Acknowledgements. Schistosomiasis Epidemiology

Size: px

Start display at page:

Download "Acknowledgements. Schistosomiasis Epidemiology"

Jeffry McDowell
5 years ago
Views:

1 Pulmonary Arterial Hypertension and Schistosomiasis Rubin M. Tuder, M. D. Brian Graham, M.D. Program in Translational Lung Program Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine University of Colorado, Denver School of Medicine PVRI 2nd International Conference Neonatal and Childhood Pulmonary Vascular Disease, UCSF 2009 Acknowledgements PVRI: Ghazwan Butrous ( Colorado: Brian Graham Recife, PE, Brazil: Angela Machado NIH: Tom Wynn, Alan Cheever, Margaret Mentink-Kane Hopkins: Hunter Champion Schistosomiasis Epidemiology Third most prevalent parasitic dx 20% of the endemic population at risk Worldwide prevalence >200 million (600 m at risk) 200,000 deaths/yr in sub-saharan Africa alone 1% of infected untreated individuals die Majority of disease burden is chronic morbidity WHO: >4.5 million disability-adjusted life years US CDC 1

Life Cycle Chronic Disease S mansoni and S japonicum -> GI system Granuloma

cirrhosis: inflammation in presinusoidal areas www.dpd.cdc.

Occurs in those with hepatosplenic shistosomiasis (PH: 7-30% of HS; HS: 30% of all

2 Life Cycle Chronic Disease S mansoni and S japonicum -> GI system Granuloma formation around schistosome eggs retained in tissues Chronic diarrhea, abdominal pain, colon polyps. Severe (15%): hepatic fibrosis, portal hypertension, splenomegaly Not liver cirrhosis: inflammation in presinusoidal areas Pulmonary Hypertension and schistosomiasis Chronic Pulmonary Vascular Disease Occurs in those with hepatosplenic shistosomiasis (PH: 7-30% of HS; HS: 30% of all patients) No differences in HS between PH vs. non- PH; also in tx vs. non-tx Up to 80% of severe PH in centers of reference in Brazil. Butrous et al. Circulation, 2008; courtesy of Dr. Angela Bandeira 2

3 HUMAN PAH BY SCHISTOSOMIASIS IPAH: Endothelial cell processes, proliferation Early Lesions: Plexiform Lesions: a b FACTOR-8 Angiomatoid (dilation) Lesions: SMA Concentric Lesions: d c e Immunopathology of schistosomiasis Ghazwan et al, Circulation, 2008 IL4 and IL13 dependent 3

Experimental Goals (Brian Graham) Develop and demonstrate applicability of a mouse model of the human

of the lung granulomatous response Investigate signaling pathways: interface between the granuloma and

models: Black 6 wild-type IL13Rα1 knockout IL13Rα2 knockout Schisto exposure methods: Ova tail vein

injection (not used here) TA Wynn lab at NIH (Margaret Mentink-Kane) IL13R α1ko: Millennium

schistosomiasis Purified ova Snails: Biomphlaria glabrata Cercariae Model #2 Infected mouse Worms Inject

4 Experimental Goals (Brian Graham) Develop and demonstrate applicability of a mouse model of the human disease Define the biochemical/morphological charac. of the lung granulomatous response Investigate signaling pathways: interface between the granuloma and the adjacent vascular remodeling narrowing- IL13/downstream signaling Mouse Model: schistosomiasis Mouse models: Black 6 wild-type IL13Rα1 knockout IL13Rα2 knockout Schisto exposure methods: Ova tail vein injection Cutaneous exposure to cercariae Sensitization to IP ova antigens, followed by ova tail vein injection (not used here) TA Wynn lab at NIH (Margaret Mentink-Kane) IL13R α1ko: Millennium Pharmaceuticals IL13Rα2ko: Wyeth Pharmaceuticals Lifecycle in the Lab Mouse model of lung schistosomiasis Purified ova Snails: Biomphlaria glabrata Cercariae Model #2 Infected mouse Worms Inject Baby snails Infected snails Purified ova Mouse liver Sacrifice Model #1 Transform Nostoc: Cyanobacterium Miracidia Inject Homogonize and strain Cercariae Model #2 Infected mouse Worms Model #1 4

