Protein antigens immunization procedure

A variety of lipid adjuvants and protein mediators have also been shown to influence the immune response to antigens encapsulated in liposomes. The most widely used examples of such adjuvants for practical immunization procedures are endotoxin (including lipid A and lipopolysaccharide) and numerous types of lipophilic derivatives of muramyl dipeptide. 

Two immunization procedures designed to enhance the immune response to multiple antigen mixtures have been reported recently. The cascade immunization technique (20) utilized in vitro depletion of E. coli proteins (ECPs) which had previously elicited an antibody response. The removal of these dominant immunogens from the mixture was accomplished by immunoabsorption with antibodies obtained from an earlier antiserum. The passive immunization procedure (21) relied on in vivo blocking of strong immunogens by the concurrent administration of early antiserum obtained previously. This latter report demonstrated the presence of an apparently poorly immunogenic ECP to which a humoral response could only be elicited by this passive procedure. 

Polyclonal antibodies are widely used in clinical laboratories for the measurement of plasma protein concentrations. However, immunoassays are often sensitive to the nature of the antibody used. The development of polyclonal antibodies is affected by several factors, such as the purity and dose of the antigen used, the species of host animal, and the immunization procedure. Monoclonal antibodies are viewed as a viable alternative to alleviate these problems. However, the expression of particular epitopes varies with the hpoprotein particles and among individuals in addition, the apohpoproteins themselves are polymorphic in nature. Therefore the use of a single monoclonal antibody might not detect a particular variant. If a monoclonal antibody is used in the determination of an apohpoprotein, it should he directed to an epitope that is expressed on all polymorphic forms of that particular apoprotein. Furthermore, the epitope should be equally reactive to the antibodies regardless of which hpoprotein class contains it. Alternatively a mixture of monoclonal antibodies directed at different epitopes of the apohpoprotein may also be used. Such mixtures are referred to as panmonoclonal antibodies. 

This chapter summarizes our recent efforts to establish two different protein/ enzyme dosing models in mice, using intratracheal and intranasal dosing. Both models have been used to measure antigen (enzyme) specific antibody responses as a function of the dose of antigen administered, the immunization procedure and regimen, and the isotype of antibody produced. 

Intrasplenic immunization is used for the production of hybridomas in situations where only very small quantities of the antigen are available. Typically, it lends itself extremely well to producing antibodies to proteins that have been purified by electrophoresis and subsequent blotting onto nitrocellulose. Antibodies produced by this route are always immunoglobulin class M as only one immunization is used. This method is covered by Animal Procedures legislation in most countries as it is an invasive surgical procedure and welfare issues must be addressed. 

Analyte A substance or chemical that is detected by an analytical procedure. Antigen A molecule that elicits an immune response (i.e., antibody production). Apaf-1 Apoptotic protease activating factor 1 a cytosolic protein that forms part... 

---