BACKGROUND & AIMS: Ligation of surface IgM on B cells responding to lipopolysaccharide (LPS) suppresses terminal differentiation and high-rate Ig secretion with no effect on proliferation. As shown here, different B cell populations show characteristic mean values of ligand concentration required for 50% inhibition, with Gaussian distributions of sensitivity to IgM receptor ligation that reflect cellular heterogeneity of 'al-or-none' inhibitions in single cells. Differential sensitivity of B cell populations to IgM ligation seems to be locally determined by the cellular environment and unrelated to the 'maturity' of the responding cells. Thus, while long-lived peritoneal B cells are 3- to 5-fold more resistant than splenic B cells, there is no difference in sensitivity between short- and long-lived B cells in the spleen. Furthermore, while B cells in bone marrow and spleen differ in sensitivity by two orders of magnitude, B cells differentiated in vitro from bone marrow pre-B cells are as resistant as splenic B cells. Moreover, bone marrow cell culture supernatants restore a high level of sensitivity in such cell populations. Differential sensitivity to IgM receptor ligation is reproduced by multivalent nominal antigen, in cell populations that show identical dose-response inhibition curves to direct activation of protein kinase C by phorbol esters. We conclude that the level of sensitivity to IgM ligation is independent of the life span or maturity of the B cell, but differentially regulated in vivo by putative tissue factors.

背景与目标： 对脂多糖 (LPS) 响应的b细胞上的表面IgM连接抑制了终末分化和高速度Ig分泌，而对增殖没有影响。如这里所示，不同的b细胞群体显示出50% 抑制所需的配体浓度的特征平均值，其对IgM受体连接的敏感性的高斯分布反映了单细胞中 “al-or-none” 抑制的细胞异质性。B细胞群体对IgM连接的不同敏感性似乎是由细胞环境局部决定的，与响应细胞的 “成熟度” 无关。因此，尽管长寿命的腹膜b细胞的抵抗力比脾b细胞高3至5倍，但脾脏中短寿命b细胞和长寿命b细胞之间的敏感性没有差异。此外，尽管骨髓和脾脏中的b细胞的敏感性相差两个数量级，但从骨髓前b细胞体外分化的b细胞与脾b细胞一样具有抵抗力。此外，骨髓细胞培养上清液在此类细胞群体中恢复了高水平的敏感性。在显示出与佛波酯直接激活蛋白激酶C相同的剂量反应抑制曲线的细胞群体中，多价名义抗原再现了对IgM受体连接的不同敏感性。我们得出的结论是，对IgM连接的敏感性水平与b细胞的寿命或成熟度无关，但在体内受假定的组织因素的差异调节。

BACKGROUND & AIMS: :Establishment of angiogenic circuits that orchestrate blood vessel development and remodeling requires an exquisite balance between the activities of pro- and antiangiogenic factors. However, the logic that permits complex signal integration by vascular endothelium is poorly understood. We demonstrate that a "neuropeptide," neurokinin-B (NK-B), reversibly inhibits endothelial cell vascular network assembly and opposes angiogenesis in the chicken chorioallantoic membrane. Disruption of endogenous NK-B signaling promoted angiogenesis. Mechanistic analyses defined a multicomponent pathway in which NK-B signaling converges upon cellular processes essential for angiogenesis. NK-B-mediated ablation of Ca2+ oscillations and elevation of 3'-5' [corrected] cyclic adenosine monophosphate (cAMP) reduced cellular proliferation, migration, and vascular endothelial growth factor receptor expression and induced the antiangiogenic protein calreticulin. Whereas NK-B initiated certain responses, other activities required additional stimuli that increase cAMP. Although NK-B is a neurotransmitter/ neuromodulator and NK-B overexpression characterizes the pregnancy-associated disorder preeclampsia, NK-B had not been linked to vascular remodeling. These results establish a conserved mechanism in which NK-B instigates multiple activities that collectively oppose vascular remodeling.

