Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 4 de 4
Filter
1.
Res Vet Sci ; 147: 74-82, 2022 Oct.
Article in English | MEDLINE | ID: covidwho-1873256

ABSTRACT

In and around poultry farms, high concentrations of endotoxins are found that have a negative impact on the health of farmers and local residents. However, little is known about the effects of chronic exposure to endotoxins on the health of poultry. The aim of this study was to identify effects of chronic exposure to airborne endotoxins (E. coli LPS) on the immune system, respiratory tract, disease susceptibility and welfare of broilers. Effects of high (HE) and low endotoxin (LE) concentrations on natural antibody titers (NAb), performance and behavior of broilers were determined. After treatment with a respiratory virus infection, infectious bronchitis virus (IBV), mRNA expression of cytokines and Toll-like receptor (TLR) 4 in the lung, tracheal ciliary activity and lesions in the respiratory tract were determined. Endotoxin affected the immune system and respiratory tract, where HE broilers tended to have lower IgM NAb binding Phosphorylcholine-conjugated to Bovine Serum Albumin, and higher interferon (IFN)-α mRNA expression and more lesions in the nasal tissue compared to LE broilers. Furthermore, HE broilers had higher TLR4 mRNA expression compared to LE broilers. However, endotoxin did not affect NAb levels binding Keyhole Limpet Hemocyanin, IFN-ß and interleukin-10 mRNA expression, IBV replication or lesions in the lung and trachea. HE and LE broilers further had similar body weight, but HE broilers showed numerically more passive behavior compared to LE broilers. In conclusion, chronic exposure to high airborne endotoxin concentrations affects components of the immune system and respiratory tract in broilers and could therefore influence disease susceptibility.


Subject(s)
Coronavirus Infections , Infectious bronchitis virus , Poultry Diseases , Animals , Chickens , Coronavirus Infections/veterinary , Disease Susceptibility/veterinary , Endotoxins/toxicity , Escherichia coli , Lung , RNA, Messenger/genetics
2.
Cell Biol Toxicol ; 38(4): 667-678, 2022 08.
Article in English | MEDLINE | ID: covidwho-1616182

ABSTRACT

INTRODUCTION: The inflammatory potential of SARS-CoV-2 Spike S1 (Spike) has never been tested in human primary macrophages (MΦ). Different recombinant Spikes might display different effects in vitro, according to protein length and glycosylation, and endotoxin (lipopolysaccharide, LPS) contamination. OBJECTIVES: To assess (1) the effects of different Spikes on human primary MΦ inflammation; (2) whether LPS contamination of recombinant Spike is (con)cause in vitro of increased MΦ inflammation. METHODS: Human primary MΦ were incubated in the presence/absence of several different Spikes (10 nM) or graded concentrations of LPS. Pro-inflammatory marker expression (qPCR and ELISA) and supernatant endotoxin contamination (LAL test) were the main readouts. RESULTS: LPS-free, glycosylated Spike (the form expressed in infected humans) caused no inflammation in human primary MΦ. Two (out of five) Spikes were contaminated with endotoxins ≥ 3 EU/ml and triggered inflammation. A non-contaminated non-glycosylated Spike produced in E. coli induced MΦ inflammation. CONCLUSIONS: Glycosylated Spike per se is not pro-inflammatory for human MΦ, a feature which may be crucial to evade the host innate immunity. In vitro studies with commercially available Spike should be conducted with excruciating attention to potential LPS contamination.


Subject(s)
Endotoxins , Macrophages , Spike Glycoprotein, Coronavirus , COVID-19 , Endotoxins/toxicity , Escherichia coli , Glycosylation , Humans , Inflammation/chemically induced , Inflammation/metabolism , Lipopolysaccharides/toxicity , Macrophages/metabolism , Macrophages/virology , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/metabolism
3.
Biosci Rep ; 41(12)2021 12 22.
Article in English | MEDLINE | ID: covidwho-1592575

