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| 5396958475 | Innate immunity | Arm of the immune system that is *present from birth and present before the onset of infection* that constitutes *non-specific immune mechanisms* for defense against pathogens. |  | 0 |
| 5397388052 | Acquired Immunity | Requires *recognition specificity* to foreign, non-self, antigens. Must be *induced b*y other immunoregulatory agents, usually part of the *innate immune system*, to become active against infections or tumors. Properties include: 1.* Antigen-specificity*- recognizes antigens, proteins, carbohydrates, lipids, or nucleic acids. 2. *Memory*- Results in increased reactivity upon repeated antigen or infectious agent exposure. 3. *Regulation*- Discrimination between* self and non-self *to prevent autoimmune reactions. |  | 1 |
| 5397426615 | Components of Acquired immunity | *B- lymphocytes* which differentiate into plasma cells that produce antibodies. *T-lymphocytes: T-helper cells* which activate macrophages and other lymphocytes, *Cytotoxic T-cells *which kill infected or tumor targets, *Regulatory T-cells* which down-regulate, suppress or tolerize other lymphocytes. | | 2 |
| 5397448248 | Antigen presenting cells (APCs) | Cells that can ingest foreign molecules or pathogens and display the antigens on the cellular surface resulting in activation of humoral and adaptive responses. Includes: Macrophages, Dendritic cells, Langerhan's cells. |  | 3 |
| 5397460042 | Immunoglobulins | Aka Antibodies, produced by B-cells and have antigen-specific receptor cells. Consist of 2 heavy chains and 2 light chains linked via disulfide bridges. 5 sub-types: IgM, IgD, IgG, IgA, IgE. |  | 4 |
| 5397479641 | VDJ joining | Generation of antigen binding diversity through extensive DNA rearrangement resulting in a unique combination of VDJ DNA regions. Occurs after exposure to antigens. The order of the VDJ segments before recombination is conserved between individuals. The mechanism of recombination is coordinated by *recombinase-activating genes RAG-1 and RAG-2* which recognize specific DNA signal sequences of a heptamer,spacer (12 or 23 bp) and a nonamer recombination signal sequence. *If RAG gene is impaired or missing SCID can arise.* |  | 5 |
| 5397397903 | Immunogen | Any substance capable of inducing an immune response | 6 | |
| 5397486271 | Clonal Selection | The binding of B or T lymphocytes to specific antigens results in a large proliferation of antigen-specific activated lymphocytes. | 7 | |
| 5397496755 | Secondary response of adaptive immunity | Memory of previously encountered antigens results in a faster and greater immune response upon subsequent antigen exposure. |  | 8 |
| 5397400612 | Antigen | Substances capable of reacting with preformed antibodies or activatable cells (specific portions of substances that have high specificity for antibody binding sites). | 9 | |
| 5397349587 | Immunodeficiency or Hyporeactivity | Inability to recognize and control health-threatening agents leading to an absence of immune function or specific immune response. Causes can be congenital or acquired, due to senescence, iatrogenic, due to malnutrition, malignancies or infectious organisms, or due to trauma or stress. | 10 | |
| 5397364844 | Categories of immunodeficiency | 1. Neutrophil disorders 2. Antibody deficiency 3. Complement Deficiency 4. T-cell dysfunction | 11 | |
| 5397308409 | Hypersensitivity Disease | A definable immune response that produces harm to the host as opposed to protection. Can occur due to inappropriate response to foreign material, excessive magnitude of response, prolonged duration of response, or the Innocent bystander effect where an immune cell displaying foreign antigens of a virus or bacteria is killed by the host immune response. | 12 | |
| 5397272067 | Type 1 Hypersensitivity | IgE mediated hypersensitivity Ex: Allergies |  | 13 |
| 5397273800 | Type 2 Hypersensitivity | Cytotoxic ANTIBODY mediated cell destruction Ex: Autoimmune hemolytic anemia | | 14 |
| 5397276389 | Type 3 Hypersensitivity | Immune Complexes of Antigen and Antibody Ex: Serum sickness | | 15 |
