Question | Answer |
Adaptive immunity | has a very diverse array of antigen specificities |
The CD protein on all T lymphocytes | CD3 |
The common myeloid progenitor gives rise to | macrophages |
Which is a primary lymphoid tissue? | Thymus |
The secondary antibody response | no lag phase in antibody production |
M cell | specialized epithelial cell overlying GALT that delivers bacteria across the gut epithelium |
In addition to antibody, this protein can initiate binding and complement activation via the classical pathway | C-reactive protein (CRP) |
The complement fragment that provides the greatest amount of amplification of the complement cascade is | C3b |
Protein that coats a pathogen surface targeting the pathogen for phagocytosis | opsonin |
Properdin (Factor P) enhances complement system activation by | binding to C3bBb |
Which receptors present on macrophages are NOT used to initiate phagocytosis? | Toll-like receptors |
Septic shock is a direct effect of macrophage overproduction of cytokine | TNF-α |
Acute phase response primarily increases production of what proteins by the liver? | Complement CRP and MBL |
Type I interferons are used to combat | viral infections. |
The effector T lymphocytes designated as T helper cells are identified by what T cell co-receptor molecule? | CD4 |
Which protein domain functions in antigen binding? | TCRα variable domain |
Transfer of protective immunity from one individual to another in the form of preexisting antibody is called | passive immunity |
It would be correct to say that there are 3 CDR within the hypervariable region of an immunoglobulin heavy chain | TRUE |
The correct description of the “immunoglobulin-like” domain in a protein | two anti-parallel β-sheets held together by a disulfide bond |
The two C gene segments closest to the variable gene segments in immunoglobulin heavy chain locus | Cμ and Cδ |
The “12/23” rule is utilized in the process of | somatic recombination |
Which process uses alternative RNA processing to occur? | The production of membrane-bound vs. secreted immunoglobulin |
Sensitizes mast cells | IgE |
Highest concentration in mucus | IgA |
Most abundant in serum and body fluids | IgG |
Junctional diversity is used in the formation of | both TCR and BCR |
Which protein domain forms a portion of a TCR? | Vβ |
Which CD protein is found on the surface of γδ T lymphocytes? | CD3 only |
Which T cell co-receptor molecule associates a TCR with MHC Class I? | CD8 |
Which protein is involved in antigen processing and proper MHC Class II peptide loading? | HLA-DM |
The monomeric protein(s) that pair(s) with MHC Class I α chains to form the MHC Class I heterodimer is/are | β2-microglobulin |
Antigen cross-presentation refers to presentation of peptides derived from | exogenous virus proteins within MHC Class I molecules. |
Which can result from transplantation of bone marrow to an HLA-mismatched recipient? | Graft vs. Host Disease (the transplanted bone marrow cells give rise to mature effector B and T cells that “see” the new host as foreign and attack it) |
How is MHC peptide-binding diversity generated within an individual? | Degenerate peptide binding |
Most humans express _ HLA Class I isoforms and _ HLA Class II isoforms. | 6,6 |
Why is IgM secreted as a pentamer instead of a monomer? | It provides 10 antigen-binding sites to compensate for the low affinity of each individual antigen-binding site. (=higher avidity) |
Antibody isotype is a synonym for antibody | class |
Describe what is meant by respiratory burst | Consumption of oxygen by a phagocytic cell to drive the electron transport chain which pumps H+ out of the phagosome, raising the pH, and activating neutral proteases within granules that fuse to the phagosomes |
The surrogate light chain is composed of | VpreB + λ5 |
Stromal cells that are essential for B lymphocyte development are located in the | bone marrow |
