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MCB5252 Exam 2 Test With
Complete Solution
Innate immune cells include... - ANSWER Macrophages, granulocytes, natural killer cells, dendritic cells
Innate immunity chemical mediators - ANSWER lysozyme
complement
defensins
Acquired immunity cells - ANSWER B and T cells, antigen presenting cells (APC)
Acquired vs innate: which distinguishes self from non-self? - ANSWER Acquired (failure results in autoimmune disease)
Innate immunity specificity - ANSWER specific for molecules and molecular patterns associated with pathogens and molecules produced by dead/damaged cells
Adaptive immunity specificity - ANSWER highly specific, discriminates even minor differences in molecular structure; details of microbial or nonmicrobial structure recognized with high specificity
Innate immunity: soluble components of blood or tissue fluids - ANSWER many antimicrobial peptides and proteins
Adaptive immunity: soluble components of blood or tissue fluids - ANSWER antibodies
Sebum - ANSWER produced by skin cells; keeps the skin oily; involved in innate immunity along with low pH
Innate immunity in small intestine - ANSWER bile salt
lactoferrin and transferrin - ANSWER By binding iron, an essential nutrient for bacteria, these proteins limit bacterial growth.
Sequester iron in the liver and remove it from circulation (which makes you tired because hemoglobin is less available)
Skin-associated lymphoid tissue (SALT) - ANSWER
Gut-associated lymphoid tissue (GALT) - ANSWER GALT includes Peyer's patches in the gut and the diffuse lymphatic tissue in the gastrointestinal tract and respiratory system
bronchial-associated lymphoid tissue (BALT) - ANSWER These neoplasms fall under the broader umbrella of mucosa associated lymphoid tissue (MALT) lymphomas. It is sometimes considered a type of primary pulmonary lymphoma.
Urogenital system MALT - ANSWER a diffuse system of small concentrations of lymphoid tissue found in various sites of the body, such as the gastrointestinal tract, thyroid, breast, lung, salivary glands, eye, and skin.
primary lymphoid organs - ANSWER bone marrow and thymus
secondary lymphoid organs - ANSWER lymph nodes, spleen, tonsils
Monocytes, macrophages, and neutrophils are... - ANSWER phagocytic
macrophages are also antigen presenting cells
Dendritic cells - ANSWER present in small numbers in blood, skin, and
APCs present cells to... - ANSWER T cells (through MHC I and MHC II)
What happens when bacteria are caught by phagocytic cells? - ANSWER 1. bacterium becomes attached to membrane
- bacterium is ingested, forming phagosome
- phagosome fuses with lysosome
- lysosomal enzymes digest captured material
- digestion products released from cell
PAMPs (pathogen-associated molecular patterns) - ANSWER Molecules associated with groups of pathogens that are recognized by cells of the innate immune system (such as teichoic acid, fimbriae, etc)
PAMPs are recognized by - ANSWER Toll-like receptors on phagocytic cells
Toll-like receptors - ANSWER a class of molecules that functions exclusively as signaling receptors; binding is communicated to host cell nucleus which initiates the host response
True/False: PAMPs are unique to microbes but not the host - ANSWER True
ex: LPS of gram negs; peptidoglycan of gram pos
What is inside the lysosome? - ANSWER Digestive enzymes
- lysozyme
- proteases
- lipases
- nucleases
reactive oxygen intermediates (free radicals such as peroxide, superoxide, etc.)
Compounds produced by bacteria that inhibit phagocytic killing - ANSWER Carotenoids (antioxidant)
Leukocidins (exotoxin - WBC)
Capsule (inhibit fusion between phagosome and lysosome; such as TB)
The classic complement pathway is activated by: - ANSWER antibody-antigen complexes
These complexes stimulate C1, them there is other protein breakdown
Alternate complement pathway is activated by: - ANSWER bacterial products (LPS, teichoic acid, proteases, immune complexes)
These products bind C
What is complement? - ANSWER serum proteins that destroy extracellular bacteria and viruses
Three major activities of complement - ANSWER 1. defending against bacterial infections
- bridging innate and adaptive immunity
- disposing of waste
complement activation results in lysis of the foreign cell
Is the complement system innate or adaptive? - ANSWER usually innate, but can be turned on by adaptive immune system
chemotaxis (phagocytosis) - ANSWER chemical signals attract phagocytes to
Give examples and describe the function of Spleen - ANSWER filter liquid and look for any infection has specific and innate community blood pass through
red pulp: where RBCs are recycled
white pulp: filters blood for possible infection
Give examples and describe the function of lymphoid tissues - ANSWER network of loosely attached tissues
filter liquid and look for infection
Define inflammation and list its components. Describe events happening during inflammation. Which type of immunity does inflammation provide? - ANSWER Inflammation is a tissue reaction to infection or injury. Symptoms: redness, swelling, heat, & pain (cardinal signs)
mediated by mast cells if localized or basophils in blood for systemic response
Can be innate or adaptive depending on transcription factors expressed from the adaptor proteins produced via tissue trauma, infection, PAMPs, or foreign substances.
