Term
| In what two forms are Ab's found? |
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Definition
| Attached to B-cell membranes or Secreted by Plasma cells |
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Term
| T/F Edelman & Porter used ultracentrifugation, Papain digestion, Pepsin digestion, & Mercaptoethanol to break down IgG and discover it's structure. |
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Definition
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Term
| What connects the heavy and light chains of IgG? |
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Definition
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Term
| On what end of the light chain do you find the constant & variable regions? In which region do you find kappa or lambda types? |
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Definition
Constant: C-terminal, kappa & lambda
Variable: N-terminal |
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Term
| How many basic sequence patterns are found on the heavy chain constant region? |
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Definition
|
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Term
| What defines the isotype of an Ab? |
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Definition
| The heavy chain type (IgM, IgG, IgA, IgD, IgE) |
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Term
| What are the Ag-binding sites of Abs, and where are they found? |
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Definition
| Hypervariable or Complementary-Determining Regions; on the variable portion of the heavy & light chains |
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Term
| T/F CDR's are not found adjacent on the primary structure, but they are adjacent in the secondary structure. |
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Definition
| True; they fold to be in the same area |
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|
Term
| What is the term for the Ag Determinant binding site? |
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Definition
|
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Term
| What gives the Hinge region its flexibility, what is it susceptible to, and in what Ig's is it found? |
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Definition
| Flexibility - Proline Residues; Susceptible - Proteolytic Enzymes; IgG, IgD, and IgA |
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Term
| What is the most abundant Ig in serum? What is its structure? |
|
Definition
| IgG; monomer of 2γ H-Chains and 2κ or λ L-Chains |
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|
Term
| How many subclasses does IgG have & what makes them different? |
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Definition
| 4 (numbered by their serum concentration); size of hinge region & number and position of interchain S-S bonds b/w H-chains |
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|
Term
| Which Immunoglobulin molecule is pentameric and has 10 potential Ag-binding sites? |
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Definition
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Term
| Which Ab is the first produced during primary immune response and is the Ag receptor on B cells? |
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Definition
|
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Term
| What is the predominant Ig class in mucosal secretions? In what forms does it exist? |
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Definition
| IgA; monomeric in serum & dimeric/tetrameric in secretions |
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Term
| What is the main effector Ab in mucosal secretions, and how is it formed? |
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Definition
| S-IgA; IgA binds pIgR and is internalized, a portion is then cleaved leaving the other portion bound to IgA which forms S-IgA |
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Term
| Which type of Ab mediates Type 1 hypersensitivity reactions and binds Fc receptor of basophils & mast cells? |
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Definition
|
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Term
| What induces degranulation and releases histamine? |
|
Definition
| Cross-linking or receptor bound IgE by Ag |
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Term
| Which two Immunoglobulins are membrane-bound and co-expressed on mature B cells? |
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Definition
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Term
| T/F Multiple Ab's can recognize the same Ag because there are many different epitopes on a single Ag. |
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Definition
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Term
| What is the Ab response to an Ag which induces a mixture of Abs to one Ag? What does this result in? |
|
Definition
| Polyclonal Ab Response; Ab heterogeneity = increases immune protection |
|
|
Term
| What is the Ab response to a single epitope? |
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Definition
|
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Term