ABSTRACT

Parasporin-2Aa1 (PS2Aa1) is a toxic protein of 37 KDa (30 kDa, activated form produced by proteolysis) that was shown to be cytotoxic against specific human cancer cells, although its mechanism of action has not been elucidated yet. In order to study the role of some native peptide fragments of proteins on anticancer activity, here we investigated the cytotoxic effect of peptide fragments from domain-1 of PS2Aa1 and one of the loops present in the binding region of the virus spike protein from Alphacoronavirus (HCoV-229E), the latter according to scientific reports, who showed interaction with the human APN (h-APN) receptor, evidence corroborated through computational simulations, and thus being possible active against colon cancer cells. Peptides namely P264-G274, Loop1-PS2Aa, and Loop2-PS2Aa were synthesized using the Fmoc solid-phase synthesis and characterized by mass spectrometry (MS). Additionally, one region from loop 1 of HCoV-229E, Loop1-HCoV-229E, was also synthesized and characterized. The A4W-GGN5 anticancer peptide and 5-fluorouracil (5-FU) were taken as a control in all experiments. Circular dichroism revealed an α-helix structure for the peptides derived from PS2Aa1 (P264-G274, Loop1-PS2Aa, and Loop2-PS2Aa) and ß-laminar structure for the peptide derived from Alphacoronavirus spike protein Loop1-HCoV-229E. Peptides showed a hemolysis percentage of less than 20% at 100 µM concentration. Besides, peptides exhibited stronger anticancer activity against SW480 and SW620 cells after exposure for 48 h. Likewise, these compounds showed significantly lower toxicity against normal cells CHO-K1. The results suggest that native peptide fragments from Ps2Aa1 may be optimized as a novel potential cancer-therapeutic agents.


Subject(s)
Antineoplastic Agents/pharmacology , Colorectal Neoplasms/drug therapy , Endotoxins/pharmacology , Peptide Fragments/pharmacology , Spike Glycoprotein, Coronavirus/pharmacology , Alphacoronavirus , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/toxicity , CD13 Antigens/metabolism , CHO Cells , Cell Line, Tumor , Cell Proliferation/drug effects , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/pathology , Cricetulus , Endotoxins/toxicity , Hemolysis/drug effects , Humans , Molecular Docking Simulation , Peptide Fragments/chemical synthesis , Peptide Fragments/toxicity , Protein Conformation, alpha-Helical , Sheep, Domestic , Spike Glycoprotein, Coronavirus/toxicity , Structure-Activity Relationship
4.
Biosci Rep ; 41(12)2021 12 22.
Article in English | MEDLINE | ID: covidwho-1526113

ABSTRACT

Parasporin-2Aa1 (PS2Aa1) is a toxic protein of 37 KDa (30 kDa, activated form produced by proteolysis) that was shown to be cytotoxic against specific human cancer cells, although its mechanism of action has not been elucidated yet. In order to study the role of some native peptide fragments of proteins on anticancer activity, here we investigated the cytotoxic effect of peptide fragments from domain-1 of PS2Aa1 and one of the loops present in the binding region of the virus spike protein from Alphacoronavirus (HCoV-229E), the latter according to scientific reports, who showed interaction with the human APN (h-APN) receptor, evidence corroborated through computational simulations, and thus being possible active against colon cancer cells. Peptides namely P264-G274, Loop1-PS2Aa, and Loop2-PS2Aa were synthesized using the Fmoc solid-phase synthesis and characterized by mass spectrometry (MS). Additionally, one region from loop 1 of HCoV-229E, Loop1-HCoV-229E, was also synthesized and characterized. The A4W-GGN5 anticancer peptide and 5-fluorouracil (5-FU) were taken as a control in all experiments. Circular dichroism revealed an α-helix structure for the peptides derived from PS2Aa1 (P264-G274, Loop1-PS2Aa, and Loop2-PS2Aa) and ß-laminar structure for the peptide derived from Alphacoronavirus spike protein Loop1-HCoV-229E. Peptides showed a hemolysis percentage of less than 20% at 100 µM concentration. Besides, peptides exhibited stronger anticancer activity against SW480 and SW620 cells after exposure for 48 h. Likewise, these compounds showed significantly lower toxicity against normal cells CHO-K1. The results suggest that native peptide fragments from Ps2Aa1 may be optimized as a novel potential cancer-therapeutic agents.


Subject(s)
Antineoplastic Agents/pharmacology , Colorectal Neoplasms/drug therapy , Endotoxins/pharmacology , Peptide Fragments/pharmacology , Spike Glycoprotein, Coronavirus/pharmacology , Alphacoronavirus , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/toxicity , CD13 Antigens/metabolism , CHO Cells , Cell Line, Tumor , Cell Proliferation/drug effects , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/pathology , Cricetulus , Endotoxins/toxicity , Hemolysis/drug effects , Humans , Molecular Docking Simulation , Peptide Fragments/chemical synthesis , Peptide Fragments/toxicity , Protein Conformation, alpha-Helical , Sheep, Domestic , Spike Glycoprotein, Coronavirus/toxicity , Structure-Activity Relationship
SELECTION OF CITATIONS
SEARCH DETAIL