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- 2. https://ecampusontario.pressbooks.pub/microbio/chapter/energy-matter-and-enzymes/ Energy, redox Reactions, and Enzymes
- 3. Lecture Overview Electron transport systems (ETS) or Electron Transport Chain: ETC) The proton motive force The
- 4. Introduction We have learned previously how microorganisms can catabolize nutrients and obtain energy in the form
- 5. Flow of electrons Microbes transfer energy by moving electrons. Electrons move from reduced food molecules onto
- 6. Energy transfer pathway Flow of electron from Donor to acceptor Reduced food molecules Energy carriers Oxygen
- 7. Proton potential In each step of the ETS, a molecule becomes reduced (gains an electron), while
- 8. Electron transport system The electron transport system (ETS) or electron transport chain (ETC) generates a proton
- 9. The ETS is embedded in the membrane The ETS can convert its energy into an ion
- 10. Complete redox reaction Basic principle: Combination of 2 redox couple e- Acceptor : Reduction e-Donor :
- 12. Cytochrome is a component of the ETS The ETS is composed of electron carriers (proteins and
- 13. Light absorbance spectrum of a cytochrome. Cytochromes are colored proteins whose absorbance spectrum shifts when there
- 14. Electron transport system Each cytochrome molecule receives electrons from a stronger donor and transfer them to
- 15. Summary of ETS The reduction potential E for a complex redox reaction must be positive to
- 16. Electron Transport Chain: Oxidative phosphorylation Excellent video on Electron Transport Chain: Chemiosmotic Theory. Note that the
- 17. The proton motive force The sequential transfer of e- from one ETS protein to the next
- 18. The transfer of H+ through a proton pump generates an electrochemical gradient of protons, called a
- 19. Electrical Potential and pH Difference
- 20. Rotation of flagella Uptake of nutrients Efflux of toxic drugs. Δp drives many cell Functions Processes
- 21. Either pH difference or charge difference drives ATP synthesis.
- 22. The ETS components include enzymatic reactions Oxidoreductases catalyzes the removal of remove e- (oxidation of one
- 23. A respiratory electron transport system includes at least 3 functional components 1. An initial substrate oxidoreductase
- 25. 1. The substrate dehydrogenase receives a pair of electrons from an organic substrate, such as NADH,
- 26. Oxidoreductase Protein Complexes – 3 The oxidation of NADH and reduction of Q is coupled to
- 27. The Proton Potential Drives ATP Synthesis – 2
- 28. Oxidoreductase Protein Complexes – 6
- 29. Oxidoreductase Protein Complexes – 7
- 30. Mitochondrial Electron Transport
- 31. The Proton Potential Drives ATP Synthesis – 1 The F1Fo ATP synthase is a highly conserved
- 32. The Proton Potential Drives ATP Synthesis – 2
- 33. Electron Transport Chain hhttp://www.youtube.com/watch?v=xbJ0nbzt5Kw&feature=related NDSU Virtual Cell Animations Project animation 'Cellular Respiration (Electron Transport Chain)'. For
- 34. Terminal electron acceptors In organotrophy or chemoorganotrophy: It is a form of metabolism in which organic
- 35. Oxidized forms of nitrogen - Nitrate is successively reduced as follows: NO3– → NO2– → NO
- 36. Anaerobic Respiration in Organotrophs Obligate aerobes are organisms that grow only using O2 as a terminal
- 37. Anaerobic respiration is unique to prokaryotes. They usually possess alternative electron donors and electron acceptors. Electron
- 38. An important class of anaerobic respiration involves the reduction of metal cations, or dissimilatory metal reduction.
