EXAM 3- REVIEW SLIDE CHAPTER 15

•Define the term immunological surveillance

Cancer cells display foreign antigens. These may be produced by a virus, a mutated gene due to exposure to carcinogens, embryonic or fetal antigens produced by the tumor cells or others. This should stimulate immune attack

•A type of lymphocyte that shuts off the immune response is

•Suppressor T lymphocyte

•Red blood cells contain surface molecules that correspond to blood types A, AB, B or O (none). A person who is A-positive also contains the ___________________ surface molecule.

_________Rh________

•Describe the actions of interferons

•The interferons are produced by cells infected with viruses and they act to protect neighboring cells from viral attack. The ability of the viruses to replicate and assemble new virus particles is hindered. Different interferons also help protect against certain cancers.

•Describe the role of the thymus in cell-mediated immunity

•The thymus is seeded with lymphocytes by the bone marrow and then becomes the site where the specialized T lymphocytes originate. T lymphocytes from the thymus can then seed the secondary lymphoid organs.

•An autoimmune attack of pancreatic beta cells is known to result in ________________

•Type I diabetes

•Describe: allergy

•Allergy is the body's immune response to a pathogen that is not actually harmful

•Describe the difference between an antibody and an antigen

•Antibodies are produced by B cells; they bind to antigens, which are molecules that are detected as non-self

•Explain why cancer cells are believed to be dedifferentiated

•Cancer cells become less specialized than the normal cells from which they are derived, and they divide in an unrestricted way more characteristic of embryonic than of specialized cells.

•Define immunological tolerance

•Immunological tolerance refers to the ability of the immune system to mount an immune response against foreign (nonself) antigens while not attacking self-antigens.

•Cells of the liver that monitor pathogens and phagocytize them are called

•Kupffer cells

•Describe passive immunity

•Passive immunity refers to immune protection provided by antibodies produced by another animal or person.

•Mast cells secrete -Antibodies -Perforins -Lysosomal enzymes -Histamine

-Histamine

•Mast cell secretion during an immediate hypersensitivity reaction is stimulated when antigens combine with -IgG antibodies -IgE antibodies -IgM antibodies -IgA antibodies

-IgE antibodies

•Macrophages cells secrete -Antibodies -Perforins -Lysosomal enzymes -Histamine

-Lysosomal enzymes

•Which of these cell types aids the activation of T lymphocytes by antigens? -Macrophages -Neutrophils -Mast cells -Natural killer cells

-Macrophages

•Explain immunoassay

presence of an antigen. The monoclonal antibody is first conjugated to an enzyme so that, on binding to its antigen, the enzyme will become activated to carry out a reaction forming a detectable product (through color formation).

•Describe antibody structure

Antibodies bond to antigens on bacteria The Fc and Fab, and the heavy and light chains are labeled in this figure.

•The secondary immune response allows a person to avoid experiencing symptoms of disease because they have created populations of _____________ cells.

memory

•During a secondary immune response, -Antibodies are made quickly and in great amounts -Antibody production lasts longer than in a primary response -Antibodies of the IgG class are produced -Lymphocyte clones are believed to develop -All of these apply

-All of these apply

•Which of these statements about the Fab portion of antibodies is true? -It binds to antigens -Its amino acid sequences are variable -It consists of both H and L chains -All of these are true

-All of these are true

•Plasma cells secrete -Antibodies -Perforins -Lysosomal enzymes -Histamine

-Antibodies

•Killer T cells secrete -Antibodies -Perforins -Lysosomal enzymes -Histamine

-Perforins

•Which of these statements about complement proteins C3a and C5a is false? -They are released during the complement fixation process -They stimulate chemotaxis of phagocytic cells -They promote the activity of phagocytic cells -They produce pores in the victim cell membrane

-They produce pores in the victim cell membrane •MORE INFORMATION: C3a and C5a stimulate mast cells to release histamine. They also serve as powerful chemokines to attract macrophages, neutrophils, monocytes, and eosinophils to the site of infection

•Draw a graph illustrating the primary and secondary immune response

LOOK AT SLIDE

•Explain the HIV life cycle

PENDING

•Describe three methods used to induce active immunity.

•1) use live viruses with attenuated virulence. These can provoke a primary response and thereby sensitize the immune system to subsequent exposures to the virulent form of the virus. •2) inoculate a person with "killed" viruses that would otherwise by virulent. •3) use genetic engineering and recombinant technology to produce isolated viral proteins, given by themselves to provoke a primary immune response and confer immunity against subsequent exposure to the viruses.

•Describe "delayed hypersensitivity"

•An allergic response in which the onset of symptoms may not occur until 2 or 3 days after exposure to an antigen. Produced by T cells, it is a type of cell-mediated immunity

•B cells are produced in

•B cells are produced in bone marrow

•Describe complement fixation

•Complement fixation refers to the insertion of complement proteins C5 through C9 into the bacterial cell membrane such that they form a pore, the membrane attack complex.

•Define the term cytokines

•Cytokines are autocrine regulators released by many different cell types. Lymphokines are the cytokines released by lymphocytes.

•Explain the clonal selection theory and indicate how this theory accounts for the secondary response.

