Antivirals, interferon and vaccines lect copy

3,167 views

Published on

Hey guys....sorry for the delay...I just got the ppt now since I did not come home for lunch...
Good luck!!

0 Comments
7 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
3,167
On SlideShare
0
From Embeds
0
Number of Embeds
2
Actions
Shares
0
Downloads
372
Comments
0
Likes
7
Embeds 0
No embeds

No notes for slide

Antivirals, interferon and vaccines lect copy

  1. 1. ANTIVIRALS, INTERFERON AND VACCINES EDWARD-BENGIE L. MAGSOMBOL, MD, FPCP, FPCC, DASNC Assistant Professor in Microbiology Fatima College of Medicine
  2. 2. The Viral Replication Cycle: Several Important Targets for Antiviral Therapy
  3. 3. 4 Ways to Combat Viruses: <ul><li>Immune System </li></ul><ul><li>Antiviral therapy </li></ul><ul><li>Interferon therapy </li></ul><ul><li>Vaccines </li></ul>
  4. 4. Viruses treatable with antivirals <ul><li>HSV </li></ul><ul><li>VZV </li></ul><ul><li>CMV </li></ul><ul><li>HIV </li></ul><ul><li>Influenza A </li></ul><ul><li>RSV </li></ul><ul><li>Hepatitis A, B and C viruses </li></ul><ul><li>Papillomavirus </li></ul><ul><li>Picornavirus </li></ul>
  5. 5. Antivirals <ul><li>APPROACH TO ANTIVIRAL CHEMOTHERAPY </li></ul><ul><li>1. Adsorption, Penetration and Uncoating </li></ul><ul><li>= little is known about the specific reactions involved </li></ul><ul><li>= only amantadine, rimantadine used vs influenza A </li></ul><ul><li>= HIV, rhino, EBV now being researched on </li></ul><ul><li>2. Replication of Viral Nucleic Acids </li></ul><ul><li>= attack enzymes which catalyze replication </li></ul><ul><li>= not present in uninfected cells </li></ul><ul><li>= all RNA viruses, pox, herpes and </li></ul><ul><li>adenovirus </li></ul>
  6. 6. Antivirals <ul><li>APPROACH TO ANTIVIRAL CHEMOTHERAPY </li></ul><ul><li>3. Integration of Viral Genomes into Cellular Genomes </li></ul><ul><li>= as part of multiplication cycle (retrovirus and its integrase) </li></ul><ul><li>= tumorigenesis (papovavirus, herpes) </li></ul><ul><li>4. Synthesis of Viral Messenger RNA’s </li></ul><ul><li>= virus-encoded RNA polymerases, capping enzymes </li></ul>
  7. 7. Antivirals <ul><li>APPROACH TO ANTIVIRAL CHEMOTHERAPY </li></ul><ul><li>5. Synthesis of Viral Proteins </li></ul><ul><li>= viral mRNA translation different from host mRNA </li></ul><ul><li>6. Viral Morphogenesis </li></ul><ul><li>= enzymes which cleave precursors for viral capsid CHONs </li></ul><ul><li>= ex. viral proteases </li></ul>
  8. 8. Antivirals <ul><li>CLASSES OF ANTIVIRAL AGENTS </li></ul><ul><li>Synthetic Antiviral Agents </li></ul><ul><li>I. Analogues of Ribonucleosides and Deoxyribonucleosides </li></ul><ul><li>= nucleic acids base or derivatives </li></ul><ul><li>= included into nucleic acid, usually DNA </li></ul><ul><li>= interfere with nucleic acid function </li></ul><ul><li>= selectively inhibit viral polymerases </li></ul><ul><li>A. Idoxuridine and Trifluorothymidine </li></ul><ul><li>= analogues of thymidine, inhibits viral DNA formation </li></ul><ul><li>= inhibit multiplication of herpesviruses </li></ul><ul><li>= used for topical treatment of herpes simplex </li></ul><ul><li>keratitis </li></ul><ul><li>= not for systemic use because of toxicity </li></ul>
  9. 9. Herpes keratoconjunctivitis
  10. 10. Herpes simplex
  11. 11. Herpes simplex
  12. 12. Herpes simplex
  13. 13. Antivirals <ul><ul><ul><ul><li>B. Vidarabine (Adenosine arabinoside, Ara-A) </li></ul></ul></ul></ul><ul><li>= inhibits HSV and VZV multiplication </li></ul><ul><li>= act as chain terminators; inhibit viral DNA polymerase more than host DNA polymerase </li></ul><ul><li>= herpes simplex keratitis; herpes simplex encephalitis (IV route) </li></ul><ul><ul><ul><ul><li>C. Acyclovir, Famciclovir </li></ul></ul></ul></ul><ul><li>= guanine linked to an open ring analogue of ribose, deoxyribose </li></ul><ul><li>= thymine or cytosine derivative </li></ul><ul><li>= phosphorylated by HSV and VZV TKinases </li></ul><ul><li>= topical or IV in mucocutaneous herpes simplex in immunocompromised hosts and also in genital </li></ul><ul><li>herpes simplex infections </li></ul>
  14. 14. CHICKENPOX (VARICELLA)
  15. 15. Antivirals <ul><ul><ul><ul><ul><li>D. Ganciclovir </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= close relative of acyclovir; inhibits HSV multiplication </li></ul></ul></ul></ul></ul><ul><ul><ul><li>= better substrate for HSV TK than acyclovir </li></ul></ul></ul><ul><ul><ul><li>= best inhibitor of CMV multiplication in use </li></ul></ul></ul><ul><ul><ul><li>= probably not a strict chain terminator unlike acyclovir </li></ul></ul></ul>
  16. 16. Antivirals <ul><ul><ul><ul><ul><li>E. Zidovudine (Azidothymidine, AZT, Retrovir ) </li></ul></ul></ul></ul></ul><ul><ul><ul><li>= inhibits retrovirus reverse transcriptase (RT) </li></ul></ul></ul><ul><ul><ul><li>= chain terminator because it does not possess a 3’-OH group </li></ul></ul></ul><ul><ul><ul><li>= demonstrated clinical efficacy in HIV </li></ul></ul></ul><ul><ul><ul><li>= others: zalcitabine, didanosine, stavudine, lamivudine </li></ul></ul></ul><ul><ul><ul><li>nevirapine </li></ul></ul></ul><ul><ul><ul><li>= lamivudine: newer generation RT inhibitor effective vs hepatitis B </li></ul></ul></ul><ul><ul><ul><li>= new antivirals that don’t look like nucleosides but still block RT </li></ul></ul></ul>
