Studied by 19 people
Diapedesis
monocytes mature into macrophages which can leave the blood vessels and enter tissues
Antigen-presenting cells
lymphocytes that phagocytose germs and present their antigens to CD4 cells
AMP
antimicrobial peptides; tiny proteins secreted from the skin to prevent infections, a chemical barrier; defensin, lysozyme
Antibody
proteins secreted by effector B-cells; bind specifically to one pathogen antigen and are highly specific; mark that cell for death
IgM
large antibody (pentamer); released by plasma cells
IgD
acts as a B-cell receptor
IgG
most abundant, small, and can cross placental barrier
B- cells (lymphocyte)
produce antibodies to pathogens
Memory cells
remember the antibodies produced towards a specific germ to “prime” them in case of reinfection
Plasma cells (effector cells)
secrete antibodies to the antigen (up to 2k/sec); antibodies mark any cell with that antigen for death; most cloned b-lymphocytes become this
Cytokines
get cells to change their behavior and do something new
Fever
presence of certain PAMPs results in another chemical cascade that triggers the hypothalamus to increase the normal temperature of the body; increases the efficiency of complement and decreases growth rate of pathogens
Hapten
Very small molecules that are foreign to the body, but not immunogenic; will combine with a self protein and cause an immune response that will attack your own cells and not the hapten itself
Immunogenicity
stimulation of the proliferation of lymphocytes and antibodies
Inflammation
acute and chronic; reddened skin, localized heat, edema and pain; increased temperature heat stresses the bacteria, and they don’t grow as fast
Acute inflammation
dilates blood vessels and makes them more permeable; delivers more blood and resources to the site of infection, results in rapid healing; recruits phagocytes to kill infections pathogens and prevent the spread of infection
Chronic inflammation
long, lasting, generally damaging reaction to infection which itself can cause disease
MHC
protein matrix on your cells that displays either “self” or “non-self” proteins that are being made in the cell; each has a different shape
MHC 1
inside body cells and will display either self-proteins or non-self proteins (sick cells); connect with CD8 cells
MHC 2
displayed on immune cells and will display self-proteins or antigens to activate immune response; connect with CD4 cells
Mucus
traps bacteria in its viscous and acidic fluid which eats away at the bacteria; more likely to have an infection because it’s wet
Opsonization
antibodies or other proteins mark the pathogen for death
PAMP
germ antigen; pathogen associated molecular patterns; all are antigens; identifies pathogens and reveals them to the immune system to activate innate immune response; specific immune responses for specific PAMPs
Pathogen
virus, bacteria, or microorganism that will cause a disease; unicellular, parasites are multicellular
Phagocytosis
WBCs surround and engulf pathogens
Reactivity
the antibodies’ ability to react to whatever’s going on in the system; react to activated lymphocytes and antibodies produced by the immune response
ROS (reactive oxygen species)
formed by enzymes in the cell membranes of cells that secrete toxic compounds; used to kill nearby cells; example is hydrogen peroxide
T-lymphocytes
release cytokines to attract other cells to an area of infection
CD4 cells
helper cells that help coordinate immune response; connects with MHC II of antigen presenting IMMUNE cell and realizes that there’s a foreign antigen in the body; both immune and CD4 release cytokines and T-cells clone itself; the clones release different cytokines to activate B cell antibody production and CD8 cells are activated to become cytotoxic and kill the germ
CD8 cells
cytotoxic killer cells that destroy the body’s infected body cells; connect with MHC I on body cell that has been infected and CD8 cell produces perforins and granzymes; perforins form holes in the cell’s membrane and granzymes enter the cell and break down the inside, resulting in apoptosis
Granulocytes
many stained organelles giving them a grainy look; basophils, neutrophils, eosinophils
Agranulocytes
few or no organelles; lymphocytes and monocytes
Epitope
the specific spot on an antigen that the antibody binds to; a combination of antigens that your body can build antibodies to; this is where antibodies or leukocyte receptors bind to attack
Basophils
produce histamine leading to inflammatory response
Neutrophils
phagocytose bacteria and viruses
Eosinophils
lead attack against parasitic worms
Lymphocytes
produce antibodies against specific invaders
Monocytes
function to phagocytose bacteria and other invading pathogens; can mature into macrophages
Interleukins
cytokines that dampen the immune response
An infectious agent enters your body after cutting your finger. Describe the body responses put into place to intercept and destroy the infectious agent.
