Bio 205 Dr. Raymond Specific Immunity/Vaccination

specific immunity

the ability to recognize and defend against pathogens, pathogen products and abnormal cells. Also, the third line of defense

antigen

a molecule that triggers a specific immune response

epitope

small portion of an antigen that the specific immune system responds to

exogenous antigen

antigens that come from outside the body and can be phagocytized

endogenous antigen

antigens that are generated inside the cell due to infection of the cell by a microbe or the cell becoming cancerous

plasma cell

B cell that produces a specific antibody

antibody

Y shaped protein that has antigen binding sites identical to B cell receptors

CD 4 coreceptor

receptor on the surface of helper T cells

CD 8 coreceptor

receptor on the surface of cytotoxic T cells

B cell receptor

antibody that has binding sites for one specific antigen

Major Histocompatibility Complex (MHC)

protein that marks cells as self

antigen presenting cells

Immune cells that process and display antigen fragments on their class II major histocompatibility molecules to activate other immune cells such as helper T cells.

T1 helper cells

cells that produce cytokines to activate macrophages

T2 helper cells

cells that produce cytokines that activate B cells

perforins

proteins that poke holes in pathogens and allow toxins to enter

granzymes

enzymes that cause apoptosis of foreign or infected cells

vaccination

inoculation with weakened or dead microbes, or viruses, in order to generate immunity

humoral immunity

type of immunity that includes B cells and antibodies

cell-mediated immunity

type of immunity that includes T cells and antigens

lymphatic vessels, lymph, lymphoid organs, lymph nodes

what are the components of the lymphatic system

Lympathic vessels

vessels that return leaked fluids from the circulatory system back into the circulatory system

lymph

fluid leaked from the circulatory system that keeps cell moist, transports oxygen/hormones/nutrients, removes wastes and transports antibodies and lymphocytes to the blood

lymph organs

organs that trap pathogens (like the tonsils, pancreas and spleen

lymph nodes

structures that receive lymph and contain b and t cells that screen for antigens and mount specific immune responses when they are found

maturation process of b cells

cells that develop and mature in the bone marrow

production of antibodies

what is the major function of plasma b cells

compliment is activated, inflammation increases, bacterial toxins are neutralized, viruses/bacteria cannot attach to host cell, bacteria cannot divide by binary fission, phagocytosis increases, filtration by the spleen

What happens when compliment is activated

IgM

first antibody produced, indicates you just got the disease and is short lived

IgG

most abundant antibody, can cross the placenta

IgA

antibody that prevents attachment of bacteria and viruses to epithelial surfaces/transfers from mom to baby in colostrum

IgD

antibody that helps differentiate b cells into plasma or memory cells

IgE

antibody that causes cells to trigger an allergic response

primary antibody respose

response that occurs the first time the immune system encounters an antigen

secondary antibody response

the second and additional times the immune system encounters the same antigen. It is more rapid due to the presence of memory cells

maturation of t cells

they arise in the bone marrow and travel to the thymus to mature

Cytotoxic T cells

T cells that have a specific t cell receptor, a CD8 coreceptor and recognize and kill abnormal cells

Helper T cells

T cells that have a specific t cell receptor, a CD4 coreceptor, and aid in both humoral and cell mediated immunity

Class I

Type of major histocompatibility complex that is found on the surface of all cells except red blood cells and is recognized by cytotoxic t cells

Class II

Type of major histocompatibility complex that is found on the surface of antigen presenting cells and is recognized by helper t cells

After an initial exposure to a pathogen, there are cells created that recognize that same pathogen if seen again and mount a stronger attack

how does specific immunity have memory

Only one specific antibody will bind to an antigen, in the case of T cells, double recognition is needed

how is specific immunity specific

active immunity

type of immunity where the immune system responds to an antigen and produces memory b and t cells. It can be acquired naturally by infection or artificially via exposure to epitopes of an antigen in a vaccine

passive immunity

type of immunity that develops when an antibody enters the body from an outside space. it can be acquired naturally from mom to baby (as in IgG through the placenta or IgA thorough colostrum) or artificially through an antibody injection

generation of immunity

what is the goal of vaccination

herd immunity

a type of immunity that occurs when a significant proportion of a community has been vaccinated against a disease and that immunity confers protection on those who cannot be vaccinated

it requires 95% vaccination rate to be effective

what is the limitation of heard immunity

attenuated

type of vaccine where you are given a virus that has been weakened in a lab so it cannot cause infection/provides life long immunity

inactivated

type of vaccine where the pathogen that is injected has been killed using chemicals/heat or radiation

toxoid

type of vaccine where an inactivated bacterial exotoxin is administered and stimulates production of antibodies, and B an t cells that recognize the exotoxin

subunit

type of vaccine that is made from just a small piece of the antigen

conjugate

type of vaccine where the pathogen being prevented produces a glycocalyx and must be attached to a toxoid to be recognized as foreign

mRNA

type of vaccine in which an mRNA sequence for a virus is delivered inside a lipid sphere that once inside the body, disintegrates and the mRNA translates into a protein

suspending fluid

saline or sterile water vaccine component that contains the chemical used to weaken or kill a pathogen

stabilizers

substances in a vaccine that keep it from being altered when exposed to light/heat/acidity

preservatives

substances in a vaccine that control the growth of microbes during production/storage

adjuvants

substances in a vaccine that increase its effectiveness

1. the antigen binds to a specific b cell receptor

2. The B cell is activated and produces clones by mitosis

3. Some clones become memory cells and hang around in case the same antigen is detected in the future

4. Some clones become plasma cells and create antibodies to fight antigens

What are the steps in clonal activation of b cells

1. The antigen is phagocytized by an antigen presenting cell (APC) and sent to lysosomes to be broken into epitopes

2. The APC displays the epitope in the groove of MHC II cells

3. matching has to occur between the APC epitope in MHC II, the inactive T cell's receptor and the CD4 coreceptor

4. Helper T cell is activated and divides by mitosis to make clones: Some clones become memory cells and some secrete chemicals that activate other immune cells

How are helper T cells activated

1. The epitope in the groove of MHC I displays an "I am abnormal/I am infected" message and the correct inactive cytotoxic t cell to activate has to be found.

2. matching has to occur between the epitope in MHC I, the inactive cytotoxic T cell's receptor and the CD8 coreceptor

3. Cytotoxic T cells are activated: Some become memory cells and come become killing cells which kill more abnormal cells

How are cytotoxic T cells activated