Dataset Information

Lactoferrin and lactoferricin endocytosis halt Giardia cell growth and prevent infective cyst production.

ABSTRACT: Lactoferrin (LF) is an 80 KDa iron-binding glycoprotein that plays a significant role in the innate immune system and is considered to be an important microbicide molecule. It has been suggested to be effective in the treatment of giardiasis, an intestinal disease caused by the protozoan parasite G. lamblia. However, the molecular mechanisms by which LF exerts its effect on this parasite are unknown. Most of the microbicidal activity of human or bovine LF (hLF or bLF) has been associated with the N-terminal region of the mature LF - lactoferricin (LFcin). LFcin is produced by pepsin cleavage of the native protein in vitro and likely in vivo. In this work, we analyse the participation of the endocytic machinery of G. lamblia in the internalization of bLF and bLFcin and their effects on cell homeostasis. Our results show that, when bLF or bLFcin are internalized by receptor-mediated endocytosis, cell growth stops, and morphological changes are produced in the trophozoites, which ultimately will produce immature cysts. Our findings contribute to disclose the fine mechanism by which bLF and bLFcin may function as an antigiardial molecule and why they have therapeutic potential to eradicate giardiasis.

SUBMITTER: Frontera LS

PROVIDER: S-EPMC6303297 | biostudies-literature | 2018 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Lactoferrin and lactoferricin endocytosis halt Giardia cell growth and prevent infective cyst production.

Frontera Lorena S LS Moyano Sofía S Quassollo Gonzalo G Lanfredi-Rangel Adriana A Rópolo Andrea S AS Touz María C MC

Scientific reports 20181221 1

Lactoferrin (LF) is an 80 KDa iron-binding glycoprotein that plays a significant role in the innate immune system and is considered to be an important microbicide molecule. It has been suggested to be effective in the treatment of giardiasis, an intestinal disease caused by the protozoan parasite G. lamblia. However, the molecular mechanisms by which LF exerts its effect on this parasite are unknown. Most of the microbicidal activity of human or bovine LF (hLF or bLF) has been associated with th ...[more]

PMID: 30575774

Similar Datasets

Project description:BackgroundGiardia lamblia parasitizes the human small intestine to cause diarrhea and malabsorption. It undergoes differentiation from a pathogenic trophozoite form into a resistant walled cyst form. Few cyst proteins have been identified to date, including three cyst wall proteins (CWPs) and one High Cysteine Non-variant Cyst protein (HCNCp). They are highly expressed during encystation and are mainly targeted to the cyst wall.Methodology and principal findingsTo identify new cyst wall proteins, we searched the G. lamblia genome data base with the sequence of the Cryptosporidium parvum oocyst wall protein as a query and found an Epidermal Growth Factor (EGF)-like Cyst Protein (EGFCP1). Sequence analysis revealed that the EGF-like repeats of the EGFCP1 are similar to those of the tenascin family of extracellular matrix glycoproteins. EGFCP1 and HCNCp have a higher percentage of cysteine than CWPs, but EGFCP1 has no C-terminal transmembrane region found in HCNCp. Like CWPs and HCNCp, the EGFCP1 protein (but not transcript) was expressed at higher levels during encystation and it was localized to encystation-specific vesicles in encysting trophozoites. Like HCNCp, EGFCP1 was localized to the encystation-specific vesicles, cyst wall and cell body of cysts, suggesting that they may share a common trafficking pathway. Interestingly, overexpression of EGFCP1 induced cyst formation and deletion of the signal peptide from EGFCP1 reduced its protein levels and cyst formation, suggesting that EGFCP1 may help mediate cyst wall synthesis. We also found that five other putative EGFCPs have similar expression profiles and similar locations and that the cyst formation was induced upon their overexpression.Conclusions and significanceOur results suggest that EGFCPs may function like cyst wall proteins, involved in differentiation of G. lamblia trophozoites into cysts. The results lead to greater understanding of parasite cyst walls and provide valuable information that helps develop ways to interrupt the G. lamblia life cycle.

Project description:The iron-binding protein lactoferrin (Lf) present in blood is metabolized by the liver. Isolated rat hepatocytes vigorously endocytose bovine Lf via recycling Ca2(+)-dependent binding sites, but the uptake of iron from Lf by hepatocytes has not been examined. In this study, isolated rat hepatocytes were incubated with radiolabelled bovine Lf (125I-Lf, 59Fe-Lf or 125I-59Fe-Lf) at 37 degrees C, then washed at 4 degrees C in the presence of dextran sulphate with either Ca2+ or EGTA to distinguish between total bound and internal radioactivity respectively. Cells internalized 125I-Lf protein and Lf-bound 59Fe at maximal endocytic rates of 1700 and 480 mol.cell-1.s-1 respectively. When Lf was normalized for 59Fe content, these endocytic rates were equivalent and reflected an uptake potential of at least 3400 mol of iron.cell-1.s-1. Cells prebound with 125I-59Fe-Lf to Ca2+(-)dependent sites at 4 degrees C internalized more than 80% of both 125I-Lf protein and Lf-bound 59Fe approx. 6 min after warming to 37 degrees C at similar rates (125I-Lf: k(in) = 0.276 min-1, 59Fe: k(in) = 0.303 min-1). Within 4 h at 37 degrees C, cells had released 25% or less internalized Lf protein in the form of acid-soluble 125I-by-products but retained all the Lf-delivered 59Fe. Hyperosmotic disruption of clathrin-dependent endocytosis blocked the uptake of 125I-Lf and Lf-bound 59Fe. Incubation of cells with 125I-59Fe-Lf and a 100 molar excess of diferric transferrin reduced slightly the endocytosis of 125I-Lf protein and 59Fe accumulation. Treatment of cells with the ferric chelator desferrioxamine did not alter uptake of 125I-Lf protein or Lf-bound 59Fe, but the ferrous chelator bathophenanthroline disulphonate slightly elevated endocytosis of 125I-Lf protein and Lf-bound 59Fe. These findings indicate that Lf does not release its bound iron before endocytosis. It was concluded from this study that hepatocytes take up iron from Lf at high rates by a process that requires endocytosis of Lf-iron complexes.

Dataset Information

Lactoferrin and lactoferricin endocytosis halt Giardia cell growth and prevent infective cyst production.

Publications

Lactoferrin and lactoferricin endocytosis halt Giardia cell growth and prevent infective cyst production.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets