12.E: Introduction to Adaptive Immunity (Exercises)

These are homework exercises to accompany Kaiser's "Microbiology" TextMap. Microbiology is the study of microorganisms, which are defined as any microscopic organism that comprises either a single cell (unicellular), cell clusters or no cell at all (acellular). This includes eukaryotes, such as fungi and protists, and prokaryotes. Viruses and prions, though not strictly classed as living organisms, are also studied.

12.1: An Overview of Innate and Adaptive Immunity

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1. Describe what is meant by the following:
   1. innate immunity (ans)
   2. adaptive (acquired) immunity (ans)
2. Define the following:
   1. antigen (ans)
   2. immunogen (ans)
   3. epitope (ans)
   4. humoral immunity (ans)
   5. cell-mediated immunity (ans)

12.2: Antigens and Epitopes

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1. Match the following:

   _____ Asubstance that reacts with antibody molecules and antigen receptors on lymphocytes. (ans)

   _____ An antigen that is recognized by the body as non-self and stimulates an adaptive immune response. (ans)

   _____ The actual portions or fragments of an antigen that react with receptors on B-lymphocytes and T-lymphocytes as well as with free antibody molecules. (ans)

   _____ An antibody molecule composed of 4 glycoprotein chains whose Fc portion is anchored to the membrane of certain lymphocytes; able to recognize epitopes on protein and polysaccharide antigens. (ans)

   _____ A molecule composed of 2 glycoprotein chains anchored to the membrane of certain lymphocytes; able to recognize peptide epitopes from protein antigens presented by the body's own cells by way of MHC molecules. (ans)

   _____ Antigens are proteins found within the cytosol of human cells such as viral proteins, proteins from intracellular bacteria, and tumor antigens. (ans)

   _____ An organism’s own antigens (self-antigens) that stimulate an autoimmune reaction. (ans)

   _____ Antigens that enter from outside the body, such as bacteria, fungi, protozoa, and free viruses. (ans)

   1. B-cell receptor
   2. T-cell receptor
   3. immunogen
   4. hapten
   5. epitope
   6. antigen
   7. autoantigens
   8. endogenous antigens
   9. exogenous antigens.
2. Briefly describe how the body recognizes an antigen as foreign. (ans)
3. In terms of infectious diseases, describe 2 categories of microbial materials that may act as an antigen.
   1. (ans)
   2. (ans)
4. Describe 3 groups of noninfectious materials that may act as an antigen.
   1. (ans)
   2. (ans)
   3. (ans)
5. Multiple Choice (ans)

12.3: Major Cells and Key Cell Surface Molecules Involved in Adaptive Immune Responses

12.3A: Major Histocompatibility Complex (MHC) Molecules

12.3B: Antigen-Presenting Cells (APCs)

Study the material in this section and then write out the answers to these questions. Do not just click on the answers and write them out. This will not test your understanding of this tutorial.

1. Match the following in terms of antigen-presenting dendritic cells presenting antigens to naive T4-lymphocytes:

   _____ Dendritic cells engulf ____________ antigens. (ans)

   _____ Once engulfed by dendritic cells, protein antigens are degraded into peptides by organelles called ____________. (ans)

   _____ Dendritic cells bind peptides to grooves in _________________. (ans)

   _____ The dendritic cell then presents the MHC/peptide complex to the ___________________. (ans)

   _____ Dendritic cells produce co-stimulatory signals after pathogen-associated molecular patterns bind to ___________________. (ans)

   1. TCR of T4-lymphocytes
   2. TCR of T8-lymphocytes
   3. MHC-I molecules
   4. MHC-II molecules
   5. exogenous
   6. endogenous
   7. toll-like receptors
   8. lysosomes
   9. proteasomes
   10. cytosol
2. Match the following in terms of ntigen-presenting dendritic cells presenting antigens to naive T8-lymphocytes:

   _____ Dendritic cells engulf ____________ antigens. (ans)

   _____ Once engulfed by dendritic cells, protein antigens are degraded into peptides by organelles called ____________. (ans)

   _____ Some proteins escape from phagosomes and phagolysosomes into the ____________. (ans)

   _____ Once in the cytosol, protein antigens are degraded into peptides by organelles called ____________. (ans)

   _____ Dendritic cells then bind peptides to grooves in _________________. (ans)

   _____ The Dendritic cell then presents the MHC/peptide complex to the ___________________. (ans)

   1. TCR of T4-lymphocytes
   2. TCR of T8-lymphocytes
   3. MHC-I molecules
   4. MHC-II molecules
   5. exogenous
   6. endogenous
   7. toll-like receptors
   8. lysosomes
   9. proteasomes
   10. cytosol
3. Name the primary type of cell that functions as an antigen-presenting cell to naive T4-lymphocytes and naive T8-lymphocytes. (ans)
4. State the role of T4-effector cells in activating macrophages (ans) .
5. State the role of T4-effector cells in the proliferation and differentiation of activated B-lymphocytes. (ans)
6. Multiple Choice (ans)

