The shrimp defense mechanism: simple but efficient. Pikul Jiravanichpaisal

Transcription

1 The shrimp defense mechanism: simple but efficient Pikul Jiravanichpaisal

2 Germs are everywhere

3 Infectious disease process Dose 1. Entry the host- getting in 2. Establishment- staying in 3. Avoid, evade, or compromise the host defense- defeat the host defenses 4. Damage the host 5. Exit Source: Y_tambe, dual-license with GFDL and CC-by-SA,\ png

4 Mode of infection Ingestion Wounds (gill, shell)

5 Shrimp diseases Pathogenic microorganisms/ pathogens Viruses Fungi Enterocytozoon Protozoa Bacteria

6 Pathogens can be found in various compartments of the body WSSV YHV Vibrio Nucleus Cell Digestive organ

7 The Immune System A body system designed to protect us from pathogens that attack and try to invade our bodies

8 1. Innate, natural or non-specific immunity 2. Acquired, adaptive or specific immunity Innate immune system Adaptive immune system Response is non-specific Pathogen and antigen specific response Exposure leads to immediate maximal Lag time between exposure and maximal response response Cell-mediated and humoral components Cell-mediated and humoral components No immunological memory Exposure leads to immunological memory Found in nearly all forms of life Found only in jawed vertebrates Germ-line coded Gene rearrangement

9 More than 95% of all known species belongs to the invertebrates!

10 Invertebrates rely solely on innate immunity

11 Blood circulatory system Vertebrates Closed circulation Invertebrates Open circulation Blood: bloodplasma + red & white blood cells Hemolymph: plasma + hemocytes

12 Shrimp haemocytes Text Hyaline cells Semigranular cell Granular cell

13 How do shrimp defend themselves?

14 First line of defense Optimal goal: Prevent microorganisms from gaining access - The exoskeleton or cuticle - layer of non-cellular material - thin, but tough and flexible, - cover the whole external body surface, stomach and hindgut and reproductive ducts Function: - To limit the entry or loss of water - Form an efficient barrier protecting against invasion by eukaryotic parasites and infection by microorganisms.

15 Structure and formation of cuticle of shrimp the Shell/cuticle/skin Epicuticle Exocuticle Endocuticle The inner-most layer Epidermal cell

16 Shrimp gut Physical and biochemical barrier

17 Shrimp cuticle Shrimp stomach

18 The immune role of the shrimp cuticle -Physical component of the cuticle defense -Biochemical component of the cuticle defense -Mounting as a component of cuticle defense

19 Most pathogens aiming to colonize the haemocoel

20 The last line of defense or haemocoelic internal defense Optimal goal: Neutralized and destroy invaders Complex network of cellular and humoral responses that work together to protect the body

21 Clotting protein Phagocytosis Antiviral defense Antimicrobial peptides Pattern recognition protein ProPO Ecapsulation/ nodule formation Lectins

22 Haemocoelic internal defense

23 Staphylococcus aureus - injected crayfish

24 E. Coli - injected crayfish a b c d

25 a Aeromonas hydrophila - injected crayfish b c d

26 Normal saline - injected crayfish a b c d

27 Intestinal Immunity

28 The digestive tract is a first entry point for many pathogens AHPND/Early Mortality Syndrome (EMS) Vibriosis Gregarines Enterocytozoon White Feces Syndrome 28 Aqua Biz and www. Shrimpcenter.com Photo credits

29 Oral administration with V. parahaemolyticus to induce EMS/AHPND in shrimp Control h scar

30 Control midgut EMS/AHPND-infected midgut

31 Bacterial infection in midgut Phagocytosis He Bac Encapsulation and melanization

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33 The intestine and its microflora are partners for the protection of the host Intestine Mucosal barriers Local immune system Microflora Photo credits

34 The bacterial community in the digestive tract of shrimp Jiravanichpaisal et al. unpublished data 34

35 Relative expression of six genes in midgut (AM) and hindgut (PH) of shrimp during V. harveyi challenge by immersion method Soonthornchai W. et al., 2010, Developmental and Comparative Immunity

36 Shrimp intestinal Immune system Pathogens Lectins Commensal bacteria AMPs Peritrophic membrane Epithelial cells Basement membrane Hemocytes Jiravanichpaisal P Adaptive immunity Penlectin? Phagocytosis Melanization Clotting protein

37 Conclusion Healthy Gut = Healthy Shrimp

38 THANK YOU