Immunology Study Guide PDF

complement proteins - native protein in blood circulation Immune System - induce inflammation as response against pathogens - in autoimmune diseases, complement is consumed...

complement proteins - native protein in blood circulation Immune System - induce inflammation as response against pathogens - in autoimmune diseases, complement is consumed Key Terms - example B anti-A antibody + A antigen + complement immunity - resistance = immune complex → lysis → hemoglobin release → death - long-lasting: e.g. chicken pox, measles B anti-A antibody + A antigen → agglutination - Zinc is a mineral and a good immunobooster epithelial barriers immune system - identifies pathogens as foreign - example impenetrable skin due to waxy keratin, - protection against diseases by avoiding antigen in IS as long as it is intact - cells and organs are key players phagocytes immunology - study of IS in states of health and diseases - example - deals with malfunctions of IS MPS (mononuclear phagocyte system) cannot recognize self vs non-self - lysozyme: targets PDG Gram (+) serology - study of antigen-antibody reaction : found in saliva and tears APC (antigen-presenting cell) - highly phagocytic Malfunctions of Immune System - first to encounter/welcome invaders autoimmune diseases - self (autoantibody) vs self-antigen - middle of innate and adaptive immunity - example SLE (systemic lupus erythematosus) - common in females - brings foreign substance in its lysosome, then processed as fragmented antigen, hypersensitivities which is coupled to MHC class II - example type 1 (allergic) (major histocompatibility complex) immunodeficiency - lose capacity of self vs. self then released into vesicle and out of APC to be presented to T-cells - examples immunocompromised (e.g. HIV) - e.g. macrophage - most common APC geriatric - 65 y/o dendritic cell and mast cell - due to immunosenescence neutrophil everytime cell enters mitosis, tip of chromosomes become thinner natural killer cells - lymphocytes with granules that automatically destroy virally infected and cancer cells G1 becomes G0 gastric acid pediatric - 6 mos to make antibody - has diminishing maternal antibody Adaptive that lasts for 6-12 mos - specific antibody response depends on antigen - due to underdeveloped IS parameter of adaptive immunity transplant rejection e.g. anti-hepa B antibody targets hepa B antigen - graft vs host: graft tissue attacks host all are immunogammaglobulin - host vs graft: host attacks graft (rejection) - lymphocytes can be distinguished but T-cell vs. B-cell - example blood transfusion cannot be determined in peripheral blood smear best stain for blood is Wright-Giemsa Types of Immune System T-cell - cell-mediated - mature = effector T-cell 1. when MHC class II tag is recognized 2. lymphoblast - lymphocyte enlargement 3. lymphoblast proliferation to amplify IS basophil, mast cell, and dendritic cells - generated in bone marrow, matures in thymus - types TH - helper, upregulates IS - 2 TH : 1 TS = immunocompetent Natural/Innate - low no. / reversal of TH:TS = immunodeficiency - non-specific - when vaccine is not effective, - causes generic, localized inflammation for protection it could be due to inactivated TH and weak IS redness/rubor heat/calor TS - suppressor, downregulates gene expression swelling/tumour pain/dolor TC - cytotoxic, analogous to NK cell loss of function/functio laesa - when activated by antigen, it destroys virally infected and tumor cells B-cell - humoral (liquid), through the help of antibodies - erythroblastosis: newborn complication - generated and matures in bone marrow : Rh- female + Rh+ male → 1st born is and Rh+ alive, but mother produces anti-Rh - in birds, it matures in bursa of fabricius neutralized by RhoGAM Additional Information attaching to it, preventing lysis → 2nd born is attacked by antibody Serum is the liquid after blood has clotted, but plasma is the liquid with an addition of anticoagulant. - majority of Filipinos are Rh+ Leishmania can survive inside highly acidic environments - ABO compatibility: mild effects due