More Immunology Lecture Notes from Old Notes Flashcards
What does MHC stand for?
Major Histocompatibility Markers
What are the purpose of MHC?
They help the cells of your body distinguish them as self
MHC I
A self marker
Contains a binding site for a protein fragment which the cell is producing
Red Blood Cells lack MHC I markers since they lack nuclei and cannot produce proteins; therefore red blood cells can be transfused
T/F: Red blood cells lack MHC I markers
T; since they lack nuclei and cannot produce proteins
Why do RBC lack MHC I markers?
They lack nuclei and cannot produce proteins; therefore, red blood cells can be transfused
MHC II
Incorporate protein fragments from protein that were consumed by the cell
These are foreign proteins
Only presenter cells such as Phagocytic cells contain MHC II markers
Incorporate protein fragments from protein that were consumed by the cell
These are foreign proteins
Only presenter cells such as Phagocytic cells contain these:
MHC II
Non-specific immune response
The defending cell are non-specific in what they attack
Specific Immune Response
Defending cell attacks one specific type of foreign invader
Antigen
A specific non-self molecule that is recognized
They have antigenic determination sites
Ex: Chicken pox virus is the antigen, proteins on the viral coat that are recognized are the determination sites
Virus
Non-living
They are made up of nucleic acid surrounded by a protein coat
They cannot make copies of themselves on their own; they need to invade other cells and get those cells to make more viruses
There are DNA and RNA viruses
Virus first has to attach to your cell and insert its DNA into the host cell’s chromosome
If a virus is RNA based it is
Retrovirus
T/F: As virus takes over a cell and makes new viral proteins it will insert fragments into the cell’s MHC I marker, thus making the cell recognized as a foreign object
T
How does a retrovirus work?
A retrovirus inserts RNA, reverse transcribes and inserts into host genome thus forcing host cells to make copies of it
Phagocytic White Blood Cell
Monocytes become macrophages:
They are the “big eaters”
They are located in blood, lymph as well as tissue spaces
Some can hang out in specific organs giving them specific names
These cells can reshape and squeeze through a tiny opening: Diapedesis
Diapedesis
The outward movement or passage of blood cells through pores in intact vessel walls
How do phagocytic cells work?
Endocytosis
Chemotaxis
Endocytosis with phagocytic cells
Membrane of phagocytic cell surrounds and envelopes foreign entity
Membranes join and pinch off, forming a vacuole within
Digestive enzymes do their work on the vacuole: the enzymes are packaged in lysosomes, the lysosome will merge with the food vacuole, exposing the digestive enzymes to the vacuole; if lysosome explodes it can cause inflammation
As the entity is broken down to basic unites (amino acids, etc) it can be taken up to the membrane and released into the cell for use
Phagocytes move via
Pseudopods (fake legs)
Chemotaxis
Chemical communication attracting other phagocytes to area
Do the cells of our specific immune system get rid of foreign invaders?
No the cells of our specific immune system do NOT get rid of foreign invaders but make them easy for nonspecific cells to do their job
Specific Immune Cells
Lymphocytes; B-Cells, T-Cells
Lymphocytes are non-specific or specific?
Specific Immune Cells
Are B-Cells specific or non-specific?
Specific Immune Cells
Are T-Cells specific or non-specific?
Specific Immune Cells
Where do B-Cells start?
They mature in the bone marrow and stay there
Where do T-Cells start?
They mature in the bone marrow and go to the thymus gland
How do specific immune cells work?
These cells have immune receptors on their membrane that corresponds to an antigen on a pathogen
During development of B and T cells they start producing these immune receptors
The number of non-self molecules is potentially limitless
Binding of antigen to immune receptor on lymphocyte causes it to be activated; the cell starts to divide and make copies of itself: Clonal Formation
Describe the Immune Receptor Structure
Immune receptors have 2 copies of 2 different length proteins
The part that binds to an antigen is comprised of a portion of heavy chain and light chain:
Heavy chain: stem part is in membrane of B-cell
Light chain; variable region: varies from different immune receptors
Which are the most abundant classes of antibodies?
IgG and IgM
Where is IgA antibody associated?
In saliva and mother’s milk
Where is IgE antibody associated?
Involved in inflammation response and allergy
Where is IgD antibody associated?
Rare floating freely in blood because the D is the constant region that inserts into B-cell membrane, therefore these are the immune receptors on its surface; it is used for the insertion of protein into the membrane of B-cell
Job of Plasma cells
Secrete immune receptors (antibodies) into the bloodstream;
Gamma globulins are another name for antibodies
Immunoglobulins are another name for antibodies
Plasma cells are antibody manufacturing plants
What is an antibody’s primary job?
To bind to the markers on an antigen allowing for macrophages to easily eat the antigen
Which is the first antibody the body produces?
The body first produces IgM and then changes to IgG production
Why does the body change IgM production to IgG?
This change is mediated by chemicals that induce the plasma cells to change its constant region, thereby changing the class of antibody
What function do antibodies serve?
Neutralization
Agglutination
Precipitation
Complement Fixation
Explain neutralization as applies to antibody function
Antibodies prevent foreign particles from doing damage by coating them, preventing virus or bacteria from entering your cell; Antibodies do NOT kill antigens
T/F: Antibodies kill antigens
FALSE