InVivo Anti-mouse OX40 (CD134

OX40是肿瘤坏死因子受体（TNFR）家族的成员，也称为CD134或TNFRSF44。OX4于1987年首次在活化的大鼠CD4+T细胞表面发现。随后研究表明，OX40在活化的CD4+和CD8 +T细胞、中性粒细胞和自然杀伤（NK）细胞上均有表达。抗原刺激导致初始CD4+和CD8+T细胞的激活，从而诱导OX40 的瞬时表达。OX40主要表达在活化的T细胞上，在初始T细胞群上不表达。促炎细胞因子（IL-1、IL-2、IL-4和TNF-α）可进一步促进OX40在活化的T细胞上的表达。此外，OX40的表达也可能发生NKT细胞、NK细胞和中性粒细胞等

OX40是一种Ⅰ型跨膜糖蛋白，由约275个氨基酸组成，具有三个全半胱氨酸结构域（CRD）和一个部分C端CRD，分子量约为50kDa。

OX40是由配体激活的T细胞共刺激物，在自身免疫、传染病和癌症的多种动物模型中介导CD4+和CD8+T细胞的存活和扩增，还参与控制效应T细胞和记忆T细胞反应。

OX40的配体（OX40L,也称为CD252）是TNFR受体超家族 (TNFRSF) 的成员。

OX40L是一种II型糖蛋白，具有包括23个氨基酸的胞浆尾部和包括133个氨基酸的细胞外结构域。

 

OX40 (CD134) and its binding partner, OX40L (CD252), are members of the TNFR/TNF superfamily and are expressed on activated CD4 and CD8 T cells as well as a number of other lymphoid and non-lymphoid cells. Costimulatory signals from OX40 to a conventional T cell promote division and survival, augmenting the clonal expansion of effector and memory populations as they are being generated to antigen. OX40 additionally suppresses the differentiation and activity of Treg, further amplifying this process. OX40 and OX40L also regulate cytokine production from T cells, antigen-presenting cells, NK cells, and NKT cells, and modulate cytokine receptor signaling. In line with these important modulatory functions, OX40/OX40L interactions have been found to play a central role in the development of multiple inflammatory and autoimmune diseases, making them attractive candidates for intervention in the clinic. Conversely, stimulating OX40 has shown it to be a candidate for therapeutic immunization strategies for cancer and infectious disease. This review provides a broad overview of the biology of OX40, and the intracellular signals from OX40, that impact many aspects of immune function, and have promoted OX40 as one of the most prominent costimulatory molecules known to control T cells.

The OX-86 monoclonal antibody reacts with mouse OX-40 also known as CD134. OX-40 is a 50 kDa type I membrane glycoprotein and a member of the TNF receptor superfamily. OX-40 is expressed on activated CD4 and CD8 T cells, but is not found on resting naïve T cells or most resting memory T cells. Although it was originally thought that OX-40 expression was restricted to activated conventional T cells, it has now been visualized on activated regulatory T cells, NKT cells, NK cells, and neutrophils. OX-40 plays a major role in regulating both CD4 and CD8 T cell clonal expansion. It provides a costimulatory signal to an antigen-reacting naive T cells to prolong proliferation, as well as augment the production of several cytokines. This is demonstrated by OX-40 knockout mice which generate fewer primary effector CD4 T cells after immunization. Furthermore, in vivo treatment with an agonist antibody to OX-40 has been shown to strongly enhance the generation of antigen-specific effector T cells and prevent the induction of T cell tolerance. The OX-86 antibody is an agonistic antibody that has been shown to delay tumor growth in vivo.