Term
| Necessary for proper Immunity |
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Definition
| ability of the body to differentiate between 'self' and 'non-self' |
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Term
Categories of immune reactions (4 total) |
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Definition
1. innate immunity 2. acquired immunity 3. cellular immunity 4. humoral immunity |
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Term
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Definition
Quick and non-specific
consists of: -mucosal and cutaneous barriers -the complement system -phagocytes (macrophages and neutrophils) -natural killer cells |
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Term
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Definition
-More finely tuned and specific -formation of antigenic memory -enables faster and specific immune response folloing a future introduction of the pathogen consits of -B lymphocytes -T lymphocytes -antigen presenting cells |
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Term
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Definition
neutralization of pathogens is accomplished by cells (maily t cells) |
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Term
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Definition
| utilized antibodies to neutralize pathogens |
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Term
| Non-Cellular components of Immune System |
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Definition
Antigen Epitopes Cytokines Clusters of differentiation molecules Antibodies |
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Term
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Definition
-has ability to react with antibody -when bound to IgG or IgM = activate complement system -results in destruction of certain microorganisms |
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Term
| Epitopes (antigenic determinants) |
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Definition
-small molecular regions of antigen -contribute to specificity of humoral immunity (B cell response) -specificity from proteins asscoiated with MHC present on surface of antigen-presentign cells |
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Term
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Definition
-low molecular weigh proteins and glycoproteins -produced mainly by macrophages and lymphocytes aslo by endothelial cells and fibroblasts -wide range of activity -can affect cells outside the immune system -inflammatory response, wound healing, hemapoiesis, and immunity |
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Term
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Definition
Interleukins: affect leukocytes Chemokines: draw leukocytes to site of inflammation Interferons: produced by virus-infected cells to decrease viral replication |
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Term
| Clusters of Differentiation (CD) Molecules |
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Definition
-surface markers -distinguish seperate lineages/functions of lymphocytes: CD3 - on T cells
CD4 - T helper cells (T-h) CD8 - cytotoxic T cells CD20 - found on B cells
CD40 - B cells; allows cell to be activated byT-h cells
CD45 - leukocyte common antigen |
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Term
| Antibodies (immunoglobulins) |
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Definition
-circulation glycoproteins -produced in response to epitope -interact with antigen -produced by plasma cells -secreted into blood and/or lymphatic circulation -lable substances as foreign - target for destruction -form a coat that percipitates groups of bacteria = enhanced phagocytosis
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Term
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Definition
-2 light chains+ 2 heavy chains held by disulfide bond -stem = Fc region =binds receptors on surfaces of certain cells -arm = Fab region = amino acid variability = specificity of immune reaction |
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Term
Classes of antibodies (5 total) |
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Definition
1. IgG (75-80%) 2. IgA (10-15%) 3. IgM (10%) 4. IgE (<1%) 5. IgD (<1%) |
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Term
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Definition
-can cross placental barrier -responsible for protecting fetus and newborn -activates phagocytosis through opsonization -stimulates NK cell activity |
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Term
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Definition
-predominant antibody in secretions -present as dimer -connected by protein known as J chain and secretory component -monomer within blood -neonatal passive immunity -mucosal immunity -helps epsinophils id and kill parasites |
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Term
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Definition
-present as pentamer -held together by J chains -commonly found on surface of B cells -acts as antigen receptor =B cell proliferation and differentiation into plasma cells -first Ig ti be produced in an initial response -can activate te complement system |
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Term
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Definition
-binds to receptors on basophils and mast cells -cross-linking by antigen = degranulation = release of things such as histamine = allergic reaction -assists in targeting parasitic worms for destruction |
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Term
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Definition
-poorly understood -found on surface B cells -similar function to IgM
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Term
Cells of the Immune System (4 Total) |
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Definition
1. Lympoid Cells 2. Mononuclear Phagocytes 3. Antigen-Presenting Cells 4. Granulocytes |
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Term
Lymphoid Cells B cells T cells Natural Killer cells |
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Definition
-20-40% of leukocytes -continuosly circulate in blood and lymph -able to migrate into tissue and lymphoid organs -round cells, larger than erythrocytes -round nucleus with small indentation H&E = dark blue -thin rim of basophilic cytoplasm -few organells -abundent ribosomes |
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Term
| Initial response of lymphoid cells |
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Definition
-slow to evolve -lymphocytes undergo clonal expansion =proliferation to form effector memory cells -second exposure is faster and more powerful b/c of immunological memory B effector cells = plasma cells T effector cells = cytotoxic and helper cytotoxic - destroy foreign/abnormal helper - secrete cytokines that activate stuff |
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Term
B Lymphocytes formation of memory and plasma cells |
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Definition