背景与目标： : 建立协调血管发育和重塑的血管生成回路需要在促血管生成因子和抗血管生成因子的活性之间取得完美的平衡。然而，允许血管内皮进行复杂信号整合的逻辑知之甚少。我们证明了 “神经肽”，即神经激肽-B (nk-b) 可逆地抑制了内皮细胞血管网络的组装并反对鸡绒毛膜尿囊膜中的血管生成。内源性NK-B信号的破坏促进了血管生成。机理分析定义了一种多组分途径，其中nk-b信号传导会聚在血管生成必不可少的细胞过程上。Nk-b介导的Ca2振荡消融和3 '-5' [校正] 环磷酸腺苷 (cAMP) 升高降低了细胞增殖，迁移和血管内皮生长因子受体表达，并诱导了抗血管生成蛋白钙网蛋白。NK-B发起了某些反应，而其他活动则需要增加cAMP的额外刺激。尽管nk-b是一种神经递质/神经调节剂，并且nk-b过表达是妊娠相关疾病先兆子痫的特征，但nk-b与血管重塑无关。这些结果建立了一个保守的机制，其中NK-B引发了共同反对血管重塑的多种活动。

BACKGROUND & AIMS: :The signaling pathways mediating lysophosphatidic acid (LPA)-stimulated PKD(2) activation and the potential contribution of PKD(2) in regulating LPA-induced interleukin 8 (IL-8) secretion in nontransformed, human colonic epithelial NCM460 cells were examined. Treatment of serum-deprived NCM460 cells with LPA led to a rapid and striking activation of PKD(2), as measured by in vitro kinase assay and phosphorylation at the activation loop (Ser706/710) and autophosphorylation site (Ser876). PKD(2) activation induced by LPA was abrogated by preincubation with selective PKC inhibitors GF-I and Ro-31-8220 in a dose-dependent manner. These inhibitors did not have any direct inhibitory effect on PKD(2) activity. LPA induced a striking increase in IL-8 production and stimulated NF-kappaB activation, as measured by NF-kappaB-DNA binding, NF-kappaB-driven luciferase reporter activity, and IkappaBalpha phosphorylation. PKD(2) gene silencing utilizing small interfering RNAs targeting distinct PKD(2) sequences dramatically reduced LPA-stimulated NF-kappaB promoter activity and IL-8 production. PKD(2) activation is a novel early event in the biological action of LPA and mediates LPA-stimulated IL-8 secretion in NCM460 cells through a NF-kappaB-dependent pathway. Our results demonstrate, for the first time, the involvement of a member of the PKD family in the production of IL-8, a potent proinflammatory chemokine, by epithelial cells.

背景与目标： : 检测了介导溶血磷脂酸 (LPA) 刺激的PKD(2) 激活的信号通路，以及PKD(2) 在调节LPA诱导的白介素8 (IL-8) 分泌中的潜在作用。未转化的人结肠上皮NCM460细胞。用LPA处理血清剥夺的NCM460细胞导致PKD(2) 的快速和惊人的激活，如通过体外激酶测定和激活环 (Ser706/710) 和自磷酸化位点 (Ser876) 测量的。通过与选择性PKC抑制剂gf-i预孵育消除LPA诱导的PKD(2) 激活，并以剂量依赖性方式Ro-31-8220。这些抑制剂对PKD(2) 活性没有任何直接抑制作用。通过NF-κ b-DNA结合，NF-κ b驱动的荧光素酶报告活性和ikappaba磷酸化来测量，LPA诱导了IL-8产生的显着增加并刺激了NF-κ b活化。利用靶向不同PKD(2) 序列的小干扰rna沉默PKD(2) 基因显著降低LPA刺激的NF-κ b启动子活性和IL-8产生。PKD(2) 激活是LPA生物学作用中的一个新的早期事件，并通过NF-κ b依赖性途径介导NCM460细胞中LPA刺激的IL-8分泌。我们的结果首次证明了PKD家族成员参与了上皮细胞产生IL-8 (一种有效的促炎趋化因子)。

BACKGROUND & AIMS: :Group B streptococcal (GBS) infections are the leading cause of bacterial disease and death among newborns in the United States and an important cause of morbidity among peripartum women and nonpregnant adults with chronic medical conditions. Disease in infants usually presents as sepsis, pneumonia or meningitis but also may include cellulitis or osteomyelitis. In 1990, GBS infections caused an estimated 7600 serious illnesses and 310 deaths among U.S. infants aged < or = 90 days; infections among infants aged < 7 days (i.e., early-onset disease) accounted for approximately 80% of these illnesses. To determine the incidence of GBS disease during 1993-1995, CDC conducted surveillance for this disease in an aggregate population of 12.5 million persons with 190,000 annual live-born infants. This report summarizes the findings of surveillance in this population, which indicate that a statistically significant decline in the incidence of early-onset GBS disease occurred in some surveillance areas.

