Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Immunoglobulin class switching is controlled by cytokines. Thus, interleukin-4 (IL-4) directs class switching to both IgG1 and IgE. Consistent with this are the results reported here on restriction endonuclease analysis of active and inactive alleles of the IgH locus in IgE-producing cells. In cells that were stimulated in vitro by lipopolysaccharide and IL-4 the silent alleles preferentially switched to gamma 1, whereas in cells that were stimulated by antigen in vivo both active and inactive alleles switched to epsilon. Thirty percent of the recombined switch regions (S mu/S epsilon) contain S gamma 1 sequences, which we interpret as footprints of a previous switch to gamma 1. Since this percentage is a minimum estimate, between 30% and 100% of switching to epsilon must occur sequentially via gamma 1.
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PMID:The murine IgG1/IgE class switch program. 162 26

Activation of immature thymocytes or transformed T lymphocytes via T-cell receptor (TCR)/CD3 signalling can induce programmed cell death (apoptosis). Recent data indicate that anti-CD3/TCR monoclonal antibodies (mAb) also trigger apoptosis in activated (but not resting) mature peripheral blood T lymphocytes. Here we report that triggering of resting CD4-CD8-TCR alpha beta+ and/or TCR gamma delta+ via the alternative CD2-dependent activation pathway is able to induce programmed cell death. A pair of mitogenic anti-CD2 mAb provoked a dramatic rise in [Ca2+]i that was almost entirely sustained by extracellular fluxes, and the inhibition of membrane [Ca2+/Mg2+] ATPase. The resulting endonuclease activation was able to induce DNA fragmentation, as revealed by propidium iodide staining and gel electrophoresis. Induction of apoptosis was prevented by the presence of interleukin-4 (IL-4) as well as by endonuclease inactivation with 100 microM ZnCl2, but enhanced by the contemporary block of protein kinase C. Thus it seems that in resting T lymphocytes the strong calcium signal delivered by the alternative CD2 activation pathway may act as a negative apoptotic signal in both alpha beta and gamma delta T cells with low (non-major histocompatibility complex restricted) antigenic affinity, so limiting the extension of polyclonal T-cell growth.
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PMID:IL-4 is able to reverse the CD2-mediated negative apoptotic signal to CD4-CD8- alpha beta and/or gamma delta T lymphocytes. 855 74

The cytokine cluster located on chromosome 5 has been shown by linkage studies to play a role in the genetic determination of circulating immunoglobulin E (IgE) levels in atopic subjects. In the study presented here, the reported chromosome 5 linkage has been investigated in two sets of subjects. The first consisted of a general population sample of 230 nuclear families (n = 1004) from Busselton, a small West Australian country town. The second group consisted of 124 unrelated atopic asthmatics and 59 unrelated non-atopic, non-asthmatic controls, all resident in the Oxfordshire Regional Health Authority area in the United Kingdom. A previously reported interleukin-4 (II-4) promoter polymorphism (-590 C-->T) was analysed in these populations by a newly designed method of specific PCR amplification and BsmFI restriction endonuclease digestion. In the Busselton population the polymorphism was shown to be weakly associated with specific IgE to house dust mite (Mann-Whitney-U test, p = 0.013) and to wheeze (MWU test, p = 0.029), but not with specific IgE to grass pollen, total serum IgE, bronchial hyperresponsiveness, eosinophil count, or asthma. In the Oxfordshire subjects there were no statistically significant associations with any measure of asthma or atopy. These data show that the -590 C-->T II-4 promoter polymorphism is only weakly associated with certain measures of asthma and atopy in some subjects. It was specifically not associated with serum IgE concentration or asthma in either of the two groups in this study.
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PMID:Investigation of an interleukin-4 promoter polymorphism for associations with asthma and atopy. 886 63

The transcription factor X-box binding protein 1 (XBP-1) is essential for the differentiation of plasma cells and the unfolded protein response (UPR). Here we show that UPR-induced splicing of XBP-1 by the transmembrane endonuclease IRE1 is required to restore production of immunoglobulin in XBP-1-/- mouse B cells, providing an integral link between XBP-1, the UPR and plasma cell differentiation. Signals involved in plasma cell differentiation, specifically interleukin-4, control the transcription of XBP-1, whereas its post-transcriptional processing is dependent on synthesis of immunoglobulins during B cell differentiation. We also show that XBP-1 is involved in controlling the production of interleukin-6, a cytokine that is essential for plasma cell survival. Thus, signals upstream and downstream of XBP-1 integrate plasma cell differentiation with the UPR.
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PMID:Plasma cell differentiation and the unfolded protein response intersect at the transcription factor XBP-1. 1266 Jul 29