ANTIGENS & ANTIBODIES Flashcards
Macromolecules that is capable triggering an adaptive immune response by inducing formation of antibodies or sensitized T- cells of an immunocompetent host
Immunogen
Can evoke an immune response
Immunogen
An immunogen enters the body, the naive T and B cells will be sensitized forming the ________
Antibody
Substance that reacts with antibody or sensitized T cells but may not evoke an immune response
Antigen
Can only bind sensitized T cells or antibody, not capable of sensitizing T and B cells (no reaction)
Antigen
TRUE OR FALSE
If there is a specific antibody present in the body, it will be able to bind with the antigen
True
Ability to induce a humoral and/or cell-mediated immune response
Immunogenicity
Ability to combine specifically with the final products of the immune response
Antigenicity
Antigenicity:
Final products- secreted antibodies and/or surface
receptors on _____
T-cells
Factors Influencing Immune Response: AGE
1. decreased response to antigenic stimulation and they are considered as immunocompromised (weak immune system)
Elderly
Factors Influencing Immune Response: AGE
Their immune system is not completely developed
Neonates
Factors Influencing Immune Response: Age NEONATES
a. Pediatricians monitor closely neonates that get sick from _____________
b. Even a simple fever can be fatal
c. Their immune system is not yet capable of defending itself
d. As compared to adults or teens- stronger immunity
a. 0-3 months old
Factors Influencing Immune Response: Overall-Health
the immune system won’t work well if the body
does not receive the enough nutrition that it needs (especially here in the Philippines and children)
Malnutrition
What are the Factors Influencing Immune Response?
Age
Overall health
Dose
Route of inoculation
Genetic Capacity
Factors Influencing Immune Response: DOSE
a. Generally, the larger the amount of an immunogen one is exposed to, the ________ the immune response
b. Exceptions: pathogens that are very _______
c. Some bacteria, even in the slightest exposure or small dose of bacteria, can already illicit an immune response
a. greater
b. immunogenic
Factors Influencing Immune Response: Route of Inoculation
Into a vein
Intravenous
Factors Influencing Immune Response: Route of Inoculation
The fastest route of entry of an immunogen because it will enter directly into the bloodstream
Intravenous
Factors Influencing Immune Response: Route of Inoculation
Into the skin
Intradermal
Factors Influencing Immune Response: Route of Inoculation
Beneath the skin / tissue
Subcutaneous
Factors Influencing Immune Response: Route of Inoculation
The route where the immunogen enters the body also determines which cell populations will be involved in the response
Oral contact
Factors Influencing Immune Response: Route of Inoculation
a. What is the primary organ to fight off the immunogen in Intravenous route?
b. Subcutaneous is in the ___________ (located in the
armpit, neck or groin)
a. Spleen
b. local lymph nodes
Factors Influencing Immune Response: Genetic Capacity
Linked to _________________________________ and to receptors generated during T and B lymphocyte development
MHC (Major Histocompatibility Complex)
Factors Influencing Immune Response: Genetic Capacity
system of genes that code for cell surface molecules that play an important role in antigen recognition. It has also something to do with transplantation
MHC
TRUE OR FALSE:
greater the molecular weight, the more
potent the molecule to induce an immune response
True
What are the potent stimulus?
Bacteria, parasites, viruses, fungi
These 2 are the best immunogens
Proteins and polysaccharides
Less immunogenic
Carbohydrates
Least immunogenic
Lipid and nucleic acids
must be attached to a carrier particle before being an immunogen
Lipids and nucleic acids
may be repeating copies or they may have differing specificity
Epitopes
amino acids following one another on a single chain
SEQUENTIAL OR LINEAR EPITOPES
results from the folding of one chain or multiple chains, bringing certain amino acids from different segments of a linear sequence or sequences into close proximity with each other so they can be recognized together
CONFORMATIONAL OR DISCONTINUOUS EPITOPE
RECOGNITION OF EPITOPES BY B CELLS:
React with both _____ and ______________ present
on the surface of an immunogen
linear and conformational epitopes
It is direct and can trigger B cell activation
Recognition of Epitopes by B cells
RECOGNITION OF EPITOPES BY T CELLS
Able to recognize an immunogen it must first be degraded into small peptides by a/ an
antigen-presenting cell (APC)
RECOGNITION OF EPITOPES BY T CELLS:
Must undergo __________ first
phagocytosis
RECOGNITION OF EPITOPES BY T CELLS:
Peptides form a complex with _________ and are carries to the surface of the APC before being recognized by the T cells
MHC proteins
Example are dendritic cells
RECOGNITION OF EPITOPES BY T CELLS
Small organic compound that are antigenic but not
immunogenic
Haptens
HAPTENS:
Capable of reaction with antibody however precipitation or agglutination will not occur
a. reactions that we observe in the serology laboratory indicating an antigen-antibody reaction
a. Precipitation/ agglutination
HAPTENS:
Coupling to a carrier: ________________ this complex is considered as an immunogen
hapten- carrier conjugate
Haptens will bind to the _______________
B cell receptor
form a bridge producing a stronger reaction
Cross-linking
He wrote the specificity of serological reactions
KARL LANDSTEINER
His contribution is the Study on haptens
KARL LANDSTEINER
He Immunized rabbits with haptens attached to a carrier molecule
KARL LANDSTEINER
He discovered that antibodies not only recognize chemical features such as polarity, hydrophobicity, and ionic charge, but the overall three-dimensional configuration is also important.
a. Most proteins are three-dimensional- made up of ________ and ___________, making them more
complex in structures and the best immunogen
KARL LANDSTEINER
a. Amino acid and cholesterol