PURIFIED RABBIT POLYCLONAL ANTIBODY

Purified rabbit polyclonal antibody

Purified rabbit polyclonal antibody

Introduction

With the emergence of first antibiotics and later recombinant monoclonal antibody therapy, the use of hyper-immune serum has declined. The main reason for this is that methods for consistent manufacturing of safe hyper immune immunoglobulin products have been lacking. In contrast, manufacturing processes of recombinant monoclonal antibodies follow a well established schedule and it appears obvious to use similar methods to produce recombinant polyclonal products. This review describes aspects of this novel technology with emphasis on the generation, production and characterization procedures employed, and provide comparison with alternative polyclonal antibody manufacturing strategies (Antoni, 2006, 143).

Polyclonal Antibodies

These are produced by B lymphocytes when an antigen is introduced into an immunocompetant host. Although different B lymphocytes each respond to a specific epitope on the antigen molecule and produce an antibody to that epitope only after differentiation, due to the numerous B cells and epitopes a polyclonal antibody as isolated from the serum of the host is a complex mixture of antibodies. Polyclonal antibodies used experimentally for protein identification in such techniques as Western blotting may be made more specific by differential absorption of non-specific components.

The immune systems of most mammals are believed to be comprised of approximately 1000 clonal populations of lymphocytes, as characterised by their antigen-receptor specificity. This diversity permits immune responses to a broad range of immunogens, for example, foreign proteins, carbohydrates, peptides and bacterial and viral components. The lymphoid organs (spleen, lymph nodes, and gut-associated lymphoid tissue, including tonsils) are the production sites of a vast range of antibodies by stimulated B lymphocytes (plasma cells). Each antibody molecule recognises a specific antigenic epitope, possibly as small as 5-6 amino acids or between one and two glucose or other monosaccharide units, and is able to bind to the immunogen. A polyclonal humoral response, making use of the entire range of antibodies (pAbs), results in high avidity (defined as the product of the affinity constants of all binding antibodies) and gives the organism the ability to defend itself successfully against pathogens.

A homogeneous antibody produced by a hybridoma. Hybridomas are the fusion product of an immortal myeloma tumor cell and a short-lived B cell or plasma cell that is making an antibody of the desired specificity. Such antibodies are referred to as “polyclonal ” because they are the product of only one B cell and its progeny (i.e., its clone) and are therefore identical. Since a myeloma tumor cell itself generally secretes an antibody of unknown specificity, only tumor cell lines that have lost this ability are suitable for hybridoma production. The successful hybridomas possess both genomes and therefore retain the immortality of the myeloma and the desired antibody production of the original B cell (Pasko, 2000, 590).

Functions

Kohler & Milstein were the first to make B-cell hybridomas by using a fusion technique with Sendai virus. Subsequent workers have carried out successful fusions by using other agents, for example, polyethylene glycol. The fusion technique permits the immortalisation of single ...