B-cell determinants

B-cell determinants or haptenic determinants, as they are frequently called, are comparatively well defined with regard to dimensions and specificity relationships. The problem of their size has attracted considerable interest during the last two decades and seems now satisfactorily elucidated. A recent careful review of these aspects has been provided by Goodman (1975). It has been known for some time that haptenic groups such as DNP and BPO do not comprise the entire deter-... 

CA-DNP. On the other hand, conjugates such as RAT-EACA-RAT induced delayed hypersensitivity or helper activity but no anti-RAT antibody. Thus RAT and DNP in this system are distinctive T-cell and B-cell determinants. 

Fitzmaurice, C. I, Brown, L. E., Mclnerney, T. L., Jackson, D. C., 1996, The assembly and immunological properties ofnon-linear synthetic immunogens containing T-cell and B-cell determinants. Vaccine 14 553-60. 

Sharma, P., Kumar, A., Batni, S., Chauhan, V. S., 1993, Co-dominant and reciprocal T-helper cell activity ofepitopic sequences and formation ofjunctional B-cell determinants in synthetic T B chimeric immunogens. Vaccine 11 1321-6. 

A total charge of 4.5 kC is passed through an electrolytic- cell. Determine the quantity of substance produced in each case (a) the mass (in grams) of bismuth metal from a bismuth nitrate solution (b) the volume (in liters at 273 K and 1.00 atm) of hydrogen gas from a sulfuric acid solution ... 

The stems of the tree were foimd to contain polysaccharides consisting of arabinose, galactose and galacturonic acid and only minor amoimts of rham-nose. Structural studies indicate that the polymeric material consists of 1,4-linked galacturonic acid residues, terminal, 1,4-, 1,6- and 1,3,6 galactose units and terminal and 1,5-linked arabinofuranose residues. Further studies must be performed on this in order to determine what type of pectin it can be classified as. The Hnkage data indicate that both AG-I and AG-II are present. This polymer was shown to activate polyclonal B-cells [78]. 

Plot the numbers of A and B cells versus iterations Determine the average values of [A] and [B] and their standard deviations using the last 500 iterations of the run Determine from these average values Compare the with the expected deterministic value. 

Determine the maximum concentration of the B cells ([BJ ax) for this example and note the iteration Bmax at which [BJ ax occurs. 

When an antigen is injected into an animal, the resulting antibodies are polyclonal, being synthesized by a mixture of B cells. Polyclonal antibodies are directed against a number of different sites (epitopes or determinants) on the antigen and thus are not monospecific. However, by means of a method developed by Kohler and Milstein, large amounts of a single monoclonal antibody specific for one epitope can be obtained. 

Idiotypic network. Idiotypic determinants (idiotypes) are unique antigenic epitopes characteristic of the antigen receptors on the surface of T and B cells. They are associated with the variable regions of these receptors. Antibodies produced by B cells as the result of antigenic stimulation can themselves stimulate the production of auto-anti-idiotypic antibodies which have the ability to combine with the B-cell receptor (Ig) and thus can dampen down the immune response. Idiotypes may likewise stimulate the production of T cells specific for idiotypic determinants. Jerne (1974) postulated his... 

Rituximab is a monoclonal antibody to the CD20 receptor expressed on the surface of B lymphocytes the presence of the antibody is determined during flow cytometry of the tumor cells. Cell death results from antibody-dependent cellular cytotoxicity. The pharmacokinetics of rituximab are best described by a two-compartment model, with a terminal half-life of 76 hours after the first infusion and a terminal half-life of 205 hours after the fourth dose.36 Rituximab has shown clinical activity in the treatment of B-cell lymphomas that are CD20+. Side effects include hypersensitivity reactions, hypotension, fevers, chills, rash, headache, and mild nausea and vomiting. 

Hardtke S, Ohl L, Forster R. Balanced expression of CXCR5 and CCR7 on follicular T helper cells determines their transient positioning to lymph node follicles and is essential for efficient B-cell help. Blood 2005 106 1924-1931. 

The most frequent application of SPOT-synthesis has been in the preparation of peptide arrays for the identification of linear B-cell epitopes. If the protein antigen is known, a set of overlapping peptides that encompass the entire sequence can be readily synthesized and assayed for binding of antibody (Reineke et al., 1999). The individual residues critical for binding can then be determined by SPOT-synthesis of peptides containing amino acid substitutions. 

Fig. 13.7 Effect of MTX-LDH hybrid on cell proliferation (A) and viability (B) as determined by MTT assay and Trypan Blue exclusion, respectively. HOS cells were incubated with free MTX, MTX-LDH hybrid or LDH for 72 h.

Fig. 4 The effect of proteins on cell adhesion, (a) Kretschmann configuration for SPR. (b) Reflectance (R) as a function of incident angle (9), before (black) and after (red) the adsorption of substances, (c) Left. Time course of SPR angle shift during exposure to culture medium supplemented with 2% FBS (solid line) and the fraction of adherent cells determined by TIRFM (circles) on NH2-SAM. The dashed line is a manual fit to the symbols, included simply as a guide [42]. Right The concentrations of serum proteins in FBS...

FIGURE 7.5 7,8-BPQ increases intracellular Ca2+ in murine spleen cells (A) and in both B and T cells (B). Single cell suspensions were prepared from murine spleens. Splenocytes were loaded with Fluo-3/AM dye for one hour and then treated with 7,8-BPQ, 1,6-BPQ, 3,6-BPQ, or DMSO (control). Surface-marker-defined T cells and B cells were treated with 7,8-BPQ or DMSO. Following treatment, the immediate intracellular Ca2+ response was continuously monitored for 15 minutes. Results are shown as the change in Mean Channel Fluorescence SEM. The numbers shown in this figure were the averages of triplicate determinants. Adapted from Gao et al., 2005. 

Hart, P. H. et al., Dermal mast cells determine susceptibility to Ultraviolet B-induced systemic suppression of contact hypersensitivity responses in mice, J. Exp. Med. 187, 2045-2053, 1998. 

Lymphocytes, the effector cells of the acquired immune system, include morphologically indistinguishable T and B cells, the former divided into CD4+ T helper cells and CD8+ cytotoxic T cells. Since the functions of those cell subsets differ so drastically, it became important to develop tools to distinguish them from each other. Efforts to identify cell subsets according to their expression of different surface antigens have been successful, including various Cluster of Determination (CD) markers (Table 23.1). In addition, cross-reactive monoclonal antibodies, and subsequently developed species-specific polyclonal and monoclonal antibodies towards the major histocompatibility complex (MHC) have been used to label cells in circulation and in tissue sections (Table 23.1). 

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