The primary antibody isotype secreted by B-1 B lymphocytes is | IgM |
Which cell is NOT normally present in a germinal center? | plasma cell |
Which represents the normal path of a B lymphocyte that does not become activated by its antigen in a lymph node? | HEV->T cell zone->primary lymphoid follicle->efferent lymph vessel |
What cell interaction triggers isotype switching and somatic hypermutation by a B lymphocyte? | Stimulation by a T helper cell |
Binding to soluble self-antigen in the bone marrow will cause a B lymphocyte to undergo: | clonal anergy |
The molecule produced by FDC that provides periodic survival signals for naïve mature B lymphocytes is | BAFF |
What cell type is found throughout the thymus? | Macrophages |
After birth, what percent of thymocytes end up becoming αβ T cells? | 90% |
A double-positive thymocyte expresses both | CD4 and CD8 |
What T lymphocyte receptor gene loci begin rearranging following successful pre-TCR formation? | α, β, and δ |
B cells undergo | negative selection only |
The cell that accomplishes positive selection of T lymphocytes in the thymus is: | cortical thymic epithelial cells |
Central tolerance of T lymphocytes is essentially the same as _______ within the thymus. | Negative selection |
The important effector role of T helper 1 cells is | provide help to activate macrophages |
This protein becomes expressed on activated T lymphocytes late in a response to antigen and provides a negative signal to the T cell to shut down the immune response | CTLA-4 |
What is the main factor that determines the ultimate effector phenotype a CD4+ T cell will choose once activated by antigen? | The cytokines present during the antigen-activation process. |
The signature cytokine secreted by T helper 1 cells is | IFN-γ |
Soluble protein antigens represent the vast majority of foreign antigens presented by this antigen-presenting cell | B lymphocytes |
The three main cells that accomplish cell-mediated immunity are | Th1, macrophages, Tc |
FasL has a primary role in | induction of apoptosis |
What cell(s) express(es) CD40L? | both Th1 and Th2 |
What cytokine is very important in viral immunity? | IFN-γ |
The Tc lytic granule proteins that polymerize to form the pore in a target cell membrane are | perforins |
Which of the following effector T cells would stay in secondary lymphoid tissues instead of travelling to the site of infection? | Th2 |
The cytokine required for differentiation of FDC is | LT |
The cell-surface molecule on a helper T cell that is critical for driving T-dependent antibody responses: | CD40L |
An antigen that contains a TLR ligand would be classified as what kind of antigen in regard to B lymphocyte activation? | T-independent 1 (TI-1) antigen |
Which of the following is NOT a normal function of FDC? | Antigen presentation |
The relative order of antibody isotype production comparable to adult levels by a child (newborn to 5 years) is | IgM, then IgG, then IgA |
The protein necessary to produce IgA as a dimer is | J-chain |
This FcR triggers granule exocytosis of mast cells when antigen binds | FcεRI |
This FcR transports IgG across capillary endothelium into tissues: | FcRn |
What receptor on RBC allows them to remove immune complexes from blood plasma? | CR1 |
List the four cell types that are minimally required to allow a T-dependent antibody response to occur. | Dendritic cell, Th, B cell, follicular dendritic cell |
Describe the two-signal hypothesis of T cell activation. (Be specific!) | Both signals are required for naïve T cell activation:Both signals are required for naïve T cell activation:
1) TCR – MHC I peptide complex
2) CD28 stimulated by B7 |
What is thymic involution? | Loss of thymic production of T lymphocytes with age; thymic lobules fill with fat tissue. |
Explain why Ig light chain rearrangement has a higher rate of success than Ig heavy chain rearrangement | 1) Light chain is simpler: only V-J for light chain, while heavy is V-D-J.
