2024年3月15日发(作者：)

化学专业英语文献翻译

专业英语文献翻译

班级：化学(师范)11—1

姓名：董文姣

学号：11055104

Quantifying the Cluster of Differentiation 4 Receptor Density on Human T Lymphocytes

Using Multiple Reaction Monitoring Mass Spectrometry。

ABSTRACT： Cluster of differentiation 4 （CD4） is an important glycoprotein containing

化学专业英语文献翻译

four extracellular domains, a transmembrane portion and a short intracellular tail.

It locates on the surface of various types of immune cells and performs a critical role

in multiple cellular functions such as signal amplification and activation of T cells。

It is well-known as a clinical cell surface protein marker for study of HIV progression

and for defining the T helper cell population in immunological applications。 Moreover，

CD4 protein has been used as a biological calibrator for quantification of other surface

and intracellular proteins. However， flow cytometry, the conventional method of

quantification of the CD4 density on the T cell surface depends on antibodies and has

suffered from variables such as antibody clones, the ommatophore and conjugation

chemistries, the fixation conditions， and the flow cytometric quantification methods

used. In this study, we report the development of a highly reproducible na no liquid

chromatography−multiple reaction monitoring mass spectrometry-based quantitative

method to quantify the CD4 receptor density in units of copy number per cell on human

CD4+ T cells. The method utilizes stable isotope—labeled full—length standard CD4

as an internal standard to measure

endogenous CD4 directly, without the use of antibodies. The development of the mass

spectrometry-based approach of CD4 protein quantification is important as a

complementary strategy to validate the analysis from the cytometry-based conventional

method。 It also provides new support for quantitative understanding and advanced

characterization of CD4 on CD4+ T cells。

Cluster of differentiation 4 （CD4） is a glycoprotein that locates on the surface of

immune cells such as T helper cells, monocytes, macrophages， and dendritic cells. As

a co receptor， CD4 amplifies the signal generated by the T cell receptor, which is

essential for activation of many molecules involved in the signaling cascade of an

activated T cell. In human T lymphocytes, CD4 receptor protein is encoded by the CD4

gene1and has four distinct extracellular domains （D1 to D4）, a transmembrane portion,

and a short intracellular tail。2The use of antihuman CD4 monoclonal antibodies generated

against the four extracellular domains has been widely used to define T helper cells

in phenotypical. Although the number of CD4+ T cells decreases in the progression of

HIV-1 viral infection deriving from the gp120 viral protein binding to the CD4 receptor，

Ponce let et al. reported that the surface CD4 density still remained constant on T

helper cells of HIV-1 infected individuals。3Since then, multiyear research has

supported the theory that CD4 expression/density can be used as a biological calibrator

for quantification of other surface

and intracellular proteins.4

Quantitative multicolor flow cytometry incorporating anti— bodies and a fluorescence

detection method has played a critical role in clinical diagnostics and immunotherapies.