RECOMBINANT ANTIBODY PRODUCTION BY CLONING OF Pepper yellow leaf curl Indonesia virus (PepYLCIV) COAT PROTEIN GENE

Pepper yellow leaf curl Indonesia virus (PepYLCIV) is an important pathogen on chili cultivation and is transmitted through the seed. Serological tests are sensitive, accurate, efficient and it has been widely used for the detection of seed-transmitted plant viruses. This study aimed to produce PepYLCIV recombinant protein as a material to produce recombinant antibodies PepYLCIV. DNA was extracted from infected chili leaves collected from Congkrang, Muntilan, Central Java verified using primer PepYLCIV-BamHI and PepYLCIV-EcoRI and produced an amplicon at 840 bp. The amplified fragments were cloned into the pET32a then transformed to Escherichia coli BL21. The percentage of nucleotide sequence identity and sequence of amino acid, PepYLCIV CK-6 isolates had the highest similarity of nucleotide and amino acid sequences to of chili isolates from Bandung. The expressed recombinant protein was obtained with IPTG concentration 0,5 mM and harvested at 6 hours after IPTG induction. SDS PAGE analysis of the recombinant plasmid Begomovirus CK-6 showed that the coat protein size was about 29 kDa. Immunization was carried out on rabbits by injecting 150 µg of recombinant protein 4 times with an interval of 1 week to produce crude antiserum and pure antiserum capable of detecting PepYLCIV in chili and Ageratum conyzoides using I-ELISA and DIBA tests.

Alginate from Sargassum siliquosum Simultaneously Stimulates Innate Immunity, Upregulates Immune Genes, and Enhances Resistance of Pacific White Shrimp (Litopenaeus vannamei) Against White Spot Syndrome Virus (WSSV)

Although alginate is known as an immunostimulant in shrimp, the comprehensive and simultaneous study on its activity to resolve the relationship of the hematological parameters, upregulation of immune-related gene expression, and resistance to pathogen has not been found in shrimp. We performed experiments to evaluate the effect and mechanism of alginate from S. siliquosum on Pacific white shrimp immune system. Hematological parameters were examined after oral administration of Na alginate in the shrimp. White spot syndrome virus (WSSV) was injected to the shrimp at 14 days, and its copy number was examined quantitatively (qRT-PCR). Immune-related gene expression was evaluated by qRT-PCR. Alginate increased some hematological immune parameters of shrimp. Before WSSV infection, expression levels of Toll and lectin genes were upregulated. The lectin gene were upregulated post infection, and the Toll gene in all the treatments were downregulated, except the shrimps fed with alginate at 6.0 g kg-1 at 48 h post infection (hpi). The shrimps fed with alginate at 6.0 g kg-1 were the most resistant and gave the least WSSV copy number at 48 hpi. Resistance of shrimps fed the alginate-supplemented diets against WSSV was significantly higher compared to that of the control treatment with 56% and 10% of survival rates, respectively. Oral administration of alginate did not affect the growth and total protein plasma. At 120 h post challenge, alginate treatment at 6.0 g kg-1 exhibited the highest survival rate. It is concluded that oral administration of alginate enhanced the innate immunity by upregulating immune-related gene expression. Consequently, the enhancement of the shrimp innate immunity improves the resistance against WSSV infection.

Innate immune-stimulating and immune genes up-regulating activities of three types of alginate from Sargassum siliquosum in Pacific white shrimp, Litopenaeus vannamei

The Total Haemocyte Count (THC), phenoloxidase (PO), Superoxide Dismutase (SOD) activity, Phagocytic Activity/Index and Total Protein Plasma (TPP) were examined after feeding the white shrimp Litopenaeus vannamei with diets supplemented with three different types of alginates (acid, calcium and sodium alginates). Immune-related genes expression was evaluated by quantitative Real Time PCR (qRT-PCR). Results indicated that the immune parameters directly increased according to the doses of alginates and time. The 2.0 g kg(-1) of acid and sodium alginate treatments were gave better results. Four immune-related genes expression i.e. LGBP, Toll, Lectin, proPO were up regulated. It is therefore concluded that the supplementation of alginate of Sargassum siliquosum on the diet of L. vannamei enhanced the innate immunity as well as the expression of immune-related genes. It is the first report on the simultaneous evaluation of three alginate types to enhance innate immune parameters and immune-related genes expression in L. vannamei.