- 39. Dissimilatory Metal Reduction – 2 Anaerobic environments, such as the bottom of a lake, offer a
- 40. Chapter Summary Electron transport systems (ETS) consist of membrane-embedded proteins that transfer electrons from an initial
- 41. BACTERIAL PATHOGENESIS Lecture 20 (Ch.25)
- 42. Chapter Overview Host-pathogen interactions How microbes attach to host cells How toxins subvert host functions How
- 43. Introduction Mammals have elaborated physical, chemical, and immunological defenses that protect against disease-causing microbes. However, every
- 44. The Language of Pathogenesis
- 45. The Language of Pathogenesis – 1 By definition, a parasite is an organism that receives benefits
- 46. The Language of Pathogenesis – 1 By definition, a parasite is an organism that receives benefits
- 47. The Language of Pathogenesis – 3 Primary pathogens: cause disease in healthy hosts For example: Shigella
- 48. The Language of Pathogenesis – 2
- 49. The Language of Pathogenesis – 4 Pneumocytis jirovechi cysts in bronchoalveolar materials Cold sore produced by
- 50. The Language of Pathogenesis – 5 Pathogenicity refers to an organism’s ability to cause disease. It
- 51. The Language of Pathogenesis – 6 Virulence is measured by determining the infectious dose (ID50, #
- 52. Immunopathogenesis It is often “friendly fire” by our immune system reacting to a pathogen that causes
- 53. Infection Cycles
- 54. Infection Cycles – 1 The infection cycle describes the route of transmission of an infectious organism.
- 56. Infection Cycles – 3 Complex infection cycles often involve vectors as intermediaries (usually arthropods like mosquitoes,
- 57. Infection Cycles – 4 A reservoir is an animal, bird, or arthropod that normally harbors the
- 58. Portals of Entry Infectious agents enter the body through one or more portals of entry that
- 59. Effect of Infections on Microbiota A pathogen’s growth and the host’s resulting immune response also will
- 60. Bacteria can attach to surfaces in bulk, forming a biofilm. Biofilms play an important role in
- 61. Virulence Factors
- 62. To cause disease, all pathogens must . . . Enter a host Find their unique niche
- 63. Virulence Factors and How to Find Them – 2 A suspected virulence gene can be confirmed
- 64. Pathogenicity Islands – 1 Some virulence genes reside on plasmids or in phage genomes. Virulence genes
- 65. Pathogenicity Islands – 2
- 66. Dangerous pathogens caught in the act of evolving include: Escherichia coli O104:H4, which caused a major
- 67. Examples of Pathogen Evolution by Horizontal Gene Transfer – 2
- 68. Microbial Attachment
- 69. 25.2 Microbial Attachment: First Contact – 1 The human body has many ways to exclude pathogens.
- 70. Pili – 1 Many bacteria typically attach to specific host cells using hairlike appendages called pili
- 71. Figure 25.12 Figure 25.13
- 72. Nonpilus Adhesins – 3 Why are some people susceptible to certain infections, whereas others are not?
- 73. Bacteria also carry afimbriate adhesins that mediate binding to host tissues. Nonpilus Adhesins Streptococcus pyogenes: M
- 74. Microbial Toxins
- 75. 25.3 Toxins Subvert Host Functions – 1 Bacterial toxins can be divided into two main types.
- 76. Endotoxin (LPS) Is Made Only by Gram-Negative Bacteria – 2 Made only by Gram-negative bacteria Present
- 77. Categories of Microbial Exotoxins – 1 Microbial exotoxins fall into several categories based on their mechanisms
- 78. Categories of Microbial Exotoxins – 2 Pore-forming toxins assemble in target membranes and cause leakage of
- 79. Membrane Disruption – 1 Some exotoxins disrupt host cell membranes by forming pores that cause leakage
- 80. Membrane Disruption – 2 Two types of exotoxins disrupt host cell membranes. Pore-forming proteins insert themselves
- 81. Microbial exotoxins fall into nine categories based on their mechanisms of action: Plasma membrane disruption Cytoskeleton
- 82. 25.5 Deploying Toxins and Effectors Many protein secretory systems evolved from, and bear structural resemblance to,
- 83. Figure 25.16 Pore-forming toxins assemble in target membranes and cause leakage of compounds into and out
- 84. Membrane Disruption – 3 3D image of the pore complex, comprising 7 monomeric proteins. Cross section
- 85. Two-Subunit AB Exotoxins – 1 AB exotoxins consist of two subunits, usually called A and B,
- 86. Two-Subunit AB Exotoxins – 2 Typical AB toxin consists of an A subunit and a pentameric
- 87. Two-Subunit AB Exotoxins – 3 Cholera toxin is an AB5 exotoxin made by Vibrio cholerae that