| 5397276390 | Type 4 Hypersensitivity | Delayed type hypersensitivity reactions. T-cell and Macrophage mediated. Ex: Tuberculosis | | 16 |
| 5396976316 | 4 components of innate immunity | 1. Anatomic 2. Physiologic 3. Phagocytic and endocytic 4. Inflammatory | 17 | |
| 5397004283 | Anatomic barriers of innate immunity | *Skin*: thin outer epidermis, and thicker underlying dermis. Impedes entry of foreign material. *Sebaceous glands*: produce* sebum, comprised of lactic acid* and fatty acids which *reduce skin pH* inhibiting microbial growth. *Mucous membranes*: covered by cilla, serve to trap organisms and propels them out of the body. |  | 18 |
| 5397028341 | Physiologic barrier | Includes *body temperature, low pH, chemical mediators, lysozymes, complement system, lactoferin* (breast milk and skin secretion-inhibits bacterial growth), low stomach pH. All of these factors work to inhibit bacterial growth and prevent entry into the body. | | 19 |
| 5397065520 | Phagocytic and Endocytic barriers | *Blood monocytes, tissue macrophages, PMNs*. Bacteria are ingested into phagocytic vessicles and *fuse with lysosomes creating phagolysosomes* which degrade entrapped microorganisms. *Interferons Alpha and Beta* are found within nucleated cells which* inhibit viral expansion*. | 20 | |
| 5397108701 | Inflammation | A response of living tissue to damage of vascular tissue. Its purpose is to deliver defensive materials into the damaged areas. | 21 | |
| 5397118893 | 4 signs of inflammation | Redness (rubor)- due to dialtion of small blood vessels. Swelling (tumor)- Extravascular fluid accumulation (edema) and inflammatory cell migration. Heat (calor)- vascular dilation and increased blood flow (hyperaemia) chemical mediators lead to systemic fever. Pain (dolor)- stretching and distortion of tissues by edema, pus pressure. Chemical mediators (bradykinin, prostaglandins, serotonin). | 22 | |
| 5388364794 | Harmful effects of fluid exudate | release of lysosomal enzymes by inflammmmatory cells.Destruction of normal tissues by enzymes. Swelling and obstruction of ducts, lymphatics or possible ischemic damage (vascular constriction due to inc. pressure) | 23 | |
| 5388380896 | Chemical mediators of inflammation | chemical mediators can act on the local level or systemic level. Some local mediators can move into the blood stream and have systemic effects as they work at longer distances. |  | 24 |
| 5388414398 | Kinin | any of a group of substances formed in body tissue in response to injury. They are polypeptides and cause vasodilation and smooth muscle contraction. *Bradykinin* is very important in both *inflammatory reactions* and *pain signalling* *INC Vasodilation, INC vascular permeability, INC Pain sensation* |  | 25 |
| 5388440747 | Fibrinolytic cascade | | 26 | |
| 5388443327 | Arachidonic acid metabolites | 27 | ||
| 5388452076 | Hematopoiesis | The formation of blood cells derived from pluripotent hematopoietic stem cells in the bone marrow. |  | 28 |
| 5388468825 | Leukocytes | White blood cells that provide either innate or specific adaptive immunity. Includes: 1. *myeloid cells- non-specific innate* immunity. 2. *non-specific lympohid* cells (*NK-cells*) 3.*Lymphoid* cells: *Humoral (B Cell*) and *Cell mediated* specific immunity (*T Cell*) |  | 29 |
| 5388473596 | PMNs or polymorphic neutrophils | *First to arrive at inflammation site* and most numerous leukocyte that is a major cell type involved in the initiation of immune response, inflammation, *phagocytosis* of foreign molecules. PMNs produce *myeloperoxidases* for enhancing *oxidated antimicrobial effects*, *lactoferrin and lyzosyme* for direct antimicrobial activity, and *leukotrines and prostogalndins* to mediate vascular changes. Attracted by *chemotactic factors* stimulated by tissue damage esp *IL-8* (complement proteins, chemokines, clotting proteins). |  | 30 |
| 5505550964 | Eosinophil | *Pink staining granulocyte* that is active in *parasitic infections and asthmatic reactions*. Eosinophils secrete enzymes that punch holes in parasitic worms. Eosinophils are also capable of phagocytosis but they are not the major phagocytotic cell. |  | 31 |
