Antigens & MHC Flashcards by Marlo Roque

Macromolecules capable of triggering an ____________ immune response by inducing the formation of antibodies or ______________ in an immunocompetent host

IMMUNOGENS
adaptive
sensitized T cells

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A substance that reacts with antibody or sensitized T cells but (may/may not) be able to evoke an immune response

ANTIGEN
may not

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T/F: All immunogens are antigens but not all antigens are immunogens

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The nature of the immunogen itself

All immunogens are antigens but not all antigens are immunogens

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_________ of MHC molecules that must combine with an __________ before T cells are able to respond

Genetic coding
immunogen

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Immunogen processing and presentation

All immunogens are antigens but not all antigens are immunogens

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FACTORS INFLUENCING IMMUNE RESPONSE

Age
Overall Health
Dose
Route of Inoculation
Genetic Capacity

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Older individuals are more likely to have a (increased/decreased) response to antigenic stimulation

AGE
decreased

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______ do not fully respond to immunogens, because their immune systems are not completely developed

AGE
Neonates

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Individuals who are ________, __________, or ________ are less likely to mount a successful immune response

OVERALL HEALTH
malnourished
fatigued
stressed

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A ____________, allows the innate immune response to take care of small amounts of pathogens and leave the ____________ response for pathogens that are present in large numbers

DOSE
threshold dose
adaptive

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Include ________(into a vein), ____________ (into the skin), ____________ (beneath the skin), and _______________

ROUTE OF INOCULATION

intravenous
intradermal
subcutaneous
oral administration

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Linked to the _____ and to the receptors generated during T and B lymphocyte development

GENETIC CAPACITY

MHC

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Enumerate the traits of immunogens

Macromolecular size
Chemical composition and molecular complexity
Foreignness
The ability to be processed and presented with MHC molecules

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Molecular weight of at least ___________ to be recognized by the immune system

MACROMOLECULAR SIZE
10,000

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and the best immunogens typically have a molecular weight of over _________________

MACROMOLECULAR SIZE
100,000 daltons

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The rule of thumb is that the (greater/smaller) the molecular weight, the more potent the molecule is as an immunogen

MACROMOLECULAR SIZE

greater

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__________ and ____________ are the best immunogens (amino acids)

CHEMICAL COMPOSITION AND MOLECULAR COMPLEXITY

Proteins
Polysaccharides

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______ recognize structures that project from the external surfaces of macromolecules

CHEMICAL COMPOSITION AND MOLECULAR COMPLEXITY

B cells

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Proteins have ___________ that also stimulate T cells, which is essential to generating T-cell help in antibody production

CHEMICAL COMPOSITION AND MOLECULAR COMPLEXITY

epitopes

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T/F: Carbohydrates are somewhat less immunogenic than protein - __________, or ___________

True

glycolipids
glycoproteins

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Example of glycolipids

A, B, and H blood group antigens

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Example of glycoproteins

Rh and Lewis antigens

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Pure ________ and _________ are not immunogenic by themselves

nucleic acids
lipids

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Pure nucleic acids and lipids are not immunogenic by themselves, although a response can be generated when they are attached to a suitable carrier molecule (______________)

DNA protein complex

Being able to distinguish between self and non-self,

Foreignness

T/F: those substances recognized as non- self are NOT immunogenic

F; they are immunogenic

Involves ______________ to create small peptides or pieces that can be complexed to MHC molecules to present to ______________

THE ABILITY TO BE PROCESSED AND PRESENTED WITH MHC MOLECULES enzymatic digestion responsive lymphocytes

Determinant site

EPITOPE

Molecular shapes or configurations that are recognized by __________ , may be repeating copies, or they may have differing specificities

EPITOPE B or T cells

Linear or conformational

EPITOPE

Surface antibody on B cells may react with both________ and ____________ epitopes present on the surface of an immunogen

EPITOPE RECOGNITION BY B CELLS linear conformational

Surface antibody on B cells may react with both________ and ____________ epitopes present on the surface of an immunogen

EPITOPE RECOGNITION BY B CELLS linear conformational

T cells recognize an epitope only as a part of a complex formed with _________ on the surface of an _________________

EPITOPE RECOGNITION BY T-CELLS MHC proteins antigen-presenting cell

Non-immunogenic materials that, when combined with a carrier, create new antigenic determinants

HAPTENS

May be complexed artificially with carrier molecules in a _____________, or this may occur naturally within a host and set off an ______________

HAPTENS laboratory setting immune response

Antigens that belong to the host

AUTOANTIGENS

These do not evoke an immune response under normal circumstances

AUTOANTIGENS

From other members of the host’s species

ALLOANTIGENS

Capable of eliciting an immune response

ALLOANTIGENS

Alloantigens are important to consider in _________________ and in __________________

tissue transplantation blood transfusions

From other species, such as other animals, plants, or microorganisms

HETEROANTIGENS

Are heteroantigens that exist in unrelated plants or animals but are either identical or closely related in structure so that antibody to one will cross-react with an antigen of the other

