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  • ThesisItemOpen Access
    PRODUCTION, ISOLATION AND CHARACTERIZATION OF IgY ANTIBODIES TO CANINE PARVOVIRUS
    (SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2016-12) ATCHUTHARAM, A; SREENIVASULU, D(MAJOR); SREEDEVI, B; ESWARAPRASAD, P
    ABSTRACT: The overall goal of this study was to develop practical, natural, and efficient antimicrobials from egg. The existence of an IgG-like molecule in avian eggs, referred to as IgY, has been well documented, and extensive research has been carried out on its characterization, production and purification. Although it is the functional equivalent of mammalian IgG, the major serum antibody found in mammals, IgY is structurally different, and has been found to exhibit several important differences when compared to mammalian antibodies, including its physico-chemical properties and immunological capabilities. Recently, considerable research has focused on the use of IgY as an alternative to mammalian antibodies in several applications, including immune therapeutic applications, especially for the oral passive immunization against various bacteria and viruses. Much research has also been carried out on the use of IgY as a replacement for IgG in various immunodiagnostic and immune affinity purification purposes. The use of IgY offers several advantages over polyclonal antibodies produced in mammals, including providing a much more hygienic, cost efficient, convenient, humane and plentiful source of antigen-specific antibodies. Chicken immunoglobulin Y (IgY) may provide a new modality in the therapy of various infectious animal diseases. This study presents evidence of its efficacy for canine parvovirus (CPV), which is a highly infectious, fatal viral disease in dogs. Initially IgY antibody production and separation was standardized using BSA as antigen. BSA 0.2 mg/ml was used to immunize three 21weeks old white leghorn chicken. Additional booster doses were administered weekly intervals up to 6 weeks following the first injection. Sera from immunized chicken were collected on 21st day to confirm the immune response to BSA. Among three BSA immunized birds, one birds did not show any response to BSA antigen. Initially BSA specific IgY antibodies were separated from eggs laid by immunized chicken using Ammonium sulphate method. The specificity of IgY antibody raised against BSA was determined by agar gel immunodiffusion test. A clear precipitation line was observed between BSA and anti BSA IgY antibody precipitated from egg yolk, which shows specificity of immune response to BSA. Anti BSA IgY antibody levels were monitored up to 120 days by indirect ELISA and found that the titres were maintained up to 120 days of immunization with the highest titre on 75th day. The present study was conducted as a preliminary step to monitor the in vitro efficacy of IgY as a passive immunotherapeutic agent to control Canine parvovirus infection in dogs. Canine parvovirus vaccine containing 103viral particles/ml was used as antigen to immunize 21 weeks old white Leghorn chicken. The eggs from immunized chicken were collected from 1st day to 135th day. Sera from immunized chicken were also collected on 21st day to confirm the immune response to canine parvovirus. Presence of antibodies against canine parvovirus was checked using hemagglutination inhibition assay (HI). The HI titres of the serum collected from immunized hens was found to be 256 HI units. Water soluble fraction was isolated from eggs collected after the immunization and estimated the protein content and the maximum protein concentration was found (35.20 ± 1.32a mg/ml) in the water soluble fraction collected from egg yolk on 75th day of post immunization. The IgY was separated from the WSF by using Ammonium sulphate method, Sodium chloride method, Sodium sulphate method and PEG method. Among the four methods used for IgY separation, Sodium chloride method and Sodium sulphate methods were found to yield high protein content (6.70 to 6.71mg/ml) compared with Ammonium sulphate method and polyethylene glycol method. IgY was purified using DEAE cellulose column chromatography. Highest protein concentration was observed in the 4th and 5th fractions. The purity of the immunoglobulin present in the 4th and 5th fractions of DEAE cellulose column elute was checked by determining the molecular weight of the protein. A single protein band showing molecular weight 180 KDa was recorded. The titre of the purified canine parvovirus specific IgY antibody was found to be 2048 HI units. Anti canine parvovirus IgY antibody levels were monitored up to 135 days by indirect ELISA. It was found that the titres were be maintained up to 135th day with peak titre (1.186) on day 75th after immunization. Stability of canine parvovirus IgY antibody was studied by exposing to different temperatures and different pH using HI assay. The HI titre gradually decreased when the temperature increased to 50ºC and above. At 25ºC and 37ºC the IgY antibody was found to be stable when exposed to 10, 20 and 30 minutes. Purified IgY antibody when subjected to pH 7 for 8 hours its HI titre was 1024. The HI titre gradually decreased when the pH decreased below 7 and also when pH increased above 7. The stability of purified anti canine parvovirus antibody was completely lost when it is exposed to pH 3 in the presence of pepsin as reflected by complete loss of HI activity. HI titre of the IgY antibody was found to be 32 to 64 when exposed to pH 4.0 and pH 5.0 respectively in the presence of pepsin. The results indicated that the activity of immunoglobulins reduced in the presence of pepsin. Hence, there is a need to protect IgY immunoglobulins against the action of pepsin in the stomach of puppies. Present study was helpful for production of desired IgY antibodies, which can be obtained in large quantities against specific pathogen (canine parvovirus).