p.1
Innate Immunity vs. Adaptive Immunity
What cells are involved in innate immunity?
Phagocytes, dendritic cells, complement, and natural killer (NK) cells.
p.1
Immune Response Phases
What are the two main types of immune responses?
Humoral immunity and cell-mediated immunity.
p.18
Immune Response Phases
What happens to HIV strains within a patient over time?
Many different strains may arise within a patient even over a period of just a few months.
p.18
Immune Response Phases
How do DNA viruses like CMV and EBV evade the immune response?
They may downregulate MHC or prevent apoptosis, compromising the innate response and immunologic memory.
p.18
Immune Response Phases
What strategy do intracellular bacteria like mycobacteria use to evade the immune response?
They have waxy coats and secrete catalase to block the respiratory burst.
p.13
Antigens and Antibodies
How do larger antigens interact with antibodies?
Larger antigens bind in a groove, such as linear peptide epitopes.
p.7
Immune Response Phases
What are the phases of an immune response?
Cognitive phase, Activation phase, Effector phase.
p.14
Immune Response Phases
What are the steps involved in the killing of infected cells?
1. Dendritic cell with antigen 2. Recognition in lymphoid organs 3. Differentiated effector and memory T cells enter circulation 4. Migration to the site of antigen leading to cytokine secretion or macrophage activation.
p.17
Vaccine Types and Mechanisms
What is the purpose of vaccines being developed for SARS-CoV-2?
To counter or help duplicate and elicit an immune response to the spike protein.
p.5
Innate Immunity vs. Adaptive Immunity
What is the role of T helper cells in the immune response?
They activate macrophages and lead to inflammation, as well as the proliferation and differentiation of T and B lymphocytes.
p.5
Immune Response Phases
What is the function of Cytotoxic T-Lymphocytes (CTL)?
Killing of infected cells.
p.5
Innate Immunity vs. Adaptive Immunity
How do Natural Killer (NK) cells differ from Cytotoxic T-Lymphocytes?
NK cells do not need previous exposure to an antigen to kill infected cells, while CTLs require prior recognition.
p.2
Innate Immunity vs. Adaptive Immunity
What are PAMPs?
Pathogen-Associated Molecular Patterns, which are conserved molecular structures specific to foreign microorganisms.
p.7
Immune Response Phases
What is the primary function of TH1 T-cells?
To respond to intracellular pathogens.
p.16
Active and Passive Immunity
What is active immunity?
Immunity that can be brought about by exposure to infection or having the infection yourself.
p.18
Active and Passive Immunity
What is the longevity of the immune response after smallpox vaccination?
There is still a level of antibody effective until 60 years after vaccination.
p.6
Immune Response Phases
What do T-lymphocytes transform into after activation?
Helper T-cells or cytotoxic T-cells.
p.3
Innate Immunity vs. Adaptive Immunity
What are inflammasomes?
Multi-protein complexes involved in the acute inflammatory response.
p.9
Antigens and Antibodies
What is the role of IgM in the immune response?
Elevated in primary responses and most efficient in activating complement.
p.10
Antigens and Antibodies
What is present during acute Hepatitis B infection?
Hepatitis B antigen (HBsAg) and viral DNA.
p.3
Innate Immunity vs. Adaptive Immunity
What do eosinophils primarily target?
Parasites and they can also appear during allergic reactions.
p.12
Immune Response Phases
What are CD antigens?
Cell surface molecules exposed on leukocytes relevant for the immune system.
p.12
Epitopes and Antibody-Antigen Interaction
How are linear epitopes recognized?
By B cells and T cells, with adjacent amino acid residues.
p.1
Innate Immunity vs. Adaptive Immunity
What is the role of B-lymphocytes in adaptive immunity?
They produce antibodies in response to an antigen.
p.11
Antigens and Antibodies
What happens to HBsAg and viral DNA if control of hepatitis B infection is lost?
HBsAg and viral DNA may reappear.
p.7
Immune Response Phases
What are the three types of immune response?
Type 1: Intracellular pathogens, Type 2: Surface arthropods, Type 3: Extracellular pathogens.
p.11
Antigens and Antibodies
What is an immunogen?