- 88. Two-Subunit AB Exotoxins – 4 Vibrio cholerae (SEM). Note the slight curve of the cell and
- 89. Anthrax Toxin Made by Bacillus anthracis Two active toxins: Edema factor (EF) raises cAMP levels. Causes
- 90. 25.4 Deploying Toxins and Effectors – 1 Many protein secretory systems evolved from, and bear structural
- 91. Secretion Systems for Bacterial Toxins
- 92. Type III Secretion Is an Injection Machine – 1 The type III secretion system (T3SS) is
- 93. Type II Secretion Resembles Type IV Pilus Assembly The type II secretion system (T2SS) is a
- 94. Similar to Type IV pilus Modified for secreting proteins Can extend and retract Proteins to be
- 95. Type III Secretion Is an Injection Machine – 1 The type III secretion system (T3SS) is
- 96. Type III Secretion Is an Injection Machine – 2 The type III secretion complex from Salmonella
- 97. Type III Secretion Is an Injection Machine – 4 Some microbes do not rely solely on
- 98. Type III Secretion Is an Injection Machine – 5 A. Model of entropathogenic E. coli (EPEC)
- 99. Some microbes do not rely solely on the natural array of host receptors for attachment. Instead,
- 100. Type IV Secretion Resembles Conjugation Systems The type IV secretion system (T4SS) is an evolutionary modification
- 101. Use a molecular syringe to inject proteins from the bacterial cytoplasm directly into host cell Similar
- 102. Similar to conjugation pilus Modified to secrete proteins only, or proteins plus DNA Can secrete proteins
- 103. Various sensing systems act in concert to recognize any specific environmental niche. Two-component signal transduction systems
- 104. Cell ingests pathogens in phagosome. Some pathogens use hemolysin to break out. Shigella dysenteriae, Listeria monocytogenes
- 105. Chapter Summary A pathogen is any microbial agent of disease. Primary pathogens cause disease in normal
- 106. CHAPTER 26 MICROBIAL DISEASES
- 107. Chapter Overview Skin and soft-tissue infections Respiratory tract infections Gastrointestinal tract infections Genitourinary tract infections Cardiovascular
- 108. Introduction Microbial diseases are with us daily and are major contributors to global mortality. The need
- 109. Characterizing and Diagnosing Microbial Diseases Microbial diseases may be classified based on several criteria: By organism
- 110. Zoonotic Diseases Francisella tularensis Diarrheal disease of the travellers Tularemia Coxiella burnetii Q fever
- 111. Many infectious diseases display similar symptoms, making diagnosis difficult. Thus, knowledge of a patient’s history is
- 112. Skin and Soft-Tissue Infections Staphylococcus aureus Streptococcus pyogenes, also called Group A Streptococcus (GAS) Lancefield groups
- 113. Lancefield groups Lancefield grouping is a serological method for classifying streptococci into one of 20 groups
- 114. Skin and soft-tissue infections Skin and soft-tissue infections Staphylococcus aureus Streptococcus pyogenes Beta hemolytic
- 115. 26.2 Skin and Soft-Tissue Infections Staphylococcus aureus Boils: walled off from body with fibrin Can produce
- 116. Streptococcus pyogenes Best known for causing sore throats and immunological sequelae, such as rheumatic fever Also
- 117. S. pyogenes Necrotizing fasciitis can spread so rapidly that patients often must get surgery done very
- 118. Respiratory Tract Infection Bordetella pertussis Steptococcus pneumoniae Mycobacterium tuberculosis Pneumocystis Jirovecci
- 119. 26.3 Respiratory Tract Infections The mucociliary escalator is primary respiratory defense. Bordetella pertussis (cause of whooping
- 120. Figure 26.5 A B C Pneumonia caused by S. pneumoniae
- 121. Mycobacterium tuberculosis An acid-fast bacillus An ancient and reemerging pathogen Forms calcified tubercles in the lung
- 122. Gastrointestinal Tract Infection Salmonella enterica serovar Thyphimurium Campylobacter enteritis Campilobacter jejuni Shigella dysenteriae Vibrio cholerae Helicbacter
- 123. Gastrointestinal Tract Infections The main symptoms of gastroenteritis are watery diarrhea and vomiting. The most frequent
- 124. Remarkably, Staphylococcus aureus causes gastrointestinal disease without ever producing infection. Some strains can secrete enterotoxins into
- 125. Pseudomembranous colitis refers to swelling or inflammation of the large intestine (colon) due to an overgrowth
- 126. Enterobacterial toxin-producing strains Inject toxin via type III secretion Bacteria invade epithelial mucosa. Salmonella Shigella, enteroinvasive
- 127. Other bacterial agents of gastrointestinal disease Campylobacter jejuni Most frequent bacterial cause of diarrhea Vibrio cholerae:
- 128. Genitourinary tract infections Uropathogenic E. coli (UPEC)
- 129. 26.5 Genitourinary Tract Infections The urinary tract includes the kidneys, ureters, urinary bladder, and urethra. Active
- 130. The urinary system
- 131. Uropathogenic strains of Escherichia coli (UPEC) Cause about 75% of UTIs Invade the bladder up from
- 132. Sexually Transmitted Diseases Syphilis by Treponema pallidum Chlamydia trachomatis Chlamydia pneumoniae
- 133. Sexually Transmitted Diseases Syphilis Caused by the spirochete Treponema pallidum Primary syphilis: chancre at site of
- 134. Chlamydia Most frequently reported STD in the United States Caused by unusual Gram-negative bacteria Chlamydia trachomatis
- 135. Trachoma Trachoma is a bacterial infection that affects the eyes. It is caused by the bacterium
- 136. Figure 26.12 Elementary bodies are the infective form. They enter eukaryotic cells by endocytosis or phagocytosis
- 137. Gonorrhea Caused by the Gram-negative diplococcus Neisseria gonorrhoeae Over the decades, it has incrementally developed resistance
- 138. Central Nervous System Infections Meningitis Infection of membrane surrounding brain Some bacteria cross blood-brain barrier Streptococcus
- 139. Neisseria meningitidis Has thick capsule and type IV pili Dangerous if it gets into the bloodstream
- 140. Clostridium toxins C. botulinum: botulism toxin (“Botox”) Anaerobe, grows in canned food Spores survive unless autoclaved
- 142. Cardiovascular Diseases Infections of the cardiovascular system include: Endocarditis: inflammation of the heart’s inner lining Septicemia:
- 143. Bacterial Endocarditis Bacterial causes are usually viridans streptococci from the oral microbiota: Streptococcus mutans Enters the
- 144. Systemic Infections Septicemia disseminating throughout body Plague Caused by the bacterium Yersinia pestis Bite of flea
- 145. Zoonotic disease A zoonosis is another name for zoonotic disease. This type of disease passes from
- 146. Lyme disease Caused by Borrelia burgdorferi, a spirochete Transmitted by ticks Bacterium can travel to any
- 147. Figure 26.25
- 148. Immunization Vaccines are typically given in childhood Most are administered as multiple booster doses Except influenza:
- 149. Chapter Summary Pathogens can be classified as food-borne, airborne, blood-borne, or sexually-transmitted. Patients histories are vital
- 150. Chapter Summary The main cause of UTIs is uropathogenic Escherichia coli (UPEC) Sexually transmitted diseases include:
- 151. Viral diseases Paramyxovirus Herpes virus Togavirus Influenza virus and rhinovirus Rotavirus Hepatitis virus Human immunodeficiency virus
- 152. Viral Diseases Causing Skin Rashes Viruses cause a maculopapular skin rash. Usually infect through respiratory tract
- 153. Viral Diseases of the Lung Numerous viruses can cause lung infections Influenza virus and rhinovirus SARS
- 154. Gastroenteritis caused by viruses Rotavirus is the single greatest cause of gastroenteritis Double-stranded RNA viruses Highly
- 155. Hepatitis Viruses Hepatitis is a term meaning inflammation of the liver. Caused by several blood-borne viruses,
- 156. Viral endocarditis Association between enterovirus endomyocardial infection and late severe cardiac events in some adult patients
- 157. Figure 26.14 ACQUIRED IMMUNODEFICIENCY SYNDROME (AIDS) Human Immunodeficiency Virus
- 158. Acquired immunodeficiency syndrome HIV: a lentiviral retrovirus Attacks CD4+ T cells, glial cells First stage: AIDS-related
- 159. Fungal Diseases Most fungi are not dangerous: Mild fungal skin diseases can look like a rash
- 160. Blastomyces dermatitidis Dimorphic fungus found in the soil Infection usually associated with occupational and recreational activities
- 161. Pathogenic Monocellular Eukaryotes Amoeba Entamoeba Cryptosporidium Naegleria Acanthamoba Giarda lamblia Trichomonas
- 162. Pathogenic Ameba Unicellular eukaryotic organism Entamoeba histolytica causes amebic dysentery Which is a more severe form
- 163. Entamoeba Cryptosporidium Naegleria Acanthamoeba Giardia lamblia attaches to the intestinal wall Figure 26.9 Protozoal infections
- 164. Trichomoniasis ~ 2–3 million infections per year in the United States Caused by Trichomonas vaginalis, a
- 165. Figure 26.23
- 166. Prions Proteinaceous infectious particles Cause spongiform encephalopathies Improperly folded proteins form aggregates that damage the brain
- 167. Malaria Causes 1–3 million deaths per year. Four protozoan Plasmodium species: P. falciparum, P. malariae, P.