12.3C: T4-Lymphocytes (T4-Cells)

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1. Match the following in terms of activation and function of T4-lymphocytes:

   _____ Epitopes of antigens are recognized by T4-lymphocytes by way of their ____________. (ans)

   _____ The TCR/CD4 molecules of T4-lymphocytes recognize ________________________ on antigen-presenting cells (APCs) such as dendritic cells, macrophages, and B-lymphocytes. (ans)

   1. peptides from exogenous antigens bound to MHC-II molecules
   2. peptides from endogenous antigens bound to MHC-I molecules
   3. MHC-I molecules
   4. toll-like receptors
   5. B-cell receptors
   6. T-cell receptors
   7. plasma cells
   8. lysosomes
   9. proteasomes
2. Matching

   _____ Promote cell-mediated immunity against intracellular pathogens; enhance the killing ability of macrophages, promote diapedesis and chemotaxis of macrophages, and promote the production of opsonizing antibodies. (ans)

   _____ Help to limit immune responses and prevent autoimmunity by suppressing T-lymphocyte activies, promote immune memory, help to sustain pregnancy, and control established inflammation. (ans)

   _____ Promote a local inflammatory response to stimulate a strong neutrophil response and promote the integrity of the skin and mucous membranes. (ans)

   _____ Promote the production of the antibody isotype IgE in response to helminthsand allergens, attract and activate eosinophils and mast cells, promote the production of antibodies that neutralize microbesand toxins, and promote the removal of microbes in mucosal tissues. (ans)

   1. CD4 T_H2 cells
   2. CD4 T_H1 cells
   3. CD4 T_reg cells
   4. CD4 T_H17 cells
   5. CD4 T_FH cells
3. Multiple Choice (ans)

12.3D: T8-Lymphocytes (T8-Cells)

Study the material in this section and then write out the answers to these questions. Do not just click on the answers and write them out. This will not test your understanding of this tutorial.

1. Match the following in terms of activation and function of T8-lymphocytes:

   _____ Epitopes of antigens are recognized by T8-lymphocytes by way of their ____________. (ans)

   _____ The TCR/CD8 molecules of naive T8-lymphocytes recognize ________________________ on antigen-presenting dendritic cells. (ans)

   _____ After activation, T8-lymphocytes proliferate and differentiate into _____________________ (ans)

   1. peptides from exogenous antigens bound to MHC-II molecules
   2. peptides from endogenous antigens bound to MHC-I molecules
   3. MHC-I molecules
   4. toll-like receptors
   5. B-cell receptors
   6. T-cell receptors
   7. plasma cells
   8. cytotoxic T-lymphocytes (CTLs)
   9. natural killer cells (NK cells)
2. State the overall function of activated T8-lymphocytes in adaptive immunity. (ans)
3. Multiple Choice (ans)

12.3E: Invarient Natural Killer T-Lymphocytes (iNKT Cells)

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1. Epitopes of glycolipid antigens are recognized by iNKT lymphocytes by way of their _______. (ans)
2. The TCR molecules of iNKT lymphocytes recognize ________________________ on antigen-presenting dendritic cells. (ans)
3. iNKT lymphocytes can also be activated by the cytokine __________ (ans) produced by activated dendritic cells.
4. iNKT cells promote both innate and adaptive immunity and may also regulate immune responses by way of the ____________ they produce once activated. (ans)

12.3F: B-Lymphocytes (B-Cells)

Study the material in this section and then write out the answers to these questions. Do not just click on the answers and write them out. This will not test your understanding of this tutorial.

1. Match the following in terms of activation of B-lymphocytes by T-dependent antigens:

   _____ Epitopes of antigens are recognized by B-lymphocytes by way of their ____________. (ans)

   _____ Once engulfed by APCs, protein antigens are degraded into peptides by organelles called ____________. (ans)

   _____ B-lymphocytes bind peptides to grooves in _________________. (ans)

   _____ The B-lymphocyte then presents the MHC/peptide complex to the ___________________. (ans)

   _____ B-lymphocytes eventually differentiate into antibody-secreting cells called ___________________. (ans)

   1. TCR of T4-lymphocytes
   2. TCR of T8-lymphocytes
   3. MHC-I molecules
   4. MHC-II molecules
   5. B-cell receptors
   6. CD4 molecules
   7. plasma cells
   8. lysosomes
   9. proteasomes
2. State the overall function of B-lymphocytes in adaptive immunity. (ans)
3. Multiple Choice (ans)

12.3G: Natural Killer Cells (NK Cells)

Study the material in this section and then write out the answers to these questions. Do not just click on the answers and write them out. This will not test your understanding of this tutorial.

1. Briefly describe how NK cells bind to and kill infected cells and tumor cells through ADCC. (ans)
2. Briefly describe how NK cells recognize and kill infected cells and tumor cells that suppress MHC-I production. (ans)

12.3A: Major Histocompatibility Complex (MHC) Molecules

Study the material in this section and then write out the answers to these questions. Do not just click on the answers and write them out. This will not test your understanding of this tutorial.

