Immunology Overview and Key Discoveries

Immunological Surveillance

• Supported by Frank Burnet and Lewis Thomas in 1970.
• Confirmed by various scientific studies and observations.

Antibody Structure Discovery

• Discovered by D. Edelman and P. Porter in 1959.
• Refers to the structure of antibodies.

Nobel Prize for MHC

• Awarded to J. Dosset, B. Benacerraf, and J. Snell for their discovery of the Major Histocompatibility Complex.

Immune Defence Levels

• Organism's defense is categorized as innate and adaptive.
• The immune response is categorized and defined as having innate and adaptive components.

Immunobiological Drug Groups

• Include monoclonal antibodies.
• Other immunobiological drugs are likely included and may vary by source/study.

Thymocyte Development Factors

• Interleukin 7 and thymosins are crucial.
• Crucial factors for thymocyte development are present.

Thymus Involution

• Accelerated involution begins after puberty (around 12-14 years old).
• Thymus involution is associated with age, with accelerated changes following puberty.

Lymphocyte Population

• T cells are the largest population of lymphocytes.
• More details on lymphocyte populations and their respective roles should be present for further explanation including B cells and NK cells which are also critical components.

T-Lymphocyte Differentiation

• Antigen-dependent differentiation and proliferation occur in secondary lymphoid organs, such as lymph nodes and spleen.
• Antigen-dependent T cell differentiation and proliferation occur in specific lymphoid organs and secondary lymphoid organs.

Antigen Neutralisation Cells

• Neutrophils and Natural Killer (NK) cells neutralize antigens without prior exposure or antigen-dependent differentiation.

• Neutrophils and NK cells are important innate immune cells.

• Additional cells may also play a role in antigen neutralization.

• Macrophages: Phagocytic cells of the immune system.

• Live Attenuated Vaccine (e.g., MMR): A type of vaccine containing attenuated but live microorganisms.

• Antigen: A substance recognized by the immune system and can stimulate an immune response.

• Immunoglobulins (Ig): Serum proteins produced by B cells, binding to antigens for neutralization or marking for destruction by other immune cells. Classes include IgG, IgM, IgA, IgE, and IgD.

• Plasma cells: Antibody-producing cells.

• Fab region: The region of an antibody that binds to an antigen.

• Liver: Organ where complement system components are mainly synthesized.

• Complement System: A complex of defense proteins constantly present in the blood, enhancing the ability of antibodies and phagocytic cells to clear pathogens.

• Hapten: An incomplete antigen.

• B Lymphocytes: Responsible for humoral immunity, producing antibodies.

• Antigen-presenting cells (APCs): Dendritic cells, macrophages, and B cells.

• Class I histocompatibility antigens: Present on all nucleated cells (except erythrocytes).

• T lymphocytes: Play a crucial role in the specific immune response.

• Specific defenses of the organism: Alien (pathogen) → Presenting (APCs process and display antigens) → Recognition (T-cells, B-cells) → Neutralizing (Antibodies, Cytotoxic T-cells) → Memory Formation (Memory T-cells, B-cells) -> Rapid Response Upon Re-exposure

• APC (Antigen Presenting Cell): Macrophages, dendritic cells, and B cells; the first cell to interact with the antigen

• Antigen-independent differentiation of T-lymphocytes occurs in: Thymus

• C-reactive protein (CRP): Increases in the acute phase of bacterial inflammation.

• Exotoxins: Harmful bacterial proteins neutralized by specific antibodies.

• Light chain domains: 1 variable (VL) and 1 constant (CL) domain, allowing antigen recognition and immune functions.

• MHC: Molecule presenting antigens to lymphocytes.

• Alternative pathway of complement activation: Activated by lipopolysaccharide.

• Cytokines (e.g., IL-2, IFN-alpha): Used in therapy to enhance immune response.

• Complement membrane-attack complex: Component C5b-C9.

• Classical pathway activation of complement system: c1 binds to antigen-antibody complex.

• Properdin: Serum protein required in alternative complement activation.

• Perforin: Forms pores in target cell membranes, allowing entry of granzymes for killing.

• Paul Ehrlich: Coined the term "complement" in 1899.

• Langerhans cells: Macrophages localized in the skin.

• Histocompatibility antigens: Molecules involved in antigen presentation and immune recognition.

• Immunosuppressive therapy: Used to suppress rejection in organ/tissue transplantation.