Mouse Pathology IL4 and IL13 Receptors Receptor 1: IL4Rα Binds IL4 only Receptor 2: IL4Rα + IL13Rα1

remodeling, fibrosis, eosinophil chemotaxis STAT-6 downstream signaling Receptor 3: IL13Rα2 Binds

Overall Design Set 1 Set 2 2 wt (controls) 4 wt (controls) 5 wt + eggs 3 wt + eggs 3 IL13Rα1 ko +

controls) Ova injected by tail vein: 8 day delay Cercariae percutaneous infection: 99 day delay PA

5 Mouse Pathology IL4 and IL13 Receptors Receptor 1: IL4Rα Binds IL4 only Receptor 2: IL4Rα + IL13Rα1 Binds IL4 and IL13 Found on fibroblasts, smooth muscle cells, epithelial cells Regulates tissue remodeling, fibrosis, eosinophil chemotaxis STAT-6 downstream signaling Receptor 3: IL13Rα2 Binds IL13 only; higher affinity than IL4Ra + IL13Ra1 No apparent downstream signaling: decoy receptor Overall Design Set 1 Set 2 2 wt (controls) 4 wt (controls) 5 wt + eggs 3 wt + eggs 3 IL13Rα1 ko + eggs 3 IL13Rα1 ko + eggs 4 IL13Rα2 ko + eggs 4 IL13Rα2 ko + eggs 5 wt + cercariae 7 wt (external controls) Ova injected by tail vein: 8 day delay Cercariae percutaneous infection: 99 day delay PA and RV catheterization Ova injected by tail vein: 8 day delay RV catheterization only; no placebo injection in control mice 5

RV Catheterization N 15 10 12 14 7 13 7 12 14 6 11 3 1 n = 6 8 6 8 ANOVA: p =

volume ~ 30,000 um 3 (50 x 25 x 25 um) Smooth muscle cell ANOVA: p < 0.

6 RV Catheterization N n = ANOVA: p = Mouse IV Ova WT - WT + Ra1 ko + Ra2 ko + 1 cell volume ~ 200 um 3 Ova volume ~ 30,000 um 3 (50 x 25 x 25 um) Smooth muscle cell ANOVA: p < Pairwise multiple comparisons (vs. WT, no eggs) WT+eggs IL13Ra1ko+eggs IL13Ra2ko+eggs 6

7 Cell proliferation Fibroblasts and Collagen 9 days-eggs 99 days cercaria Apoptosis WT + Ova: TUNEL, DAPI + Control (DNAse I) TGF beta signaling: psmad 2/3 WT + Ova psmad 2/3 7

IL13Ra2ko + Ova psmad 2/3 Conclusions: Human Schistosomiasis induced PAH: the most frequent form of PH Overall incidence: 10-20% of patient with HS form Experimental: No clinical PAH in

TGF-beta and psmad 2/3 signaling Not significant in smooth muscle cells Th1 vs.

8 IL13Ra2ko + Ova psmad 2/3 Conclusions: Human Schistosomiasis induced PAH: the most frequent form of PH Overall incidence: 10-20% of patient with HS form Experimental: No clinical PAH in small numbers of mice IL13Ra1 ko: DECREASED: granuloma volume; cell proliferation ; Smooth muscle hyperplasia / hypertrophy Fibroblasts appear later in the disease course Little apoptosis TGF-beta and psmad 2/3 signaling Not significant in smooth muscle cells Th1 vs. Th2 Inflammation Early post-infection: Th1 response (parasite) Ova laying -> Th2 response IL-4, IL-5, IL-13 levels are increased Administering IL-12 prevents the Th2 response Prevents hepatic fibrosis IL-13 is significant for liver fibrosis Blocking or knocking out the pathway decreases fibrosis 8

10/14/2009. Helminths: Trematoda - non-segmented flat worms. The schistosomes: Schistosoma mansoni Schistosoma haematobium. Schistosoma mekongi

10/14/2009. Helminths: Trematoda - non-segmented flat worms. The schistosomes: Schistosoma mansoni Schistosoma haematobium. Schistosoma mekongi Helminths: Trematoda - non-segmented flat worms The schistosomes: Schistosoma mansoni Schistosoma haematobium Schistosoma japonicum Schistosoma mekongi 1 Japan is schistosome-free as of 1976 2 Aquatic