Innate and Adaptive Immunity

Vascular (level of) Inflammation

-Arterioles and Venuoles constrict briefly, then dilate, promoting congestion -Increased permeability in capillaries loads to increase of fluid -Causing heat, redness, swelling, pain, loss of function

Endogenous

-Bacteria that naturally reside in a closed system. Disease can occur when microbes included in normal bacteria flora enter a sterile area of the body such as the brain or muscle. A prime example of this is when the residential bacterium E. coli of the GI tract enters the urinary tract.

Cellular (level of) Inflammation

-Neutrophils -Leukocytes adhere to cell wall and by Emigration, squeeze through membrane -Leukocytes wander through tissues following chemical trail (Chemotaxis) -leukocytes phage infectious agents -Products of phagocytosis form exudates, causing swelling and pain -Chemical mediators release bioactive agents to mediate inflammatory response -Histamine is released from Mast cells & Basophils causing dilation and increased permeability of capillaries -Plasma derived mediators: Bradykinin, causes pain, induces vasodilation -Fibrinogen traps exudates, microorganisms, and foreign bodies causing clotting -Complement Cascade

Inflammation

-Triggered by tissue damage or noxious agents -Occurs before immune response and aims at removing infectious agent -Occurs in two overlapping stages: Vascular & Cellular

Types of antibodies

IgD - Tethered to B-cell IgM = First into production (large pinwheel) IgG - main type during infection, can cross placenta IgE - attach to mast cells (allergy) IgA - found on mucosa, becomes dimer

Exogenous

Infections caused by bacteria when microbes that are noncommensal enter a host. These microbes can enter a host via inhalation of aerosolized bacteria, ingestion of contaminated or ill-prepared foods, sexual activity, or the direct contact of a wound with the bacteria.

2nd Line of Defense

Innate Internal: Phagocytes Fever Natural killer cells Inflammation Antimicrobial proteins

1st Line of Defense

Innate: -Skin -Mucous Membranes -Chemicals (oil on skin, mucous, tears, saliva)

Fever (2nd Line of Defense)

Interleukin-1 leukocytic pyrogen and prostaglandins act on the hypothalamic neurons, the thermostatic center of your brain, causing an increase in the thermostat set-point. Fever raises the body temperature, enhances the immune response, increases the production WBCs and interferon proteins, and may slow down the multiplication of some pathogens

Antibodies

Known as an immunoglobulin (Ig), is a large, Y-shaped protein produced mainly by plasma cells that is used by the immune system to identify and neutralize pathogens such as bacteria and viruses. Proteins such as IgG and C3b, which can promote opsonization, are designated as opsonins.

MALT area

Located between two epithelial cells in the mucous membrane. The M-Cell endocytosis the pathogen and releases it into the pocket containing helper T-cells, B-cells, and macrophages. The activated B-Cells mature and release IgA creating and antigen

Self-Tolerance

Lymphocyte ability to recognize and not respond to it's own fellow cells

Immunocompetence

Lymphocyte ability to recognize one specific agent and bind to it

B-Lymphocytes

Make antibodies

Active Immunity

Make your own antibodies -Vaccine containing antigen -Exposed or have the disease

Innate Immunity (1st Line of Defense)

Non-Specific General Immediate response No immunological memory

Defensins

Non-specific, bactericidal

Innate Immunity - Humoral

Pattern receptors Compliment Enzymes Cytokines

Innate Immunity - Cellular

Phagocytes Natural Killer Cells Gd Lymphocytes Neutrophils

Passive Immunity

Receive from someone else -Immunization containing antibody -From mother during pregnancy

T-Cell Receptors

Recognize a single antigen

Adaptive (Specific) Immunity 3rd Line of Defense

Specific to Antigen Lag time from exposure to response Immunological memory after exposure Recognizes self from self Surveillance by WBC's throughout the body looking for whatever Innate missed, programmed to respond to non-self (looking for markers on microbe cell surfaces)

B-Cells formed

Spleen or Lymph nodes

Compliment Cascade

Stimulation of phagocytes to clear foreign and damaged material, proxy inflammation to attract additional phagocytes, and activation of the cell-killing membrane attack complex. Innate: works alone It can be recruited and brought into action by the adaptive immune system to act in combination with specific antibodies

CD-4

Synthesize & secrete cytokines, regulate response, enhance inflammation, cell differentiation

T-Cells

T lymphocyte, a type of lymphocyte that plays a central role in cell-mediated immunity. They are called T cells because they mature in the thymus or tonsils. T cells rearrange their alpha and beta chains on the cell receptor and are termed alpha beta T cells (αβ T cells) and are part of the adaptive immune system. Specialized gamma delta T cells, can effectively present antigens to other T cells and are part of the innate immune system. T-cells are 'blind' and must be 'handed' the molecule and touch it. Must meet two criteria to live: 1) Must be able to fit to a 'holder molecule" on a cell surface 2) Not react to markers on fellow cells Only about 2% make it HIV shuts down THC (T-Helper Cells) Must also have a T-Cell receptor to touch a piece of bacteria after it has been digested by a macrophage TCR's are specific for each possible bacteria piece. May live your entire lifetime