| T/F It is feasible to purify monoclonal Ab from polyclonal Ab. |
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Definition
| False; it is NOT feasible |
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|
Term
| What two cells are fused in the preparation of mAbs? |
|
Definition
| Ab-producing B cell & plasmacytoma |
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|
Term
| Describe the Ag-Ab Interaction. |
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Definition
| Reversible & Non-covalent Van der Waals interactions |
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|
Term
| What is defined as the measure of the strength of the binding ease of association or dissociation? |
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Definition
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|
Term
| What is defined as an increase in affinity due to multivalent binding or the summation of multiple affinities? |
|
Definition
|
|
Term
| What is a substance able to generate antibody or T cell responses? |
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Definition
|
|
Term
| What are the three most important characteristics of a good antigen? |
|
Definition
Size: larger is better
Chemical Composition: Proteins > Carbohydrates > Lipids
Similarity to self-antigens: multiple differences are better |
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|
Term
| What is an important characteristic for T cell Ag response? |
|
Definition
|
|
Term
| What is the term for a Non-immunogenic substance, usually low molecular weight, that can induce Ab formation when coupled to a larger "carrier" molecule? |
|
Definition
|
|
Term
| Which three Hapten examples can you make monoclonal Ab's to? |
|
Definition
| Cortisol, Estradiol, & Testosterone |
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|
Term
| What is the term for Ab's binding Ag's & sticking together? |
|
Definition
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Term
| T/F Antibodies can inhibit attachment of bacteria to cells. |
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Definition
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|
Term
| What does a bacteria tagged with Ab's bind to on the macrophage cell surface? |
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Definition
|
|
Term
| What is the term for any molecule that acts as a binding enhancer for the process of phagocytosis? |
|
Definition
| Opsonization (via Fc Receptor) |
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|
Term
| Is it typical to find a peptide on an MHC? What are the two possibilities for it? |
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Definition
| Always has a peptide; usually from self, but if it is a foreign peptide it alerts T cells |
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|
Term
| What are the four good Ag-Ab reactions In Vivo? |
|
Definition
| Neutralization, Opsonization, Complement Lysis, & Prevention of Adherence |
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|
Term
| What test is used to see if a person has been infected with a virus such as HIV? |
|
Definition
| Enzyme Linked ImmunoSorbent Assay (ELISA); first line assay/preliminary test |
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Term
| After an ELISA test is preformed what is done to determine which viral G's the patient has made Ab's to? |
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Definition
| Western Blot (second line assay) |
|
|
Term
| Is it possible to have Ab's without being exposed to a particular virus? |
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Definition
| Yes, because some viral Ag's are cross-reactive |
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|
Term
| What is screened for in a pregnancy test? |
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Definition
| Human Chorionic Gonadotrophin; prevents Ab's from agglutinating |
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|
Term
| After Ab binds Ag, the outcome depends on what? What determines effector functions? |
|
Definition
| Constant region of the heavy chain; Ab isotype |
|
|
Term
| At what level does diversity operate? |
|
Definition
|
|
Term
| What causes isotype switching? |
|
Definition
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Term
| Describe the parts found in an original DNA sequence. (as it relates to isotype switching) |
|
Definition
| Leading Region, Variable Regions, Joining Regions, Constant Regions, and Introns |
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|
Term
| Describe the parts of an mRNA strand. |
|
Definition
| Leading region, Variable region, and Constant region (no introns) |
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|
Term
| What is the process of splicing together segments of genes in order to generate tremendous diversity without monopolizing the genome? |
|
Definition
| Ig or TCR gene rearrangement |
|
|
Term
| What are the segments found in light chains? |
|
Definition
| κ and λ light chains each have; Leading, Variable, Joining, and Constant |
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|
Term
| What are the segments found in heavy chains? |
|
Definition