T-cells (CD4) will recognize the cell with that antigen fragment and cause a release of cytokines (this happens before CD8 activation) which then activates CD8 cells and the proliferation of B cells. B-cells whose antigen receptor connects with the PAMP will start to clone themselves after connecting, then they become effector cells after cloning and throw their antibodies at the germs. The process of opsonization with complements that bind the germs together. Humoral immunity intercepts the germs. Inflammation causes the germs to denature and dilates the blood vessels to send more WBCs to the site of infection. Diapedesis makes the monocytes become macrophages and leave the blood vessels through the lymph to get to the site of infection. WBCs find the infection through chemotaxis. Phagocytosis and the WBC (dendritic cell) eats the germ; it migrates to the lymph nodes and shares the antigen with CD4 and CD8 cells.
What are some behavioral responses to systemic infection and how are they beneficial?
Systemic infection is an infection through the blood stream, e.g. flu. Gives headache and makes you tired so that you isolate yourself to prevent spreading and allows your body to use all your energy to fight. Your body gets colder so that you stay warm. Staying warm will help you fever.
What is the difference between innate and acquired (adaptive) immunity?
Innate immunity is something you’re born with and adaptive immunity is gained through time with exposure to pathogens. Innate immunity can include- skin and WBCs; acquired immunity includes- CD4 and CD8, b cells, and antibodies
What are antibodies and why are they so limited in their effectiveness against infectious agents?
Proteins secreted by effector B-cells; they’re limited because they’re so specific that they only fit to certain PAMPs. If the pathogen mutates, that antibody will no longer be useful against the infectious agent.
What are allergies?
A condition in which the immune system reacts abnormally to a foreign substance; IgE is involved in this
What are the major differences between the cellular and humoral immune responses?
Cellular immune response is when T-cells recognize non-self antigen fragments. The cellular response kills the germs and directs immune response. The humoral immune response is just the process of antibodies being made to stop the movement of these germs and inactivate the PAMPs. The memory (B) cells remain after the infectious agent is gone while the CD8 also remain but are inactive until the signal from CD4.
How has the immune system been exploited for diagnostic work?
FISH is used to put a tracer molecule on nonsticky part of antibody to have the infected cells glow. ELISA puts a linked enzyme on an antibody and if the antigen is present and they link, the enxyme will go through a color change.
Why is fever beneficial in the long run?
It slows down the proliferation of the foreign agent as well as denaturing the protein, allowing the T-cells and B-cells time to kill the germs. It also dilates the blood vessels to allow more WBCs to go to the site of infection.
How are immune cells “educated” to combat subsequent infections?
Since B-cells and T-cells were already exposed to the infectious agent before, they remember the PAMP through memory cells and this allows them to be able to quickly attack the agent during the second infection through antibodies and T-cells.
How do immune cells recognize the plethora of infectious agents that could possibly infect the body?
Through gene shuffling, the bone marrow creates B-cells with different antigen receptors on them, creating a large variety of antigen receptors. The recognition of these agents is only through chance.
What is a differential WBC count and what does it tell us?
Depending on the pathogen, an infection will cause changes in the proportions of WBCs in the blood. This different proportion can show what kind of infection the body is dealing with.
What characteristics of the skin prevent infection?
The high salt concentration rids the skin of moisture, preventing bacterial growth. Dead, dry skin cells because no moisture means no growth. Dendritic cells phagocytose invading microorganisms. AMPs prevent infections. Lysozyme lyses bacterial cell membranes and causes the virus to pop
What’s the difference between a local and a systemic infection?
A local infection is at a certain area and causes a mini-fever while a systemic infection affects a whole system and will cause a fever all around.
How are antibodies produced?
B-cells win the lottery and connect with the PAMP. They then start cloning themselves and after a certain amount of cloning, they become effector cells which throw their antibodies in the plasma.
What’s the difference between a parasite and a pathogen?
Pathogens are unicellular and parasites and multicellular organisms.
Where are the immune cells produced?
Red bone marrow
Why is the lymphatic system so important to immunity?
Provides the WBCs and pathogens with a battleground and drains them from the body, effectively killing and removing the invading pathogen.
What is herd immunity?
The majority of a population gains immunity to a disease which prevents the spread of the disease.
How has modern medicine changed the way infectious disease spreads through human populations?
With the creation of vaccines, it’s prevented the spread of diseases as well as with quarantining. Medication has also allowed for the infectious diseases to die faster, however, they’ll be more likely to mutate.
passive humoral immunity
Immune response is solely due to “artifical” antibodies​; maternal antibodies or antivenom; protection ends when antibodies degrade
active humoral immunity
b-cells encounter antigens and MAKE the antibodies; can also be gained through vaccines
dendritic cell
modified monocytes that phagocytose invading microorganisms
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