to IgM pentamer like lysosomes (strong hydrolytic enzymes). Platelets/Thrombocytes Cells of the Immune System - 150,000-400,000 per μL - not true cells, but remnants of megakaryocytes granules and cytoplasm grows by 4x in size → tears apart → platelet located only in bone marrow - anucleated, but has mtDNA WBC/Leukocytes - fewest in count hematopoietic stem cell - multipotent/pluripotent cell - visit immunologist when high/low WBC count - found in bone marrow, where all IS cells originate - -philia means high WBC (infection) - lymphoid stem cell: mainly produces adaptive immunity - -penia means low WBC (weak IS) - myeloid progenitor: produces natural immunity histiocytes - tissue macrophages WBC/Leukocytes - Granulocytes RBC/Erythrocytes eosinophil - bilobed, red-orange granules in cytoplasm - high eosinophil = asthma - most abundant due to O = parasitism (Charcot Leyden crystals) - biconcave, anucleated for efficient O distribution causes perennial cough and cold hence, never used for genetic analysis basophil - bilobed, large, blue-black granules in entire cell maturation of erythroblast - mast cell: tissue basophil in bone marrow, leads to loss of nucleus then it releases in peripheral blood - high basophil = allergic reaction - visit hematologist when RBC is nucleated neutrophil - in cytoplasm, pinkish, azurophilic granules - males have 5.5 L due to high androgen due to neutral stain erythropoietic in action - bilobed or trilobed - females have 4.5 L due to low androgen and menstruation - first line of defense; hence, most important - lifespan of 2-3 mos - in presence of antigen, it becomes microphage - when near death, it changes osmotic pressure, - high neutrophil = bacterial infection becomes permeable, allows water to enter, and bursts (discocyte → spherocyte) WBC/Leukocytes - Agranulocytes - upon death, it releases hemoglobin lymphocytes - high nucleus to cytoplasmic ratio heme = ferrous (Fe+2) + protoporphyrin - large and compact nucleus, favorable for genetic analysis recycled - found in blood, lymphoid tissue, and most organs excess is stored - act as receptor for specific antigens, in ferritin (a protein) mediating adaptive immune response of liver as ferric (Fe+3) - for DNA molecular study and identity analysis metabolite - high lymphocytes = immunodeficiency or viral infection becomes bilirubin (yellow pigment) - T-cell and B-cell B1 - high affinity with brain fats; hence, toxic and monocytes - largest WBC in peripheral blood causes mental retardation - horseshoe/kidney-shaped nucleus - causes cyanotic due to few O, - along with amorphous, collagen-producing fibroblast, then jaundice they fill-in wounds that are almost healed globin (protein) is recycled - in presence of antigen, it becomes macrophage - high RBC = erythrocytosis - high monocyte = TB, other bacterial infection - low RBC = anemia  - myeloma protein: first model to study antibody structure Organs of the Immune System multiple myeloma - due to abnormal protein that may lead to bone cancer Primary Lymphoid - when turned on, it is on cell surface bone marrow - replaced by fetal liver and Y-shaped with quotation mark hematopoietic, 2 heavy chain 2 light chain bursa-like organ linked by disulfide bond thymus - atrophies/decreases in size as we age determines antibody type has kappa or lambda gene Secondary Lymphoid 1 variant and 1 constant region - when removed, slightly weakens IS - when turned off, it is mature - where APC proceeds after activation to be introduced - secreted by plasma into blood : T-cell gets bigger (swelling), divides, mature antibody-producing cell, from B-cell and releases cytokines to activate other lymphocytes - J-chain: joins monomers, making them heavy; : swollen means infection due to APC hence cannot cross placental barrier - lymph nodes: has lymph vessel carrying lymphatic fluid - 1 monomer = 2 heavy chain and 2 light chain = 2 FAB that is water and where lymphocytes are found - paratope/fragment antibody binding site : swollen at back of ear or neck = weak lungs : binds antigen epitope : swollen at armpit = breast infection : composed