A substance that causes an immune response by itself, e.g., HBsAg.
p.7
Immune Response Phases
What immune system components are involved in Type 1 immune response?
Interferon, macrophages, NK cells.
p.11
Central and Peripheral Tolerance
What is a tolerogen?
A substance recognized by the adaptive immune system but programmed not to elicit a response, e.g., peanuts.
p.18
Immune Response Phases
What strategy do worms like schistosomes use to evade the immune response?
They coat themselves in host antigens and secrete protease inhibitors to block gut enzymes.
p.13
Hypersensitivity Reactions
What is epitope spreading?
A response initiated against one antigen can prime others, leading to the activation of additional antigens and exacerbation of autoimmune diseases.
p.2
Innate Immunity vs. Adaptive Immunity
How do Nucleotide Oligomerization domain-like receptors (NLR) function?
NLRs are cytoplasmic sensors that recognize bacterial, viral, parasitic, and fungal PAMPs and form inflammasomes.
p.7
Immune Response Phases
What is clonal selection in the immune response?
Activation and proliferation of antigen-specific B cells.
p.13
Major Histocompatibility Complex (MHC)
What are Human Leukocyte Antigens (HLA) associated with?
HLA are associated with autoimmune diseases.
p.8
Antigens and Antibodies
What distinguishes IgA from IgM?
Only IgA has a secretory component.
p.12
Epitopes and Antibody-Antigen Interaction
What are the two types of epitopes?
Linear (continuous) and conformational (discontinuous).
p.4
Innate Immunity vs. Adaptive Immunity
What are the two types of phagocytes mentioned?
Neutrophils and macrophages.
p.14
Major Histocompatibility Complex (MHC)
What is the role of β2 microglobulin in MHC Class I?
It is a soluble protein required for folding and expression of the Class I molecule.
p.7
Immune Response Phases
What pathogens are associated with Type 1 immune response?
Mycobacteria (e.g., tuberculosis), viruses, protozoa.
p.5
Central and Peripheral Tolerance
What is the role of Regulatory T-Lymphocytes?
They suppress the immune response, especially when the threat is eliminated.
p.16
Central and Peripheral Tolerance
What can suppression of regulatory cells in peripheral tolerance lead to?
Allergies or failure to respond to activation, causing problems with antigen recognition.
p.8
Antigens and Antibodies
What is the main function of IgG?
It is the main antibody in the secondary response, opsonizes bacteria, fixes complement, neutralizes toxins and viruses, and crosses the placenta.
p.7
Immune Response Phases
What is the role of plasma cells in the effector phase?
Secretion of antibodies to eliminate antigens.
p.2
Innate Immunity vs. Adaptive Immunity
What is the significance of Major Histocompatibility Complexes (MHCs) in adaptive immunity?
MHCs are involved in the presentation of antigens to T-cells.
p.8
Antigens and Antibodies
What is the role of IgE in the immune response?
It mediates immediate hypersensitivity and defense against worm infections.
p.3
Innate Immunity vs. Adaptive Immunity
What are polymorphonuclear cells?
Granulocytes, including neutrophils and eosinophils, involved in the immune response.
p.12
Central and Peripheral Tolerance
What are maternal antibodies against paternal MHC molecules indicative of?
Maternal exposure to fetal antigens during pregnancy.
p.3
Innate Immunity vs. Adaptive Immunity
What are tissue-resident macrophages?
Also called fixed macrophages, they maintain homeostasis.
p.3
Innate Immunity vs. Adaptive Immunity
How does the complement system contribute to immunity?
It binds to organisms to induce cell death via lysis and produces opsonins to facilitate phagocytosis.
p.1
Innate Immunity vs. Adaptive Immunity
What triggers the production of effector T-cells in adaptive immunity?
The presentation of an antigen by dendritic cells to T-lymphocytes.
p.14
Major Histocompatibility Complex (MHC)
What is the primary function of MHC Class I molecules?
To present peptide antigens to CD8+ T cells.
p.6
Innate Immunity vs. Adaptive Immunity
What is the function of macrophages in the immune response?