-mature in bone marrow -have membrane-bound immunoglobulins (antigen receptor)-each Ig has same binding site -activated by antigen binding to antibody -undergoes clonal proliferation =many memory and plasma cells
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Term
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Definition
-produce and secrete a specific antibody -ovoid in shape -round, eccentrically place nucleus 'clock-face' distribution of heterochromatin -cytoplasm deeply basophilic except perinuclear area Perinuclear Area = centriols and Golgi have pale staining quality
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Term
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Definition
-express either B cell receptors or TCRs -do NOT participate in initial immune reaction -live for years -stronger attraction to antigens than naive B cells -formed in large numbers after exposure of original clone to antigen -rapid/effective response when antigen re-introduced
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Term
B Lymphocytes After exposure and acivation |
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Definition
-produce IgM which attaches to surface of pathogen =activated complement system or IgM coats viruses and prevent them from attaching to hosts -later, B cells can produce different antibody class if exposed to certain cytokines released by T cells |
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Term
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Definition
-formed in bone marrow -mature in thymus -cell membrane carries antigen-binding T-recepto cell (TCR) - similar to Ig molecules -TCR does NOT recognize free antigen -recognized MHC (aka human leukocyte antigen) -Ag-MHC present on antigen - presenting cells, cancer cells, virus-infected cells, and graft tissue
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Term
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Definition
-found on all nucleated cells --short peptides derived from post-cell proteins -allows T-h to see if cell is producing self or nonself protiens |
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Term
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Definition
-two types I and II -each genetically distinct person has own type of MHC molecule -to be stimulated: T cell must recognize epitope and MHC complex |
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Term
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Definition
-found on antigen-presenting cells -long peptides form sources outside the cell -allow T-h to see if antigen presenting cell (APC) is encountering self or nonself proteins |
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Term
| CD Molecules of Lymphocytes |
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Definition
-subclasses of lymphocytes -present on surface CD4+ T cells : only recognize MHC II molecules T HELPER CELLS CD8+ T cells: only recognize MHC I molecules T CYTOTOXIC CELLS Normal = 2 CD4: 1 CD8 Aids = ratio drops - less t helper cells
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Term
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Definition
-interact with MHC I on cell membrane of host -in conjunction with cytokines -cells multiple and differentiate into cytotoxix T lymphocyte (CTL) CTL can detect and destroy altered host cells |
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Term
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Definition
-MHC II on antien presenting cell -undergo clonal proliforation to make cells specific for Ag-MHC complex -after can produce cytokines - interact tith other cells in immune response -types of cytokines can modify type of immune response elicited |
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Term
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Definition
-cytokines involves activate certain T cells and macrophages -sytokines support an inflammatory reaction -invloves an underlying bacterial or viral infection |
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Term
| Virally-Transformed Cells |
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Definition
-APC presents epitope to T-h1 cell - activation -T-h1 releases TNF, IL-2 = cell proliferation, INF-gamma (activatesT-c cells)
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Term
Virally-Transformed Cells CTL activation |
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Definition
Only if: 1. CTL is bound to APC 2. CD8 molecule on CTL recognizes the epitope-MHC 1 complex on the APC |
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Term
Virally-Transformed Cells CTL Activated and Proliferated |
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Definition
Daugther cells look for infected cells to kill via: a. Perforins: -released by CTL after binding to target cell -glycoproteins that insert into targent cell memb -assemeble into strucures and form pores -more assembeled = mem distrupted = lysed b. Perforins + Granzymes: -released by CTL after binding to target cell -granzymes enter target through perforin pores -induce apoptosis |
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Term
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Definition
-engulfed by macrophages -retain ability to proliferate inside phagosomes To Destroy: Machrophages must be activated by T-h1 cells |
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Term
To Destroy bacteria: The process of activating macrophages via T-h1 cells |
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Definition
1. TCR and CD4 of T-h1 recognize epitope MHC II complex of macrophage 2. T-h1 cell produces IL-2 receptors on itself and secretes IL-2 to activate = rapid proliferation of Th-1 cells which contact bacteria macrophages 3. After recognizing epitope, T-h1 releases IFN-gamma = activate macrophage 4. Macrophage expresses surface TNF-alpha receptors, then releases TNF-alpha 5. IFN-gamma and TNF-alpha bind to their receptors =macrophage produce O2 radicals = KILL bacteria |
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Term
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Definition
activates B cells and antibody-dependent immune reactions usually invlolves parasitic infection or infection of the mucosa |
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Term
T Helper Cell 2 response Step 1
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Definition
Step 1 -antigen bound to B cell receptor go into cytoplasm -epitope cleaved off -fuse to MHC II molecule -new colpex goes to cell surface and presented to T-h |
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Term
T Helper Cell 2 response Step 2 |
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Definition
| Step 2 -two signals made 1. T-h must recognize epitope with TCR and MHC II complex with CD4 molecule 2. CD40 receptor must bind to the CD40 molecule on the surface of B cell |
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Term
T Helper Cell 2 response Step 3 |
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Definition
Step 3 -B cell activated and begins dividing -simultaneously, T-h cell produces IL-4, 5, and 6 -causes differntiation of new cells into memory and plasma cells -produced IL-10 = inhibits T-h proliferation |