How fever is produced? List molecules that may induce fever. These molecules are called___________ - ANSWER Called Pyrogens
Pyrogens trigger hypothalamus to increase core temp.
Bacterial toxins
cytoplasmic contents of lysed bacteria
Ab-Ag complexes
IL-
Pyrogens
Prostaglandins "reset" hypothalamus
What are cytokines? Give examples. - ANSWER immune modulators - any of a number of substances, such as interferon, interleukin, and growth factors, that are secreted by certain cells of the immune system and have an effect on other cells
What is meant by mucosal immunity? Which class of antibody is mainly involved in mucosal immunity? - ANSWER Steric hindrance:
Antibodies combine with the surfaces of microorganisms and block their attachment to susceptible cells or mucosal surfaces. Ab against a viral component can block attachment of the virus to susceptible host cells and thereby reduce infectivity.
Secretory IgA can block attachment of pathogens to mucosal surfaces.
Compare naturally acquired immunity and artificially acquired immunity. Give examples - ANSWER Natural acquired immunity: self-production of antibodies during infection or transfer of antibodies from mother to offspring
Artificial acquired immunity: vaccination and other immunization procedures
APCs = macrophages (long-lived, for chronic infection) (dendritic cells, B cells)
What are the differences between different forms of B cells (Plasma vs. Memory cells)? - ANSWER Plasma cells: produce antibodies
Memory: don't produce antibodies, remember antigen information for next infection, APC
Compare characteristics of B cell and T cells - ANSWER B cells: APC, produce antibodies
T cells: help determine nature of immune response
3 types - helper, cytotoxic lymphocytes, regulatory
Regulatory - maintain homeostasis, secrete cytokines
T helper - receptor binds to APC antigen, activate B cells and macrophages
cytotoxic T lymphocytes - kill infected cells
Compare cell-mediated immunity (CMI) and Humoral immunity (antibody-mediated, AMI) - ANSWER antibody mediated (ami): antibodies released by plasma cells (activated B cells)
cell mediated ( cmi): T cells and NK cells l. cleaning up the system
Roles of the antibody mediated (Humoral) immunity (AMI) and CMI Responses in Host Defense - ANSWER AMI - B cells produce antibodies to antigens for memory
CMI - T cells produce T helpers to keep stimulating B cells and macrophages and dendritic cells, Cytotoxic lymphocytes kill the infected cell
Name cells involved in cell-mediated immunity - ANSWER In non-immune animals' precursor T-cells (pT cells) exist as "resting T cells". They bear receptors for specific antigens. Stimulation with Ag results in their activation. The cells enlarge, enter into a mitotic cycle, reproduce and develop into effector T-cells whose activities are responsible for this type of immunity. They also develop into clones of identical reactive T-cells called memory T-cells.
Compare different classes of antibodies.
IgM
IgA
IgE
IgG
IgD - ANSWER IgM - first in immune responses, pentamer
IgA - secretions, mucosal surfaces
IgE - opsonization, elevated in parasites and allergies
Toxoid vaccine - ANSWER inoculum using modified toxins to stimulate antibody-mediated immunity
Adjuvant - ANSWER
Hapten - ANSWER small molecule that does not elicit an immune response by itself; also called incomplete antigen.
not antigenic but may become antigenic when bound to a larger carrier molecule
ex: penicillin - people who are allergic to penicillin have carrier molecules in their body that penicillin binds to
What are the advantages of live attenuated vaccine? - ANSWER effective, no booster required protects for longer period of time
What are the advantages of Killed/inactivated vaccines? - ANSWER This destroys the pathogen's ability to replicate, but keeps it "intact" so that the immune system can still recognize it.