- 168. Antimicrobial Chemotherapy and Discovery Lecture 22 (Ch. 27)
- 169. Chapter Overview The golden age of antibiotic discovery Basic concepts of antimicrobial therapy Measuring drug susceptibility
- 170. Introduction The discovery of antibiotics about 80 years ago has played a major role in increasing
- 171. The Golden Age of Antibiotic Discovery Antibiotics are compounds produced by one microbe that adversely affect
- 172. Figure 27.1
- 173. Gerhard Domagk (1930s) Discovered sulfa drugs Inactive until converted by the body to active agents Analogs
- 174. Fundamentals of Antimicrobial Therapy Antibiotics comprise mostly of chemotherapeutic agents used to treat microbial diseases. The
- 175. Antibiotic must affect target organism. But it must not affect humans. Many have side effects at
- 176. Broad spectrum Effective against many species Narrow spectrum Effective against few or a single species Source
- 177. Bactericidal antibiotics kill target organisms. Many drugs only affect growing cells. Inhibitors of cell wall synthesis
- 178. Measuring Drug Susceptibility One critical decision a clinician must make when treating an infection is which
- 179. The MIC is the lowest concentration that prevents growth Varies for different bacterial species Test by
- 180. The time required to evaluate antibiotic effectiveness can be reduced by using a strip test that
- 181. Clinical labs can receive up to 100 or more isolates in one day, so individual MIC
- 182. The following are standardizations used to make the test reproducible and easier: Size of the agar
- 183. Figure 27.5
- 184. Peptidoglycan synthesis is rather complex. However, it may be summarized in these four steps: 1. Precursors
- 186. Figure 27.7
- 187. Figure 27.7
- 188. Penicillins, cephalosporins The beta-lactam ring chemically resembles the D-Ala-D-Ala piece of peptidoglycan. This molecular mimicry allows
- 189. Other Antibiotics That Inhibit Synthesis of the Cell Wall Vancomycin: binds ends of peptides Prevents action
- 190. Gramicidin Cyclic peptide produced by Bacillus brevis Forms a cation channel, through which ions leak Drugs
- 191. Quinolones: nalidixic acid, ciprofloxacin Block bacterial DNA gyrase, and so prevent DNA replication Metronizadole Nontoxic, unless
- 193. Figure 27.12 A C B
- 196. Antibiotics that inhibit transcription are bactericidal and most active against growing bacteria Rifampin Binds to the
- 197. Figure 27.14
- 198. Drugs that affect the 30S subunit Aminoglycosides cause the translational misreading of mRNA Are bactericidal Include
- 199. Drugs that affect the 50S subunit Macrolides: inhibit translocation Lincosamides: inhibit translocation Chloramphenicol: inhibits peptidyl transferase
- 200. Challenges of Drug Resistance Antibiotics are considered secondary metabolites because they often have no apparent primary
- 201. Antibiotic resistance is a growing problem worldwide Antibiotics are overused Overprescribed; used in farm animal feed
- 202. There are four basic forms of antibiotic resistance Figure 27.18
- 203. Modify the target so that it no longer binds the antibiotic. Antibiotic-Resistance Mechanisms Destroy the antibiotic
- 204. Add modifying groups that inactivate the antibiotic. Three classes of enzymes are used to modify and
- 205. How Does Drug Resistance Develop? De novo antibiotic resistance develops through gene duplication and/or mutations. Can
- 206. Integrons Integrons are genetic mechanisms that allow bacteria to adapt and evolve rapidly through the stockpiling
- 207. The Future of Drug Discovery Evolutionary pressure is constant. Requires constant search for new antibiotics The
- 208. Antibiotics from the sea The hero marine bacteria, Planctomycetes, naturally produce antibiotic compounds to fight against
- 209. Potential targets for rational antimicrobial drug design include proteins expressed only in vivo or proteins expressed
- 210. Methods to Identify Drug-Resistant Pathogens The proportion of antibiotic-resistant infections has doubled since 2002, rising from
- 211. Evolving, and Sharing, Drug Resistance Genes De novo antibiotic resistance develops through gene duplication and/or mutations.