•Each lymphocyte inherits the ability to produce one specific form of antibody that can bind to one antigen or antigenic determinant site. The B lymphocytes have this antibody on their cell surface, where it functions as a receptor. When the person is exposed to the antigen, the binding of the antigen to its specific antibody receptor stimulates multiple cell division of the lymphocyte, producing a clone. This occurs during the primary response. When the person is again exposed to the same antigen, the antigen now meets the clone of lymphocytes able to produce antibodies against it in a secondary response. •

•A woman has a fungus growing in her lung. The fungus has been removed several times and was at first thought to be cancer. No matter how many times her lungs are cleared of fungi, the fungi grows back. Her doctor has ordered to receive bi-annual injections of antibodies because she is thought to have a week immune system. •The effect of these antibodies will be to stimulate the immune system to produce its own antibodies against the fungus. •True •False

•False

•T-lymphocytes are called "T" because they are produced in the thymus. •True •False

•False (they are produced in bone marrow; they migrate to the thymus where they mature)

•Describe the innate immune system

•Innate immunity is the first line of defense when pathogens enter the body. Then cells that provide innate immunity distinguish between body cells ("self") and the pathogens using receptors for pathogen-associated molecular patterns (PAMPS) that are unique to the invaders. The innate immune mechanisms are always present and do not require prior exposure to the pathogens to be effective.

•Explain innate versus adaptive immunity

•Innate immunity is the first line of defense when pathogens enter the body. Then cells that provide innate immunity distinguish between body cells ("self") and the pathogens using receptors for pathogen-associated molecular patterns (PAMPS) that are unique to the invaders. The innate immune mechanisms are always present and do not require prior exposure to the pathogens to be effective. •Adaptive immunity requires prior sensitization to specific antigens, which are molecules that provoke the production of antibodies (or other aspects of the adaptive immune system) and can combine with antibodies or otherwise react with the adaptive immune system in a specific manner.

•Which of these offers a nonspecific defense against viral infection? •Antibodies •Leukotrienes •Interferon •Histamine

•Interferon

•identify the different types of T lymphocytes.

•Killer, or cytotoxic, T lymphocytes provide cell-mediated immunity by coming into close proximity or contact with their target cells and releasing perforins and granzymes. •Helper T lymphocytes secrete cytokines called lymphokines that enhance both the B cells' ability to become plasma cells and secrete antibodies and the cytotoxic T cells ability to destroy their target cells. •Regulatory T lymphocytes inhibit the specific immune attack by reducing the activity of both B cells and killer T cells.

•Describe the requirements for activation of helper T cells by macrophages

•Macrophages and other antigen-presenting cells must present foreign antigens together with class-2 MHC molecules in order to activate helper T cells. The macrophages then secrete interleukin-1, which stimulates cell division of T lymphocytes.

•Describe opsonization and identify two types of molecules that promote this process

•Opsonization is the ability of antibodies to promote phagocytosis. When they combine with antigens on the surface of bacterial cells, they promote the phagocytosis of those bacteria. Binding of antibodies to antigens on the bacterial cells surface also activates the complement system. Some of these attract phagocytic cells to the infected area, and because phagocytic cells have receptors for complement protein C3b, this is believed to promote phagocytosis of the bacteria.

•Which type of lymphocyte engages in cell mediated immunity?

•T-lymphocytes

•Explain the importance of class-1 and class-2 MHC molecules in the function of T cells.

•The class-1 histocompatability molecules are produced by all cell types. •The class-2 molecules are produced only by antigen-presenting cells: macrophages, dendritic cells, and B lymphocytes. These antigen-presenting cells must present the foreign antigen together with class-2 histocompatability antigens to activate the helper T lymphocytes. The helper T cells then promote the action of killer T lymphocytes, which can only destroy a target cells if the target cells presents the foreign antigen together with the class-1 histocompatability antigens to the killer T cell.

•Define the term histocompatibility antigens

•The histocompatability antigens, coded by the major histocompatability complex (MHC) of genes, are antigens on all cell types (except red blood cells) that are specific for an individual and help to "type" tissues for possible tissue transplantation.

•Explain local inflammation

•The innate immune system can become activated by exposure to pathogen recognition receptors, such as toll-like receptors. Macrophages and mast cells release cytokines and chemokines that attract and activate phagocytic cells, primarily neutrophils. Complement becomes activated and these activated proteins attract and activate phagocytic cells, as well as cells of the adaptive immune system. Mast cells release histamine, which causes vasodilation to bring more blood to the infected area. Histamine also increases capillary permeability, allowing increased interstitial fluid formation that swells the infected area. Mast cells also release several other pro-inflammatory cytokines. Extravasation of neutrophils into the infected area allows them to destroy bacteria by releasing NETS and eliminating bacteria by phagocytosis. Antibodies secreted by B cells augment the phagocytic action of neutrophils and macrophages.

•List the phagocytic cells found in blood and lymph

•The major phagocytic cells found in blood and lymph are the neutrophils, monocytes, macrophages, and dendritic cells.

•Using graphs to illustrate your discussion, explain the characteristics of the primary and secondary immune responses.

•The primary and secondary immune response graph is shown in fig. 15.20. •When a person is first exposed to a pathogen, there is a latent period of 5 to 10 days, after which antibody production is sluggish. A subsequent exposure to that pathogen causes a secondary response in which maximum antibody production is reached in two hours. Larger amounts of antibodies are produced than in the primary response and this production lasts longer than in the primary response, helping to combat the pathogen.

•Explain primary versus secondary lymphoid organs

•The primary lymphoid organs are the thymus and bone marrow, because these are the sites of origin of T and B lymphocytes, respectively. •The secondary lymphoid organs include the lymph nodes, spleen, tonsils, and Peyer's patches in the intestine. The secondary lymphoid organs concentrate the antigens of pathogens, present these to antigen-presenting macrophages and dendritic cells, and circulate the lymphocytes and antigen-presenting cells so that the adaptive immune system can better combat the pathogens.

•To create the diversity of antibodies needed for humans to fight infection, antibody genes actually jump around the genome. •True •False

•True

•An autoimmune disease that attacks myelin sheaths and is predominantly found in women is

•multiple sclerosis

•The term "xenobiotic" refers to

•to a substance that is foreign to the body