  17. 17. CYTOMEGALOVIRUS
  18. 18. AIDS
  19. 19. Antivirals <ul><ul><ul><ul><ul><li>F. Ribavirin (Virazole) </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= analogue of purine precursor of 5-aminoimidazole 4-carboxamide </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= wide spectrum: good vs RNA and DNA viruses </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= target: virus-encoded nucleic acid polymerases </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= affects elongation and initiation (less extent) </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= for severe RSV infection (aerosol) in children </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= reduce mortality on patients with Lassa fever </li></ul></ul></ul></ul></ul>
  20. 20. RSV infection (bronchiolitis )
  21. 21. RESPIRATORY SYNCYTIAL VIRUS
  22. 22. Antivirals <ul><ul><ul><ul><ul><li>Others </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= analogues of thymidine (BVdU) and cytosine (FIAC) - good vs herpesvirus DNA polymerases with low toxicity </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= 2’, 3’-dideoxynucleosides act as chain terminators in retrovirus infections including HIV </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= phosphonoformic acid (foscarnet) and phosphonoacetic acid (PAA) – potent highly specific inhibitors of HSV DNA. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= toxic to bones and kidney </li></ul></ul></ul></ul></ul>
  23. 23. Antivirals <ul><ul><ul><ul><ul><li>Others </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>methyl phosphonate derivative (s)-HPMPA </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= inhibits DNA viruses ex. herpes, pox, adeno and retro </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>PMEA - for retrovirus, HIV and tumor formation </li></ul></ul></ul></ul></ul>
  24. 24. Antivirals <ul><ul><ul><ul><ul><li>Amantadine and Rimantadine </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= effective inhibitors of influenza A multiplication; bind to and block H channel </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>and prevent M1 proteins from dissociating </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>from nucleocapsid </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= affects penetration and uncoating </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= also inhibits budding and virus particle release </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= FDA approved for prophylaxis vs influenza A </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= CNS side effects worse for amantadine than rimantadine </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= useful for elderly, immunocompromised, allergies and in epidemics </li></ul></ul></ul></ul></ul>
  25. 25. Antivirals <ul><li>Pleconaril= inhibits uncoating of rhinovirus by blocking a pocket on the viral surface which controls the uncoating process </li></ul><ul><li>Same pocket is found among enteroviruses </li></ul>
  26. 26. Antivirals <ul><ul><ul><ul><ul><li>Other Antiviral Agents </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Isatin-B-thiosemicarbazone </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= very potent inhibitor of Poxvirus </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= at 3 mg/L – inhibits vaccinia multiplication (90%) </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= inhibits translation of late mRNA –> no viral capsid and CHON synthesis -> no progeny </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Marburan (n-methyl-IBT) – a derivative of IBT </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= beneficial effects for smallpox contacts </li></ul></ul></ul></ul></ul>
  27. 27. SMALLPOX
  28. 28. Antivirals <ul><ul><ul><ul><ul><li>2-Hydroxylbenzylbenzimidazole (HBB) and Guanidine </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= PICORNAVIRUSES (polio, echo, coxsackie and FMD/enteroviruses) </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= interfere with replication of viral RNA </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= prevent the initiation of the synthesis of progeny (+) strands by inhibiting protein 2C </li></ul></ul></ul></ul></ul>
  29. 29. Antivirals <ul><ul><ul><ul><ul><li>Rifampicin and Rifamycin derivatives </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= binds to bacterial RNA polymerase </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= prevent initiation of transcription </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= no binding to animal RNA polymerase </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= inhibit multiplication of pox and adeno </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= both early and late mRNAs are transcribed </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>normally (viral polymerase not inhibited) </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= accumulation of immature virus particles that lack the normal dense spicule layer </li></ul></ul></ul></ul></ul>
