OPIATE RECEPTOR MEDIATED EFFECTS OF STRESS ON IMMUNITY

Delta阿片受体(Dors)调节多种免疫功能，如T细胞增殖、IL-2产生和趋化因子介导的趋化作用。最近，有报道称，Delta型阿片激动剂能抑制多药耐药T细胞株(DOR-Ju)表达HIV-L p24抗原。1)。胸腺和脾淋巴细胞对脑啡肽的诱导表达强烈提示DORS对T细胞的调节是生理性的。虽然几个实验室已经在啮齿动物和灵长类动物的单核细胞中检测到DOR mRNA，但对DOR mRNA的调控表达知之甚少。这些研究将在存在和不存在抗CD28共刺激的情况下，通过交联T细胞受体(TCR)来评估其在体外的诱导作用。在未经刺激的培养中和通过TCR，将确定表达DOR mRNA的淋巴细胞的表型(S)以及活化的蛋白激酶C在诱导DOR中的作用。其他研究将集中在使用自然产生的超抗原葡萄球菌肠毒素B(SEB)在体内诱导DOR mRNA。介导DORS免疫调节作用的细胞内信号尚未确定。在DOR-Ju、L细胞中，虽然丝裂原活化蛋白激酶(MAPKs)L，2被DORS激活，但DOR激动剂抑制T细胞TcR依赖的ERKs的磷酸化和激活。在特定的目的#2中，将通过表征DORS激动剂对T细胞磷酸酶的表达、磷酸化和活性的影响来评估磷酸酶(如SHP-1、-2、MKP 1-3、PAC-1)在DORS抑制ERK L、2磷酸化中的作用。其他研究将评估DORS对依赖TCR激活ERK所需的早期事件的影响L，2，例如TCR复合体关键亚单位的磷酸化(例如CD3-Zeta)。具体目标#3将通过继续我们对艾滋病毒-L表达的研究来解决人外周血CD_4+T细胞多药耐药依赖的免疫调节的临床意义。在药理学研究中，两种DOR激动剂SNC-80和DADLE对感染HIV-L初级分离株的正常CD_4+T细胞表达HIV-L p24抗原的影响将与明尼苏达株进行比较。机制研究将这些激动剂的疗效与激活的人类CD4+T细胞表达DOR mRNA相关联。此外，还将评估参与反式激活HIV-L复制的核因子kappaB的结合活性，以及参与HIV-L摄取的辅助受体趋化因子受体CXCR4和CCR5的表达和磷酸化。总之，这些研究将有助于澄清我们对T细胞DORs的表达和功能的理解，以及它们在调节T细胞对HIV-1的反应中的潜在免疫药理作用。

Delta opioid receptors (DORs) modulate a myriad of immune functions such as T cell proliferation, IL-2 production and chemokine- mediated chemotaxis. Recently, delta opiate agonists have been reported to inhibit the expression of HIV- l p24 antigen by a DOR- transfected T cell line (DOR-Ju. 1). The inducible expression of enkephalins by thymic and splenic lymphocytes strongly suggests that the modulation of T cells by DORs is physiological. Although several laboratories have detected DOR mRNA in mononuclear cells from rodents and primates, little is known about the regulated expression of DOR mRNA. These investigations will evaluate its induction in vitro by cross-linking the T cell receptor (TCR) in the presence and absence of anti-CD28 costimulation. The phenotype(s) of the lymphocytes expressing DOR mRNA and the effects of activated protein kinase C on the induction of DOR in unstimulated cultures and through the TCR will be determined. Additional studies will focus on the induction of DOR mRNA in vivo, using the naturally occurring superantigen, staphylococcal enterotoxin B (SEB). The intracellular signals mediating the immunomodulatory effects of DORs have not been identified. Although the mitogen activated protein kinases (MAPKs), ERKs l, 2, are activated by the DORs in DOR-Ju,l cells, DOR agonists suppress the TCR-dependent phosphorylation and activation of ERKs in splenic T cells. In specific aim #2, the role of phosphatases (e.g. SHP-1, - 2, MKP 1-3, PAC-1) in the suppression of ERK l, 2 phosphorylation by DORs will be evaluated by characterizing the effects of DOR agonists on the expression, phosphorylation and activity of T cell phosphatases. Additional studies will assess the effects of DORs on early events required for the TCR-dependent activation of ERKs l, 2, such as the phosphorylation of key subunits of the TCR complex (e.g. CD3-zeta). Specific aim #3 will address the clinical significance of DOR-dependent immunomodulation in human peripheral blood CD4+ T cells by continuing our studies of HIV-l expression. In pharmacological studies, the effects of two DOR agonists, SNC-80 and DADLE, on HIV-l p24 antigen expression by normal CD4+ T cells infected with primary isolates of HIV-l will be compared to the Minnesota strain. Mechanistic studies will correlate the efficacy of these agonists with the expression of DOR mRNA by activated human CD4+ T cells. The binding activity of nuclear factor kappaB, which is involved in transactivation of HIV-l replication, and the expression and phosphorylation of the chemokine receptors CXCR4 and CCR5, which are co-receptors for HIV-l uptake, will also be evaluated. In summary, these investigations will help clarify our understanding of the expression and function of T cell DORs and their potential immunopharmacological role in modulating the T cell response to HIV- 1.