Products
Please contact us at ALees@FinaBio.com for ordering.
AmDex (Amino dextran, AECM dextran) is prepared from dextran using a protocol yielding a stable, amino functionalized dextran. The molecular weight profile is essentially unchanged, as determined by analytical size exclusion chromatography (Figure 1). We do extensive processing and testing to ensure that free amino reagent is removed. This approach results in a consistent product with minimal lot-to-lot variation.
Each batch of amino-dextran polymer is evaluated for molecular weight distribution and for the amine content, expressed as amines/polymer. A certificate of analysis is provided for each lot.
Custom polymer preparations are available.
Figure 1 Size exclusion chromatography of 70 kDa dextrans
Overlay of dextran and AmDex
Products: 70 kDa Dextran
100 mg $75.00
200 mg $125.00
500 mg $250.00
Bulk On request
Contact us at ALees@FinaBio.com
(alpha-delta-dex, anti-IgD dextran, anti-IgDex) (mouse and human)
Please contact us for more information: ALees@FinaBio.com
Crosslinking membrane IgD on B cells with unconjugated anti-IgD antibody induces B cell proliferation at ug/ml concentrations. By contrast, dextran-anti-IgD antibodies (alpha-delta-dex) induce vigorous B cell proliferation at ng/ml concentrations (Brunswick et al., J. Immunol. 140:3364, 1988). Further, in contrast to unconjugated anti-IgD, alpha-delta-dex-activated B cells undergo substantial Ig class switching and differentiation into Ig-secreting cells in the presence of various second signals, including cytokines and Toll-like receptor ligands (Snapper and Mond, J. Immunol. 157:2229, 1996). Thus, alpha-delta-dex is an efficient and potent polyclonal B cell activator for studying a wide range of B cell functions.
Uptake of 3H thymidine as a marker of B cell activation
References
J. Immunol. 140:3364, 1988. M. Brunswick et al.
Picogram quantities of anti-Ig antibodies coupled to dextran induce B cell proliferation. To investigate the properties which enable type 2 Ag, as exemplified by dextran and Ficoll, to stimulate high levels of antibody responses in the relative absence of T cells, we conjugated anti-IgD and anti-IgM mAb to both dextran and Ficoll and examined their B cell-activating properties. Such conjugated anti-Ig antibodies stimulated both early and later stages of B cell activation at picogram concentrations, which are at least 1000-fold lower than that required for B cell stimulation by unconjugated anti-Ig antibodies, and the level of proliferation they stimulated was on average 10-fold greater. Furthermore, concentrations of anti-Ig dextran (100 pg/ml) which modulated little sIgD from the B cell surface were strong inducers of enhanced B cell expression of MHC class II molecules. Conjugation of Fab fragments of anti-IgD or nonmitogenic anti-IgM mAb to dextran rendered them as mitogenic as dextran conjugated to strongly stimulatory anti-IgD or anti-IgM antibodies. The ability of dextran and Ficoll to serve as effective carrier molecules for anti-IgD was not related solely to their large m.w., because anti-IgD coupled to polymerized BSA (m.w. 1.5 X 10(6), was only 10- to 50-fold more potent than unconjugated anti-IgD antibodies at stimulating B cell DNA synthesis. These results suggest, therefore, that the unique ability of picogram concentrations of haptenated type 2 Ag to stimulate Ig secretion in the absence of T cells may be a function of their ability to promote effective cross-linking without resulting in the modulation of sIg. This would enable such Ag to mediate repetitive B cell signaling, a situation that cannot be achieved by unconjugated anti-Ig antibodies which result in modulation of sIg at their mitogenic concentrations. These compounds therefore may be employed to study B cell activation stimulated by sIg cross-linking at concentrations that may more closely reflect those which are achieved under physiologic conditions by type 2 Ag.
J. Immunol. 157: 2229, 1996. C. M. Snapper and J. J. Mond.
A model for induction of T cell-independent humoral immunity in response to polysaccharide antigens. Abstract. We provide a model for induction of T cell-independent, polysaccharide-specific Ig secretion in response to bacterial challenge. Two predominant pathways are defined that require the concerted action of multivalent membrane Ig cross-linking by the polysaccharide Ag with 1) various B cell-activating moieties contained within the bacterial pathogen and/or 2) cytokines, such as IFN-gamma and granulocyte-macrophage colony-stimulating factor produced by NK cells and macrophages, that become activated in a T cell-independent manner during bacterial infection.
Macrophage colony-stimulating factor, show synergistic stimulatory activity in inducing Ig secretion in B cells stimulated by a multivalent ligand that mimics TI-2 antigens. The recent finding that natural killer cells have receptors for various classes of polysaccharides supports a role for these cells in regulating responses to TI-2 antigens.