背景与目标： : B组链球菌 (GBS) 感染是美国新生儿细菌性疾病和死亡的主要原因，也是围产期妇女和患有慢性疾病的未怀孕成年人发病的重要原因。婴儿的疾病通常表现为败血症，肺炎或脑膜炎，但也可能包括蜂窝织炎或骨髓炎。1990年，GBS感染在 <或 = 90天的美国婴儿中导致估计7600种严重疾病和310例死亡; <7天的婴儿 (即早发疾病) 感染约占这些疾病的80%。为了确定1993-1995年期间GBS疾病的发生率，CDC对1250万名每年有190,000名活产婴儿的人群进行了该疾病的监测。该报告总结了该人群的监测结果，这表明在某些监测地区，早发性GBS疾病的发病率在统计学上显着下降。

BACKGROUND & AIMS: :B-cell memory is provided by populations of quiescent memory B cells and long-lived plasma cells. Whereas it is clear that both of these cell populations arise from germinal centres, the signals and circumstances that trigger germinal-centre B cells to enter and then persist in memory compartments are poorly defined. Here, I propose that germinal centres produce memory B cells and plasma cells throughout the immune response and that memory B cells arise by the emigration of B cells that are chosen at random from the pool available in the germinal centre. The ability of such emigrants to survive as memory B cells depends on their germinal-centre 'history', with the persistence of high-affinity B-cell variants being favoured.

背景与目标： : b细胞记忆是由静态记忆b细胞和长寿命浆细胞群体提供的。尽管很明显，这两个细胞群体都来自生发中心，但触发生发中心b细胞进入并随后持续存在于记忆室中的信号和环境却定义不明确。在这里，我建议生发中心在整个免疫反应中产生记忆b细胞和浆细胞，并且记忆b细胞是通过从生发中心可用的库中随机选择的b细胞的迁移而产生的。这种移民作为记忆b细胞生存的能力取决于其生发中心的 “历史”，而高亲和力b细胞变体的持久性受到青睐。

BACKGROUND & AIMS: :Fludarabine and alemtuzumab are routinely used for treatment of B-cell chronic lymphocytic leukemia (B-CLL). The present study aimed to compare the expression of signaling molecules and cytokine production by T cells of B-CLL patients in long-term unmaintained remission/plateau phase following fludarabine or alemtuzumab treatment with that of indolent/untreated B-CLL patients and healthy donors. The frequency and intensity of TCR-CD3zeta chain, p56lck, p59fyn, ZAP-70, PI3-kinase and interferon (IFN)-gamma/interleukin (IL)-4 production in CD4 and CD8 T cells was examined by flow cytometry. T-cell function was assessed by stimulation with purified protein derivative (PPD) and phytohemagglutinin (PHA). Despite a reduction in number, the expression of IFN-gamma/IL-4 in T-cells in patients was significantly higher than in healthy donors. The intensity of most signaling molecules in treated patients was relatively unaffected vs. healthy donors but lower than untreated-indolent patients. However, the total number of T cells which expressed each of the signaling molecules was decreased in patients, with no difference between fludarabine- and alemtuzumab-treated patients. The T-cell response to PHA but not PPD was reduced in treated patients. The results suggest that, despite some alterations in signaling molecules and a reduction in T-cell number, overall T-cell functions may be relatively well preserved long-term after treatment with fludarabine and alemtuzumab.

背景与目标： : 氟达拉滨和阿仑单抗通常用于治疗b细胞慢性淋巴细胞白血病 (b-cll)。本研究旨在比较在氟达拉滨或阿仑单抗治疗后长期未维持缓解/平台期的b-cll患者的T细胞与惰性/未治疗的b-cll患者和健康的T细胞的信号分子表达和细胞因子产生供体。通过流式细胞术检查CD4和CD8 T细胞中TCR-CD3zeta链，p56lck，p59fyn，ZAP-70，PI3-kinase和干扰素 (IFN)-γ/白细胞介素 (IL)-4产生的频率和强度。通过纯化蛋白衍生物 (PPD) 和植物血凝素 (PHA) 刺激来评估T细胞功能。尽管数量减少，但患者T细胞中IFN-γ/IL-4的表达显着高于健康供体。与健康供体相比，接受治疗的患者中大多数信号分子的强度相对不受影响，但低于未经治疗的惰性患者。然而，在患者中表达每种信号分子的T细胞总数减少，而氟达拉滨和阿仑单抗治疗的患者之间没有差异。在治疗的患者中，T细胞对PHA的反应降低，但对PPD的反应降低。结果表明，尽管信号分子发生了一些变化，T细胞数量减少，但在用氟达拉滨和阿仑单抗治疗后，总体T细胞功能可能长期保持良好。