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Term
| Regulatory (suppressor) T cells |
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Definition
-inhibit activity of T and B cells -therefore terminate immune response -mechanism of action debatable |
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Term
| Natural Killer Cells (NK) |
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Definition
-large lymphocytes (5-10% of circulating lymph) -granular cytoplasm -do NOT have characteristic cell surface markers -activity NOT restricted by MHC -eliminate wide range of altered host cells in absence of previous exposure -effective againd tumor cells and some virus-infected cells |
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Term
Natural Killer Cells (NK) 2 ways |
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Definition
1. detect decrease in MHC I mol or abnormalies in cell surface markers in altered host cells 2. have a receptor (CD 16) for the Fc protion of IgG; enable them to bind to antibody and destroy cell; occurs through release of perforins and granzymes -also have receptors for diff cytokins including: IFN-alpha-beta, IL-12, bacterial lipopolysaccharide -in turn secrete IFN-gamma inducing macrophages kill bacteria |
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Term
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Definition
-arise from granulocyte-monocyte lineage in bone marrow -monoblast is precursor -differentiates into promonocyte -promonocyte = big baso cell, indended nucleus -after 2 cell division, promonocyte enters bloodstream -gives rise to mature monocytes -have abundent RER and golgi |
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Term
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Definition
-do NOT have specific granules - (not granulocytes) -have cytoplasmic granules in form of primary lysosomes -circulate for about 8 hours -enter tissue and differentiate into machrophages |
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Term
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Definition
-differentiation= sign increase in size -increase in quantity and complexity of organelles -enhanced phagocytic ability -increase levels of hydrolytic enzymes -able to secrete variety of molecules in immune response -have wide distrubution |
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Term
| Distribution of Macrophages |
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Definition
1. Alveolar Macrophages = lung 2. Histocytes = connective tissue 3. Kupffer Cells = liver 4. Mesangial Cells = kidney 5. Microglia = brain 6. Osteoclasts = bone |
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Term
| Activation of Macrophages during immune response |
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Definition
-antigen phagocytosis is initiating event = increased activity following cytokine release by T-h cells (especially IFN-gamma), inflammatory mediators, and exposure to compounds on surface of bacteria -once activated=increased phagocytosis, secretion of inflammatory mediators, and T-H activation -proteins that kill bacteria, virsus and tumors made -also increases expression og MHC II molecules on cell surface = imporved ability to act as APC |
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Term
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Definition
ability to engulf and digest extracellular substances enhanced when antigen coated with antibodies -opsonization |
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Term
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Definition
-migration of marophage towards antigen to be eaten via chemotaxis -antigen binds to cell mem of macrophage -pseudopod extensions around substance form phagasome -moves to center + combines with lysosome =phagolysosome -enzymatic digestion -products expelles via exocytosis |
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Term
Antimicrobial Action 4 ways |
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Definition
1. oxygen-dependent killing 2. oxygen-independent killing 3. antigen processing and presentation 4. secretion of factors |
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Term
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Definition
-production of reactive O2 and nitrogen intermediates -ingestion of microorganism = increase in metabolism called respitory burst -results in chemical cascade converting O2 into superoxide radical =very destructive to microorganisms -NO generated when bacterial lipopolysaccaride is exposed to the macrophage in the company of IFN-gamma |
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Term
| Oxygen-Independent Killing |
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Definition
-microorganism destroyed by: lysozyme, defensins, and hydrolytic enzymes (funtion in absense of O2) -tumor necrosis factor-alpha (TNF-alpha) can be affective against certain tumor cells |
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Term
| Antigen Processing and Presentation |
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Definition
can present antigen to T-h cells after first digesting it into smaller peptides and expressing them on the surface in conjunction with MHC II molecules
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Term
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Definition
-macrophages produce wide variety of proteins with diff functions Significant Ones: IL 1, 6, alpha, TNF-alpha, and complement protein -they are concerned with: -initiation+maintenance of inflammatory response -removal of microorganisms -induction of hematopoiesis |
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Term
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Definition
-derived from bone marrow -include: B lymphocytes, Langerhans cells, dendritic cells -ingest foreing particle -break them into endosomes -express resulting smal peptides on surface by linking them to MHC II molecules (proteins from viruses and certain bacteria and parasites are linked to MHC I molecules) -process necessary for activation of T cell |
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Term
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Definition
1. dendritic cells 2. neutrophils 3. eosinophils 4. mast cells 5. basophils |
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Term
Dendritic Cells ( 4 major types) |
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Definition
1. Langerhans Cells 2. Interstitial Dendritic Cells 3. Myeloid Cells 4. Lymphoid Dendritic Cells |
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Term
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Definition
-morphologiccally = elongated cytoplasmic processes -involved in antigen presentation to T-h cells following phagocytosis and processing -cellular precursors have wide distribution (they engulf and proces antigend in peripheral tissue) -contain high quantity of MHC II and stimulatoruy surface molecules (B7) -enable quicj funtion w/out becoming activated -migrate to regional lymph nodes or spleen -make antigen presentation in areas containg large amounts of T cells |
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