Specialized for degradation and proliferation of particulate antigens to T-cells.
p.5
Active and Passive Immunity
What are examples of successful immunity?
Vaccines, natural immunity to microbes, successful transplantation, and monoclonal antibodies.
p.11
Antigens and Antibodies
What are alloantigens?
Nonself antigens from members of the same species, e.g., in graft rejection.
p.10
Antigens and Antibodies
What medium is used to culture hybridomas?
Hypoxanthine-aminopterin-thymidine (HAT) medium.
p.6
Antigens and Antibodies
What is the role of immunoglobulin in the immune response?
Functions as a receptor, internalizes, degrades, and presents antigens to T cells.
p.10
Immune Response Phases
What happens after the second dose of the Hepatitis B vaccine?
There is an increased response; faster and higher levels of antibody are produced.
p.9
Antigens and Antibodies
What triggers the allergic response?
IgE, which is bound to Fc on mast cells and basophils.
p.15
Immune Response Phases
What is the significance of naive cell proliferation?
It can lead to antibody secretion, class switching, affinity maturation, and production of memory B cells.
p.15
Hypersensitivity Reactions
What happens during the late phase reaction of hypersensitivity?
It develops 2-24 hours after exposure and is triggered by cytokines and chemokines, leading to leukocyte infiltration and bronchospasm.
p.11
Antigens and Antibodies
What is the significance of testing for antibodies to hepatitis B surface antigen (HBsAg)?
It indicates the presence of antibodies after infection and helps monitor viral load.
p.17
Active and Passive Immunity
What is one approach being tested to fight SARS-CoV-2?
Using existing vaccines against polio virus or tuberculosis to elicit a general immune response.
p.17
Central and Peripheral Tolerance
What is Severe Combined Immunodeficiency Syndrome (SCID)?
A condition where the immune system fails to have the right mix of immune elements.
p.17
Innate Immunity vs. Adaptive Immunity
What is the role of T Regulatory cells (Tregs)?
To modulate immune responses.
p.17
Immune Response Phases
What are the two types of T cells that can be produced from T cell precursors?
Cytotoxic T lymphocytes and Helper T-Cells.
p.6
Immune Response Phases
What happens to naive T-lymphocytes and B-lymphocytes in the blood and lymph?
They can circulate and find their way into secondary lymphoid organs.
p.6
Immune Response Phases
What are the stages of lymphocyte maturation?
Naive cell, activated lymphocyte, effector lymphocyte, memory lymphocyte.
p.16
Active and Passive Immunity
How can active immunity be achieved through vaccination?
By receiving a vaccine, which can provide specificity and memory during recovery.
p.9
Antigens and Antibodies
What does Pepsin cleave in the human Ig heavy chain?
Forms a fragment of F(ab’)2 and a degraded Fc fragment.
p.8
Antigens and Antibodies
What role does secretory IgA play?
It prevents the attachment of bacteria and viruses to mucous membranes.
p.10
Immune Response Phases
What is the primary immune response to Hepatitis B after the first vaccine dose?
A slow primary response with a low level of antibody produced.
p.7
Antigens and Antibodies
What is the Fab region of an antibody?
The antibody-binding region that recognizes antigens.
p.8
Antigens and Antibodies
What does the CH2 domain of the heavy chain in IgG house?
The complement-binding site.
p.12
Hypersensitivity Reactions
What is Hydrops fetalis?
A swollen fetus due to large amounts of fluid buildup.
p.15
Hypersensitivity Reactions
What triggers immediate hypersensitivity reactions?
The release of arachidonic acid, forming Prostaglandin A2 and Leukotrienes.
p.5
Antigens and Antibodies
What triggers the formation of immunoglobulins or antibodies?
Activated B and plasma cells.
p.1
Antigens and Antibodies
What is the function of antigen-presenting cells (APCs)?
To present antigens to T-cells, initiating the adaptive immune response.
p.18
Immune Response Phases
Why is there a need for re-injection of the influenza vaccine?
Because the virus can mutate, making the previous vaccine ineffective against new strains.
p.8
Antigens and Antibodies
What are the variable regions of antibodies responsible for?
