Antigen-specific antibody

There are two pneumococcal vaccines, a 7-valent conjugated vaccine for children younger than 6 years of age and a 23-purified-capsular polysaccharide antigen vaccine for adults. The 23 capsular types in the vaccine represent at least 85% to 90% of the serotypes that cause invasive pneumococcal infections among children and adults in the United States.41 After vaccination, an antigen-specific antibody response, indicated by a twofold or greater rise in serotype-specific antibody, develops within 2 to 3 weeks in 80% or more of healthy young adults.42... 

Vaccination to induce an adaptive immune response is expected for a broad range of infectious diseases and cancers. Traditional vaccines are mainly composed of live attenuated viruses, whole inactivated pathogens, or inactivated bacterial toxins. In general, these approaches have been successful for developing vaccines that can induce an immune response based on antigen-specific antibody and cytotoxic T lymphocyte (CTL) responses, which kill host cells infected with intracellular organisms (Fig. 1) [1,2], One of the most important current issues in vaccinology is the need for new adjuvants (immunostimulants) and delivery systems. Many of the vaccines currently in development are based on purified subunits, recombinant... 

A classical approach is the enzyme linked immunosorbent assay (ELISA), where the antigen (e.g., the protein to be quantified) is immobilized on the surface of a well. A first antigen-specific antibody is applied to occupy all antigens, before a second antibody binds all primary antibodies on the well. The second antibody carries an enzyme, which now catalyzes a color reaction. If the substrate of the enzyme is given in high excess, the enzyme is saturated and the production of product is linear with time and concentration of second antibody and antigen (Fig. 8). 

The acquired immune system has probably received most of the attention in marine mammals, as has been the case in rodent and human immunology. Recent advances include the production of monoclonal [22-24] and polyclonal [25] antibodies to marine mammal immunoglobulins, enabling more precise, and often species-specific, reagents for the detection and quantification of antigen-specific antibodies. 

Humoral immunity is characterized by the production of antigen-specific antibodies that enhance phagocytosis and destruction of microorganisms through opsonization. Thus, deficiencies of humoral immunity (B lymphocytes) may lead to reduced antibody titers and are typically associated with acute gram-positive... 

B-lymphocytes Antigen-specific, antibody-mediated immimeresponse 2x10 Unknown... 

In Pt2, who experienced a follow-up of 12 months, lymphocytes increased to 400 cells/pl, with slower kinetics than those observed in Ptl. The increase occurred mainly in the T-cell subset, as indicated by a significant rise in TREC levels. Pt2 also demonstrated a normalization of both Ig levels and the proliferative responses to polyclonal stimuli. Both patients developed antigen-specific antibodies in response to vaccination [515130]. 

Salmonella Oligosaccharide-Protein Conjugates for the Production of O-Antigen-specific Antibodies... 

Antibody affinity chromatography is employed to isolate antigen-specific antibodies. The most common affinity matrix for coupling of molecules is cyanogen bromide-activated... 

An electrochemical immunosensor includes a transducer (a current-conductive strip deposited on a polymer substrate) and a biorecognition substance (an antigen or antibodies) immobilized on the transducer surface. The formation of an immune complex and localization of non-antigen-specific antibodies (proteins) on this complex, which are usually labeled with enzymes, and a substrate in the solution, generates an active species capable of generating an electrochemical response. The sequential process, the use of enzymes, and occasionally unstable substrates limit and complicate a wide-scale application of such sensors. 

Fig. 3. Comparison of different enzyme-linked immuno sorbent assay (ELISA) methods adapted for immuno-polymerase chain reaction (IPCR). Dependent on the purification grade of the sample to be analyzed and the availability of specific and functionalized antibodies, several typical ELISA protocols were adapted to IPCR. In the direct approach (A), the pure antigen is immobilized to the microplate surface and subsequently detected by a labeled specific antibody. If no labeled antibody is available (e.g., because of unpurified ascites fluid containing the antibody or loss in activity following labeling), a standardized labeled secondary species-specific antibody is used for detection of the primary antigen-specific antibody (B). For the detection of the antigen from matrices such as serum, plasma, tissue homogenate, and so on, a capture antibody immobilized to the microplate surface was used either in a direct (C) or indirect (D) sandwich approach, with the latter one additionally including a secondary species-specific detection antibody. For different methods of coupling antibody and DNA, abbreviated by in this figure, compare Fig. 2. Note that protein A chimeras (Fig. 2A) are not compatible with capture antibodies (Fig. 3C, D).

After electrophoresis, proteins are transferred onto a nitrocellulose or PVDF (polyvinylidene fluoride) membrane, which is immersed in a solution of a selected antibody capable of combining with the target protein. Then the reaction of antigen-specific antibody is detected through a second antibody which is tagged enzymatically. Special attention must... 

Two types of immunity may be induced in response to an antigen, namely humoral immunity mediated by antigen-specific antibodies produced by B lymphocytes, and cell-mediated immunity produced by activated macrophages and cytotoxic T lymphocytes. Antibodies may neutralize pathogens, whereas... 

Evaluating the immune response to the vaccine at the same time as evaluating toxicity is recommended in a 2003 WHO guideline (Table 31.1). This makes good sense because any toxicity observed with vaccines is frequently related to the immune response, and correlation of these two endpoints provides a fuller explanation of the test results. Assays to measure the immune response include those which measure antigen-specific antibody responses (e.g., ELISA) and cell-mediated responses (e.g., y-interferon—ELISPOT). Developing these... 

Second, you must remember that the serum from an immunized animal contains thousands of different IgG molecules, of which only a small fraction (perhaps less than 1 %) actually recognize the antigen of interest. The IgG present in the serum prior to the introduction of the antigen is still present. The immunization process merely attempts to increase the relative concentration of antigen-specific antibodies in the serum with respect to the numerous other nonspecific antibodies that are also present. 

Figure IV-6 Immunoaffinity chromatography to purify antigen-specific antibodies.

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