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The role of Entamoeba histolytica trogocytosis (trogo-: nibble) in the pathogenesis of amoebiasis

Award Number: R01AI146914
ORGANIZATION: NATIONAL INSTITUTE OF ALLERGY & INFECTIOUS DISEASES
OPDIV: NIH
AWARD CLASS: DISCRETIONARY
AWARD ACTIVITY TYPE: SCIENTIFIC/HEALTH RESEARCH (INCLUDES SURVEYS)
PERIOD OF PERFORMANCE START DATE: 06/01/2019
PERIOD OF PERFORMANCE END DATE: 05/31/2024

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The role of Entamoeba histolytica trogocytosis (trogo-: nibble) in the pathogenesis of amoebiasis - Abstract Entamoeba histolytica is a protozoan pathogen and the causative agent of amoebiasis in humans. The species name (histo-: tissue; lytic-: dissolving) derives from the ability to destroy host tissues. E. histolytica trophozoites (“amoebae”) invade the large intestine, causing ulceration and can spread to other tissues (e.g., liver, lungs, brain), causing fatal abscesses. Amoebae possess contact-dependent cell-killing activity that is likely to drive tissue damage, but the mechanism was unclear. We established a new paradigm by discovering that amoebae kill by biting off and ingesting human cell fragments, which we named “amoebic trogocytosis” (trogo-: nibble) (Ralston, et al., Nature, 2014). Building on this discovery, here we propose to delineate the unexpected contribution of trogocytosis to immune evasion. We will apply imaging flow cytometry, host and amoeba mutants, and a variety of host cell types to dissect the contribution of trogocytosis to immune avoidance in vitro, and we will use the mouse model of amoebiasis to extend these findings to pathogenesis in vivo. Beyond E. histolytica, trogocytosis has far-reaching applications to eukaryotic biology. Several microbial eukaryotes appear to use trogocytosis for cell-killing. In multicellular eukaryotes, trogocytosis is used for cell-killing, cell-cell communication and cell-cell remodeling. Trogocytosis plays roles in the immune system, in the central nervous system, and during development. Therefore, an improved understanding of the mechanism and biology of E. histolytica trogocytosis will apply both directly to the pathogenesis of amoebiasis and broadly to eukaryotic trogocytosis in general. This work is significant and high-impact as it will define a novel strategy for immune evasion and an important aspect of amoebiasis pathogenesis. Moreover, these studies apply broadly to trogocytosis as a conserved mode of eukaryotic cell-cell interaction. !


Issue Date FY	Funding FY	Legal Entity Name	Legal Entity Address	Legal Entity City	Legal Entity State	Legal Entity Zip Code	Legal Entity COUNTY	Legal Entity COUNTRY	Assistance Listing	Award Code	Budget Year	Action Date	Action Type	Action Amount

Issue Date FY: 2023 ( Subtotal = $564,515 )
2023	2023	UNIVERSITY OF CALIFORNIA, DAVIS	1850 RESEARCH PARK DR, STE 300	DAVIS	CA	95618	YOLO	USA	Allergy and Infectious Diseases Research	000	5	4/24/2023	NON-COMPETING CONTINUATION	$564,515
														Subtotal = $564,515

Issue Date FY: 2022 ( Subtotal = $176,726 )
2022	2022	UNIVERSITY OF CALIFORNIA, DAVIS	1850 RESEARCH PARK DR, STE 300	DAVIS	CA	95618	YOLO	USA	Allergy and Infectious Diseases Research	000	4	7/5/2022	NON-COMPETING CONTINUATION	$176,726
														Subtotal = $176,726

Issue Date FY: 2021 ( Subtotal = $371,572 )
2021	2021	UNIVERSITY OF CALIFORNIA, DAVIS	1850 RESEARCH PARK DR, STE 300	DAVIS	CA	95618	YOLO	USA	Allergy and Infectious Diseases Research	000	3	5/11/2021	NON-COMPETING CONTINUATION	$371,572
														Subtotal = $371,572

Issue Date FY: 2020 ( Subtotal = $372,181 )
2020	2020	UNIVERSITY OF CALIFORNIA, DAVIS	1850 RESEARCH PARK DR, STE 300	DAVIS	CA	95618	YOLO	USA	Allergy and Infectious Diseases Research	000	2	5/4/2020	NON-COMPETING CONTINUATION	$372,181
														Subtotal = $372,181

Issue Date FY: 2019 ( Subtotal = $372,773 )
2019	2019	UNIVERSITY OF CALIFORNIA, DAVIS	1850 RESEARCH PARK DR, STE 300	DAVIS	CA	95618	YOLO	USA	Allergy and Infectious Diseases Research	000	1	5/29/2019	NEW	$372,773
														Subtotal = $372,773

Grand Total All Awards = $1,857,767

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The role of Entamoeba histolytica trogocytosis (trogo-: nibble) in the pathogenesis of amoebiasis

Award Number: R01AI146914

ORGANIZATION: NATIONAL INSTITUTE OF ALLERGY & INFECTIOUS DISEASES

OPDIV: NIH

AWARD CLASS: DISCRETIONARY

AWARD ACTIVITY TYPE: SCIENTIFIC/HEALTH RESEARCH (INCLUDES SURVEYS)

PERIOD OF PERFORMANCE START DATE: 06/01/2019

PERIOD OF PERFORMANCE END DATE: 05/31/2024

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