| 5505557514 | Basophil | Not common in blood (lowest percentage). *Involved in Type I hypersensitivity* responses. *High affinity for IgE* which binding to it causes degranulation of active mediators: histamine, prostaglandins, leukotrienes. |  | 32 |
| 5505563697 | Mast Cells | *Important in allergic reactions* like basophils, BUT ONLY FOUND IN TISSUES. Contains granules with *histamine, prostaglandins, leukotrienes*. |  | 33 |
| 5505567758 | Phagocytic Cells | Includes Neutrophils, eosinophils, monocytes, and specialized tissue macrophages. Involved with phagocytosis of foreign moelcules/pathogens, cell recruitment via molecular mediators, and presentation of peptide antigens to lymphocytes. *Monocytes are blood circulating phagocytes (circulate for 1-3 days)* before migrating to tissue to *become a macrophage.* Tissue Specialized macrophages and dendritic cells: in the brain (microglia) lungs (alveolar macrophages) liver (Kupffer cells) kidneys (mesangial cells) bones (osteoclasts) gastrointestinal tract (peritoneal macrophages). Lymph nodes (dendritic cells) Skin (Langerhan's cells) CNS (Glial Cells) |  | 34 |
| 5505575744 | Monocytes | *Circulate in blood after leaving bone marrow for approximately 1-3 days* before entering tissues to mature into macrophages. Involved in phagocytosis and intracellular killing of microorganisms. *Generation of toxic metabolites* through *respiratory burst*. Production of *nitric oxide, hydrogen peroxide, superoxide anion*. |  | 35 |
| 5388487293 | Interleukin-8 (IL-8) | chemoattractant that triggers adhesion and subsequent diapedesis of neutrophils into target tissues. | 36 | |
| 5388516568 | Neutrophil migration and Diapedesis | Neutrophils crossing endothelium via reversible binding, activation, adherence, and movement between endothelial cells. |  | 37 |
| 5388350096 | Beneficial effects of fluid exudate (vascular permeability) | Dilution of toxins, entry of abs to allow for lysis of microorganisms and opsinization and toxin neutralization. Fribrin formation. Delivery of nutrients and O2. Drainage of fluid exudate and antigens into lymphnodes for stimulation of immune response (if needed) | 38 | |
| 5388520927 | Complement C5a | Chemoattractant that initiates neutrophil migration and diapedesis along with IL-8 |  | 39 |
| 5388550965 | Pus | yellowish white opaque creamy matter produced by the process of suppuration consisting of neutrophils (some dead and dying) and tissue debris. | 40 | |
| 5388580166 | Erythrocyte sedimentation rate (ESR, sed rate) | Measure of time it takes for erythrocytes to form sediment in vitro. Elevated during infection due to increased protein, interaction with charges on RBCs and rouleaux formation (coin stacking). Increased ESR facilitates neutrophil migration by allowing extra time for PMNs to interact with adhesion molecules during diapedesis. |  | 41 |
| 5388627303 | Monocytes | Macrophages that ingest and destroy bacteria by expressing receptors specific to many bacterial constituients (Mannose receptor, TLRs, Glucan receptors, CD11b and CD18, and LPS receptor CD14). Phagocytosis forms phagosome which fuses with lysosome (phagolysome). Monocyte activation results in secretion of interferons, lysosyme, and cytokines which help mediate immune cell communication and regulation. |  | 42 |
| 5388667985 | Cytokines | small low molecular weight proteins that link innate immunity | 43 | |
| 5388538789 | Neutrophil reactivity during inflammation | *Respiratory burst, production of reactive oxygen and nitrogen intermediates*, release of primary and secondary granules with *proteases, phospholipases, elastases, and collagenases* to *destroy some host tissues to penetrate deeper* to sites of infection and inflammation. *Myeloperoxidses* to assist oxidated antimicrobial effects. *Lectoferrin and lysozyme* production (direct antimicrobial agents) *Leukotrienes and Prostaglandin* to mediate* vascular function.* | 44 | |
| 5388679508 | Big 3 proinflammatory signalling molecules | *IL-1Beta* *TNF-alpha* *IL-6* |  | 45 |
