摘要:

AbstractIncorporation of [125I]IgG into spleen cells was studiedin vivoandin vivo, the antigen after uptake into the cytoplasm migrated into cell nuclei, where it was bound to chromatin up to the saturation level. One day after immunization the constant level of [125I]IgG was 1·3 × 1012molecules per spleen (108cells). The same number of [125I]IgG molecules were bound to chromatin in cell cultures. The uptake of [125I]IgG was competitively inhibited by non‐labelled IgG. Binding of [125I]IgG molecules reextracted from cytoplasm and chromatin with specific anti‐human IgG serum argues against the uptake of degraded [125I]IgG molecules. [125I]IgG was tightly bound to DNA. Approximately 50 per cent of [125I]IgG was present in the residual chromatin fractin (after removal of 0·35Mand 2MNaCl‐soluble frations) and 40 per cent was complexed with DNA (after removal of histones and non‐histones AP1, AP2, AP3 and AP4).Binding of [125I]IgG by isolated chromatin was inhibited by the cytoplasmic fraction but not by BSA. Binding of [125I]IgG by fractionated chromatin, (chromatins remaining after removal of 0·35M, and 2MNaCl‐soluble fractions or histones + non‐histones AP1 + AP2 + AP3 + AP4) occurred at a level similar to that observed with native chromatin. The results suggest that interaction of antigen with immunocompetent cells is not restricted to the cell surface but that antigen seems to be taken up into cytoplasm, migrates to the nuclei and is bound to chromatin, probably directly to DNA. The results are discussed in relation to the induction of the

ISSN:0263-6484    

DOI:10.1002/cbf.290030112

出版商:John Wiley&Sons, Ltd.    

年代:1985

数据来源: WILEY

摘要:

AbstractIsolated hepatic nuclei and hepatic chromatin have been analysed for their DNA, RNA, protein and phospholipid content. The protein/DNA ratio is 3 for nuclei and 1·95 for chromation extracted from Triton X‐100 treated nuclei. The phospholipids, (2·36 ± 0·91 (S.D.) per cent of the total nuclear material), are lost during the chromatin preparation mainly during the Triton X‐100 washings of the nuclei. Nevertheless, 10 per cent of the total nuclear phospholipids and fatty acid composition. Thus, the chromatin‐associated phospholipid cannot be attributed simply to contaminating nuclear membrane.This is supported by the autoradiographic study of semi‐thin sections of interphase nuclei from root apices ofVicia fabain which [3H] ethanolamine is clearly localized in the chromatin and nucleolar regions of

ISSN:0263-6484    

DOI:10.1002/cbf.290030113

出版商:John Wiley&Sons, Ltd.    

年代:1985

数据来源: WILEY

ISSN:0263-6484    

DOI:10.1002/cbf.290030101

出版商:John Wiley&Sons, Ltd.    

年代:1985

数据来源: WILEY