Overview:
p53 is a key regulator of cell growth and acts as a tumor suppressor gene. Wild-type p53 gene can suppress transformation of rat embryo fibroblasts in cell culture by other oncogenes such as the adenovirus E1A and Ras (1). DNA tumor viruses such as SV40 large T antigen and the adenovirus E1A plus E1B-55Kd proteins bind to p53 and inactivate its tumor suppressor activities leading to cellular transformation. Mutational inactivation of the p53 gene is detected in more than 50% of human cancers. Mutation of p53 renders cancer cells more resistant to current cancer therapies due to lack of p53-mediated apoptosis (2).
Gene Aliases:
TP53, LFS1, TRP53
Genbank Number:
NM_000546
References:
1.Levine, A J. et al: Tumor suppressor genes: the p53 and retinoblastoma sensitivity genes and gene products.Biochim Biophys Acta. 1990 Jun 1;1032(1):119-36.2.Sun, Y. p53 and its downstream proteins as molecular targets of cancer. Mol Carcinog. 2006 Jun;45(6):409-15.
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所以一个细菌或病毒可以有很多的抗原。
若已进入细胞内。则先由巨噬细胞吞噬降解。并形成抗原-MHC复合体传送到表面。被辅助性T淋巴细胞识别和效应T淋巴细胞识别后。效应T淋巴细胞被激活。分解靶细胞。然后再由效应B细胞分泌的抗体进一步消灭病毒。
还有不清楚的么?
荚膜(capsule)是某些细菌在生长繁殖过程中分泌的一层黏液性物质,包围在细胞壁外,通常这种黏液层厚度小于0.2μm,成分是多糖或多肽,只有在营养丰富时或在动物体内,细菌才产生这种半抗原性质的黏液性物质。它具有保护菌体免受巨噬细胞等的捕捉和吞噬,因而具有抗吞噬抗消化、侵袭力强、与致病性关系密切等特点。像肺炎球菌、炭疽杆菌等都有这类荚膜。有些细菌的荚膜层较薄,小于0.2μm,称为微荚。
像链球菌的M蛋白、伤寒杆菌的Vi抗原、大肠杆菌的K抗原等都属于这类微荚膜。
请赐教!