| 5388671026 | TNF-alpa | | 46 | |
| 5388671027 | IL-6 | | 47 | |
| 5388673076 | IL-1B | | 48 | |
| 5388687105 | IL-8 (CXCL8) | Chemotactic factor recruits neutrophils, basos, TCells to site of infection. | 49 | |
| 5388704602 | Chemokines | Cytokines which act as Chemoattractants they have 2 adjacent cysteine motifs. Secreted by immune cells and react with other immune cells to mediate communication for immune response. | 50 | |
| 5388719385 | Complement system | component of the innate immunity that either alone or with the help of antibodies, recognize and attack foreign molecules resulting in complement cascade formation resulting in hypotonic lysis, increased efficiency of phagocytosis, and directed leukocytte migration to augment clearance of foreign molecules/pathogens (immune response) Classical activation= antibody mediated Alternate activation= no antibodies required |  | 51 |
| 5489099754 | Activators of immune response | Antigens: an antigen refers to a molecule that is capable of binding to the product of that immune response. Haptens: a small molecule that, when combined with a larger carrier such as a protein, can elicit the production of antibodies that bind specifically to Immunogens: immunogen refers to a molecule that is capable of eliciting an immune response by an organism's immune system. Note: All antigens are immunogens, but immunogens don't have to be antigens e.g. lipids, polysaccharides etc. ALL REQUIRE FOREIGNNESS, A MOLECULAR WEIGHT OF AT LEAST 1000 Da, DEGRADABILITY, AND CHEMICAL COMPLEXITY |  | 52 |
| 5504926111 | Poly vs. Monoclonal antibodies | Polyclonal antibodies are antibodies that have specificities for many epitopes as opposed to only having specificity for just one like a monoclonal antibody. | 53 | |
| 5489107323 | Adjuvant | a substance that enhances immune response by: 1. increasing the half-life of an immunogen. 2. Increasing local inflammation 3. Improving processing and presentation by MHC. | 54 | |
| 5489115642 | Papin cleavage of antibody structure | Fab region: Portion that can bind to the antigen Fc: portion that can be crystalized andd allows the antibody to ineract with other cells. Papain cleaves the disulfide bridge between heavy chains at the hinge region. |  | 55 |
| 5489136315 | Affinity vs. Avidity | Affinity refers to the strength of any given bond between an antibody and its antigen. However, some isotypes of antibodies are multivalent and bind to multiple antigens. The strength of that overall connection is the avidity. i.e. IgG and IgM might have the SAME affinity for an antigen, but IgM will have greater Avidity because it has more binding sites since it is pentameric. | 56 | |
| 5504951391 | Antibody Light Chains | 2 types: Each chain has a variable and a constant region. Kappa: 60% of human light chains Lambda: 40% of human light chains |  | 57 |
| 5504952366 | Antibody Heavy Chains | 5 classes of heavy chains and correspond to class name of IgG, A, M, E, D. Each chain has a variable and a constant region | | 58 |
| 5504977305 | Variable and Hypervariable regions | Each antibody has a variable region on each heavy chain, and each light chain. So for IgG which has 2 heavy and 2 light chains, it has 4 total variable regions. EACH VARIABLE REGION HAS 3 HYPERVARIABLE (HV) REGIONS. All of the HV regions for a given heavy and light chain pair make up what is known as the Complementarity determining region (CDR). So for example: An IgG has 2 heavy and 2 light chains. Each chain has 3 HVs, so 12 total. For each heavy and light chain pair, there are 6 HV regions, so there are 2 total CDRs. |  | 59 |
| 5505008358 | Fc and Hinge regions | Fc regions (constant): Allow for interaction of immune complexes with other cells Hinge regions: Allows for antibody flexibility, rich in Cysteine and Proline residues. | 60 | |
| 5432123752 | IgM | Primary antibody in response to challenge. most efficient for complement fixation. Efficient for bacterial and viral agglutination, isohemaglutinin that is naturally present with A and B blood groups. |  | 61 |
