Biomedical subjects

Li-ping Zhu

Publications and source records attributed to Li-ping Zhu.

22 records · Page 2Linked to original sources

PubMed2002

[Positive and negative selection of thymocytes].

Maturation of T cells in thymus plays key roles in antigen-specific immune response. In maturation, thymocytes undergo positive and negative selection. The MHC restriction of T cell is determined in positive selection. The tolerance of T cells to autoantigen is acquired during negative selection. Quantitation (avidity) theory points out that difference of avidity between thymocytes and stroma cells leads to difference in the signals integrated inside cells. When the signal reaches a particular threshold, positive or negative selection takes place. In this article, the selection mechanism and the relationship between positive and negative selection are mini-reviewed.

Animals↗

PubMed2002

[TCR-mediated signaling].

In recent years, major progress has been obtained in studying the early events in TCR-mediated signaling. c-Cb1 has been found to be a negative regulatory factor of the tyrosine kinases in ZAP-70/SyK family. The studies on LAT, SLP-76, ItK and Vav have shown their roles in the signal transduction of Ras and phospholipase Cx1 to Ca2+. Micro-glycolipid raft also plays important role in T cell activation. This minireview shows a brief introduction to the process of TCR-mediated signaling.

Animals↗

PubMed2002

[Progress in the study on the molecules in CD28 family].

CD28 family consists of CD28, ICOS, CTLA-4 and PD-1 molecules. The former two are activation receptors and the later two are inhibition receptors. They produce co-stimulatory signals combining with the relevant molecules in B7 family, which plays important role in T cell activation and homeostasis among T subsets. Although the mechanism of signaling by CD28 and CTLA-4 has been well studied, many questions still remain to be answered. Further investigations are required for substantiating the dual-signaling model.

Animals↗

PubMed2002

[Discovery of MHC restriction in antigen recognition of T cells].

T cell can only recognize specific antigenic peptide-MHC complex on antigen-presenting cell. This is MHC restriction in antigen recognition of T cell. This phenomenon was discovered by an Austrian scientist Peter. C. Doherty and a Swedish scientist Rolf. M. Zinkernagel by chance. Then, in order to explain the phenomenon, they proposed two hypotheses: dual receptor and modified self. In the during following 20 years numbers of scientists spent great amount of time in the study of the phenomenon. The process of cell-mediated immune response becomes clear, which greatly promotes the advancing of immunology and many related disciplines.

Animals↗