Rhomboid Proteases and Surface Adhesins During Cryptosporidium Development
Cryptosporidium parvum, a primary cause of cryptosporidiosis in humans and livestock worldwide, has a complex life cycle that includes an environmental oocyst stage, and stages of merogony, gametogony, and sporogony that are completed in a single host. Development within the host takes place in a pr...
Main Author: | |
---|---|
Format: | Others |
Published: |
North Dakota State University
2017
|
Online Access: | https://hdl.handle.net/10365/26889 |
id |
ndltd-ndsu.edu-oai-library.ndsu.edu-10365-26889 |
---|---|
record_format |
oai_dc |
spelling |
ndltd-ndsu.edu-oai-library.ndsu.edu-10365-268892021-09-28T17:10:52Z Rhomboid Proteases and Surface Adhesins During Cryptosporidium Development Tabe, Ebot Sahidu Cryptosporidium parvum, a primary cause of cryptosporidiosis in humans and livestock worldwide, has a complex life cycle that includes an environmental oocyst stage, and stages of merogony, gametogony, and sporogony that are completed in a single host. Development within the host takes place in a protected intracellular but extracytoplasmic niche at the apical surface of epithelial cells. The life cycle can be described as having alternating extracellular invasive and intracellular replicative stages. With no effective chemotherapeutics, understanding the mechanism of host cell invasion by this pathogen is paramount. The first aim dissertation was to identify functions of sporozoite surface proteins and rhomboid proteases (CpROMs) during motility and invasion of host cells. We demonstrate that two CpROMs distinctively and collectively cleaved five thrombospondin-family proteins (TSPs) and a mucin-like glycoprotein in a heterologous assay. Further, there was differential co-expression and co-localization of the CpROMs and their substartes during in vitro life cycle development; CpROM4 and CpTSP10 proteins colocalized to the anterior, middle and posterior of sporozoites and in developing intracellular stages while CpROM5 and TRAP-C1 colocalized to intact and non-intact oocyst walls, the anterior of sporozoites, and intracellular stages as early as 2 h post infection. CpTSP7, also localized to the oocyst wall, the anterior and posterior of sporozoites and intracellular stages from 6 h post infection. Similar to CpTSP10, CpTSP9 was not present in the oocyst wall; however, it was expressed in sporozoites and intracellular stages from 6 h post infection. Short synthetic peptides derived from adhesive ectodomains in thrombospondins including a TRAP-C1 apple domain (TAAP), thrombospondin type I domains in CpTSP7 (7TS) and CpTSP9 (9TS), and a kringle domain in CpTSP10 (10K1) as well as their corresponding antibodies demonstrated competitive and neutralization inhibition effect of C. parvum infection of host cells. Polyclonal antibodies against TAAP caused sporozoites to agglutinate in a concentrationdependent manner, suggesting a contribution to reduced infectivity. In conclusion, the specificity and expression profiles of CpROM4 and CpROM5 indicate that they have distinct functions in shedding surface adhesins during excystation, motility, invasion, and intracellular development. 2017-11-28T14:36:31Z 2017-11-28T14:36:31Z 2013 text/dissertation https://hdl.handle.net/10365/26889 NDSU policy 190.6.2 https://www.ndsu.edu/fileadmin/policy/190.pdf application/pdf North Dakota State University |
collection |
NDLTD |
format |
Others
|
sources |
NDLTD |
description |
Cryptosporidium parvum, a primary cause of cryptosporidiosis in humans and livestock
worldwide, has a complex life cycle that includes an environmental oocyst stage, and stages of
merogony, gametogony, and sporogony that are completed in a single host. Development
within the host takes place in a protected intracellular but extracytoplasmic niche at the apical
surface of epithelial cells. The life cycle can be described as having alternating extracellular
invasive and intracellular replicative stages. With no effective chemotherapeutics,
understanding the mechanism of host cell invasion by this pathogen is paramount.
The first aim dissertation was to identify functions of sporozoite surface proteins and
rhomboid proteases (CpROMs) during motility and invasion of host cells. We demonstrate that
two CpROMs distinctively and collectively cleaved five thrombospondin-family proteins
(TSPs) and a mucin-like glycoprotein in a heterologous assay. Further, there was differential
co-expression and co-localization of the CpROMs and their substartes during in vitro life cycle
development; CpROM4 and CpTSP10 proteins colocalized to the anterior, middle and posterior
of sporozoites and in developing intracellular stages while CpROM5 and TRAP-C1 colocalized
to intact and non-intact oocyst walls, the anterior of sporozoites, and intracellular stages as
early as 2 h post infection. CpTSP7, also localized to the oocyst wall, the anterior and posterior
of sporozoites and intracellular stages from 6 h post infection. Similar to CpTSP10, CpTSP9
was not present in the oocyst wall; however, it was expressed in sporozoites and intracellular
stages from 6 h post infection. Short synthetic peptides derived from adhesive ectodomains in
thrombospondins including a TRAP-C1 apple domain (TAAP), thrombospondin type I
domains in CpTSP7 (7TS) and CpTSP9 (9TS), and a kringle domain in CpTSP10 (10K1) as
well as their corresponding antibodies demonstrated competitive and neutralization inhibition effect of C. parvum infection of host cells. Polyclonal antibodies against TAAP caused
sporozoites to agglutinate in a concentrationdependent manner, suggesting a contribution to
reduced infectivity. In conclusion, the specificity and expression profiles of CpROM4 and
CpROM5 indicate that they have distinct functions in shedding surface adhesins during
excystation, motility, invasion, and intracellular development. |
author |
Tabe, Ebot Sahidu |
spellingShingle |
Tabe, Ebot Sahidu Rhomboid Proteases and Surface Adhesins During Cryptosporidium Development |
author_facet |
Tabe, Ebot Sahidu |
author_sort |
Tabe, Ebot Sahidu |
title |
Rhomboid Proteases and Surface Adhesins During Cryptosporidium Development |
title_short |
Rhomboid Proteases and Surface Adhesins During Cryptosporidium Development |
title_full |
Rhomboid Proteases and Surface Adhesins During Cryptosporidium Development |
title_fullStr |
Rhomboid Proteases and Surface Adhesins During Cryptosporidium Development |
title_full_unstemmed |
Rhomboid Proteases and Surface Adhesins During Cryptosporidium Development |
title_sort |
rhomboid proteases and surface adhesins during cryptosporidium development |
publisher |
North Dakota State University |
publishDate |
2017 |
url |
https://hdl.handle.net/10365/26889 |
work_keys_str_mv |
AT tabeebotsahidu rhomboidproteasesandsurfaceadhesinsduringcryptosporidiumdevelopment |
_version_ |
1719485330888851456 |