Immune Regulation by the Inositol Phosphatase Ship

限制免疫反应的机制对于避免破坏性反应至关重要，这种反应可能会导致过敏和炎症反应，在更严重的情况下，会导致致命的自身免疫性疾病。我们的目标是了解下调免疫反应、控制淋巴细胞增殖和抗体产生的机制。出于这一目的，我们开始了对肌醇磷酸酶SHIP介导的负调控途径的研究。由于骨髓增殖性综合征，缺乏SHIP会导致小鼠存活率降低，并伴有严重的脾肿大和肺内大量髓系细胞聚集。SHIP-/-小鼠的多效性表型反映了SHIP是生长因子、细胞因子、Fc和抗原受体活性的普遍下调因子。为了更准确地了解SHIP在特定细胞中的体内功能，同时避免多效性相互作用，我们已经开始在小鼠中表征组织特异性或可诱导的SHIP突变。我们已经产生了loxP侧翼SHIP小鼠，可以与几个表达Cre重组酶的小鼠杂交。在与Jeff Ravetch的合作中，我们利用巨噬细胞特异性缺失SHIP的小鼠，确定了SHIP在脾边缘区域形成中的重要作用。我们现在正在研究SHIP在T淋巴细胞选择、耐受性以及肥大细胞特异性缺失的影响中的作用。

Mechanisms that restrict the immune response are critical to avoid damaging reactivity that can lead to allergies and inflammatory responses or, in more severe cases, to lethal autoimmune diseases. Our goal is to understand mechanisms that downregulate the immune response, control lymphocyte proliferation and antibody production. With this intention we initiated a study of the negative regulatory pathway mediated by the inositol phosphatase SHIP. Absence of SHIP results in reduced viability of the mice due to a myeloproliferative-like syndrome, with profound splenomegaly and massive myeloid cell accumulation in the lungs. The very pleiotropic phenotype of SHIP-/- mice reflects the fact that SHIP is a general down-modulator of growth factor, cytokine, Fc and antigen receptor activity. To get a more precise idea of the in vivo function of SHIP in specific cells while avoiding pleiotropic interactions, we have begun to characterize tissue-specific or inducible SHIP mutations in mice. We have generated loxP-flanked SHIP mice that can be crossed to several Cre recombinase-expressing mice. In collaboration with Jeff Ravetch we have determined the essential role of SHIP in the formation of the splenic marginal zone utilizing mice with macrophage specific deletion of SHIP. We are now characterizing the functional role of SHIP in T lymphocyte selection, tolerance as well as the effects of mast cell-specific deletion of SHIP.