1. Match the following:

   _____ Produced by all nucleated cells in the body. (ans)

   _____ Produced primarily by antigen-presenting cells such as macrophages, dendritic cells, and B-lymphocytes. (ans)

   _____ Primarily bind peptides from exogenous antigens. (ans)

   _____ Primarily bind peptides from endogenous antigens. (ans)

   _____ Recognize peptides bound to MHC-II molecules. (ans)

   _____ Recognize peptides bound to MHC-I molecules. (ans)

   1. TCR of T4-lymphocytes
   2. TCR of T8-lymphocytes
   3. MHC-I molecules
   4. MHC-II molecules
2. State the role of proteasomes in binding of peptides from endogenous antigens by MHC-I molecules. (ans)
3. State the role of lysosomes in binding of peptides from exogenous antigens by MHC-II molecules. (ans)
4. Multiple Choice (ans)

12.3B: Antigen-Presenting Cells (APCs)

12.3C: T4-Lymphocytes (T4-Cells)

12.3D: T8-Lymphocytes (T8-Cells)

12.3E: Invarient Natural Killer T-Lymphocytes (iNKT Cells)

12.3F: B-Lymphocytes (B-Cells)

12.3G: Natural Killer Cells (NK Cells)

12.4: The Lymphoid System

Study the material in this section and then write out the answers to these questions. Do not just click on the answers and write them out. This will not test your understanding of this tutorial.

1. Match the following with the BEST answer:

   _____ Contain antigen-presenting cells, such as macrophages and dendritic cells, and ever changing populations ofB-lymphocytes and T- lymphocytes. Examples include the tonsils, the appendix, Peyer's patches, MALT, SALT, lymph nodes, and the spleen. (ans)

   _____ Produce B-lymphocytes and T-lymphocytes. The bone marrow and the thymus. (ans)

   _____ The fluid surrounding cells in the body. (ans)

   _____ The liquid portion of the blood. (ans)

   _____ A diffuse system of small concentrations of lymphoid tissue found in various sites of the body such as the gastrointestinal tract, respiratory tract, eye, and skin. It is populated by loose clusters of T-lymphocytes, B-lymphocytes, plasma cells, activated T_H cells, and macrophages. (ans)

   _____ The liquid found in lymph vessels. (ans)

   _____ Expose antigens found in the lymph to dendritic cells, B-lymphocytes, and T-lymphocytes. (ans)

   _____ Expose antigens found in the blood to dendritic cells, B-lymphocytes, and T-lymphocytes. (ans)

   1. plasma
   2. lymph
   3. tissue fluid
   4. primary lymphoid organs
   5. secondary lymphoid organs
   6. the spleen
   7. lymph nodes
   8. MALT
2. Briefly describe the importance of the lymphoid system in adaptive immune responses. (ans)
3. Multiple Choice (ans)

12.5: An Overview of the Steps Involved in Adaptive Immune Responses

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1. State where antigens may encounter APCs, B-lymphocytes, and T-lymphocytes if they enter the following:
   1. the blood (ans)
   2. tissues (ans)
   3. the respiratory tract (ans)
   4. the gastrointestinal tract (ans)
   5. the genitourinary tract (ans)
2. Match the following:

   _____ Use lysosomes to degrade exogenous antigens into peptides, bind them to MHC-II molecules, and present them to naive T4-lymphocytes. (ans)

   _____ Uses BCR to recognize epitopes of antigens; a few antigens are recognized by toll-like receptors. (ans)

   _____ Uses TCR and CD4 to recognize peptide epitopes from exogenous antigens bound to MHC-II molecules of antigen-presenting dendritic cells, macrophages, and B-lymphocytes. (ans)

   _____ Uses TCR and CD8 to recognize peptide epitopes from endogenous antigens bound to MHC-I molecules of cells. (ans)

   _____ Cells that allow for a heightened secondary response upon subsequent exposure to the same antigen. (ans)

   _____ Once activated itself, secretes cytokines that enable activated B-lymphocytes and T-lymphocytes to proliferate and differentiate. (ans)

   _____ Use proteasomes to degrade endogenous antigens into peptides, bind them to MHC-I molecules, and present them to naive T8-lymphocytes. (ans)

   _____ Differentiate into antibody secreting plasma cells. (ans)

   _____ Differentiate into cytotoxic T-lymphocytes (CTLs). (ans)

   1. T4-lymphocytes
   2. T8-lymphocytes
   3. dendritic cells
   4. B-lymphocytes
   5. memory cells
3. State the overall function of T4-effector lymphocytes and the importance behind rapid proliferation of activated lymphocytes. (ans)
4. The ability of the body to initiate and direct adaptive immune responses against antigenic molecules foreign to the body but not against antigenic molecules that are a normal component of the body is called ____________________________. (ans)
5. Multiple Choice (ans)