They are where antigens bind.
p.13
Antigens and Antibodies
What is the role of haptens in antibody-antigen interaction?
Haptens bind in a crevice or pocket, such as Vitamin K.
p.17
Vaccine Types and Mechanisms
What are the components of live attenuated vaccines?
Live attenuated human or non-human pathogens.
p.14
Innate Immunity vs. Adaptive Immunity
What triggers the activation of NK cells?
The presence of an activating ligand due to infected cells.
p.6
Antigens and Antibodies
What do B-lymphocytes transform into upon activation?
Plasma cells that produce immunoglobulins or antibodies.
p.11
Hypersensitivity Reactions
What is the definition of allergens?
Substances that cause allergic reactions due to failure of tolerization.
p.9
Antigens and Antibodies
What is the result of Papain cleaving at the hinge region?
Yields 2 Fab fragments and 1 Fc fragment.
p.13
Major Histocompatibility Complex (MHC)
What distinguishes Class I MHC molecules?
Class I MHC molecules are expressed on all nucleated cells and platelets and are recognized by CD8+ lymphocytes.
p.10
Immune Response Phases
What does the presence of IgG anti-HBc indicate?
It indicates a secondary immune response and is present several months after infection.
p.15
Hypersensitivity Reactions
What are the clinical manifestations of hypersensitivity reactions?
They can range from mildly annoying rhinitis to fatal anaphylaxis.
p.3
Innate Immunity vs. Adaptive Immunity
What is the role of interferons in innate immunity?
They block virus replication.
p.2
Innate Immunity vs. Adaptive Immunity
What is the main difference between innate immunity and adaptive immunity?
Innate immunity is non-specific and has a fast response, while adaptive immunity is specific and has a slow response.
p.1
Active and Passive Immunity
What is the significance of immunologic memory in vaccines?
It allows the immune system to respond more rapidly and effectively upon re-exposure to the same pathogen.
p.2
Innate Immunity vs. Adaptive Immunity
What are some components of innate immunity?
Natural barriers, phagocytes, and secreted molecules.
p.14
Major Histocompatibility Complex (MHC)
What is the significance of the peptide antigen binding groove in MHC molecules?
It allows for the binding and presentation of peptide antigens.
p.2
Innate Immunity vs. Adaptive Immunity
What is the role of Pattern Recognition Receptors (PRRs)?
PRRs recognize PAMPs and DAMPs in innate immunity.
p.2
Innate Immunity vs. Adaptive Immunity
What are DAMPs?
Damage-Associated Molecular Patterns, which are endogenous danger molecules released from damaged or dying cells.
p.11
Antigens and Antibodies
What are autoantigens?
Self antigens from normal host molecules, e.g., in systemic lupus erythematosus (SLE).
p.13
Hypersensitivity Reactions
What is molecular mimicry in the context of autoimmune diseases?
Infectious microbes may contain antigens that mimic self antigens, causing the immune response to react against self.
p.13
Major Histocompatibility Complex (MHC)
What is the function of MHC molecules?
MHC molecules display peptide fragments of protein antigens for recognition by antigen-specific T-cells.
p.12
Active and Passive Immunity
What do fetuses rely on for immunity before they can produce their own antibodies?
Maternal IgG transported across the placenta.
p.13
Major Histocompatibility Complex (MHC)
What is the primary function of Class II MHC molecules?
Class II MHC molecules are expressed on cells that present ingested antigens and respond to T-cell help, recognized by CD4+ lymphocytes.
p.15
Immune Response Phases
What is the role of T H 17 cells?
Recruitment of neutrophils and monocytes, and host defense against extracellular bacteria and fungi.
p.9
Antigens and Antibodies
What is a characteristic structure of the immunoglobulin superfamily?
A 110 amino acid polypeptide folded to create antiparallel beta pleated sheets held by intrachain disulfide bonds.
p.3
Innate Immunity vs. Adaptive Immunity
What are inflammatory mediators?
Cytokines and interleukins that can cause significant inflammation.
What is hematopoiesis?
The formation of different cellular elements of the blood from stem cells to mature forms.
p.17
Vaccine Types and Mechanisms
What does SARS-CoV-2 stand for?