Adaptive Immunity - Cellular

T-cells B-cells

Antibody Marking

Tagged, marked, coated with antibodies -Agglutination: clump the target so macrophages can easily find them -Opsonization: covered so macrophages can find them and eat them easier -Neutralization: block attachment to host (virus) -Activation of complement -ADCC: antibodies coat large worm and eosinophils spit enzymes on it to digest it

How Innate recognizes the invader

Toll Like Receptors (TLR's) located on macrophages and dendritic cells recognize structures on microbes and activate immune cell responses They attach to LPS, DNA, RNA, or flagella Once attached, secrete Cytokines then digest invader

Memory Cells

Tucked away until a repeat offender comes in, then B-Cells are manufactured much faster than the first time (Immunity)

M Protein

Used to protect microbe Capsule used to deter macrophage until opsonized Like electric current, keeps antibodies away

Lymphocytes

White Blood Cells that come from bone marrow and mature into T or B cells

Cytotoxic T-Cell

Activated by CD8 Lymphocyte Only T-Cells that attack & kill other cells Perforin is released, granzymes enter and apoptosis occurs

Antigens

Also called: Immunofens Cause immune réponse usually noticed because of wrong markers, Usually proteins or polysaccharides

Opsonization

An antibody is somewhat "Y" shaped. The binding of IgG to the bacterium is via the branching arms of the "Y." The stalk of the molecule, which is termed the Fc region, then protrudes from the surface. The Fc region is recognized by a receptor on the surface of an immune cell called a phagocyte. When the Fc region is bound to the phagocytic receptor the invading particle is taken into the phagocyte and enzymatically digested.

Effector molecule for B-Lymphocytes

Antibodies

Adaptive Immunity - Humoral

Antibodies Cytokines

Adaptive Specific Response

Assault is severe/specific, the adaptive specific response will try to deal with it first

B-Cells

B lymphocytes, white blood cell formed in bone marrow. Once released the enter the lymphatic system and can settle in lymph nodes, or enter general circulation and settle in the spleen. They function in the humoral immunity component of the adaptive immune system by producing antibodies to a specific invader after they bind to it. They have cell surface structures (IgD's, about 100,000) that differs in each B-cell. Whenever their IgD fits a specific invader, they bind to it, present the antigen to T-Cell who then sprinkles cytokines on it. Once B-cell activated: CLONAL EXPANSION B-cell clones are called PLASMA CELLS and these mfg antibodies Live only a few days

T-Cell presenting bacteria

Bacteria pieces are held on surface in MHC holder so the T-Cell can touch it. Called "presenting", these pieces are the antigen. T-Cells use their TCR to touch the MHC molecule on the cell that shows them the invader. The presenting cell is called the "antigen Presenting Cell" or APC. Formal presenting cells are: B-Cells, Macrophages, and Dendritic Cells

Cytokines

Broad term for chemical used for communication signaling molecules - tell immune system what to do Cause stem cells and immune cells to multiply Some cytokines are cytotoxic for cancer cells

Complement System

C3-convertase cleaves and activates component C3, creating C3a and C3b, and causes a cascade of further cleavage and activation events. C3b binds to the surface of pathogens, leading to greater internalization by phagocytic cells by opsonization. Both C3a and C5a have anaphylatoxin activity, directly triggering degranulation of mast cells as well as increasing vascular permeability and smooth muscle contraction. C5b initiates the membrane attack pathway, which results in the membrane attack complex (MAC), consisting of C5b, C6, C7, C8, and polymeric C9.

Membrane Attack Complex (MAC)

C5b, C6, C7, C8, and C9 pile on pathogenic bacterial cells, forming transmembrane channels. These channels disrupt the cell membrane of target cells, leading to cell lysis and death.

Kills Cytotoxicity

Complement (innate): Kills cytotoxicity, non-specific Leukocyte, especially looks for cancerous cells

Cells and proteins that work in Innate & Adaptive Immunity

Complement proteins

Infection

Condition in which pathogenic microorganisms penetrate the host defenses, enter the tissues, and multiply.

Effector molecule for T-Lymphocytes

Cytokines

CD-8

Cytotoxic T-cells, destroy target cells

Antibodies Opsonize

Effector cells spew antibodies on recognized antigen so they cannot bind to our cells and to increase phagocytosis

Regulatory T-Cells

IL-10, TGF-beta Dampen immune response to keep it in check May be involved in immune disease