| 5432128645 | IgG | Lowest molecular weight and has high affinity and can cross maternal placenta. Has both anti-viral and anti-bacterial activity. 3 roles of IgG: Neutralization Opsonization Complement activation Most common Isotype is IgG1 | | 62 |
| 5432189312 | IgA | Produced by mucosal cells esp in the GI system. *Has a J-chain and secretory component allowing corss over from basolateral side of epi cell to the lumen.* First line defense of mucosal surfaces and is *bactericidal for Gram negs in the presence of lysozymes.* Efficient bacterial and viral agglutinator and plays a important role in passive immunity passed from mother to baby in breast milk. IgA has a secretory component that is able to cross epithelial basal lamina propria out into the lumen. | | 63 |
| 5432222105 | IgD | Not found in significant amounts. Important in *Initial antigen triggering of B cells* while *bound to the membrane surface of the B cells*, NOT SECRETED antibody. Found in the bone mmarrow | | 64 |
| 5432238210 | IgE | Important for allergic reactions-Type I hypersensitivity reactions. Binds to FCepsilon receptors on Mast cells that induces degranulation, secretion of histamine, heparin into the blood stream. Ecosanoids and cytokines also released. Also found in high levels in parasitic infections. Important in asthma response due to mast cell leukotiene release. | | 65 |
| 5505061994 | Blood group Antibodies | Type A: Can receive type A and O blood. Type B: Can receive type B and O blood. Type O: Can ONLY receive type O blood. *Type O* is the *universal RBC donor* because type O lacks anyA or B antigens on the RBC cell surface. *Type AB* is the *universal RBC RECIPIENT* because type AB lacks anti-RBC antibodies in plasma. *Type O* is the *universal PLASMA RECIPIENT* *Type AB* is the *universal PLASMA DONOR* |  | 66 |
| 5432491625 | Antibody Structure | Variable domain allows for antigen-binding specificity. the constant domains are for common biological function. |  | 67 |
| 5432525017 | Paratope | Unique amino acids in the antigen binding region that interact with a specific antigen. | 68 | |
| 5432548768 | Immunoglobulin heavy chains | Located on Chr 14 in gemline configuration in all cells except B cells. B cells have multiple gene segments which are rearranged during devo: Variable (V) diversity (D) Joining (J) and Constant (C). |  | 69 |
| 5432691803 | Light chain Loci | Light chains are encoded by two separate loci, a Kappa and Lambda, on two different chromosomes which contain only V and J segments. Light chain rearrangement occurs AFTER heavy chain rearrangement. Failure of kappa rearrangement results in a backup of lambda rearrangement. |  | 70 |
| 5432731638 | Coexpression of IgM and IgD alternative splicing | IgM is ONLY expressed by IMMATURE B cells (In bone marrow). MATURE B CELLS express both IgM and IgD in circulation. |  | 71 |
| 5432752163 | Stages of B Cell development | Stem cell--> proB cell--> Pre-B cell--> immature B cell--> mature B cell (if activated by antigen then progresses to)--> Memory B cell or Plasma Cell. |  | 72 |
| 5432777918 | Complementarity determining regions- CDRs | Arise from various recombinations of VDJ segments. CDRs form the antigen binding pocket, paratope, which is the region for high antigen specificity. 3 contact points in one heavy chain (6 for heavy chain pair) and 3 contact points in the light chain (6 for light chain pair) comprise these CDRs. |  | 73 |
| 5432832410 | Five mechanisms of antibody diversity | 1. Availability of multiple V gene segments 2. Combinatorial diversity (different VDJ and VJ combination) 3. Assortment of heavy and light chains. 4. Junctional and insertional diversity results because VDJ or VJ recombination sites are not precise so recombination of some basepairs will change amino acid sequences, known as *N-region diversification*, which is mediated by *deoxynucleotidyl-transferase*. 5. Somatic hypermutation- point mutations can occur in the V regions AFTER Antigenic stimulation of the B cells. Results in affinity maturation, the selection of mutants that have higher affinity for the antigen in subsequent (secondary) responses to antigen. | 74 | |