  30. 30. Antivirals <ul><ul><ul><ul><ul><li>Arildone, Rhodanine, and WIN 51711 </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= inhibit uncoating of Picornaviruses by making the virus more stable </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= does not affect absorption or penetration </li></ul></ul></ul></ul></ul>
  31. 31. Antivirals <ul><ul><ul><ul><ul><li>Translation: Antisense </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= segments of DNA or RNA that act as mirror images to critical sections of viral genomes </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= fomivirsen: for CMV eye infections in AIDS patients </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= morpholino antisense: experimentally suppress the ff: </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>calicivirus, flavivirus, dengue, HCV, coronaviruses </li></ul></ul></ul></ul></ul>
  32. 32. Antivirals <ul><ul><ul><ul><ul><li>Translation: Ribozymes </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= enzymes that cut apart viral DNA or RNA </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= ongoing work on Hepa C and HIV </li></ul></ul></ul></ul></ul>
  33. 33. Antivirals <ul><ul><ul><ul><ul><li>Inhibitors of Proteases </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= precursors do not become the functional </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>proteins; synthetic peptides </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= (-) HIV protease: essential role in production of a functional virion </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= Saquinavir, indinavir, ritonavir, nelfinavir, amprenavir – slip into the hydrophobic active site of the enzyme </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= combine with AZT and a 2 nd nucleoside analogue in tx of AIDS </li></ul></ul></ul></ul></ul>
  34. 34. Antivirals <ul><ul><ul><ul><ul><li>Inhibitors of Viral release </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= final stage is the release of the completed virus from the host cell </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= zanamivir (Relenza) and oseltamivir (Tamiflu) block neuraminidase in the surface of influenza virus </li></ul></ul></ul></ul></ul>
  35. 35. Antivirals <ul><ul><ul><ul><ul><li>Promising New Approaches </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Inhibition of Adsorption </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= many viral receptors have been identified </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Targeted Introduction of Toxins into Infected Cells </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= directed against infected cells </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= ricin or the Pseudomonas exotoxin to CD4--- attach to gp120 --- internalized into infected cell </li></ul></ul></ul></ul></ul>
  36. 36. Antivirals <ul><ul><ul><ul><ul><li>Introduction into Cells of Specific Anti-Sense RNA Sequences </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= many mRNA splice junctions have been sequenced </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Preventing Interactions Among Protein Molecules </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= add excess oligopeptides with the same sequence as that of the interacting sequence </li></ul></ul></ul></ul></ul>
  37. 37. Interferons <ul><ul><ul><ul><ul><li>natural antiviral compounds </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>substances that have antiviral properties in adjacent, noninfected cells </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Types of Interferons </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Type I: (1) Interferon alpha = maximal </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>antiviral activity </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>(2) Interferon Beta = intermediate </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>antiviral activity </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Type II: Interferon Gamma = more lymphokine than antiviral </li></ul></ul></ul></ul></ul>
  38. 38. Interferons <ul><ul><ul><ul><ul><li>Regulation of Interferon Expression </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= not expressed in a normal resting cell </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= labile repressors bind to promoter elements, block transcription </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= production of labile suppressors drop in viral infection and allows interferon synthesis to occur </li></ul></ul></ul></ul></ul>