| Leading, Variable, Diversity, Joining, and Constant |
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|
Term
| Describe the mechanism of Immunoglobulin Gene Recombination. |
|
Definition
| (also called Somatic Recombination) Gene segment forms a loop that is then excised leaving the outer portions adjacent to each other |
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|
Term
| T/F Cells continue to proliferate between each step in Somatic Recombination resulting in even more possibilities for differentiation. |
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Definition
|
|
Term
| How many possible Ab's can be made? How many different Ab's are produced by each B cell or plasma cell? |
|
Definition
|
|
Term
| What regulates Isotype Switching by Somatic Recombination? |
|
Definition
| cytokines produced by T cells (T cells regulate B cells) |
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|
Term
| T/F Cells that do not undergo isotype switching may still respond to Ag. |
|
Definition
| False; only cells that switch will respond to Ag |
|
|
Term
| In what order and what amounts are the immunoglobulins produced in a Primary Response? |
|
Definition
| IgM followed by IgG in approximately equal quantities |
|
|
Term
| In what order and in what amounts are different isotypes expressed in a secondary response? |
|
Definition
| IgM and IgG about the same time; much more IgG than IgM (b/c cell remembers how to make IgG) |
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|
Term
| What is the Ag-binding portion of the T Cell Receptor? |
|
Definition
| Variable alpha & beta regions |
|
|
Term
| Can TCR exist in secreted form? |
|
Definition
| No, only as a transmembrane Ag receptor |
|
|
Term
| In what organ do TCR's undergo somatic gene recombination? |
|
Definition
|
|
Term
| What are the parts of the gene segment that codes for TCR variable region? |
|
Definition
| Variable, Joining, Constant |
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|
Term
| Can B cells recognize intact protein Ag's? What about T cells? |
|
Definition
| B cells - Yes; T cells - No (must be degraded) |
|
|
Term
| What results in autoreactive B and T cells that are not eliminated? |
|
Definition
|
|
Term
| What can result from chromosomal translocations arising during VDJ recombination or isotype switching? |
|
Definition
|
|
Term
| What are the major differences between B & T cell Ag Receptors? |
|
Definition
B cell: Immunoglobulin, B cell Transmembrane protein, plasma secreted effector
T cell: TCR, T cell Transmembrane protein, CD4 Th, CD8 Tc |
|
|
Term
| Where are proteins denatured to be presented? What denatures them? |
|
Definition
|
|
Term
| T/F B cell antibodies can operate at a distance. |
|
Definition
|
|
Term
| Do B cells recognize intact Ag's or bound peptides? What about T cells? |
|
Definition
| B cells: Intact Ag's T cells: degraded peptides on MHC |
|
|
Term
| T/F Ag-specific T cell function requires MHC contact, but does not require cell-to-cell interaction. |
|
Definition
| False; requires MHC and cell-to-cell contact |
|
|
Term
| What cells express MHC Class I? To which cells do they present? |
|
Definition
| All nucleated cells; CD8 T cells (Cytotoxic killer cells and kills virus infected cells) |
|
|
Term
| What cell have MHC Class II and to what cells do they present? |
|
Definition
| APC's (dendritic cells, B cells, MQ's); CD4 T cells (T helper cells) |
|
|
Term
| What occurs after T helper cells are activated? |
|
Definition
| B cells proliferate, differentiate, & isotype switch and help activate MQ's to kill intracellular pathogens |
|
|
Term
| How do CD4 T cells help B cells? |
|
Definition
| T & B cell form very close contact and T cell secretes IL-4 into the pocket b/w the cells to induce isotype switching in the B cell |
|
|
Term
| Is it possible for a B cell to express MHC class I and class II? |
|
Definition
| Yes; if it is presenting an Ag |
|
|
Term
| Describe T cell screening. |
|
Definition
| T cells go from cell to cell scanning the self-peptides on MHC Class I until it finds an MHC Class II with foreign Ag |
|
|
Term
| Is the peptide binding cleft found on the membrane proximal or distal domain of MHC classes I and II? |
|
Definition
|
|
Term
| In what portion of the MHC does the peptide sit? How does it differ between class I and II? |
|
Definition
| Beta Sheets; MHC class I is surrounded on all sides by the MHC, Class II runs the full lenth of the MHC |
|
|
Term
| How does the structure of MHC differ between classes I and II? What are the subclasses of each? |
|
Definition
Class I: 3 α and 1 β chain with A, B, & C types
Class II: 2 α and 2 β chains with DP, DQ, & DR types |
|
|
Term
| What is described as allelic variation in MHC genes and is concentrated in the peptide binding regions of Class I and Class II? |
|
Definition
|
|
Term
| How many MHC genes does each individual inherit? |
|
Definition
| 9 maternal and 9 paternal |
|
|
Term
| What are the consequences of MHC Polymorphism? |
|
Definition
| Organ tissue transplants are difficult; change peptide binding specificity of MHC; pathogens could mutate to avoid immune detection by MHC's |
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