Chapter 15 Microbio

• 1. Chemotaxis
• 2. Adherence
• 3. Ingestion
• 4. Digestion
• 5. Formation of residual body
• 6. Discharge of waste material

• Monocytes (macrophages)
• Neutrophils

• By formation vesicle (by pseudopods of phagocyte) and
• after ingestion called phagosome

Phagocyte fuses with lysosome (have digestion enzymes) --> Phagolysosome bacteria is digested

Phagolysosome containing undigested components of pathogen

Same immune response any type of pathogen

Quick response time, no memory of previous exposure

• Skin
• Mucous membranes
• Secretions
• Normal Microbiota

• 1. Sebum/oil (lysozyme) rich in fatty acid --> acidic pH on skin
• 2. Keratinized epidermis keeps skin dry
• 3. Closely packed cells
• 4. Periodic shredding of skin cells
• 5. Sweat- high salt concentration
• 6. Lysozyme present in sweat (damages peptidoglycan) hurt GM positive bacteria

• Tears (rich in salt and lysozyme)
• Tears flush out eyes

Mucous: Ciliary living (ciliary escalator)

• Acidic pH (gastric juice)
• Movement of food (peristalsis) through GI tract

• Urine- flushes the urinary tract
• Vaginal pH and normal floura is acidic (prevents pathogen growth)

reduces iron for pathogen to use

Competition among microbes (observed b/w normal microbiota and pathogens)

• Occupying niches that pathogens might occupy
• producing acids
• producing bacteriocins
• changing oxygen availability

• Complement System
• Inflammation
• Phagocytosis
• Fever
• Antimicrobial compounds

• Interferon
• Transferrin
• Antimicrobial peptides

• Plasma (fluid)
• Formed elements RBC (Erythrocytes)
• WBC (Leukocytes defense)
• Platelets (Thrombocyts) blood clotting

• Granulocytes
• Agranulocytes
• Lymphocytes

• Neutrophils
• Basophils
• Eosinophils

• Granulocyte
• Phagocytosis

• Granulocytes
• Produce histamine

• Granulocyte
• Allergic reaction, destroy helminths

Large nucleus, mature into macrophages, phagocytosis

• Wandering- Can leave blood vessel and reach infection)
• Fixed- Non motile, localized to specific tissue

• Microglia cells (nervous tissue)
• Kupffer cells (liver)

• Natural Killer cells
• T cells
• B cells

Secrete cyotkine (chem messenger) and activates other cells (B cells, T cytotxic cells) Cytotoxic T Cells (destroy infected cells)

tumor specific response

Lympohtocytes

High during allergies/ helminth infection

Neutrophils

Has blood clotting factor

• Not clotting factors present (rich in antibodies)
• Used to diagnose an infection by detecting presence of specific antibodies

• Production and maturation of blood cells
• Red Bone Marrow (production of all RBCs)
• Thymus gland (T lymphocytes mature here)

• Lymph nodes (maturation, storage of WBCs)
• Spleen
• Tonsils
• Pever's patch (small intestine)

Consists of a group of proteins called complement components (C1-C9, P, B, D). One component then triggers another. Present in inactive form in blood serum (no pathogen present)

When activated, splits into two subcomponents

All pathways activate C3 component

• Mediated by antibodies against protein or polysaccharide angiten
• (2 sites- antigen binding site; part of cell surface against which antibodies are produced)

Mediated by factor B, P (properdin), D, able to recognize LPS (lipopolysaccharide) angitens

Carbohydrate binding proteins that bind to carbohydrate antigen of a pathogen

• Opsonization
• Inflammation
• Cytolysis

• Coat the pathogen, helps phagocyte recognize and ingest pathogen easily
• C3b- oposonin, coating protein bind to antigens of pathogen

By release of histamine from some cells (mast cells, ect.)

Formation of MAC in plasma membrane of bacteria

Destroys the pathogen (forms holes in pathogens membrane) C5b+C6+C7+C8+C9 all bind together and form an attacking complex which forms holes in invading pathogens cytoplasm membrane

C5--> C5a and C5 b

Chemotatic factors (attracts phagocytes) also initiates inflammation

Mast cells have receptors for C3a, C5a, which activate mast cells to release histamine (vasodilator)

Localized, nonspecific immune response, 2nd defense

• Prevent spread of pathogen
• Destroy pathogen
• Tissue repair

Pain, localized heat, redness, swelling

• 1. Tissue Damage
• 2. Release of acute phase proteins (histamine, prostaglandins, leukotrienes)
• 3. Vasodilation: Increase in diameter of blood vessel, supplies WBC's , more O2, clotting factors
• 4. Phagocytic migration (Chemotaxis) (ex- C3a, C5a, complement componenet, leukotrienes)
• 5. Phatgocytic margination: attachment of phagocyte to inner lining of blood vessels (endothelium)
• 6. Phagocytic emigration (diapedesis)- phagocytes are released (squeezed out) between gaps of endothelial cells increased vascular permeability
• 7. Phagocytosis
• 8. Tissue Repair (more nutrients and O2)

Histamine, Protaglandins

Increases vascular permeability

A systemic immune response (not localized)

Enhances immune response; helps inhibit growth of bacteria (denatures enzymes)

Proteins produced in response to viral infection

• Host-cell-specific (species specific) but not virus specific
• Have to be of human orgin to create disease in humans

• Alpha and Beta- Inhibit viral infection
• Gmmas- activate macrophages and neutrophils (cytokines)

• Produced by a
• viruses infected cells

Infected cell secretes infereron that bind to receptor on neighboring, uninfected cell.

• Uninfected cell is stimulated to produce anti-viral
• protines (AVP’s)

• AVP’s degrade viral RNA and inhibit
• protein synthesis

Iron binding proteins in teh blood, reduces availability of free iron for pathogen

• example: Defensins, 40 amino acids long
• Broad spectrum of activity; inhibit metabolism, forms holes in membrane of pathogen