The activation antigen CD69

Abstract

One of the earliest cell surface antigens expressed by T cells following activation is CD69, which is detectable within one h of ligation of the T cell receptor/CD3 complex. Once expressed, CD69 acts as a costimulatory molecule for T cell activation and proliferation. In addition to mature T cells, CD69 is inducibly expressed by immature thymocytes, B cells, natural killer (NK) cells, monocytes, neutrophils and eosinophils, and is constitutively expressed by mature thymocytes and platelets. Recently, cDNA clones encoding human and mouse CD69 were isolated and showed CD69 to be a member of the C-type lectin superfamily. Gene mapping studies have placed CD69 on distal mouse chromosome 6 and human chromosome 12p13, close to, if not in, the NK gene complex. The structure, chromosomal localization, expression and function of CD69 suggest that it is likely a pleiotropic immune regulator, potentially important not only in NK cell function but also in the activation and differentiation of a wide variety of hematopoietic cells.

Human Vascular Endothelial Cells Stimulate Memory But Not Naive CD8+ T Cells to Differentiate into CTL Retaining an Early Activation Phenotype

“…In contrast, on BLC-stimulated CTL, the expression of CD69 and CD25 had subsided, and CD62L expression, highly expressed in CD8 ϩ T cells at the beginning of coculture, had largely been lost. The findings in BLC-stimulated CD8 ϩ T cells are in accordance with numerous in vitro and in vivo reports showing the loss of early activation markers 2-3 days after activation of T cells by BLC or other professional APC (21)(22)(23). A direct correlation between the number of cell divisions and loss of CD25 and CD69 also has recently been reported (27).…”

“…CD69 and CD25 are generally considered early activation markers (21)(22)(23), and L-selectin is usually lost rapidly during the course of T cell activation (24 -26). Also, the expression level of perforin per cell in EC-selective CTL was markedly lower than in corresponding conventional CTL.…”

The Functional Heterogeneity of Type 1 Effector T Cells in Response to Infection Is Related to the Potential for IFN-γ Production

“…2 and 3). The broad spectrum of eYFP fluorescence was paralleled by the heterogeneous surface expression of acute activation markers, such as CD25, CD69, and CD122, indicating recent antigenic stimulation (28,(32)(33)(34). Consistent with this observation, the frequency of cells presenting MHC class I-and class II-restricted antigenic peptides is indeed highest in the infected lung (S. R. Crowe and D. L. Woodland, unpublished observations) (22,35,36).…”

“…Conventional methods to identify cytokine-producing cells at the single cell level require in vitro restimulation (17,18), which alters the expression patterns of surface Ags and prevents their assessment ex vivo (28,29). In contrast, bicistronic cytokine reporter mice allow direct phenotypic analysis of cytokine-expressing cells ex vivo (20,25,30,31).…”

Effective Melanoma Immunotherapy with Interleukin-2 Delivered by a Novel Polymeric Nanoparticle

“…CD69 is recognized as a cell surface antigen expressed by activated NK cells, T cells, B cells, and other subsets of immune cells. It is a pleiotropic molecule for the mediation of T-cells and NK-cells, which lead to the secretion of Th1/Th2 cytokines and activation of immune cell proliferation and cytotoxicity (17). On day 3 after the first treatment, the percentage of CD49þ/CD69þ cells in the peripheral blood lymphocytes (PBL) of the H1/pIL-2-treated mice was 5-fold and 30-fold of that in the control H1/pEGFP-treated and 5% glucose-treated mice, respectively.…”