Proteins antigens

Vaccines can be roughly categorized into killed vaccines and Hve vaccines. A killed vaccine can be (/) an inactivated, whole microorganism such as pertussis, (2) an inactivated toxin, called toxoid, such as diphtheria toxoid, or (J) one or more components of the microorganism commonly referred to as subunit vaccines. The examples are capsular polysaccharide of Streptococcus pneumoniae and the surface antigen protein for Hepatitis B vims vaccine. 

Although acquired immunity to some parasitic diseases may lower the level of infection, absolute immunity as seen in bacterial and viral infections is seldom seen in parasitic diseases. Since parasitic infections produce a wide variety of antigens because of the many life cycle phases, it is more difficult to identify a constant antigenic protein against which specific antibodies are protective. However, malaria remains a likely candidate for a vaccine and there are ongoing studies to develop one. 

Is there any other approach or concept that can directly measure protein amount in the tissue section Ten years ago, Roth et al.38 documented a novel method, named the Midwestern assay. This method is based on using two chromogens, soluble and insoluble, for the IHC staining process, to produce sequential production of soluble and insoluble reaction products. The soluble IHC product is used to measure the amount of antigen (protein) by spectrophotometry, while insoluble product indicates the localization of protein in the tissue section. Their experimental results demonstrated that soluble reac-... 

As mentioned above, our studies and other articles demonstrate substantially complete restoration of immunoreactivity (AR rate = 100%) for many antigens (proteins) exemplified by ER, progesterone receptor (PR), HER2/neu,... 

Immunostaining was decreased in some cell types that the nuclear components were extracted, pis, isoelectric points of antigen proteins. 

Now that you understand the basis for the interactions between functional groups in water, you also understand the basis for most interactions DNA-DNA, DNA-RNA, DNA-protein, RNA-protein, protein-protein, protein-ligand, enzyme-substrate (Get the picture ), antibody-antigen, protein-chromatography column—it s all the same stuff. 

Figure 8.11 Specific enzymatic immunodetection of a blotted protein. Depicted are blocked binding sites on the membrane (1), a primary antibody (2) specifically bound to an antigenic protein, and a secondary antibody (3) bound to the primary antibody. The secondary antibody is conjugated to a reporter enzyme (4). Substrate (S) is converted to insoluble product (P) at the site of the antigen.

Western 1 i Protein Yes 12=1- or enzyme-linked antibody To measure amount of antigen (proteins) or antibody... 

An antigenic protein enters either the blood or the interstitial fluid, where it is taken up by an antigen-presenting cell (APC), digested and the peptide fragments are presented, along with MHC-11 molecules, on the surface of the APC. 

Figure 17.36 The allergic response. A protein that enters the body is taken up by an ARC, digested and the peptides presented along with MHC-II protein on cell surface. This peptide binds to its complementary receptor on the Th2 cell, which produces cytokines that stimulate B-cells to proliferate and produce plasma cells that secrete IgE antibodies. The latter bind to mast cells. This is the process of sensitisation. Upon subsequent exposure to the antigenic protein, the antigens bind to the IgE antibodies on the mast cells to produce degranulation. This results in release of the factors that cause the allergic response. If degranulation is massive the response will be severe resulting in anaphylactic shock.

Vaccine. A suspension of attenuated or killed micro-organisms or of antigenic proteins derived from them. 

Outside the remit of this present chapter, it might be noted that a significant number of DNA sequences have had no identifiable function and were initially labeled as junk. However, gradually some functions for this so-called junk DNA have been identified, especially those of a regulatory nature. This has resulted in a greater interest in the possibility of providing DNA sequences that synthesize antigenic proteins. 

Enzyme-Linked Immunosorbent Assays (ELISAs) These assays are performed in the wells of a plastic microtiter dish. The antigen (protein) is bound to the plastic of the dish. The probe used consists of an antibody specific for the particular protein to be measured. The antibody is covalently bound to an ezyme, which will produce a colored product when exposed to its substrate. The amount of color produced can be used to determine the amount of protein (or antibody) in the sample to be tested. 

---