Detection of virus-specific antibody-forming cells of mice immunized with Newcastle disease virus

Production and Purification of Rabbit's Polyclonal Antibody Against Factor VIII

The attempt is made to produce recombinant factor VIII but the first step in producing such product is production and purification of rabbit's polyclonal antibody against factor VIII. The second and third steps involve monoclonal antibody and recombinant factor VIII production. Factor VIII is one of the most important coagulating factor where its deficiency leads to diseases like hemophilia type A or classic. It is an inherited disease. Previously, it was obtained through fractionation of blood plasma of blood donors. After processing, factor VIII could be used to manage such patients. Due to transfer of viral disease like hepatitis and HIV through factor VIII obtained by fractionation, high cost of production, insufficiency of the donors and the process of virus removal, thus production of factor VIII through recombinant technology can be useful and helpful. The reaction between antibody and antigen is one the most specific reaction; therefore, such reaction can be employed to identify factor VIII. Thereby, rabbits were injected several times with adjuvant-linked antigen to produce antibody. The antibody was separated from the blood sample, purified and used to identify factor VIII in the research.

Coupling of foot-and-mouth disease virus to sheep red blood cells using tannic acid for immunological assays

A technique for coupling foot-and-mouth disease virus (FMDV) to tanned sheep red blood cells (SRBC) is reported. Different parameters influencing the procedure were studied. Subtypes C2, C3, O1 and A24 were used as antigens, and guinea pig hyperimmune sera obtained were tested for specific antibody in passive hemagglutination (PH), passive hemagglutination inhibition (PHI) and passive immune hemolysis (PIL) assays. Fresh and SRBC stored in Alsever's solution showed similar behavior when used as indicator cells. Optimal sensitization of erythrocytes was achieved using tannic acid 1:20,000 and 20 micrograms of purified virus/ml at pH 7.6. Specificity of the reaction was confirmed by PH and PHI in homologous and heterologous systems. The coupled antigen-antibody complex was sensitive to complement mediated lysis in a PIL test.

Evaluation of methods for chemically coupling foot-and-mouth disease virus to sheep red blood cells for immunological assays

Six methods of chemically coupling proteins to red blood cells were evaluated for their effectiveness in coupling foot-and-mouth disease virus (FMDV) to sheep red blood cells. The coupling agents tested were potassium periodate, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (ECDI), chromium chloride, glutaraldehyde, bis-diazotized benzidine (BDB) and N-succinimidyl 3-(2-pyridyldithio) propionate (SPDP). Of these, only the coupling methods using BDB and SPDP resulted in virus-red cell complexes that reacted with FMDV antiserum in passive hemagglutination and passive immune hemolysis assays. The BDB and SPDP methods were studied further to determine optimal coupling conditions, the kinetics of coupling and the effects of chemical couplers on viral integrity. Only the FMDV-red cell complexes formed with SPDP were suitable targets for detecting FMDV antibody producing lymphocytes in a hemolytic plaque assay.

Immune response to hepatitis B surface antigen: enhancement by prior injection of antibodies to the idiotype

Anti-idiotype reagents that recognize a common idiotype associated with the combining site of antibodies to hepatitis B surface antigen (anti-HBs) were used to manipulate the immune response to hepatitis B surface antigen in BALB/c mice. The injection of antibodies to the idiotype before antigenic stimulation resulted in an increase in the number of cells secreting immunoglobulin M antibodies to hepatitis B surface antigen. Anti-HBs-secreting cells were also induced by administration of antibodies to the idiotype without subsequent antigen exposure. These findings indicate that the immune response to hepatitis B surface antigen in mice is regulated through an idiotype-anti-idiotype network.

Detection of cells producing surface antigen-specific antibody to influenza viruses

B cells producing antibodies to influenza virus antigens were detected and quantitated by a hemolytic plaque assay. Responses of mice after primary infection and immunization with influenza viruses were measured and compared with responses after secondary immunization. The B-cell responses were specific and differentiated between A and B influenza viruses and between different subtypes of A influenza viruses. Responses to closely related influenza A virus strains of the H3N2 subtype cross-reacted but could also be differentiated. Cells secreting antibody to either of the virus surface antigens (hemagglutinin and neuraminidase) could be separately enumerated. Evidence that immunoglobulin G- secreting cells are detected in the assay without the use of facilitating anti-immunoglobulin G sera is presented.