Host Resistance review Nonspecific innate natural immune system no memory involve leukocytes Specific acquire adaptive immune system memory inc strength with repeated exposure involve leukocytes Physical barrier in aquired immune system 1 o Keratin serves as protective coating acidic ph high salt conc o trap resists penetration washes away antimicrobial secretions lysozyme o Trapped microbes are moved away from lungs alveolar macrophages Skin Mucous membrane Respiratory system Chemical Mediators Antimicrobial peptides by G G cells Complements o Cationic peptides produced by host o Bacteriocins produced by normal microbiota lethal to certain species produced o Facilitate and enhance phagocytosis opsonization activation of leukocytes bridge innate and adaptive immunity synergy with Abs o Intracellular mediators adaptive and innate immune system use them o Four types chemokines hematopoietins interleukins tumor necrosis factor Cytokines Leukocytes Responsible for specific and nonspecific responses derived from pluripotent stem cells from fetal liver and bone marrow H stem cell from bone marrow goes two routes myeloid and lymphoid Lymphoid lymphocytes specific imm to foreign matter T B cells specific Lymphoid Natural killer cells nonspecific NK cells don t kill foreign but do kill malignant cells infected with pathogens cytotoxic enzymes no phagocytic granular lymphocytes nonspecific B vs T cell organs response B cell T cell Bone marrow Circulate or reside in lymphoid Thymus Circulate or reside in lymphoid Memory B cells rapid T helper enh sup imm cell Plasma cells Ab opsonization CTL lytic enz proteins kill or infected cells tissue actions Organs and tissue of immune system Primary lymphocytes mature diff into mature B T cells Bone marrow thymus Secondary lymphocytes bind antigen mature effector cells spleen lymph nodes mucosal 2 Mucosal associated lymphoid tissue Contains special immune barrier Antigen transported by M cell to lymphoid follicle where it is neutralized by B cells Monocytes DCs NPs and MPs ingest and kill particles This is done by the fusion of lysosomes to the phagosome that contains the microbes and Innate inflammation localized to area of cellular injury or death Phagocytosis destroys it Defensive Reaction inflammation Specific adaptive immunity Three main functions o Recognize non self o Respond to non self encounter o Remember non self Branches of specific immunity Effector response destroys foreign material Anamnestic response faster stronger imm response due to second Humoral immunity antibody mediated immunity B lymphocytes activity based Cellular immunity cell mediated immunity T lymphocyte activity based T cell development Non specific antigen MHC development on DCs na ve T cell binds to DC replicate to form treg th1 th2 ctl T dependent antigen eff in activating B cell Cytokines will help T cell differentiate further They do not need B cell to activate them B cells need T cells to activate Destroy non self CTL destroys infected host cells B cell biology Specific antigen B cell activation Ig accept antigen B cell receptors replicate diff plasma cells Ab o Helper T cells produce cytokines that aid in growth o Two mech for antigen specific activation T dependent T independent 3 o Only produces Ab fight non self Antibodies Plasma cells secrete Ab to bind to antigen Antibody Ig glycoprotein made by activated B cells BCR on B cell surface Ab can bind to antigen that caused its production Immunoglobulin Structure Four polypeptide chains 2 identical heavy chains disulfide bond 2 identical light chains Both chains contain different regions o Constant regions stalk CL CH C fragments o Variable regions VL VH Fab fragments both C and V Immunoglobulin classes IgG neutralize toxins opsonizes bacteria highest conc IgM first responder expressed as mem bound Ab on Bcells IgA secretory Ab IgD on B cells surface B cell recognition of antigen IgE anaphylactic mediating Ab lowest conc Immunoglobulin response Primary response 1st IgM low very early IgG high o Latent phase no Ab weeks later longer than secondary response o Log Phase Ab B cell plasma cell o Plateau phase Ab stabilize not in secondary o Decline Phase Ab binds to antigen Secondary response 1st IgM low IgG very high o Secondary exposure to same antigen o shorter lag rapid log phase longer persistence Ab secretion higher affinity for antigen Hypersensitivities exaggerated imm response from second from antigen o Type I allergic rxn immediately after second contact secret IgE and Mast cells o allergen enters LN B cell recognizes allergen with helper T cell plasma cell syn IgE IgE binds to mast cell o allergen enter second time allergen attaches to mast cell degranulation triggers allergic response symptoms o Degranulation antimicrobial cytotoxic molecule releasing from granules secretory vesicle The compounds would cause Anaphylaxis 4 Epidemiology Multifaceted science determine Causative agent Source of disease agent Mech of transmission Host and development factors that factors Best control measures Terms Sporadic disease occurs occasionally irregular times Endemic disease stead low level frequency at a moderately regular interval Hyper endemic disease gradual inc frequency below epidemic level Communicable disease spread from one to the other Epidemic sudden increase in freq above expected number Pandemic inc of disease within large population international Zoonosis disease spread from animal to human Evidence based approach problem cause solution implementation assessment Prevalence total number of cases in a population Morbidity total number of infections from a disease Incidence amount of new cases that occur within a specific population Mortality total number of deaths due to a disease Common source epidemic when individuals pick up a disease through a common Propagated transmission epidemic disease brought into a susceptible population source which is transfer to others Epidemiological methods Surveillance methods o Review death certificates o Field investigation of epidemics o Investigation of actual cases Remote sensing Geographic information system Measuring infectious frequency o Uses satellite images to develops distribution maps of a disease o data management program that organizes and displays digital maps from RS o Determine if an outbreak epidemic or pandemic is occurring measure freq at a given time look for morbidity prevalence and mortality rates Herd immunity o Large percentage of population is