• Apoptosis: Programmed cell death.

• IgM: Synthesized first.

• Antigen-Presenting Cell: Cell presenting the antigen to lymphocytes.

• Kupffer cells: Specialized macrophages in the liver.

• Passive Immunity: Type of adaptive immunity without immunological memory

• Chemotaxis: The first stage of phagocytosis

• Tolerance: Absence of immune response to a particular antigen while responding to others.

• Phagocytes: Part of the body's non-specific defense factors

• Hepatocytes: Cells that produce acute-phase proteins.

• Memory Cells: Basis for immunological memory.

• Neutrophils, Basophils, Eosinophils: Not antigen-presenting cells.

• CD4 molecule: Binds to MHC class II.

• IgA (mucosal immunity): Major immunoglobulin in healthy upper respiratory tract secretions.

• HLA-2 (Human Leukocyte Antigen Class II): Macrophage form of antigen presentation.

• Thymus: T-killer cells (CD8) differentiate

• Monocytes: Origin of macrophages.

• IgG: Only immunoglobulin that passes through the placenta.

• IgE tropism: Basophils; triggers allergic reactions.

• Memory + Plasma Cells: Result of antigen-dependent B-lymphocyte differentiation.

• Peter Medawar: Contributed to transplantation immunity.

• CD4+ and CD8+: T-cell phenotypes.

• IgG heavy chain domains: 1 variable, 3 constant domains.

• Effector T cells (Th1, Th2, Helper): T lymphocyte differentiation in peripheral organs.

• Alternative pathway of complement activation characteristic: C3

• Inactivated vaccines (e.g., rabies, polio, Hep A): Vaccine group.

• T helper cells, macrophages, dendritic cells: Synthesize interleukins.

• Primary immunoprophylaxis: Formation of immunity, preventing disease.

• ELISA method for HIV/AIDS diagnosis: Determines specific antibodies or antigens.

• Lymphocyte transfusion test, flow cytometry, Immunofluorescence test: Tests to assess functional state of B- and T-lymphocytes.

• Nylon test, Nitroblue tetrazolium test: Test to assess the phagocytic system.

• Precipitation reaction: Used to determine the concentration of different immunoglobulin classes.

• Agglutinins alpha and beta: Found in blood plasma.

• Agglutinogens A and B: Located on RBC surfaces.

• Agglutination: Determining blood groups and presence of specific antigens.

• Rh factor determination: Agglutination test using anti-D serum.

• Complement fixation test: Serological reaction using the hemolytic system as an indicator.

• Arthus reaction: Local hyperergic inflammatory reaction.

• Opsonization: Antibodies enhance phagocytic activity.

• Antigen detection knob evaluation: Affinity, tests, ELISA.

• Neutrophils, macrophages, eosinophils, mast cells: All involved in extracellular parasite destruction.

• Opsonins (C3b, antibodies): Proteins enhancing phagocytosis.

• IgM (decavalent): Pneumococcal conjugate vaccine subtype

• Bone marrow: Site of normal, juvenile white blood cell formation.

• Type I hypersensitivity: All atopic disorders are part of this hypersensitivity type.

• Antigen-antibody complex: Reason for specificity of serological reactions.

• IgE: Initial allergen ingestion in atopy.

• Cells per microliter (µL): Unit for white blood cell count.

• Urticaria, anaphylaxis: Clinical manifestations of type I hypersensitivity.

• Aluminum salts: Example of adjuvant in vaccines.

• Hemolytic disease of newborn: Fetal and maternal blood incompatibility.

• Type II hypersensitivity: Mechanism for development of hemolytic disease of the newborn.

• Type IV hypersensitivity: Cell-mediated immunity; does not involve antibody/immune complex.

• IgG and IgM: Antibody type involved in type II hypersensitivity.

• T helper: Antigen interacts with cell during GST

• Humoral immunity (IgE): Mechanism of immediate hypersensitivity.

• Memory B, T cells: Basis for immunological memory

• Naive T lymphocytes: Differentiation of CD8+ cells.

• Type II hypersensitivity: Antibody-dependent cytotoxic allergic reactions

• Hemolytic transfusion reaction: ABO-system conflict complication.

• Booster doses: Live attenuated vaccines are often required.

• Serum sickness, SLE, rheumatoid arthritis, post-streptococcal glomerulonephritis: Examples of type III hypersensitivity.