of variable regions of heavy and light chain : swollen at groin = STI - fragment crystalline (FC) - tonsil: adenoid organ : binding site for complement and APC - spleen: filters blood and distributes T-cell and B-cell : crystallizes when low ionic salt concentration : graveyard of blood : many biological functions - gut-associated lymphoid tissue : allow crossing of placenta : has probiotics, phagocytes, and immune cells : composed of constant regions of heavy and light chain - cutaneous-associated lymphoid tissue IgG and IgA have 3 Antigen and Antibody IgM and IgE have 4 Active and Passive Antibody Antigen active → IS makes antibody (humoral) - any substance that will elicit antibody production passive → receives antibody from others antigenicity/immunogenicity natural active - body makes own antibody - ability of substance to elicit immune response - develops natural protection when exposed to antigens - immunogen: more specific in adaptive immune response natural passive - maternal antibody Adevention Antigen - Characteristics of a Good Antigen artificial active - prophylactic vaccination (e.g. anti-hepa B) foreignness - more foreign, more immunogenic artificial passive - therapeutic toxoid (e.g. anti-tetanus) - tissue of mouse to dog has stronger immune response Types of Antibodies (GMADE) than tissue of mouse to rodent chemical complexity - more complex, more immunogenic monomers - protein quaternary structure is the most immunogenic IgG - 150,000 Da molecular weight - high MW, more immunogenic - anti-Rh - when antigen is light or incomplete (e.g. Hapten), - can cross placenta, causing hemolytic disease of newborn it is combined with adjuvant to make it more immunogenic - 2nd encounter: chronic infection chemical nature - proteins are more antigenic than CHO : anamnestic response (long-lasting immunity) - CHO usually has epitope - associated with booster dose portion of antigen that will attach to - most abundant (80% of Ig) FAB (fragment-antigen-binding) site of antibody, causing humoral IR serum IgA - 160,000 Da can also bind to T-cell receptor - protects mucosal tissues from microbial invasion 5-15 amino acid long - maintains immune homeostasis with the microbiota IgD - 180,000 Da - you will have hepa D if you have had hepa B Antibody Structure IgE - 180,000-200,000 Da - characterization of antibody is based - linked to allergic response on X-ray diffraction/crystallography dimer agglutinogen - insoluble, particulate antigen secretory IgA - 385,000 Da - e.g. heme agglutination (RBC) - e.g. hepatitis B heme agglutination - found in saliva and colostrum : RBC serves as carrier of hepatitis B antigen - 2nd most abundant (13% of Ig) : added to Px serum pentamer latex agglutination (latex) IgM - 900,000 Da (heaviest, cannot cross placenta) - e.g. rapid plasma reagin (nonspecific test for syphilis) - anti-A and anti-B : latex is antigen-coated - 1st encounter with antigen (acute, recent) (cardiolipin, lecithin, cholesterol) - associated with first vaccines : added to Px serum - only 6% of Ig agglutinin - IgM antibody Additional Information has 10 FAB, creating lattice formation non-reactive IgG and IgM = have not yet encountered used in blood typing serum Overview of Stages of Immune Response Steps in Agglutination sensitization - coating/attachment antigen recognition → innate response → adaptive response lattice formation - agglutination 1. microbial invasion/priming Avoid Blood Transfusion 2. macrophage processes antigen and releases interleukin There are many blood group antigens; 3. activation and proliferation of TH antibodies may cause disseminated IV coagulation. 