Severe Acute Respiratory Syndrome Coronavirus 2.
p.11
Antigens and Antibodies
What is the role of NS-1 in dengue infection testing?
NS-1 is used to detect dengue viremia during the first 3 to 5 days of infection.
p.4
Innate Immunity vs. Adaptive Immunity
What is the role of cytokine production in macrophages?
Major functional activity, producing large amounts per cell.
p.8
Antigens and Antibodies
What is the function of the Fc region in antibodies?
It is the biologic effector region that binds to various cellular receptors and complement.
p.18
Immune Response Phases
How does Pneumococcus evade phagocytosis?
It has a large polysaccharide coat.
p.5
Major Histocompatibility Complex (MHC)
How is Ig/TCR diversity achieved?
Every B or T-cell expresses a different antigen recognition molecule created from multiple gene segments that undergo somatic rearrangement.
p.16
Active and Passive Immunity
What is an example of passive immunity?
Tetanus toxoid, usually given with an active tetanus vaccine.
p.10
Active and Passive Immunity
What is the purpose of a booster shot?
To maintain protective antibody levels over time.
p.10
Immune Response Phases
When is IgM anti-HBc present after Hepatitis B infection?
IgM is present early after infection as part of the primary immune response.
p.15
Immune Response Phases
What immunological reactions are triggered by T H 1 cells?
Macrophage activation and stimulation of IgG antibody production.
p.9
Antigens and Antibodies
What are some members of the immunoglobulin superfamily?
Antigen receptors on T & B lymphocytes, antigen-presenting molecules, NK cell receptors, and co-receptors on T-cells.
p.3
Innate Immunity vs. Adaptive Immunity
What is the purpose of neutrophil extracellular traps (NETs)?
To trap and kill pathogens extracellularly.
p.18
Immune Response Phases
What is the significance of the term 'The Great Escape' in immunology?
It refers to how pathogens develop evasion mechanisms despite the adaptive immune response, leading to the development of different vaccines.
p.2
Innate Immunity vs. Adaptive Immunity
What type of memory does innate immunity have?
Innate immunity has no memory.
p.10
Antigens and Antibodies
What are monoclonal antibodies used for?
They have a wide variety of uses in diagnostics and therapeutics.
p.14
Innate Immunity vs. Adaptive Immunity
What happens when the inhibitory receptor on NK cells is engaged?
The NK cell is not activated, resulting in no cell killing.
p.5
Major Histocompatibility Complex (MHC)
What characterizes Major Histocompatibility Complex (MHC) diversity?
MHC is polygenic and polymorphic, existing in different types of cells and exhibiting diversity.
p.2
Innate Immunity vs. Adaptive Immunity
What is the function of Toll-like Receptors (TLRs)?
TLRs are transmembrane proteins that recognize a broad range of specificities including proteins, nucleic acids, and glycans.
What distinguishes resting lymphocyte B and T cells?
They are morphologically similar when not activated.
p.10
Antigens and Antibodies
What does the suffix '-o-' indicate in monoclonal antibody nomenclature?
It indicates that the antibody is fully derived from mouse cells.
p.8
Antigens and Antibodies
What is the primary function of IgM?
It is produced in the primary response to an antigen, fixes complement, and serves as an antigen receptor on B-cells.
p.3
Innate Immunity vs. Adaptive Immunity
What is the role of Caspase 1 in inflammation?
It promotes interleukin-associated inflammatory responses.
p.12
Central and Peripheral Tolerance
What is the term used to describe the fetus in relation to the mother's immune system?
Naturally occurring allograft.
p.9
Antigens and Antibodies
Where is IgA primarily found?
In the gut mucosa and secretions.
p.3
Innate Immunity vs. Adaptive Immunity
What is the role of natural killer (NK) cells?
They induce apoptosis of virally infected or tumor-damaged cells without needing priming.
p.12
Epitopes and Antibody-Antigen Interaction
How are conformational epitopes recognized?
By B cells, created from amino acid residues in different parts of the polypeptide chain.
p.1
Innate Immunity vs. Adaptive Immunity
What is the difference in onset time between innate and adaptive immunity?