2) More loci available to attempt rearrangement for light chain because we have κ and λ that both can make light chain, while the heavy chain only has one locus. |
Which of the following chemokine receptors is responsible for the homing of lymphocytes to the skin? | CCR4 |
Which of the following functions of antibody is performed by dimeric IgA produced in mucosal sites? | Neutralization |
Which of the following best describes how the immune system compensates for a lack of mucosal IgA in “Selective IgA Deficiency”? | IgM is transported across the mucosal epithelium by the poly-Ig receptor. |
Which of the following is NOT a characteristic of gut IELs? | A rare cell, present at a rate of only 1 per 100 epithelial cells. |
Which of the following Th2 cytokines benefits immune responses to gut parasite infections by causing B cell isotype switching to IgE to arm Mast cells and other granulocytes? | IL-4 |
The primary function of “central memory cells” is to: | Provide T cell help to B cells within secondary lymphoid tissues |
Where are Vγ9:Vδ2 T cells are located in the body of an adult? | Peripheral blood, in circulation |
In general, what is the “ligand” recognized by most NK cell inhibitory receptors? | Self-MHC class I |
CD1a, CD1b, and CD1c molecules present lipids to activate: | T lymphocytes possessing αβ TCR with CD4 or CD8 T cell co-receptor |
B lymphocyte defect: | Susceptible to extracellular pyogenic bacterial infections |
Severe combined immunodeficiency (SCID): | Susceptible to ALL infectious agents (bacteria, viruses, fungi, and parasites) |
MHC class I deficiency: | Susceptible to ALL virus infections |
Complement component C7 deficiency: | Susceptible to Neisseria spp. Bacterial infections |
Which of the following tests would be most useful in diagnosing a defect in phagocyte migration (aka Leukocyte Adhesion Deficiency)? | Neutrophil expression of CD11a, CD11b, CD11c, and CD18 by flow cytometry |
AIDS due to HIV infection is classified as: | Secondary immunodeficiency |
What is the function of HIV protein gp41? | Causes fusion of virus envelope with host cell membrane |
Which strain of HIV is more common in the US? | HIV-1 |
How long is the “latent phase” of acute HIV infection? | 2-6 weeks |
An HIV infection is usually acquired with which “form” of HIV virus? | Macrophage-tropic |
An individual is infected with HIV, but when tested for HIV infection their test result is negative. This would be called: | A false negative test |
“Study of the non-cellular components in blood” is the definition of: | Serology |
The confirmatory test for HIV diagnosis in a high-risk adult is: | HIV Western Blot |
Which of the following tests is recommended for diagnosis of congenital HIV in a newborn? | HIV viral RNA test |
The HIV p24 antigen test is NOT recommended for: | Monitoring adult patient response to HAART anti-retroviral therapy |
An EIA test kit designed to detect a patient antibody response to HIV must contain which of the following reagents in the test kit? | HIV protein antigen bound to the inside of the test well |
What is the best explanation for how the HIV Western Blot adds specificity to HIV infection diagnosis? | It requires patient antibody responses to a minimum of two specific HIV proteins to be considered positive |
A physician orders an HIV EIA test on a high risk adult patient and the initial test is positive. The next appropriate step to be taken by laboratory personnel is: | Repeat the EIA test in duplicate with the same serum sample. |
The best definition of Hepatitis is: | Inflammation of the liver, due to any cause (infection, toxicity, etc.) |
The main health concern associated with most viral hepatitis is: | Chronic hepatitis leading to cirrhosis and/or liver cancer decades later. |
In general, in the case of infectious disease, which of the following would indicate resolution of acute infection and/or immunity? | Positive test for IgG antibody to the organism |
This hepatitis virus is transmitted by the parenteral route: | HCV |
This hepatitis virus only causes acute hepatitis and does not cause chronic disease: | HAV |
What percentage of infants infected with HBV will develop chronic infection? | 90% |
Presence of which of the following would indicate ongoing acute HBV infection and high virus production? | HBeAg |
A patient presents to his physician with signs of acute hepatitis. The physician orders an “Acute Hepatitis Panel.”
IgM anti-HAV negative
HBsAg negative
Anti-HCV positive
The best interpretation of these results is: | The patient has Hepatitis C infection, but this should be confirmed with the HCV RIBA test |
Describe how “protective immunity” and “immunological memory” differ | Protective immunity is short-lived (2-3 months) and provides protection against reinfection due to circulating neutralizing antibody. Immunologic memory lasts years to decades and is a rapid (1 day) response to reinfection due to memory B and T cells. |
In general, identify how γδ T cells, NK cells, and NKT cells differ from classic αβ T cells in their antigen recognition. | Classic αβ T cells must be presented peptide antigens within MHC class I or II molecules. γδ T cells, NK cells, and NKT cells see lipid antigens, phosphoantigens, and other non-peptide antigens not presented in MHC-I or II. |
Why is HAART drug therapy used in HIV infection instead of single drug therapy? | HIV rapidly becomes resistant to single drug therapy b/c of the lack of proofreading of HIV reverse transcriptase enzyme induces rapid mutations in HIV genes. |