Immunological responses selectivity

Molecular complexation is a precondition for receptor functions such as substrate selection, substrate transportation, isomeric differentiation, and stereoselective catalysis. Although the investigation of such functions with synthetically derived compounds is a relatively new development in chemistry, they are well known and extensively studied functions in the biological domain. Evolution, gene expression, cell division, DNA replication, protein synthesis, immunological response, hormonal control, ion transportation, and enzymic catalysis are only some of the many examples where molecular complexation is a prerequisite for observing a biological process. 

Interleukin-2 (IL-2) is an endogenous cytokine that normally exerts a number of beneficial immunologic responses. In particular, IL-2 stimulates the growth and differentiation of T-cell lymphocytes that are selectively toxic for tumor cells.11,33 Hence, recombinant DNA techniques are now used to synthesize IL-2 so that this agent can be used to treat cancers such as renal cancer and malignant melanoma (see... 

Modifying primary and secondary immunological response by Bifidobacterium and Lactobacillus probiotics is linked with their structures being recognized by TLR 9 present on monocytes and lymphocytes, as well as with TLR expression on dendritic cells. As a result, release of IL 12 and IFNy is increased. Also preferential recruitment of Thl lymphocytes has been observed. Saito made a hypothesis that individually selected TLR ligand doses might be administered as a medicine to infants at risk of allergy (Saito et al., 2003). 

Tumorigenicity tests are normally performed in two species, usually in mice, rats or hamsters, and in strains with low spontaneous tumor rates. Species that gave rise to specific concerns in earlier toxicity tests should be preferred. For biological substances the target species should be selected following consideration of the immunological response and its potential interference with the study. 

One of the most exciting new techniques in analytical chemistry has been the development of sensitive methods based on immunological responses. One of the main advantages of immunological techniques is their high selectivity, even in complex matrices. This approach has made a dramatic impact on clinical chemistry. As new probes are developed, they will probably be applied to ancient proteinaceous materials,... 

Membrane, with appropriate permeability characteristics, as well as, physicochemical properties, is used in bioartificial organs as selective barriers to compartmentalize isolated cells while allowing the transport of nutrients and metabolites to cells and the transport of catabohtes and specific metabolic products to blood. Moreover, the membrane avoids the contact between immune system components with xenogenic cells to prevent immunological response and rejection of xenograft. 

Since the OTC trial, there has been rapid advancement in vector development with marked improvements in the safety (and efficacy) of new viral delivery systems. There is also a better understanding of the immunological responses to gene therapy vectors. The adverse events in the SCID trial are more recent. They appear to be a likely result of the choice of vector (retrovirus) and the ex vivo selection strategy used to modify the affected stem cells of the SCID patients. The risk benefit ratio for gene therapy treatment of these children is still deemed favorable in light of the fact that without treatment, they would not be alive. 

Immunoglobulins possess high affinity and nnmatched stmctural specificity toward virtually any molecule. The experimental challenge is to harness and to select from the enormous numbers and diversity of the immunological response, molecular frameworics in the form of antibodies able not only to bind a given snbstrate bnt also to catalyze a preselected chemical transformation. 

Recent studies of Pb-associated immunotoxicity in experimental animals have been quite helpful in elucidating the relevance of developmental periods and other host factors on the expression of immunotoxicity and also helpful in revealing the full range of immunological responses not readily accessible in available pediatric or occupational epidemiological efforts. Selected reports across test species are summarized in Table 18.6. 

Taken as a whole, these observations show that parasite lines differ in an immune-dependent manner in their infection/expulsion kinetics. Furthermore, there is heritable variation in survival and fecundity in previously exposed hosts and quantitative variation in the immune response that selected parasite lines elicit. Again, taken as a whole, these observations have the necessary corollary that variation in these traits exists not only in laboratory-maintained isolates but also in helminth species in nature. The phenotypes under consideration here (infection/expulsion kinetics, survival, fecundity) are multifactorial life-history traits. Understanding the basis of variation in the components and interplay of these complex, immune-responsive phenotypes must be of crucial relevance to understanding the immunology of infections of parasitic nematodes. This is of particular relevance in view of current attempts to develop immunological methods of nematode control. 

As noted above, the primary focus of immunotoxicology has been on suppression many of the early techniques grew out of basic immunology research, in which the function of various components of the immune response was determined by selective manipu-... 

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