Serum and neutrophils alter the rate of excretory/secretory antigen release by Toxocara canis infective larvae in vitro

Infective larvae of the dog roundworm Toxocara canis survive in the tissues of their hosts for extended periods in a state of developmental arrest, successfully evading immune destruction. This survival strategy is thought to be mediated by T. canis excretory/secretory (TES) products which downregulate or divert the immune response. We purified one of the major TES products, TES-70 and gained amino acid sequence from 4 tryptic peptides. These peptides were matched to a predicted protein from a cDNA that was isolated by expression screening a T. canis cDNA library with mouse anti-TES serum. The predicted protein (Tc-CTL-4) is similar to, but larger than, Tc-CTL-1, a 32-kDa C-type lectin secreted by T. canis larvae. Tc-CTL-4 has a signal peptide, 2 Cys-rich domains and a C-terminal calcium-dependent C-type lectin domain that shares sequence similarity with host immune cell receptors such as macrophage mannose receptor and CD23. The lectin domain was expressed in bacteria and antiserum to the purified recombinant protein was used to confirm that Tc-ctl-4 did encode the native TES-70 glycoprotein. TES-70 selectively bound to ligands on the surface of Madin–Darby Canine Kidney cells in vitro in a calcium-dependent manner, inhibitable by mammalian serum, indicating that a host glycan is the native ligand for this new parasite lectin.

Download Full-text

Purifikasi Imunoglobulin Yolk Pada Ayam yang Divaksin terhadap Ekskretori/Sekretori Stadium L3 Ascaridia galli

Jurnal Agripet ◽

10.17969/agripet.v10i2.638 ◽

2010 ◽

Vol 10 (2) ◽

pp. 9-15

Author(s):

Darmawi Darmawi ◽

Ummu Balqis ◽

Risa Tiuria ◽

Muhammad Hambal ◽

Samadi Samadi

Keyword(s):

Good Choice ◽

Ascaridia Galli ◽

Agar Gel ◽

Secretory Antigen ◽

Egg Yolks ◽

Fast Performance Liquid Chromatography ◽

Excretory Secretory Antigen ◽

Incomplete Antibody ◽

Precipitation Test

Purification yolk immunoglobulin of hens vaccinated against excretory/secretory Ascaridia galli L3 larvae stageABSTRACT. The main immunoglobulin fraction of poultry is called IgY, in order to distinguish it from the mammalian IgG. This article focus on purification yolk immunoglobulin of hens vaccinated against excretory/secretory Ascaridia galli larvae to obtained purity IgY. Active vaccinations with excretory/secretory antigen were applied intra muscularly of chickens with an initial dose of 80 μg. The vaccinations were repeated three times with dose of each 60 μg with an interval of one week. The first vaccinations were excretory/secretory antigen mixed with Fruend Adjuvant Complete and subsequently mixed with Freund Adjuvant Incomplete. Antibody response in yolk was detected at weekly intervals by agar gel precipitation test (AGPT). The chicken’s eggs were collected from 49 day after vaccinations. IgY was extracted from egg yolks by means of ammonium sulphate and purified using fast performance liquid chromatography (FPLC). The purity of anti-ekscretory/secretory IgY protein was determined by Bradford method (λ = 280 nm). The result showed that antibody in yolk was begun detect with AGPT at four weeks after vaccination. IgY concentration after purification was 0,875 ± 0.251 mg/ml. This study has shown that the product released in vitro by L3 stage A. galli is capable of stimulating humoral immunity by mean of producing antibody through yolk as biologic manufacturer could be a good choice.

Download Full-text