4. TH releases interleukin to activate B cell Cross-matching test determines compatibility 5. B-cell proliferation, turning into plasma or memory cells via mixing of donor’s RBC and recipient’s serum. resistance to certain microbial outbreak due to first encounter familiarity Precipitation precipitinogen - soluble antigen Type 1 Hypersensitivity - Allergy precipitin - antibody allergic reaction - pruritus (itchiness) and equivalence zone - site of visible precipitation urticaria/hives (red, itchy, bumps on skin) - equal no. of antigen and antibody - example zoning phenomenon - no maximum precipitation chitin allergen + IgE antibody + effector = degranulation - results in false negative degranulation - when basophil granules is released in blood circulation - requires serial dilution to determine equivalence zone has substances that causes - prozone - excess antibody wheal-flare response - postzone - excess antigen due to dilation of blood vessels VDRL anaphylactic shock - life-threatening allergy, as respiration may be arrested - non-specific serological test for syphilis - shock: sudden drop in BP - detects reagin (antibody-like substance) - ER immediately Ouchterlony double immunodiffusion - pantal - antigen-antibody reaction in gel sensitization - coating of antibody to antigen, - positive line of precipitation but not yet agglutinated desensitization - familiarizing one’s body Neutralization to get used to allergen by little-by-little consumption - to overcome Chemical Mediators of Allergic Reaction - antibody nullifies toxic effect of antigen in Granules - e.g. anti-tetanus, anti-diphtheria, RhoGAM for anti-Rh heparin - natural anticoagulant (makes blood liquid) Lysis serotonin - vaso-constricting substance - requires complement that binds to FC of IgG histamine - major reason of cardinal Wheal-flare hemolysis - when incompatible RBC is transferred, - provokes allergic reaction IV coagulation occurs - treated by antihistamine (e.g. Cetirizine) to neutralize - antigen should not meet antibody (hemolysin) - when hemoglobin is released, Antigen-Antibody Reaction its stroma causes clogging in glomeruli of kidney - e.g. hemolytic disease of newborn Agglutination - cyanosis: RBC bursts open; hence, lack of O - forms clogging/aggregation - jaundice: bilirubin (hemoglobin by-product)  accumulates in skin and eyes - TC destroys β-cell of islet of Langerhans of pancreas - neurotoxicity: bilirubin and NH3 goes to brain fats type II - insulin resistance - mental retardation gestational DM - bloated stomach of pregnant women drug-induced hemolytic reaction - caused by human placental lactogen - due to allergies in certain drugs - offspring weighs 7-8 lbs or when your body develops antibody to drugs - may or may not return to normal glucose levels - hemoglobinuria: causes bright red urine bacteriolysis - e.g. Pfeiffer phenomenon - V. cholerae lysis Response against Parasites Phagocytosis/Opsonization - too large to be phagocytized IgE - FC is saturated by mast cell - requires antibody (opsonin) for allergen to be phagocytized - FAB attaches to parasite surface T-Cell Activation and Differentiation - leads to degranulation, wherein enzymes destroy parasites Hyperparasitic Px Key Terms - abdomen is bloated due to its high adult parasitic load cluster of differentiation (CD) - acts as co-receptor/ligand : Ascaris parasitizes hollow organs (lumen intestine) - seen at T-cell surface : forms bolus, clogging lumen of intestine memory/anamnestic cell - long-lasting immunity : when disturbed, it gets erratic and escapes through holes and rapid response due to previous encounter of antigen : can obstruct gall bladder/appendix, causing appendicitis - associated with graft reactive memory T-cells and graft rejection Major Histocompatibility Complex - innate memory: T-cell in intestine and lungs, which are two routes of antigen entry - large locus in DNA effector cell - stimulated/activated by antigen position occupied by gene naive cells - when not encountered/activated by antigen - genes has set of closely linked of polymorphic genes cytokines - for cell-cell communication - codes for cell surface proteins - e.g. monokine (like IL-1) lymphokine MHC I MHC II IL-6 - proinflammatory, anti-inflammatory myokine location - all nucleated cells, immune cells Types of T-Cells excluding platelets TH - secretes cytokines to communicate with other IS cells - somatic cells, labeling self - activates other T cells by CD4 (co-receptor) and B7-CD28 (co-stimulatory signal), human releasing IL-2 to generate T-cell clones leukocytic