HETEROPHILE ANTIGENS

A substance administered with an immunogen that increases the immune response;

ADJUVANTS

acts by producing a ______________ that attracts a large number of immune system cells to the injection site

ADJUVANTS local inflammatory response

_________________ are the only ones approved for clinical use in the United States

ADJUVANTS Aluminum salts

these are used to complex with the immunogen to (decrease/increase) its size and to prevent a rapid escape from the tissues

ALUMINUM SALTS increase

It must be injected into the muscle to work

Aluminum salts

The ____________ vaccination is an example of using this type of adjuvant

ALUMINUM SALTS hepatitis B

are thought to enhance the immune response by prolonging the existence of immunogen in the area,

ADJUVANTS

(decreasing/increasing) the effective size of the immunogen, and (increasing/decreasing) the number of __________ involved in antigen processing

ADJUVANTS Increasing increasing macrphage

MAJOR HISTOCOMPATIBILITY COMPLEX MOLECULES formerly referred to as _____________________________

human leukocyte antigen (HLA)-Dausset

They determine whether transplanted tissue is histocompatible and thus accepted or recognized as foreign and rejected

MAJOR HISTOCOMPATIBILITY COMPLEX MOLECULES

MAJOR HISTOCOMPATIBILITY COMPLEX MOLECULES Main function: Bring _______ to the ______________ for recognition by T cells, because T-cell activation will occur only when antigen is combined with ____________

antigen cell surface MHC molecules

T/F: MHC molecules are NOT relevant

FALSE; they ARE relevant

MHC molecules are relevant because they may be involved in _________________, ____________________, and _________________

transfusion reactions graft rejection autoimmune diseases

Genes controlling ____________ of these molecules are actually a system of genes known as the major histocompatibility complex

expression

Genes coding for the MHC molecules in humans are found on the short arm of chromosome __ and are divided into _____ categories or classes

chromosome 6 three

molecules are coded for at three different locations or loci, termed A, B, and C

CLASS I

genes are situated in the __ region, and there are several different loci known as __, __, and __

CLASS II D DR DQ DP

There is a gene that codes for the alpha chain and one or more genes that code for the beta chain

CLASS II

coded between the class I and class II regions on chromosome,

CLASS III

codes for complement proteins and cytokines such as _________________________

CLASS III tumor necrosis factor

Expressed on all nucleated cells

Structure of Class I

Highest on ______________ and low or undetected on_________________, _____________, _____________, and _________

CLASS I lymphocytes liver hepatocytes neural cells muscle cells sperm

CLASS I The alpha chain has a molecular weight of ____________

45,000

CLASS I A lighter chain associated with it, called a ________________, has a molecular weight of ___________ (alpha chain domains – a1, a2, a3)

beta2- microglobulin 12,000

reacts with CD8 on cytotoxic T cells

Found primarily on antigen-presenting cells, which include _____________, __________, _____________, and ___________

CLASS II B lymphocytes monocytes macrophages dendritic cells

CLASS II _____ is expressed at the highest level, as it accounts for about _____ of all the class II molecules on a particular cell

DR one-half

CLASS II The DR gene is the most highly (dimorphic/ polymorphic) as ___ different alleles are known at this time

polymorphic 18

CLASS II Both the chain, with a molecular weight of __________, and the chain, with a molecular weight of__________, are anchored to the __________________

33,000 27,000 cell membrane

Role of MHC Class I and Class II To bind __________ within cells and transport them to the ___________, where T cells can recognize them in the phenomenon known as _____________

peptides plasma membrane antigen presentation

Mainly present peptides that have been synthesized within the cell to_______ (cytotoxic) T cells

CLASS I CD8

The watchdogs of viral, tumor, and certain parasitic antigens that are synthesized within the cell

CLASS I

Display of hundreds of __________ molecules complexed to antigen allows CD8+T cells to continuously check cell surfaces for the presence of ____________

CLASS I class I non-self-antigens

If it recognizes an antigen as being foreign, the CD8+T cell produces _______ that causes ___________ of the entire cell

CLASS I cytokines lysis

Present antigen to CD4 (helper) T cells

CLASS II

Mainly bind ________________ proteins – those taken into the cell from the outside and degraded

CLASS II exogenous

Stimulate ___________ in the case of bacterial infections or the presence of other material that is endocytosed by the cell

CLASS II CD4 T cells

On the cell surface, ___________ molecules are responsible for forming a _____________ that occurs between ________, ____________, and an _______________________

CLASS II Class II trimolecular complex antigen class II molecule appropriate T-cell receptor

If binding occurs with a T-cell receptor on a CD4+T cell, the T helper cell recruits and triggers a _______________ resulting in ________________

CLASS II B-cell response Antibody formation

Antigens & MHC Flashcards

(82 cards)