Presented by Daren Ginete
Outline Helminths and immunomodulation Research question Figures 1-3 Microbiome Trichinella and MNV CW3 Figures 1-3 Alternative Activation of Macrophages Figure 4 Summary
What are helminths? WHO, 2011 Parasites characterized by elongated, flat, or round bodies Affects more than 1/3 of world’s population living under poverty Heavy infections can cause abdominal pain, diarrhea, blood loss, growth defects Can modify immune response (immunomodulation) http://www.cdc.gov/parasites/sth/index.html Distribution of soil-transmitted helminthiases and proportion of children (aged1-14 years) in each endemic country requiring preventive chemotherapy for the diseases, 2011 Hotez, Brindley et al, 2008 Hookworm Ascaris Whipworm
Helminths and immunomodulation THE BAD THE GOOD McSorley and Maizels, 2012
? X Research Question IMMUNE RESPONSE Adapted from McSorley and Maizels, 2012
Helminths, microbiome, and immune response Helminth infection alters microbiome Microbiome is capable of mediating various immune response Kamada et al, 2013 microbiome-mediated development of intestinal immune response
? Research Question ALTER MICROBIOME IMMUNE RESPONSE Adapted from McSorley and Maizels, 2012
Experimental Approach Adapted from McSorley and Maizels, 2012 ? ALTER MICROBIOME IMMUNE RESPONSE Establish a model of coinfection and characterize immunomodulation Check whether immunomodulation is microbiome: Dependent Independent
Model: Trichinella spiralis (Ts) and murine norovirus (MNV CW3) coinfection Parasitic nematode Causative agent for Trichinellosis From raw or undercooked pork and wild game meat 10,000 cases/year Symptoms: diarrhea, muscle pain, nausea, headache, fever, chills 2-3 weeks in the small intestine then extraintestinal phase http://www.trichinella.org/bio_lifecycle.htm http://www.cdc.gov/parasites/trichinellosis/gen_info/index.html
Model: Trichinella spiralis (Ts) and murine norovirus (MNV CW3) coinfection Noroviruses Very contagious Ingestion results in food poisoning Most common cause of acute gastroenteritis and foodborne-disease outbreak in the U.S. 19-21 million illnesses and 570-800 deaths Murine norovirus-sole norovirus that replicates in cell culture and small animal Wobus, Thackray, and Virgin 2006 http://www.cdc.gov/norovirus/about/overview.html
Figure 1: Establishment Trichinella and murine norovirus coinfection displays immuno-modulation Decrease in CD8+ T cells frequency and numbers
Figure 2: Characterization Coinfection delayed and reduced proliferation of virus-specific T cells
Figure 2: Characterization Hp: Heligmosomoides polygyrus bakeri Influenza Immunomodulatory effects are observed in lungs and are not specific to Trichinella and CW3
Immunomodulatory effects includes: Systemic infection Are Long lived Established viral infection
Experimental Plan Adapted from McSorley and Maizels, 2012 ? ALTER MICROBIOME IMMUNE RESPONSE Establish a model of coinfection and characterize immunomodulation Check whether immunomodulation is microbiome: Dependent Change in microbiome Immunomodulation in germ free mice Independent
Figure 3: Microbiome dependent? In addition Trichinella infection alters gut microbiome
Figure 3: Microbiome independent! In addition Immunomodulation observed in presence or absence of gut microbiome
Experimental Plan Establish a model of coinfection and characterize immunomodulation Check whether immunomodulation is microbiome: Dependent Change in microbiome Immunomodulation in germ free mice Independent STAT6-dependent AAMacs differentation Adapted from McSorley and Maizels, 2012 ? ALTER MICROBIOME IMMUNE RESPONSE
“Classical” activation of macrophages Activated by IFN-γ which activates NF-κB and STAT1 signaling pathway Increase production of reactive oxygen and nitrogen species and pro-inflammatory cytokines Microbe and viral clearance pro-inflammatory cytokines such as TNF-α, IL-1 Adapted from Wynn et al, 2013 and Martinez et al, 2009 From Wynn et al, 2013
Alternative activation of macrophages IL-4/IL-13 receptor STAT6 IL-4/IL-13 JAK3 Adapted from Martinez et al, 2009 Arg1 Retnla Ym1 Activated by IL-4/IL-13 which activates STAT6 signaling pathway
Alternative activation of macrophages Express immunoregulatory proteins Remodels ECM Helminth clearance IL-4 and IL-13 promote helminth expulsion AAMacs produce chitinase and chitinase-like proteins Express immunoregulatory proteins (like arginase-1 and IL-10) that regulate magnitude and duration of immune response Remodels ECM by scavenge collagen and extracellular matrix components Helminth clearance: IL-4 and IL-13 increase gut contractility and luminal fluid flowphysical expulsion of helminth AAMacs produce chitinase or chitinase-like proteins that target the glycan chitin that is usually present in helmintsh but not mammals. Adapted from Wynn et al, 2013 and Martinez et al, 2009 From Wynn et al, 2013
Figure 4 Immunomodulation is dependent on STAT6 Ym1 In addition
Figure 4 Immuno-modulation is dependent on STAT6 activated Ym1 In addition
Experimental Plan Establish a model of coinfection and characterize immunomodulation Check whether immunomodulation is microbiome: Dependent Change in microbiome Immunomodulation in germ free mice Independent STAT6-dependent AAMacs differentation Ym1 dependent Adapted from McSorley and Maizels, 2012 ? ALTER MICROBIOME IMMUNE RESPONSE
Mechanism of virus-helminth coinfection
Questions?
JIC: Salivary glands and Th2 responses Salivary gland extracts Reduce IFN-β expression Promote Th2 cytokine expression Alternate activated macrophage
JIC: Hygiene Hypothesis From Wills-Karp et al, 2001