• IgM, IgG, IgA, IgE: Sequence of antibody synthesis in the effector phase.

• Type IV hypersensitivity: Tuberculin test example.

• Sensitization of T cells: T-lymphocytes bearing specific receptors for antigens.

• 24-72 hours: Timeframe for delayed-type hypersensitivity development.

• IgG, IgM: Immunoglobulins indicating transmitted infection.

• Production of antibodies, activation of immune cells: Occur in immunological stage of hypersensitivity development.

• Vaso-active amines: Mediators deposited in mast cells and basophils.

• Passive vaccination (rabies): Example of secondary immunoprophylaxis.

• Vaccination: Forms artificial, active immunity.

• Immune activation: Intended vaccine therapy effect.

• Enzyme reactions, ELISA: Methods for cytokine content determination.

• Lymphocytes not encountering antigen: Description of naive lymphocytes.

• Adhesion of particles: Second stage of phagocytosis.

• NK cells, macrophages, neutrophils, granulocytes: Cellular factors of innate immunity.

• Acquired immunity: Result if complementary antibodies are synthesized to an antigen.

• Immune response: Nature of tissue incompatibility.

• Attenuated vaccines: Vaccine containing live but weakened microorganisms.

• Granules/multi-lobed nucleus: Distinctive microscopic feature of neutrophils.

• Plasma cells: Synthesize millions of immunoglobulin molecules in an hour.

• Passive immunity: Immunity after serum administration.

• Liver: Performs hematopoietic function in the fetus.

• Antigen-presenting cells (APCs): Essential for antigen presentation.

• Sensitized lymphocytes: Characterized by high proliferative activity.

• Enzyme tests: Quantitative determination of complement components.

• T-lymphocytes: Leukocyte migration inhibition reaction (LMIR) assessed.

• Immunization with specific antigens: Homogeneous therapeutic serum origin

• Purulent inflammation: Increased number of neutrophils occurs here.

• IgM: ELISA can be used to diagnose diseases as early as first days by determining presence of this antibody.

• Cytoplasm of the cell: Location of NOD-like family receptors (NLRs).

• Frank MacFarlane Burnet: Author of the clonal selection theory.

• Paul Ehrlich: Creator of noninfectious immunology who formed modern immunology.

• Pathogen defense: Primary function of the immune system.

• NOD-like receptors: Receptors involved in inflammasome formation.

• Medulla of the Thymus: Location of Hassall's cells.

• Lymphopoiesis: Process occurring in the central organs of the immune system.

• RIG-I and MDA5 receptors: Recognize viral RNA in the cytoplasm.

• Lymphocytes and memory cells: Features of the secondary immune response.

• T cell maturation, differentiation: Function of the thymus hormone thymosin.

• Lysozyme: Peptide produced by macrophages and neutrophils.

• Eosinophils: Protect against large parasites; release toxic granules.

• Cell wall/outer membrane: Location of the somatic antigen.

• Muramic acid: Chemical composition of lysozyme

• MyD88: Obligate adaptor protein for activating the signalling pathway.

• Liver hepatocytes: Produce C-reactive protein.

• Antigen epitope, antibody paratope: Determines antibody specificity towards antigens.

• C-type lectin receptors (CLRs): Innate immunity receptors recognizing carbohydrate structures.

• TLR 5: Innate immunity receptor recognizing bacterial flagellin.

• Longer lasting period: Description of the primary immune response characteristics.

• Fusion with lysosomes: Stage following phagosome formation in phagocytosis.

• Phagolysosomes: Resulting structure formed in phagocytosis by joining of phagosome and lysosome

• Antigen chemical structure: Determines antigenicity.

• Mycobacterium tuberculosis: Pathogen inhibiting phagosome-lysosome fusion.

• T helper cells (CD4+), etc.: Subpopulations of T-lymphocytes.

• T cells and B cells: Macrophages cooperate with these cells during primary antigen recognition.

• Secretion of superoxide dismutase: Mechanism helping pathogens avoid phagocytosis.

• Spleen, lymph nodes: Organs involved in antigen stimulation to produce specific immune response and antigen neutralization.

• Complete/incomplete: Categorization of antigens by structure.

• Alternative pathway of complement activation: Description of the process.

• Macrophages/neutrophils: Most active cells in immune phagocytosis.

• M cells: Cells transporting antigens across the epithelium to MALT.

• Mucosa-associated lymphoid tissues (MALT): Initiation of mucosal immune response.