| 5432923493 | Isotype switching | change in the heavy chain isotype expressed by a given B cell thereby allowing other heavy chain isotypes to be expressed after antigen exposure. Ex: switching from IgM to IgG3. Stimulated by antigen exposure + cytokines produced by TH cells and interaction with TCell surface molecules.. V region and antigen binding specificity DO NOT change. |  | 75 |
| 5444812281 | *T-lymph intracellular pathogen* response | *T-cells have evolved to handle intracellular pathogens* whereas *B cells recognize extracellular pathogens.* T-cells recognize small antigenic determinants expressed on the surface of host cells associated with MHC molecules (major histocompatibility complex) | 76 | |
| 5444837240 | Functions of T-lymph response | T-cells express a TCR with specifficity for an antigenic determinant. Regulates immune responses, integral in cell mediated immunity, and critical in B-cell antibody production. | 77 | |
| 5444845824 | TCR heterodimer | Alpha and beta chains (majority of TCRs) or gamma and delta chains. An individual Tcell can express either an *alpha/beta* or *gamma/delta* but never BOTH. transmembrane (fixed onto membrane, not secreted) *heterodimer* composed of two disulfide-linked polypeptide chains. |  | 78 |
| 5444875310 | T cell Receptor Structure |  | 79 | |
| 5444899137 | TCR-CD3 Complex | *CD3 surrounds TCR chains *that allows *signal transduction* to be effective for activation of T cell once an antigen binds to the antigen-binding site. |  | 80 |
| 5444940372 | TCR antigen binding | MHCs bound to an APC will present an antigen held in it's peptide groove to the TCR CDR. |  | 81 |
| 5444966428 | Genes coding for TCRs | TCR genes closely related to members of the immunoglobulin gene superfamily. Each chain consists of a Constant (C) and variable (V) region formed by a gene-sorting mechanism similar to antibody formation, i.e. combinatorial joining of VDJ genes and by N region diversification via deoxynuclytidyl-transferase. Recombination is coordinated by RAG-1 and RAG-2. Alpha and gamma regions only have V and J segments. Beta and Delta have V D and J segments. Alpha and beta have ore variable (V) genes than gamma and delta (more diversity with Va and Vb) | 82 | |
| 5445051663 | REVIEW B VS T CELL RECEPTORS (COMPARE AND CONTRAST) | 83 | ||
| 5433013678 | Membrane vs secreted Ig Expression | Alternative splicing of the RNA transcript produces Ig that lacks membrane exon needed for surface bound properties. So splicing determines section vs membrane bound antibody | 84 | |
| 5433165708 | Primary Lymphoid organs | Where cells originate: bone marrow and Thymus. | 85 | |
| 5433168394 | Secondary lymphoid organs | Where immune response develops, ie lymph nodes, spleen and tonsils and MALT/GALT/BALT | 86 | |
| 5433178316 | Thymus | Thymocyes are found here, NOT T-CELLS |  | 87 |
| 5505597208 | Thymus (again) | Thymocytes are educated to become T lymphs. T cells learn to recognize self vs. non-self |  | 88 |
| 5433185893 | Hassl's corpsucles |  | 89 | |
| 5433199920 | Thymus Cortex |  | 90 | |
| 5433206525 | Thymus Medulla |  | 91 | |
| 5433215230 | Lymph nodes | Act as a type of filter for material collected from interstitial space. "lymphocyte meeting spots" |  | 92 |
| 5433240678 | Lymph node CORTEX | Site of activity of lymphocytes. |  | 93 |
| 5433260003 | Primary follicles and germinal centers of lymph nodes | Note the different sites of localization between T and B lymphs. T cells are found in the marginal mantle area whereas B cells congregate in the germinal centers. |  | 94 |
| 5433310379 | Medullary Cords and Sinuses of lymph nodes | Cords are the more densely dark staining areas and the sinuses run between the cords indicating the flow of lymph fluid. |  | 95 |
| 5433331615 | Direction of lymph flow | Lymph vessels have one way valves that prevent backflow of lymph fluid. |  | 96 |
| 5433342226 | High endothelial venules (HEV) | Allows circulation from blood into the cortex and medulla and into the lymphatic vessels. HEVs are a Good indicator of a lymph node. |  | 97 |