- 212. How Did We Get into This Mess? – 2 Another proposed source of antibiotic resistance is
- 213. How Did We Get into This Mess? – 3 Many of these situations have conspired to
- 214. How Did We Get into This Mess? – 4
- 215. How Did We Get into This Mess? – 5 When should antimicrobials be used? Antibiotic stewardships
- 216. Biofilms, Persisters, and the Mystery of Antibiotic Tolerance Why do some infections return after bactericidal antibiotic
- 218. Fighting Resistance and Finding New Drugs – 1 The prudent use of current antibiotics and innovative
- 219. Fighting Resistance and Finding New Drugs – 2 Finding new antibiotics Brute-force screening of microbes, plants,
- 220. Fighting Resistance and Finding New Drugs – 3 Antipersister and antibiofilm approaches Kill persisters directly Prevent
- 221. Introduction to the Immune System The Innate and Adaptive Immunity
- 222. What is the immune system? The immune system is a system of defense to protect the
- 223. Exterior Defense
- 224. Interior or Systemic defense In the body there are cells and soluble factors that deal with
- 225. Components of the immune system The immune system is composed of specialized organs, tissues, cells and
- 226. Components of the Immune System The immune system is composed of lymphoid organs, tissues, cells and
- 227. The Bone Marrow The bone marrow consists of connective tissue that is contained in the cavity
- 228. The Thymus The thymus is an encapsulated bilobed organ that is located in the thoracic cavity,
- 229. The thymus The thymus is a bilobed organ that is divided into lobules. Immature thymocytes are
- 230. The lymph nodes The lymph nodes are small encapsulated organs that are located at major junctions
- 231. Lymph nodes Afferent duct Efferent duct Proliferating B cells in T cell zone B cell zone
- 232. The Spleen The spleen is the largest encapsulated secondary lymphoid organ. In humans, the spleen is
- 233. The spleen The spleen is the largest secondary lymphoid organ, in which antigens in the blood
- 234. Tissues Blood circulation Hematopoiesis All blood cells are derived from a common precursor, the hematopoietic stem
- 235. Non-Immune cells: Erythrocytes & Megakaryocytes. Erythrocytes, also referred to as red blood cells (RBCs) are the
- 236. Monocytes are the largest white blood cells, which constitutes 3–7% of the leukocytes in the circulating
- 237. Macrophages Macrophages are larger than the monocytes, with larger cytoplasm t hat is heavily vacuolated. Macrophages
- 238. Monocyte-Derived Dendritic cells Monocyte-Derived Dendritic cells belong to a heterogeneous population of professional antigen-presenting cells (APCs).