BACKGROUND & AIMS: :Professional antigen-presenting cells (APC) are able to process and present exogenous antigen leading to the activation of T cells. Antigen-immunoglobulin (Ig)G complexes (IC) are much more efficiently processed and presented than soluble antigen. Dendritic cells (DC) are known for their ability to take up and process immune complex (IC) via FcgammaR, and they have been shown to play a crucial role in IC-processing onto major histocompatibility complex (MHC) class I as they contain a specialized cross-presenting transport system required for MHC class I antigen-processing. However, the MHC class II-antigen-processing pathway is distinct. Therefore various other professional APC, like macrophages and B cells, all displaying FcgammaR, are thought to present IC-delivered antigen in MHC class II. Nonetheless, the relative contribution of these APC in IC-facilitated antigen-presentation for MHC class II in vivo is not known. Here we show that, in mice, both macrophages and DC, but not B cells, efficiently capture IC. However, only DC, but not macrophages, efficiently activate antigen-specific MHC class II restricted CD4(+) T cells. These results indicate that mainly DC and not other professional APC, despite expressing FcgammaR and MHC class II, contribute significantly to IC-facilitated T cell activation in vivo under steady-state conditions.

背景与目标： : 专业抗原呈递细胞 (APC) 能够处理和呈递导致T细胞活化的外源性抗原。抗原-免疫球蛋白 (Ig)G复合物 (IC) 比可溶性抗原更有效地处理和呈现。树突状细胞 (DC) 以其通过FcgammaR吸收和处理免疫复合物 (IC) 的能力而闻名。并且它们已被证明在IC处理到主要组织相容性复合体 (MHC) I类上起着至关重要的作用，因为它们包含MHC I类抗原处理所需的专门交叉呈递转运系统。然而，MHC II类抗原处理途径是不同的。因此，其他各种专业的APC，如巨噬细胞和b细胞，都显示FcgammaR，被认为在MHC II类中呈现IC递送的抗原。尽管如此，这些APC在体内MHC II类的IC促进抗原呈递中的相对贡献尚不清楚。在这里，我们表明，在小鼠中，巨噬细胞和DC，但不是b细胞，有效地捕获IC。然而，只有DC，但不是巨噬细胞，有效激活抗原特异性MHC II类限制性CD4(+) T细胞。这些结果表明，尽管表达FcgammaR和MHC II类，但主要是DC而不是其他专业APC，在稳态条件下对IC促进的T细胞激活有显着贡献。

BACKGROUND & AIMS: :CD5 (Ly-1) B cells are a minor subpopulation in mouse spleen and are thought to be responsible for the production of natural autoantibodies to bromelain-treated autologous erythrocytes (Br-RBC). Here it is shown that substantial numbers of conventional, CD5-negative, splenic B cells also secrete these antibodies in CBA and (NZB x NZW)F1 mice, whereas in NZB and BALB/c mice they are all produced by the CD5 B-cell population. However, stimulation with bacterial lipopolysaccharide in vivo preferentially activates the CD5 B-cell group to anti-Br-RBC antibody secretion.

背景与目标： : CD5 (Ly-1) b细胞是小鼠脾脏中的次要亚群，被认为负责产生针对菠萝蛋白酶处理的自体红细胞 (br-rbc) 的天然自身抗体。这里显示大量的常规CD5-negative脾b细胞也在CBA和 (NZB x NZW)F1小鼠中分泌这些抗体，而在NZB和BALB/c小鼠中，它们都是由CD5 b细胞群体产生的。然而，体内用细菌脂多糖刺激优先激活CD5 b细胞组，使其分泌抗br-rbc抗体。