| 5433395917 | Summary of Thymus and Lymph nodes |  | 98 | |
| 5433406082 | Function of spleen | Immune surveillance and response in BLOOD. Collects antigens in blood and also degrades old RBCs and damaged RBCs. |  | 99 |
| 5433434528 | PALS of the White Pulp of spleen | White Pulp: contains the lymphoid tissue, arranged around a central arteriole as a periarteriolar lymphoid sheath (PALS). PALS composed of a Germinal Center surrounded by a Mantle and Marginal Zones. |  | 100 |
| 5433469597 | Red pulp of spleen | Consists of *splenic cords and splenic sinuses (aka the Cords of Billroth). * Look for *high concentration of RBCs* giving a very red color. *Specialized endothelial cell lining with fenestrated capillaries* in sinuses allowing RBCs to pass across. *Function of red pulp is the destruction of old worn out RBCs.* |  | 101 |
| 5505585700 | Splenic Germinal Center | Germinal center contains active B-lymphocytes. Helper T-cells mingle with plasma cells at the periphery of the nodule. PALS are pariarterial sheaths surrounding the central arteriole |  | 102 |
| 5433516282 | Mucosa-associated lymphoid tissues (MALT) | Inductive sites are sites where antigen is first encountered and the primary immune response takes place. *Tonsils and Peyer's patches are permanent lymphoid structures and are NOT encapsulated*. Do NOT have afferent lymphatics. Effector sites are diffuse sites where specific immune cells can respond to antigen immediately. Includes: lymphatic nodules, laminapropria in nasal passages, intestinal tract and intraepithelial lymphocytes. |  | 103 |
| 5433551258 | Peyer's Patches | *Non-encapsulated lymphatic tissue.* *Have M-cells (VIP) which are specialized epithelial cells that sample antigen* from the gut. Allow the passage of antigens so that APCs can process and present antigens to T and B cells. Peyer's patches are known for IgA secretion and formation of germinal centers and lymphatic nodules. |  | 104 |
| 5433592433 | Tonsils | *Partially encapsulated with an epithelial covering.* Usually have lots of germinal centers. |  | 105 |
| 5433605437 | Tonsil distribution | Many germinal centers, and M cells also present within tonsils. |  | 106 |
| 5433622009 | Non-encapsulated Mucosal Tissues | GALT: Gut associated lymphatic tissue. BALT: bronchus associated lymphatic tissue.. No capsule present. The major antibody produced is IgA from Plasma Cells and offers protection against foreign antigens. |  | 107 |
| 5433670072 | Appendix | Have lots of goblet cells and lymphoid follicles (usually active with germinal centers). acute corners in which inflammation can occur due to entrapped debris leading to appendicitis. |  | 108 |
| 5433693176 | BALT |  | 109 | |
| 5433719992 | Lymphadenopathy | Enlarged lymphnode due to cellular infiltration and edema. | 110 | |
| 5445104428 | MHC Class I | synthesized in RER. *participates in ENDOGENOUS antigen presentation to CD8+ lymphocytes (Cytotoxic lymphocytes).* *ALL NUCLEATED CELLS EXPRESS MHC Class I.* |  | 111 |
| 5445108608 | MHC Class II | synthesized in RER. *participation in EXOGENOUS antigen presentation to CD4+ lymphocytes (TH Cells). * *MHC II are found on macrophages, dendritic cells and B cells.* |  | 112 |
| 5445114643 | MHC Class III | complement proteins, TNF and lymphotoxin. | 113 | |
| 5445186159 | Beta2 microglobulin | A globulin that binds to, and stabilizes, the transmembrane portion of HLA A, B, C proteins. | | 114 |
| 5445087189 | MHC | Major histocompatibility complex is a highly polymorphic (Allotypic polymorphism ) locus on a chromosome comprised of multiple genes encoding histocompatibility antigens that play critical roles in recognition of "self" vs. "non-self" and regulation of interactions among immune system cells such that antigen presentation on MHC molecules results in activation of adaptive immune responses. Particular MHC alleles are associated with better protection against infectious disease. |  | 115 |
