Immunity t o Microbes

1. Immunity to Microbes DiniAgustina MikrobiologiFKUJ 2017

3. Immunity • Means  Protection from the disease and, more specifically, infectious disease • Immune system defense against infectious microbes Mediated by Innate immunity early reactions Adaptive immunity later respons

4. Immune System Microbe Adaptive immunity Innate immunity B lymphocytes Antibodies Epithelialbarriers T lymphocytes Effector T cells Phagocytes Complement NK cells Hours Days 0 6 12 1 3 5 Time after infection

5. Types of pathogenic microorganism

8. Extracellular Bacteria

10. Capable of replicating outside host cells, for example in the circulation, in connective tissues and in tissues spaces such as the airways and intestinal lumens. • Two principal mechanisms cause the diseases : • induce inflammation • produce toxin • Innate immunity  complement activation, phagocytosis, inflammatory response • Adaptive immunity  humoral immunity: eliminate the microbes and neutralize their toxins

12. Innate immunity to extracellular microbes: Phagocytosis

13. Phagocytosis of Streptococcus pyogenes by a macrophage. CELLS alive! Pathogens may resist phagocytosis by: Evading phagocytes by growing in regions of the body which are not accessible to them Avoiding engulfment by phagocytes after contact Being able to kill phagocytes either before or after engulfment Being able to survive inside of phagocytes (or other types of cells) and to persist as intracellular parasites Kenneth Todar, Ph.D.

14. Innate immunity to extracellular microbes: Complement Activation

15. Adaptive immunity to extracellular microbes

16. Immune evasion by extracelluler bacteria

17. Intracellular Bacteria

19. Characteristic : ability to survive and even replicatewithin phagocytes • Innateimmunity may control bacterial growth, • adaptive immunity required elimination of bacteria • Innate immune response : phagocytes and natural killer (NK) cells • intracellular bacteria activate NK cells : • Directly • Stimulating macrophage production of IL-12 • NK cells produce IFN Ý actvates macrophages • Adaptive immune response : cell-mediated immunity • consists of two types of reactions : • Macrophage activation by the Tcells-derived signals CD40 ligand and IFN Ý  killing of phagocytosed microbes • Cytolytic T lymphocytes  lysis of infected cells

20. Innate immunity to intracellularmicrobes

21. Adaptive immunity to intracellular microbes

22. Immune evasion by intracelluler bacteria

26. Fungi

28. Innate immunity : neutrophils and macrophages • Adaptive immunity : cell-mediated immunity Example: • Histoplasmacapsulatum: cellular mechanisms of intracellular bacteria • Cryptococcus neoformans: cooperate between CD4+ and CD8+ • Candida : cell-mediated immunity

31. Viruses

32. Innate immunity : inhibition of infection by type I IFNand NK cells (by killing injured or/and infected cell) • Adaptive immunity : cell-mediated immunity • Antibodies • Block virus binding and entry into host cell (Neutralization) • Act as opsonin to increase phagocytic killing by phagocyte • CTL’s eliminate the infection by killing infected cells

33. Immunity to viruses

34. Immune evasion by viruses: Antigenik drift vs Antigenik shift

35. Inhibition of virus antigen presentation to CTL

36. Parasites (helminth)

37. Innate immunity to parasites: EOSINOPHIL

38. Adaptive immunity to parasites: Th2 FUNCTION

40. Immune evasion by parasites

41. Latihan soal

42. Seorangremajaberusia 21 tahundatangkerumahsakitswastadengankeluhannyeripinggangkanan, setelahdilakukanpemeriksaanlengkap, pemudatersebutdidiagnosa (Glomerulonephritis Akut) GNA. Dari anamnesaternyatadidapatkanriwayatseringmenderitanyeritenggoroksejakkecil.

43. Termasukdalamjenismikroorganismeapakahagenpenyakittersebut … • Ekstraselulermikroba • Intraselulermikroba • Multiselulermikroba • Fungi • Virus

44. Mekanismepatogenesitaspadamikroorganismetersebutadalah … • Aktivasimakrofag • Inflamasiakut yang diinduksiolehdindingsel • Inflamasiakut yang diinduksiolehtoksin • Inflamasi granuloma • Menghambatsintesis protein