BACKGROUND & AIMS: :An immediately inducible gene by gonadotropin was isolated from rat ovaries primed with pregnant mare serum gonadotropin (PMSG) by using a subtraction cloning procedure. Homology analysis revealed that the gene is a rat homologue of scavenger receptor class B-I, which was recently identified as a specific receptor for high density lipoprotein (HDL). The structure of rat SRBI was determined by nucleotide sequence analysis of full-length cDNAs for SRBI. Northern blot analysis revealed that rat SRBI mRNA levels were rapidly and strongly increased within 3 h by the injection of PMSG. In situ hybridization study revealed that SRBI mRNA was strongly induced in theca interna cells of immature rat ovary stimulated with 30 IU of PMSG for 6 h. SRBI mRNA expression was also observed in corpora lutea of the adult rat ovary. These findings indicate that expression of SRBI mRNA is restricted to and induced in the ovarian steroidogenic cell types where cholesterol is used as a substrate for synthesis of steroid hormones. Our data strongly suggest that SRBI may play a significant role in the ovarian steroidogenesis by mediating selective uptake of cholesterol from HDL to ovarian theca interna cells or to corpus luteum.

背景与目标： : 使用减法克隆程序从用妊娠母马血清促性腺激素 (PMSG) 引发的大鼠卵巢中分离出促性腺激素立即诱导的基因。同源性分析表明，该基因是清道夫受体B-I类的大鼠同源物，最近被鉴定为高密度脂蛋白 (HDL) 的特异性受体。通过SRBI全长cdna的核苷酸序列分析确定大鼠SRBI的结构。Northern印迹分析显示，通过注射PMSG，大鼠SRBI mRNA水平在3小时内迅速且强烈地增加。原位杂交研究表明，用30 IU的PMSG刺激6 h，在未成熟大鼠卵巢的卵泡膜细胞中强烈诱导SRBI mRNA。在成年大鼠卵巢的黄体中也观察到了SRBI mRNA的表达。这些发现表明，SRBI mRNA的表达仅限于并在其中胆固醇用作合成类固醇激素的底物的卵巢类固醇生成细胞类型中诱导。我们的数据强烈表明，SRBI可能通过介导胆固醇从HDL到卵巢卵泡膜细胞或黄体的选择性摄取而在卵巢类固醇生成中起重要作用。

BACKGROUND & AIMS: :Phosphorus MRS was evaluated as a monitor of tumour therapeutic response to the herpes simplex virus thymidine kinase suicide gene therapy paradigm. In vivo 31P spectra were obtained from subcutaneous rat C6 gliomas constitutively expressing the HSVtk gene post treatment with ganciclovir (GCV, 15 mg/kg i.p., twice-daily). Significant regression (p < 0.1) of tumour volume was observed 10 days after beginning GCV administration. However, no changes in tumour pH or energy metabolites from pre-treatment values were observed. High-resolution 31P spectra of tumour extracts revealed a statistically significant reduction in the phosphocholine to phosphoethanolamine ratio six days post-GCV administration. These results indicate that the HSVtk/GCV-induced killing of tumours is not associated with corresponding changes in 31P MRS-observable energy metabolites and pH. The observed reduction in the PE/PC ratio may provide a non-invasive in vivo indicator of therapeutic efficacy.

背景与目标： : 磷MRS被评估为对单纯疱疹病毒胸苷激酶自杀基因治疗范例的肿瘤治疗反应的监测仪。体内31p光谱是从用更昔洛韦治疗后组成性表达HSVtk基因的皮下大鼠C6神经胶质瘤获得的 (GCV，15 mg/kg i.P.，每天两次)。在开始GCV给药10天后观察到肿瘤体积的显著回归 (p <0.1)。然而，未观察到肿瘤pH或能量代谢物与治疗前值的变化。肿瘤提取物的高分辨率31p光谱显示，GCV给药六天后，磷酸胆碱与磷酸乙醇胺的比率在统计学上显着降低。这些结果表明，HSVtk/GCV诱导的肿瘤杀伤与31P MRS可观察到的能量代谢产物和pH的相应变化无关。观察到的PE/PC比率的降低可能提供治疗功效的非侵入性体内指标。

BACKGROUND & AIMS: :In this study, the contribution of the CD5+ B cell to the preferential expression of VH 7183 and Q52 observed early in development was determined. CD5+ and CD5- B cells from BALB/c mice were isolated by fluorescence-activated cell sorter and the expression of particular VH gene families was determined directly by in situ hybridization. The results indicate that CD5+ B cells obtained from both adult and neonatal animals express Q52 at increased levels compared with CD5- B cells. Preferential expression of VH 7183 was observed only in the neonatal CD5- B cell subset. Thus, the increased expression of VH 7183 early in development is caused by the CD5- subset whereas increased Q52 expression is caused by the CD5+ subset. These results indicate that the fetal/neonatal conventional B cell is distinct from conventional adult B cells in terms of Ig gene repertoire expression.