| 5445228185 | MHC inheritance patterns | MHC class I is inherited from mom and MHC class II is inherited from dad. Since an individual gains one strand of DNA from each parent, most people have two distinct variants of A, B and C for a total of 6 distinct MHC I genes. |  | 116 |
| 5445290759 | MHC Class II polymorphisms |  | 117 | |
| 5445329019 | Structure of MHC I |  | 118 | |
| 5445137230 | HLA gene complex | interchanged with MHC, same thing. In humans, the MHC loci is designated as HLA. HLA Class I consists of: HLA- A, B, and C loci. HLA Class II region consists of: HLA- DP, DQ, DR. |  | 119 |
| 5445329020 | Structure of MHC II | The base is made of Beta-pleated sheets in an immunoglobulin domain. The sides of the groove that hold the peptides are alpha-helices. |  | 120 |
| 5455457740 | *Endogenous* Antigen Processing | *TAP (transporter of antigenic peptides)* needed to transport antigens to the cell surface. |  | 121 |
| 5455478290 | *Exogenous* Antigen Processing | *CLIP is the protein* that mediates the loading of the peptides to the MHC II molecules. |  | 122 |
| 5455511888 | T lymphocyte development | T-lymphs develop in the thymus and interact with MHC molecules to determine self vs. non-self differentiation. (auto-recognizing T-lymphs are destroyed). | 123 | |
| 5455533926 | Activation of T Cells |  | 124 | |
| 5455557496 | B cell internalization and display of foreign antigens | - B cells can take up exogenous antigen via binding through their surface Ig in a receptor mediated endocytotic mechanism. - Proteins are internalized, broken down to peptides. - Peptides are presented on the B cell surface held in the peptide binding grooves of MHC class II. |  | 125 |
| 5511389055 | Process of phagocytosis and antigen display by APC |  | 126 | |
| 5455614928 | CD4+ T-Helper Cells | -CD4+ and CD3+ -MHC class II restricted - assist phagocytes to kill intracellular pathogens (optimizes the innate immune response) - aid antigen-stimulated B cells to become plasma Cells. -Help T cells proliferate/differentiate to effector CTLs |  | 127 |
| 5455711745 | TH1 Cells | *TH1 cells helps to promote activation of cell mediated immunity to INTRACELLULAR pathogens.* Secretes: 1. IL-2 2. IFN-gamma 3. TNF-Beta |  | 128 |
| 5455713248 | TH2 Cells | *TH2 Cells promote activation and optimization of humoral mediated immunity *to *EXTRACELLULAR PATHOGENS.* Secretes: IL-4, 5, 10, 13. | | 129 |
| 5455619632 | CD8+ Cytotoxic T-lymphocytes | *CD8+* *MHC-I restricted* Mediates cell mediated immunity to: - *Viral infection, intracellular pathogens* - *Tumor cells* *Upregulated by TH1 activity* IL-2 receptors on CTLs are activated by TH-cells secretion of IL-2. | 130 | |
| 5455812599 | CTL Mechanisms of Target Cell Killing | 1. Perforins- perforates holes within the target cell membrane to result in tonicity-based lysis. 2. Granzymes- eliminates viral lifecycle by killing the host cell. 3. *CD95/95L (Fas/FasL)- activation of apaotosis* |  | 131 |
| 5455867410 | Overview of CD4 mediated CTL Activation |  | 132 | |
| 5455876065 | Natural Killer T-Cell | *NK T-cells (different from NK-cells which are innate immune cells that rely on antibody-dependent mechanisms)*. Make up less than 0.2% of peripheral blood T Cells. Have *CD3 and TCR:* These cells recognize *lipid and glycolipid antigen.* | 133 | |
| 5455918284 | T-cell and B cell cooperativity | B cells require TH activation to progress to an antibody producing plasma cell. CD40 is a critical ligand/receptor interaction needed for isotype switching. IL-4 promotes B-cell growth. IL-6 promotes B-cell proliferation. |  | 134 |
| 5455976517 | T-Independent Response | B-cell activation without the normal TH-cell assist mechanism. Occurs when an antigen has many repeating polymerized epitopes that stimulates B-Cell activation of ONLY IgM isotypes. DOES NOT GENERATE IMMUNOLOGICAL MEMORY. | 135 | |
| 5455997372 | Vaccine development | Vaccines are similar to T-cell independent response, but the addition of the polysaccharide epitopes are conjugated to a larger carrier protein which can be ingested and presented on MHC-II thus stimulating a T-Helper Dependent IgG response for production of long term immune memory. |  | 136 |