Innate immunity has a brief onset (within hours), while adaptive immunity has a slower onset (1-5 days).
p.18
Immune Response Phases
How do small RNA viruses evade the immune response?
They use RNA polymerase, an error-prone enzyme, leading to frequent mutations in the antigenic peptide sequence.
p.16
Central and Peripheral Tolerance
What is the fundamental property of the immune system regarding self-antigens?
Tolerance (unresponsiveness) to self-Ag.
p.16
Central and Peripheral Tolerance
What is the consequence of the breakdown of tolerance in the immune system?
It is the basis of autoimmune diseases.
p.11
Antigens and Antibodies
What is a hapten?
A substance that can bind to immunologic receptors but cannot elicit an immune response by itself.
p.10
Antigens and Antibodies
What is the first step in the process of harvesting monoclonal antibodies?
A mouse is challenged with an antigen.
p.13
Epitopes and Antibody-Antigen Interaction
What is an extended surface epitope?
An epitope that binds to an extended surface site, typically found on folded proteins like lysosomes.
p.16
Active and Passive Immunity
What is passive immunity?
Immunity achieved by injecting antibodies from an immune individual into an uninfected individual.
p.16
Active and Passive Immunity
What is a key difference between active and passive immunity regarding memory?
Active immunity provides memory, while passive immunity does not.
p.12
Hypersensitivity Reactions
What is Erythroblastosis fetalis?
A condition that exhibits cystic hygroma and can lead to hydrops fetalis.
p.3
Innate Immunity vs. Adaptive Immunity
What is the function of dendritic cells?
They capture protein antigens and present peptides for T lymphocyte recognition.
p.16
Central and Peripheral Tolerance
What is the role of antigen presenting cells in central tolerance?
They develop regulatory T cells.
What is clonal selection important for?
Creation of immunologic memory.
p.8
Antigens and Antibodies
What structural feature allows antibodies to interact with antigens that may be spaced far apart?
The hinge region provides flexibility.
p.10
Antigens and Antibodies
What are hybridomas?
They are formed by fusing spleen cells with myeloma cells.
p.17
Immune Response Phases
What is opsonization in the context of phagocytosis?
A process that enhances the ability of phagocytes to engulf and destroy pathogens.
p.14
Immune Response Phases
What is the role of dendritic cells in the immune response?
They present antigens to T cells in lymphoid organs.
p.14
Immune Response Phases
What is the outcome of the activation of CTLs (Cytotoxic T Lymphocytes)?
They can directly kill infected cells.
p.3
Innate Immunity vs. Adaptive Immunity
What triggers the formation of inflammasomes?
The presence of pathogenic bacteria, damaged mitochondria, or fragments like extracellular ATP.
p.9
Antigens and Antibodies
What is the function of IgG?
Can cross the placenta, binds to viruses, and neutralizes viruses and toxins.
p.13
Immune Response Phases
How is the T-cell receptor structure compared to immunoglobulin?
The T-cell receptor structure is comparable to a membrane-bound Fab fragment, consisting of alpha and beta chains.
p.9
Antigens and Antibodies
What is the immunoglobulin superfamily?
A group of molecules that share the immunoglobulin domain fold.
p.15
Hypersensitivity Reactions
What is the first step in the allergic response?
Dendritic cells present the antigen to naive T-cells or B cells, leading to T H 2 cell production.
p.8
Antigens and Antibodies
What is the structure of IgG composed of?
Two light chains and two heavy chains, with each chain having variable and constant regions.
p.3
Innate Immunity vs. Adaptive Immunity
What is the function of neutrophils?
Phagocytosis and bactericidal mechanisms.
p.3
Innate Immunity vs. Adaptive Immunity
What do macrophages do?
Involved in phagocytosis, bactericidal mechanisms, and antigen presentation to T-cells.
p.12
Immune Response Phases
What is the significance of the CD nomenclature established in 1982?
It categorizes cell surface molecules recognized by specific monoclonal antibodies.
p.15
Hypersensitivity Reactions
What mediators are released during immediate hypersensitivity reactions?
Vasoactive amines and lipid mediators.