- 239. Polymorphonuclear granulocytes Neutrophils (50-70% of leukocytes) have a multilobed nucleus and cytoplasmic granules that are small
- 240. Eosinophils (>0-5% of leukocytes) have a bilobed nucleus and cytoplasmic granules that are stained in red
- 241. Mast Cells Mast cells are only found in tissues, in both connective tissue (Connective tissue mast
- 242. Cells of the innate immunity Neutrophil Eosinophil Basophil Monocyte Mast cell Dendritic cell Macrophage
- 243. Recap Cells of the innate immunity Polymorphonuclear granulocytes (Neutrophils, Eosinophils and Basophils) Monocytes that differentiate into
- 244. Cells of the Adaptive Immunity
- 245. Cells of the adaptive immunity
- 246. Clonal selection of B cell by antigen and differentiation into plasma cells producing antibodies
- 247. T-helper cell and B-cell Interaction
- 248. The Killing Action of Cytotoxic T Cells
- 249. Recap The cells of the adaptive immunity include B and T cells B cells which differentiate
- 250. The Immune Responses
- 251. Lecture contents The systemic Immunological response to foreign antigens involves two lines of defense First line
- 252. Innate Immunity or First Line of Defense The importance of the innate immunity is the readiness
- 253. Phagocytosis Neutrophils and macrophages are professional phagocytic cells Macrophages are the main phagocytes in tissues. Neutrophils
- 254. Phagocytosis Macrophages and neutrophils are referred to as professional phagocytic cells or phagocytes. Phagocytosis is facilitated
- 255. Steps in phagocytosis Step 1 Binding of bacterium by surface receptors on phagocytes. Ex. CD14 binding
- 256. Step 3 Internalization of the bacterium in a phagosome Step 4 Fusion of the lysosome with
- 257. Killing of bacteria in the phagolysosome
- 258. The beneficial acute inflammatory response
- 259. Inflammation The five cardinal signs of inflammation Redness Heat Pain Swelling Loss of function Question: What
- 260. The Inflammatory Response Beneficial acute inflammatory response to injury and infection Macrophages performing phagocytosis of bacteria
- 261. The 5 signs of inflammation Redness resulted from vasodilation caused by histamine and prostaglandin produced by
- 262. Neutrophil undergoing NETosis Neutrophils can extravasate (get out of blood vessel) in response to the chemokine
- 263. Functions of the complement system The them more attractive to phagocytic cells such as macrophages (a
- 264. Complement activation The complement system is composed of over 30 heat-labile proteins that are produced mainly
- 265. Initiation or Activation of the Complement The Alternative pathway is initiated by the binding of a
- 266. Formation of C5 convertase and MAC Formation of C5 convertase. This step is similar in the
- 267. Membrane attack complex https://www.youtube.com/watch?v=vbWYz9XDtLw The Classical Pathway of the complement system MAC
- 268. Antimicrobial soluble factors Alpha and beta defensins Alpha-2 macroglobulins Lysozyme Polyamines Kinins Pentrexins
- 269. Antimicrobial Factors Antimicrobial factors include: Antimicrobial peptides: Alpha and beta defensins that disrupt microbial membranes. Alpha-2
- 270. Natural Killer Cells NK cells have the natural (or innate) ability to detect and kill infected,
- 271. Cells of the Lymphoid lineage B lymphocytes or B cells. These cells express B cell receptors
- 272. Cytokines Produced by Macrophages in the Inflammatory Response Killing of cancer cells, virus or bacteria-infected cells
- 273. Function of NK cells NK cell has inhibitory receptors that bind to body cell expressing MHC-I.
- 275. The adaptive immune response
- 276. The Adaptive Immunity The Adaptive Immunity is also called Acquired Immunity. This form of immunity is
- 277. B lymphocytes As illustrated, there is a repertoire of B cells that differ from each other
- 278. T Lymphocytes or T cells. These cells are cells of the adaptive cell-mediated immunity. There are
- 279. CD4+ T cells, also called CD4 T cells include T helper cells (Th), follicular T helper
- 280. Elimination of infected body cells Elimination of extracellular antigens Functions of T-helper (Th) cells vs cytotoxic
- 281. Killing of Target cells by Cytotoxic T cells Tc recognizes target cell by TCR-2 of Tc
- 283. Antigen Processing & Presentation There are two pathways of antigen processing and presentation. The exogenous or
- 284. 2. The endogenous or cytosolic pathway of antigen processing. The foreign or worn-out protein antigen is
- 285. Endocytic or exogenous pathway of antigen and presentation to Th cells Only Antigen Presenting cells (APCs)
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