An Immunoglobulin G1 Monoclonal Antibody Highly Specific to the Wall of
            <i>Cryptosporidium</i>
            Oocysts

Weir, Christopher; Vesey, Graham; Slade, Martin B.; Ferrari, Belinda C.; Veal, Duncan; Williams, Keith L.

doi:10.1128/cdli.7.5.745-750.2000

Cited by 25 publications

(17 citation statements)

References 20 publications

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“…This result is consistent with COWP1 being the most antigenic and the first C. parvum wall protein that was molecularly characterized (20,28,33,37,44). COWP6 and COWP8 are also relatively abundant in oocyst walls.…”

Section: Resultssupporting

confidence: 77%

Evidence for Mucin-Like Glycoproteins That Tether Sporozoites of Cryptosporidium parvum to the Inner Surface of the Oocyst Wall

et al. 2010

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Cryptosporidium parvum oocysts, which are spread by the fecal-oral route, have a single, multilayered wall that surrounds four sporozoites, the invasive form. The C. parvum oocyst wall is labeled by the Maclura pomifera agglutinin (MPA), which binds GalNAc, and the C. parvum wall contains at least two unique proteins (Cryptosporidium oocyst wall protein 1 [COWP1] and COWP8) identified by monoclonal antibodies. C. parvum sporozoites have on their surface multiple mucin-like glycoproteins with Ser-and Thr-rich repeats (e.g., gp40 and gp900). Here we used ruthenium red staining and electron microscopy to demonstrate fibrils, which appear to attach or tether sporozoites to the inner surface of the C. parvum oocyst wall. When disconnected from the sporozoites, some of these fibrillar tethers appear to collapse into globules on the inner surface of oocyst walls. The most abundant proteins of purified oocyst walls, which are missing the tethers and outer veil, were COWP1, COWP6, and COWP8, while COWP2, COWP3, and COWP4 were present in trace amounts. In contrast, MPA affinity-purified glycoproteins from C. parvum oocysts, which are composed of walls and sporozoites, included previously identified mucin-like glycoproteins, a GalNAc-binding lectin, a Ser protease inhibitor, and several novel glycoproteins (C. parvum MPA affinity-purified glycoprotein 1 [CpMPA1] to CpMPA4). By immunoelectron microscopy (immuno-EM), we localized mucin-like glycoproteins (gp40 and gp900) to the ruthenium red-stained fibrils on the inner surface wall of oocysts, while antibodies to the O-linked GalNAc on glycoproteins were localized to the globules. These results suggest that mucin-like glycoproteins, which are associated with the sporozoite surface, may contribute to fibrils and/or globules that tether sporozoites to the inner surface of oocyst walls.

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Section: Resultssupporting

confidence: 77%

Evidence for Mucin-Like Glycoproteins That Tether Sporozoites of Cryptosporidium parvum to the Inner Surface of the Oocyst Wall

et al. 2010

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“…Although the final precipitation step has been used before as a potent way to present antigens with low immunogenicity (18), using soluble proteins sets our process apart, as most other vaccines are derived from ethanol fixed or irradiated whole cells (19)(20)(21). These soluble proteins are then reduced with TCEP, which permanently breaks disulfide bonds and provides a stable environment for proteins (22,23).…”

Section: Discussionmentioning

confidence: 99%

Streptavidin: A Novel Immunostimulant for the Selection and Delivery of Autologous and Syngeneic Tumor Vaccines

Weir

Hudson

Moon

et al. 2014

Cancer Immunology Research

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Induction of antitumor immunity using autologous tumor proteins is an attractive approach to cancer therapy. However, better methods and stimulants to present these autologous proteins back to the immune system are needed. Here, we identify streptavidin as a novel carrier protein and stimulant, and test the efficacy of both syngeneic (rat) and autologous vaccines (dogs) using streptavidin in combination with reduced soluble tumor proteins. Initial syngeneic vaccine studies in the 9L rat glioma model were used to optimize vaccine dose and selectivity. Cytokine and blood analysis was used to monitor the response. Rats receiving two vaccinations of syngeneic tumor vaccine demonstrated a statistically significant (P < 0.05) survival advantage compared with controls (adjuvant only). Notably, vaccination also led to remission rates of between 30% and 60% in the aggressive 9L glioma model. Antibodies to streptavidin were detected in the serum of vaccinated rats; however, antibody levels did not correlate with the response. The cytokine TNF-a was upregulated in vaccine-treated rats, whereas ICAM1 was downregulated. After engraftment, vaccinated rats maintained CD4þ T cells, and total lymphocyte levels closer to normal baseline than those in the controls. Twenty-five dogs treated with autologous vaccine preparations using streptavidin as a stimulant showed no adverse reactions, irrespective of additional chemotherapy and other medications. In this study, we developed a novel method for producing syngeneic and autologous vaccines using streptavidin selectivity and immunogenicity. These vaccines show efficacy in the 9L glioma rat model. Safety was also demonstrated in canine patients presenting with cancer treated with autologous vaccine.

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“…Briefly, a fecal slurry was prepared for each sample by suspending fecal material (1 g) in 9 ml of dispersion solution (Tween 80 at 0.05% in distilled H 2 O). An aliquot (1 ml) of the slurry was then exposed to paramagnetic beads coated with monoclonal antibody CRY104 (Macquarie Research Ltd., Sydney, Australia), which is specific to the Cryptosporidium oocyst wall (30). Cryptosporidium oocysts bind to the paramagnetic beads, allowing removal of fecal debris.…”

Section: Methodsmentioning

confidence: 99%

Patterns ofCryptosporidiumOocyst Shedding by Eastern Grey Kangaroos Inhabiting an Australian Watershed

Power

Sangster

Slade

et al. 2005

Appl Environ Microbiol

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The occurrence of Cryptosporidium oocysts in feces from a population of wild eastern grey kangaroos inhabiting a protected watershed in Sydney, Australia, was investigated. Over a 2-year period, Cryptosporidium oocysts were detected in 239 of the 3,557 (6.7%) eastern grey kangaroo fecal samples tested by using a combined immunomagnetic separation and flow cytometric technique. The prevalence of Cryptosporidium in this host population was estimated to range from 0.32% to 28.5%, with peaks occurring during the autumn months. Oocyst shedding intensity ranged from below 20 oocysts/g feces to 2.0 ؋ 10 6 oocysts/g feces, and shedding did not appear to be associated with diarrhea. Although morphologically similar to the human-infective Cryptosporidium hominis and the Cryptosporidium parvum "bovine" genotype oocysts, the oocysts isolated from kangaroo feces were identified as the Cryptosporidium "marsupial" genotype I or "marsupial" genotype II. Kangaroos are the predominant large mammal inhabiting Australian watersheds and are potentially a significant source of Cryptosporidium contamination of drinking water reservoirs. However, this host population was predominantly shedding the marsupial-derived genotypes, which to date have been identified only in marsupial host species.

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An Immunoglobulin G1 Monoclonal Antibody Highly Specific to the Wall of Cryptosporidium Oocysts

Cited by 25 publications

References 20 publications

Evidence for Mucin-Like Glycoproteins That Tether Sporozoites of Cryptosporidium parvum to the Inner Surface of the Oocyst Wall

Evidence for Mucin-Like Glycoproteins That Tether Sporozoites of Cryptosporidium parvum to the Inner Surface of the Oocyst Wall

Streptavidin: A Novel Immunostimulant for the Selection and Delivery of Autologous and Syngeneic Tumor Vaccines

Patterns ofCryptosporidiumOocyst Shedding by Eastern Grey Kangaroos Inhabiting an Australian Watershed

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