Coggeshall K M
Ohio State University, Department of Microbiology, Columbus 43210, USA.
Curr Opin Immunol. 1998 Jun;10(3):306-12. doi: 10.1016/s0952-7915(98)80169-6.
The fact that B cells undergo feedback suppression, or negative signaling, through the interaction of secreted antibody with specific antigen has been extensively documented but the mechanisms involved in the process have been elusive. Experiments over the past year using B cell deletion mutants and dominant-negative enzymes have firmly established an important role for SH2-domain-containing inositol 5-phosphatase (SHIP) in negative signaling. Negative signaling through SHIP appears to inhibit the Ras pathway through SH2 domain competition with Grb2 and Shc and may involve consumption of intracellular lipid mediators that act as allosteric enzyme activators or that promote entry of extracellular Ca2+.
B细胞通过分泌的抗体与特定抗原的相互作用经历反馈抑制或负向信号传导，这一事实已得到广泛记载，但该过程所涉及的机制一直难以捉摸。过去一年使用B细胞缺失突变体和显性负性酶进行的实验已明确证实含SH2结构域的肌醇5-磷酸酶（SHIP）在负向信号传导中起重要作用。通过SHIP的负向信号传导似乎通过与Grb2和Shc的SH2结构域竞争来抑制Ras途径，并且可能涉及消耗作为变构酶激活剂或促进细胞外Ca2+内流的细胞内脂质介质。
