-cells surface.

MHC2-found only on B lymphocytes, macrophages, dendritic cells, and other APCs (antigen presenting cells). Present to helper T-cells by binding to CD4 molecule on the helper t-cells surface.

 

[Contach]

Immunology was one of my favourite courses i ever took. Too bad I barely remember anything from it.

MHC I is indeed located on every nucleated cell (not erythrocytes). The reason is because MHC displays intracellular pathogens. This refers to a pathogen that makes it inside a cell's cytoplasm. A common example is the virus which inserts its DNA/RNA into the cytoplasm of a cell. The machinery of MHC I involves a proteosome that cuts up useless proteins into small fragements. A viral protein would be such a protein, and would be sent to the proteosome to be degraded, and then displayed on

MHCII displays extracellular pathogens. These are the pathogens that are ingested by a cell. Much like how a phagocytic macrophage/monophage/neutrophil will phagocytose a bacteria. The bacteria will remain in a compartment, be degraded and then be displayed on MHCII fragments on the surface.

Thus both the MHCI and MHCII have very different functions. And if you remember these functions you can remembers which cells they will be present on. Because not all cells can phagocytose. Only immune cells will be able to do this. The MHC I is present in all cells that make proteins.

If there is an immune reaction, such receptors may be upregulated as well. This will help guide the immune response to infected cells. Alternatively, certain viruses will try and deregulate the expression of the MHC I so they can symbioticallly exist for longer.

The answer to your question is two of the above, unless you want to get really picky and say the RBC is a cell, and MHC isnt found on RBC. so a isn't true. But let's discount that for now... haha

MHC class 1 receptors are found on all cells
upon an immune rxn the MHC receptors display proteins of the foreign body

 

[Contach]

MHC (major histocompatibility complex) binds to fragments of the antigen and presents it to T cells (does so by degrading the antigen within the cell so it can present it); because T cells are "MHC restricted" meaing they must have a MHC to present the antigen.

erm.. I vaguely remember MHC restriction meaning something else. It's a complicated phenomenon that says that in order for a T cell to be activated, the cell presenting the protein must have the MHC that the T cell recognizes. Thus, there is must be a self-MHC, and MHC are restricted to one's that your T cells have seen before. For example, a cell in my body with MHC (ironman-type) cannot activate the T cell in your body because in your body the T cells have been 'sensitizes' or 'negatively selected' for MHC (batman-type). I think this made it possible for them to explain organ transplants and how sometimes its not rejected, and sometimes it is.

 

[Contach]

now I have a question for you guys:

1) Explain how bacteria induce harmful effects onto humans. Like we know how virus's work, they inject DNA, then enter the lysogenic or lytic cycle and target a specific cell and end up killing them. But what do bacteria do? Surely they do not inject THEIR DNA into our cells? or do they?


2) A bacterial cell enters my blood stream through a cut. What happens next? And where does this cell travel to? What does it activate?

 

[Albuterol]

also MHC Class II receptors are ONLY found on Antigen Presenting Cells such as macrophages, B cells, and dendritic cells

welll gram negative bacteria have LPS on their membranes and some bacteria release endotoxins such as (enterotoxins, neurotoxins etc) these cause an adverse reaction from your body.

for your 2nd question some bacteria must enter only through certain ways to cause harm for example an oral-fecal route entery bacterium must enter that way to cause damage to your body...while other bacterial cells the route of entry does not matter. im guessing the cell enter your body where the foreign proteins on the bacterial cell are detected by neutrophils/macrophages which then destroy the bacterial via phagocystosis and act as APcells (antigen presenting cells). these migrate towards the lymph nodes and and display the digested peptides to T-Helper cells who in turn go through some cascade and activate b-cells to proliferate and produce memory and plasma cells.

 

[Contach]

also MHC Class II receptors are ONLY found on Antigen Presenting Cells such as macrophages, B cells, and dendritic cells

welll gram negative bacteria have LPS on their membranes and some bacteria release endotoxins such as (enterotoxins, neurotoxins etc) these cause an adverse reaction from your body.

for your 2nd question some bacteria must enter only through certain ways to cause harm for example an oral-fecal route entery bacterium must enter that way to cause damage to your body...while other bacterial cells the route of entry does not matter. im guessing the cell enter your body where the foreign proteins on the bacterial cell are detected by neutrophils/macrophages which then destroy the bacterial via phagocystosis and act as APcells (antigen presenting cells). these migrate towards the lymph nodes and and display the digested peptides to T-Helper cells who in turn go through some cascade and activate b-cells to proliferate and produce memory and plasma cells.

very good! haha. yeah thanks for that reminder about APCs.. but I feel that most ppl don't know what dendritic cells are.. so that would have been pointless.
also, to complete the process.. the plasma cells are terminally differentiated and will secrete antibodies that will be released into the bloodstream. the antibodies will (depending on the type of toxin/pathogen) opsonize, lyse, neutralize or agluttinate the pathogen.

another question: B cells produce memory via the memory b cells. what are the t cells that are repsonsible for immunological memory called?

 

[Albuterol]

memory T cells? haha i'm not too sure about this one though

Also the complement system will help in aiding of opsonization, lysing, and inflammation

 

[klpennin]

now I have a question for you guys:

1) Explain how bacteria induce harmful effects onto humans. Like we know how virus's work, they inject DNA, then enter the lysogenic or lytic cycle and target a specific cell and end up killing them. But what do bacteria do? Surely they do not inject THEIR DNA into our cells? or do they?


2) A bacterial cell enters my blood stream through a cut. What happens next? And where does this cell travel to? What does it activate?

1)The release endotoxins and exotoxins. Also, your immune reaction to a foriegn invador produces a lot of symtoms that we associate with bactierial infections including redness, swelling, pain, and fever. These are all associated with the immune reponse of your body.

2) Generally, a macrophage (a monocyte that has entered the tissue) will digest the bacteria and display it to a Helper T, which will then activate B cells to produce antiboidies. The antibodies will then neutralize (happens in a variety of ways) the bacteria.

 

[diplo123]

I thought they were stored in lymph nodes?