Know the examples of both bacterial and viral vaccines listed in the required readings - ANSWER
What is the difference between passive and active immunization? - ANSWER Active immunization: antibodies produced in the body (either naturally or artificially)
Passive immunization: antibodies are produced by a different organism and they're introduced to the body (either naturally or artificially)
Define Antibody-dependent cytotoxicity or ADCC - ANSWER ADCC-NK cells are capable of antibody-dependent killing and hence are called ADCC. The cytoplasmic granules contain cytolytic proteins to mediate the killing.
What are some practical uses of ELISA? Difference between direct and indirect ELISA - ANSWER pregnancy tests, viral tests, allergen tests
Describe the diagnostic procedure(s) that is (are) appropriate to determine/detect: HSV in pap smear - ANSWER
Describe the diagnostic procedure(s) that is (are) appropriate to determine/detect: Presence of anti HIV antibody in serum - ANSWER
Complement fixation (activation) - ANSWER Binding of complement to an antigen-antibody complex. Basis of diagnostic tests that determine if antibodies to an antigen are present in patient's serum.
such as blood banking
Define hypersensitivity. List and briefly describe four types of hypersensitivity and give examples. - ANSWER exaggerated immune response upon second or subsequent contact with antigen. causes tissue damage. reactions described at immediate or delayed
type 1 : immediate (anaphylactic reaction)
are systemic or localized
result of antigen cross linking with membrane bound IgE antibody of a mast cell or Basophil
mech: initial exposure to allergen causes Th2 cells to stimulate B cells to produce IgE antibodies which attach to mast cells and Basophil
second exposure = IgE cross linking on mast cells and Basophil which results in ( degranulation) the immediate release of vasoactive amines
type 2: cytotoxic reaction (antibody dependent)
tyoe 3: immune complex reaction
type 4: cell mediated ( delayed hypersensitivity)
Define graft-vs-host disease. Why tissue/organ transplants are often rejected? Why fetus is not rejected? - ANSWER Graft-Versus-Host Disease: Can occur in organ transplant recipients. Immunocompetent cells in donor tissue reject host.Grafts perceived as foreign by the recipient undergo rejection. Rejection is a normal immune response against foreign major histocompatibility complex (MHC) proteins on the surface of graft cells. Likelihood of graft rejection depends on the degree to which the graft is foreign to the recipient. Sites at which grafts are not likely to be rejected are: Brain, Cornea, TestesFetus rejection is prevented by the many different immunosuppressive mechanisms. Early embryos do not express MHC class I and II molecules on the placental layer that is in contact with maternal tissues. Cytokines that enhance MHC expression have no effect on placental cells. T cells are prevented from functioning in the placenta to reject the fetus.
What is the significance of presence of Fc receptors on surface of mast cells and basophils? - ANSWER The Fc receptor on the surface of mast cells/basophils binds IgE. When two IgE bind the same antigen, it causes a signal cascade that leads to degranulation.
List cells capable of interacting with Fc portion of an antibody that is attached to a target cell - ANSWER Host tissue
Various cells of immune system (Examples: NK cells, macrophages, basophils, and mast cells)First component of complement system
C-reactive protein (CRP) - ANSWER a protein whose blood levels rise in response to inflammation
Arthus reaction - ANSWER local reaction seen in the skin after subcutaneous or intradermal injection of an antigenic substance
Serum sickness - ANSWER
Subunit vaccine - ANSWER
Fc vs Fab portion - ANSWER
Quelling reaction (used in pneumococcal capsular serotyping) - ANSWER seen under microscope
swelling of capsules material following add of antiserum specific to a capsular type
Widal test - ANSWER Agglutination test using killed Salmonella typhi organisms and the patient's blood serum; a diagnostic aid in typhoid fever.
Superantigens - ANSWER Most antigens have a specific component that they
bind to but these do not
Stimulate stronger response than normal antigens by tricking T cells into activation even if they would not have been triggered by that antigen otherwise
Stimulate a large fraction of T cells to proliferate nonspecifically, and stimulate release of large quantities of cytokines (cytokine storms) from T cells - circulatory shock, multi-organ failure, drop in BP, severe vomiting
Example of superantigen - ANSWER staphylococcal enterotoxin B - causes toxic shock syndrome
this is an exotoxin
Most to least antigenic compounds - ANSWER Proteins
Carbohydrates
Lipids and Nucleic acids
Where in the human body one can find the majority of immune system components? - ANSWER Lymphatic system: network of loosely attached tissues spread all over the body