• Alpha-fetoprotein test: Diagnostic test for embryonal-type tumors.

• Trimer, dimer, J-chain, secretory component: Structure of secretory IgA molecules.

• Specificity: Immunoglobulins' ability to react with only a specific antigen.

• TGF-β: Cytokine playing a significant role in IgA production.

• Syncytiotrophoblasts: Cells expressing receptors for Fc-fragment of IgG.

• Plasmapheresis, immunosuppressants: Treatment methods for reducing autoantibody levels.

• IL-2: Cytokine activating cytotoxic T-lymphocytes.

• APCs: Cells expressing class II MHC

• Necrosis: Mechanism of cell destruction by T-killers.

• Leukocytes: Produce interferons.

• IgG: Ig found in blood of newborns.

• Activation of cells of innate immunity: Primary function of the Fc-fragment.

• Destroy target cells without phagocytosis: Correct characteristic of NK cells.

• MHC class II, CD80: Molecules expressed on antigen-presenting cells.

• BCR, CD40-CD40L: Receptor involved in B lymphocyte activation.

• Plasma cells: Cells involved in antibody production.

• C1, C4, C2, C3: Proteins activated by classical pathway triggering.

• Suppress immune response: Primary function of regulatory T cells (Tregs).

• TCR, MHC: Structure for interaction.

• APC, helper T cells: T-killer interaction partners.

• Antiviral immunity: Function of type I interferons (alpha and beta).

• Recognition of missing/attenuated MHC-I molecule: Mechanism of NK-cell activation.

• B cells: CD 19 marker.

• Activate B cells for antibody production: Th2 activating cells.

• Recognize PAMPs (pathogen-associated molecular patterns): Function of TLRs.

• IL-12, IL-18: Cytokines promoting interferon-gamma production.

• IgG, IgM: Immunoglobulins with antitumor activity

• Immune evasion by tumor cells: Cause of tumor development with immune response.

• DAF (decay-accelerating factor): Complement inhibitor.

• Antigen-specific suppression of immune response: Characterization of induced tolerance.

• Transcytosis: Transfer of antibodies from blood to mucosal secretions.

• Neutrophils, macrophages, cytotoxic T cells: Phagocytic cells.

• Activate macrophages; cytotoxic T cells: Primary function of Th1 cells.

• Immune system (ex. adaptive immune system): Not part of non-specific defense.

• Immunoglobulins, etc: Not humoral factors of non specific defense.

• Dendritic cells, macrophages: Cells preferentially activated via TLRs.

• Negative selection, central tolerance: Processes ensuring tolerance to self-antigens.

• Blood smear/differential count: Method for determining the different types of leukocytes.

• CD3, CD19: Surface marker receptors identifying T and B lymphocytes.

• Humoral immune system: System having serum immunoglobulin levels reflecting functional status.

• Immunoassay: Reaction involving labelled antigens or antibodies.

• Enzymatically: How antigen or antibody is labelled in ELISA.

• T-lymphocytes: Organism for EAC-rosette formation reaction function identification and counting.

• IgE, mast cells: Mediators for immediate-type hypersensitivity.

• T-lymphocytes (CD4+, Th1 cells): Participants in delayed-type hypersensitivity.

• Tissue damage from extra immune response: Clinical manifestation of hypersensitivity.

• Rapid onset, life-threatening allergic reactions: Characteristic of anaphylaxis.

• T-lymphocyte, macrophage: DHT reaction cell participants.

• Rh incompatibility between mother and fetus: Cause of hemolytic disease in newborns.

• IL-5: Interleukins stimulating eosinophil activation in allergic reactions.

• V-D-J recombination: Process providing antibody diversity.

• Hybridoma technology: Method for producing monoclonal antibodies.

• Memory cells: Factors responsible for difference between primary and secondary response.

• Lymph nodes: Site of antigen presentation by a macrophage to a T cell.

• CD4+, CD8+: T-cell phenotypes.

• 1 variable, 3 constant: Domains in IgG heavy chain.

• Effector T cells (Th1, Th2, Helper): T-lymphocyte differentiation in peripheral organs.

• C3: Characteristic of alternative pathway.

• Immune activation: Vaccine therapy purpose.

• Lymphocytes not encountering antigen: Correct term for naive lymphocytes.

• Various : Cell origin, localization and function

• Chemical structure of antigen: Determines antigenicity.