Concanavalin A Con

A single cell suspension of LNC is prepared under aseptic conditions and cultured for various periods of time. The production by LNC of type lcytokines (such as IFN-y and IL-12) and type 2 cytokines (such as IL-4, IL-5, IL-10 and IL-13) is measured using cytokine specific ELIS As or cytokine microarrays. It is possible to measure the spontaneous production of IL-5, IL-10, IL-12, IL-13 and IFN-y by LNC without restimulation in vitro. However, IL-4 appears to be produced in comparatively small amounts and to induce detectable levels of this cytokine an additional stimulus is required concanavalin A (con A), a T lymphocyte mitogen. Culture of LNC derived from mice treated with chemical respiratory sensitizer with con A will stimulate the production of detectable levels of IL-4. Treatment with the same mitogen of LNC derived from naive or vehicle-treated mice fails to induce measurable IL-4 secretion [86],... 

Recent studies with BN 52021 have demonstrated that PAF can modulate various immune processes. BN 52021 can inhibit the suppressive effect of PAF on T-lymphocyte proliferation and cytokine production. When PAF is added to human peripheral blood lymphocyte cultures (containing 5-10% monocytes) stimulated with phytohaemaglutinin (PHA) or concanavalin A (Con A), a non-toxic concentration-dependent inhibition of lymphocyte proliferation is... 

Mitogen responses of lymphoid cells (phytohaemagglutinine (PHA), concanavalin A (Con A) as T cell mitogens, lipopolysaccharide (LPS) as B cell mitigen)... 

The various organs of the immune system such as spleen, lymph nodes, thymus and bone marrow containing the cells involved in the various immune responses offer the possibility to harvest these cells and perform in vitro assays for evaluation of effects on the immune system. When part of an in vivo animal study this may indicate a direct toxic effect of pharmaceuticals, that is, immunosuppression (Table 18.2). So, it is feasible to obtain cell suspensions for further evaluation such as determination of cellular subsets of T and B leukocytes by fluorescent activated cell sorter analysis (FACS analysis), and determination of natural killer (NK) cell activity of the spleen cell population. An advantage of this approach is that it may lead to identification of a biomarker to be used in clinical studies. In addition, in vitro stimulation of spleen cells with mitogens activating specific subsets may indicate potential effects on the functionality of splenic cell populations. Concanavalin A (Con A) and phytohemagglutinin (PHA) activate Tcells, while lipopolysaccharide (LPS) activates primarily B cell populations. Blood is collected for total white blood cell (WBC) determination and blood cell differential count. In addition, serum can be obtained for determination of serum immunoglobulins. 

FIGURE 7.38. Computer generated model of a liposome-streptavidin conjugate (a), a schematic representation of a liposome-streptavidin (Sav)-concanavalin A (Con A)-streptavidin multilayer (b) and of streptavidin crosslinked vesicles (c). 

For many years this laboratory has been studying the interactions of concanavalin A (con A), a carbohydrate binding protein of considerable interest (X—4 ), with simple and complex carbohydrates (578)- It was established that compared to monosaccharides, oligosaccharides composed of a- (l- -2)-linked D-roannose units exhibited an enhanced affinity for con A (9). This increased affinity for con A was explained both in terms of an extended binding site (5,10) and a statistical mode (11). 

Concanavalin A (con A) has been reported to interact with specific membrane saccharide receptors and agglutinate a wide variety of transformed cells at low concentrations of the lectin without affecting the normal untransformed parent line (1,2). ... 

One recent trend has been away from using a photochromic dye itself merely as an individual component of a solution, polymer film or bulk polymer matrix. Instead, the photochromic is chemically linked to a polymer, which may be a natural polymer such as a cellulose derivative, an enzyme, a protein, or synthetic polymers from acrylates, urethanes, and vinyl compounds. The properties of the polymer can then be modified by external irradiation, and conversely, the properties of the photochromic are modified by the polymer. A recent biochemical example is the photocontrolled binding of monosaccharides to concanavalin A (Con A) modified with spiropyran units.208... 

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