  39. 39. Interferons <ul><ul><ul><ul><ul><li>Mechanism of action </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= synthesis, secretion, diffusion and binding to cellular receptors </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= taken up by uninfected cells </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= viral replication (-) via cellular enzymes </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Type I </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= (-) viral protein synthesis (very specific) </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= 2 enzymes activated: </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>1. oligo-A synthetase  adenine nucleotide  viral mRNA digestion </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>2. protein kinase ->phosphorylates EF-2 -> blocks CHON synthesis </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= block other stages of replication including budding </li></ul></ul></ul></ul></ul>
  40. 40. Interferons <ul><ul><ul><ul><ul><li>Type II : </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= antiviral effects mediated by: </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>1. nitric oxide synthetase—increased intracellular nitric oxide levels </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>2. upregulation of MHC I and II expression </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>3. activation of monocytes, macrophages and NK cells </li></ul></ul></ul></ul></ul>
  41. 41. Interferon
  42. 42. Interferons <ul><ul><ul><ul><ul><li>Clinical Uses: </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>IFN-A : </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= treatment of viral infections: condylomata acuminata and chronic hepa B and C </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= prophylactic or therapeutic agent in immunocomp. hosts (VZV, HSV 1 and 2) </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= prophylaxis vs CMV in renal transplant </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= treatment of AIDS-associated Kaposi’s sarcoma and hairy cell leukemia </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>IFN-G: immunostimulant in oncologic and immunedeficiency disorders </li></ul></ul></ul></ul></ul>
  43. 43. <ul><li>Sites for effective action of various Antivirals </li></ul><ul><li>versus Viruses </li></ul>
  44. 44. Vaccines <ul><ul><ul><ul><ul><li>TYPES OF VACCINES: </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>1. Inactivated Virus Vaccines </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= complete inactivation of infectivity with minimum loss of antigenicity </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= ex. a. UV irradiation </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>b. photodynamic inactivation </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>and white light irradiation </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>c. beta-propiolactone </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>d. formaldehyde (most effective) </li></ul></ul></ul></ul></ul>
  45. 45. Vaccines <ul><ul><ul><ul><ul><li>2. Attenuated Active Virus Vaccines </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= Jenner’s smallpox , Theiler’s yellow fever </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>virus, Sabin poliovirus, MMR, adenovirus </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= repeated passage of human pathogens in </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>other host species </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= effective in small amounts: amplification </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>effect </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= recombinant DNA technology has </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>improved attenuation </li></ul></ul></ul></ul></ul>
  46. 46. POLIO VACCINE
  47. 47. MEASLES
  48. 48. Vaccines <ul><ul><ul><ul><ul><li>3. Subunit Vaccines </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= viral proteins that elicit formation </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>of neutralizing Ab’s </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= smaller range of Ab’s (IgA, IgM) </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>produced </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= genes of these CHONs now can be </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>cloned </li></ul></ul></ul></ul></ul>
  49. 49. Vaccines <ul><ul><ul><ul><ul><li>4. Viral Vectors </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= genes of viral CHONs inserted into avirulent </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>viral vectors </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= thymidine kinase gene of Vaccinia virus </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= genes are expressed without disease and </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>Ab’s are produced </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= HA gene of influenza, glycoprotein B gene </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>of herpesvirus, surface Ag of HBV </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>= major limitation is the infectivity of </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>vaccinia itself </li></ul></ul></ul></ul></ul>
  50. 50. THANK YOU

×