HLA-A, HLA-B, HLA-C HLA-D (DP, DQ, - basis of classification: cytokine that induce differentiation antigen DR) (HLA) gene TH2 - muster transcriptional regulation cytokine it produces and secretes nature of endogenous exogenous TH17 - stimulates neutrophil to site of bacterial infection antigen (inside body (extracellular presented like cytosolic peptides like - IL-22: chemical mediator proteasome) lysosomal proteins) : induces epithelial cell to produce antimicrobial peptide peptide ER specialized vesicle TS / TReg - limits immune response, preventing autoimmunity loading site - low levels may cause SLE recognition CD8 CD4 - high levels in immunocompromised Px TC - granulated lymphocyte structure 1 membrane 2 membranes α-chain (MHC gene) more amino acids has granulysin and granzyme β-chain longer peptides has lysozyme that perforates target cell (β2-microglobulin gene) - concentrated in lymphoid organ and bone marrow - highly proliferative MHC III - complement components (e.g. Tnf) - CD8: recognize antigen with MHC I - found in lytic reaction and immune complex : co-stimulation/activation occurs by IL-2 Systemic Lupus Erythematosus and other cytokines produced by TH - excessive immune complex settle at glomeruli of kidney - CD28: costimulatory signal - antinuclear antibody (ANA): Dx of Px with SLE - associated with polymyositis, liver cirrhosis, and hepatitis C - complement assay: confirmatory test - associated with diabetes mellitus : low complement = antigen-antibody uses them type I - insulin absence  Other Notes T-Cell Dependent v.s. T-Cell Independent sepsis - treated by latest generation IV antibiotics T-cell dependent - requires T-cell for IS activation (100% bioavailability) - antigen processing and presentation Sweets provoke cough and tonsilitis. 1. opsonin tags antigen Weil-Felix test for Rickettsiae 2. macrophage phagocytize antigen Widal test for Salmonella typhi 3. antigen is delivered into lysosome to be fragmented protein denaturation - 40-60oC (56oC for complement) 4. antigen is coupled to MHC II parasites and low Fe = decreased brain function 5. macrophage releases cytokines (IL-1) to activate T-cell Blood type O lacks antigen. 6. antigen is transported by vesicle to present it to TH, Haptoglobin - transport protein of free hemoglobin, activating cellular immune response bringing them to spleen 7. TH proliferates (clonal expansion) - continuous hemolysis → binding sites are saturated with hemoglobin → haptoglobin level is zero 8. TH releases IL to activate B-cell Schistosoma eggs that are trapped in liver parenchyma are 9. B-cell becomes plasma coated by WBC (granuloma) and collagen fiber (fibrosis)., 10. plasma creates antibody causing hepatosplenomegaly T-cell independent - readily stimulates B-cell 1st line of defense - intact skin, mucus membrane 2nd line of defense - antimicrobial substances, peptides, inflammatory reactions, fever 3rd line of defense - cells of adaptive IS T-cell epitopes are short peptides B-cell epitopes are more complex Rh - IgG Kappa and Lambda are light chains of immunoglobulins and cannot be both present in a single antibody molecule, but a person can produce both types. Protease enzyme 1. Pepsin - Cleaves below the hinge region, producing F(ab’)2 and an Fc fragment. 2. Papain - Cleaves above the hinge region, producing two Fab fragments and an Fc fragment. Phytohemagglutinin (PHA) / Lectin “Dogta” in Tagalog refers to plant extracts (lectins). PHA is used to stimulate lymphocyte division in culture, not just growth. Blood sample process (for karyotyping) 1. Collect lymphocytes. 2. Culture and add phytohemagglutinin (PHA) → stimulates mitosis. 3. Add colchicine to stop cells in metaphase. 4. Hypotonic treatment to spread chromosomes. 