Immunoglobulin expression

Serum concentrations lie between 0.5 and 2.5mgml. IgM can fix complement and a single molecule can initiate the complement cascade. IgM (with IgD) is the major immunoglobulin expressed on the surface ofB cells where it acts as an antigen receptor. 

Early evidence pointing to a restriction in immunoglobulin expression was the demonstration that, in individuals who are heterozygous for allotype, myeloma proteins carry one or the other, but never both, of the allelic determinants found in the pooled immunoglobulin of that person (M rtensson, 1961 Harboe et al., 1962). This finding was interpreted to indicate that the alternate allotypic determinants are present on different immunoglobulin molecules, which are produced by different cells. Oudin (1960) had observed a presumably related phenomenon in rabbits. 

Gil. Goodnow, C. C., Crosbie, J., Adelstein, S., Lavoie, T. B., Smith-Gill, S. J., et al., Altered immunoglobulin expression and functional silencing of self-reactive B lymphocytes in transgenic mice. Nature 334, 676-682 (1988). 

N8. Ngan, B., Warnke, A., and Cleary, M. L., Variability of immunoglobulin expression in follicular lymphoma. An immunohistologic and molecular genetic study. Am. J. Pathol. 135, 1139-1144 (1989). 

As a new platform alternative to CHO and NSO, which supports the production of fully human proteins, they describe the evaluation of human designer cell lines of various tissues created directly from primary cells. The hybridoma was shown to secrete the antibody in a stable manner at a rate of 45 pg (cell X day)over a period of 2 years. This is in striking contrast to the majority of heterohybridomas, which tend to quickly lose human chromosomes, resulting in unstable immunoglobulin expression. Moreover, expression was preserved when the cell line was cultivated in high-density fermentation and remained stable in five independent fermenter runs which had a mean duration of 66 days. Expression did not decrease below 30 pg (cellxday) when the medium was... 

In Section 3 of this chapter, the patterns of immunoglobulin gene expression that are characteristic of different stages of differentiation were described, and Section 4 summarises our present knowledge about the various levels at which expression is regulated. In this final section, the ways in which the various regulatory elements and mechanisms contribute to the overall pattern of immunoglobulin expression in different cell types are considered. 

Ushmorov A, Ritz O, Hummel N, Leithauser F, Moller P, Stein H, Wirth T. Epigenetic silencing of the immunoglobulin heavy-chain gene in classical Hodgkin lymphoma-derived cell lines contributes to the loss of immunoglobulin expression. Blood. 2004 104 3326-34. 

Li M, Zheng H, Duan Z, Liu H, Hu D, Bode A, Dong Z, Cao Y. Promotion of cell proliferation and inhibition of ADCC by caneerous immunoglobulin expressed in cancer cell lines. Cell Mol Immunol. 2012 9 54-61. 

Kearney, J.F., Radbruch, A, Liesegang, B., and Rajewsky, K. (1979) A new mouse myeloma cell line that has lost immunoglobulin expression but permits the construction of antibody-secreting hybrid cell hues. /. Immunol. 123,1548-1550. 

Another application shows the preparative purification and polishing of a therapeutic fusion protein with a humanized recombinant IgG protein. The fusion protein was expressed by the fermentation of baby hamster kidney cells. The filtered culture supernatant (155 liters) contained 2.2 g of IgG and 75.5 g of total protein. After the immunoglobulins were isolated by expanded bed adsorption and rebuffering, the IgG fraction was bound to Fractogel EMD SOj (M). This column achieved baseline separation of complete antibodies (fusion protein) from small amounts of antibodies lacking the fusion part. The resulting highly purified IgG fraction (110 ml) was diluted to 150 ml and... 

A B lymphocyte is a specific type of white blood cell (leucocyte) derived from bone marrow stem cells. Each B lymphocyte expresses an immunoglobulin (antibody) specific for a particular antigen. Following antigenic stimulation, a B lymphocyte may differentiate and multiply into plasma cells that secrete large quantities of monoclonal antibody. 

The role of NFAT in the immune system is not restricted to T cells. NFAT proteins are also expressed in other cells of the immune system, such as B cells, NK cells, and mast cells, where they have been shown to regulate the expression of cytokines, cell surface receptors, and immunoglobulins [4, 5]. 

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