5. Fix and stain (e.g., Giemsa stain) for visualization. Lectin General term for carbohydrate-binding proteins that agglutinate cells, especially RBCs. Dolichos biflorus & Ulex europaeus Dolichos biflorus - Binds A1 antigen (used to distinguish A1 from A2). Ulex europaeus - Binds H antigen (used to identify H antigen presence). Anti-A = Blue, Anti-B = Yellow (Standard serological testing color coding). Epistasis Epistasis refers to gene interaction where one gene can mask the effect of another (e.g., H gene masking ABO blood type in Bombay phenotype). B-cell receptor (BCR) Membrane-bound immunoglobulin (IgM or IgD) with CD79A/CD79B as signaling molecules. Light & Heavy Chains (Loci) 1. Kappa chain - Chromosome 2 (2p11) 2. Lambda chain - Chromosome 22 (22q11) 3. Heavy chain - Chromosome 14 (14q32) Chemical Bonds Correct: Ester bond - Lipids Disulfide bond - Antibodies (holds heavy and light chains together) Peptide bond - Proteins (bonds between amino acids) Glycosidic bond - Carbohydrates Hydrogen bond - DNA base pairing Protein Electrophoresis (PAGE) Proteins are negatively charged at pH 8.6. Polyacrylamide gel electrophoresis (PAGE) is used for protein separation. Setup: Vertical electrophoresis (cathode - to anode +). Antibody (Ab) Functions Heavy chain determines the isotype (IgG, IgA, IgM, IgE, IgD). Heavy chain is responsible for the biological function of the antibody. When an allergen binds to IgE (via Fab), mast cells bind to FcεR, causing degranulation. Mast Cell Mediators in Allergy (Hypersensitivity) Histamine - Increases blood vessel permeability, causing swelling and redness. Heparin - Anticoagulant. Serotonin - (In some species, not in humans) causes smooth muscle contraction. Vasodilation → Leads to allergy symptoms (redness, swelling, itching). Complement System A group of plasma proteins that enhance innate and adaptive immunity. Heat-sensitive (thermolabile). Glycoproteins produced mainly in the liver. Key functions: Opsonization, cell lysis (via MAC), chemotaxis. Jules Bordet Identified the complement system. Complement Inactivation 56°C for 30 minutes inactivates complement (important for serological tests like VDRL). VDRL vs. RPR VDRL (Venereal Disease Research Laboratory test) - Uses heat-inactivated serum to detect syphilis (Treponema pallidum). RPR (Rapid Plasma Reagin test) - Uses charcoal particles for macroscopic agglutination. Complement Activation C1q is the largest component of the complement system and binds to antibody-antigen complexes. Complement Components: B is bigger than A, except for C2A (C2A is larger than C2B). Key Complement Functions Membrane Attack Complex (MAC) - Forms pores in bacterial membranes (C5b-C9). Chemotaxis - Attracts WBCs to infection site. Systemic Lupus Erythematosus (SLE) Multisystem autoimmune disease. Diagnostic tests: ANA (Anti-Nuclear Antibody test) - Detects autoantibodies. Anti-dsDNA - More specific for SLE. ASO (Anti-Streptolysin O test) - Used for post-streptococcal complications (e.g., rheumatic fever), not SLE. Complement System Enhances Immune Response Three pathways of complement activation: 1. Classical Pathway - Activated by antigen-antibody complexes (C1, C2, C4). 2. Lectin Pathway - Activated by mannose-binding lectin (MBL) binding to microbial surfaces. 3. Alternative Pathway - Spontaneous activation on pathogen surfaces (C3). Lectins Lectins are carbohydrate-binding proteins that agglutinate RBCs. Phytohemagglutinin (PHA) - Plant-derived lectin used to stimulate lymphocyte proliferation. Dolichos biflorus - Specific for A1 antigen (distinguishes A1 from A2). Ulex europaeus - Binds H antigen (used for Bombay phenotype typing). ABO Subgroups A1 has a strong reaction; A2 reacts weakly with anti-A reagents. Distinguishing A1B from A2B → Use Dolichos biflorus lectin (binds only to A1). Avidity Refers to the strength and speed of antigen-antibody binding. Final Corrections & Clarifications Summary 1. Pepsin cleaves below hinge → produces F(ab’)2 + Fc. 2. Papain cleaves above hinge → produces 2 Fab + Fc. 3. IgE binds allergens → mast cell degranulation → histamine, heparin, serotonin release. 4. Serotonin is not a major human mast cell mediator (histamine is). 5. Complement system activation has 3 pathways (classical, lectin, alternative). 6. Ulex europaeus binds H antigen (used in Bombay phenotype typing). 7. VDRL (microscopic) vs. RPR (macroscopic charcoal test) for syphilis. 8. A1B vs. A2B → Use Dolichos biflorus lectin.