背景与目标： : 在这项研究中，确定了CD5 b细胞对发育早期观察到的VH 7183和Q52的优先表达的贡献。通过荧光激活细胞分选仪分离BALB/c小鼠的CD5和CD5-b细胞，并通过原位杂交直接确定特定VH基因家族的表达。结果表明，与CD5-b细胞相比，从成年动物和新生动物获得的CD5 b细胞表达Q52的水平更高。仅在新生儿cd5-b细胞亚群中观察到VH 7183的优先表达。因此，VH 7183在发育早期的表达增加是由CD5-子集引起的，而Q52表达增加是由CD5 + 子集引起的。这些结果表明，就Ig基因库表达而言，胎儿/新生儿常规b细胞与常规成人b细胞不同。

BACKGROUND & AIMS: :The utility of the Aspergillus fumigatus cellobiohydrolase cbhB promoter for controlled gene expression has been investigated. cbhB message was present at high levels in the presence of carboxymethylcellulose and undetected in the presence of glucose. A reporter construct using the cbhB promoter showed similar behaviour and gave lower message levels than the Aspergillus nidulans alcA promoter under repressing conditions. An RNAi construct driven by the cbhB promoter was used to down-regulate the alb1 gene; transformants showed low alb1 message levels and a loss-of-function phenotype with carboxymethylcellulose, while both wild-type message levels and phenotype were seen with glucose. The cbhB promoter is therefore tightly controlled and can be exploited for the study of A. fumigatus.

背景与目标： : 研究了烟曲霉纤维二糖水解酶cbhB启动子在控制基因表达中的效用。cbhB信息在羧甲基纤维素存在下以高水平存在，而在葡萄糖存在下未检测到。在抑制条件下，使用cbhB启动子的报告构建体表现出相似的行为，并且给出的信息水平低于构巢曲霉alcA启动子。由cbhB启动子驱动的RNAi构建体用于下调alb1基因; 转化子显示出较低的alb1信息水平和羧甲基纤维素的功能丧失表型，而葡萄糖则观察到野生型信息水平和表型。因此，cbhB启动子受到严格控制，可用于烟曲霉的研究。

BACKGROUND & AIMS: :Our recent study demonstrated that defects in p110delta result in B-cell immunodeficiency that is very similar to that observed in BTK-deficient mice. We revealed that the p110delta fit the B-cell signal transduction complex and played a non-redundant role in the development and function of B cells. In humans, most children with primary B-cell immunodeficiency have mutations in the BTK, whereas a few have defects in the components of the B-cell signal transduction complex. But little is known about the genetic variation of p110delta in children with defects in B-cell immunodeficiency of unknown aetiology. Sixteen patients from 15 unrelated families and 112 normal controls underwent sequence analysis to identify genetic variations of the p110delta. Allele frequency in each group was also analysed and compared. We identified five single base-pair polymorphic nucleotide exchanges in both patient and control groups with similar allele frequencies, which did not contribute to the immunodeficiency. Three of them are novel (m.953A>G, m.1200C>T and m.1561A>G), and the m.953A>G and m.1561A>G nucleotide exchanges are non-synonymous (N253S and T456A, respectively). The novel m.1561A>G was in complete linkage disequilibrium with the known m.873A>G in our study of Taiwanese group. In addition, one novel single base-pair missense mutation, m.3256G>A (E1021K), was identified in one boy with typical clinical features of primary B-cell immunodeficiency and could not be found in either his family or the normal control population. By atomic structural analysis of the amino acid as well as the alignment comparison between species, it resulted in the replacement of the negative-charged amino acid E with the positive-charged amino acid K at codon 1021, located in the highly conservative and important catalytic functional domain. Our findings could shed light on further understanding the polymorphisms of p110delta in B-cell immunodeficiency and different populations. Moreover, the 3256G>A missense mutation raised the attention and warranted further extensive analysis to elucidate the role of p110delta in human immunodeficiency.

背景与目标： : 我们最近的研究表明，p110delta的缺陷导致b细胞免疫缺陷，这与BTK缺陷小鼠中观察到的非常相似。我们揭示了p110delta符合b细胞信号转导复合物，并且在b细胞的发育和功能中起着非冗余的作用。在人类中，大多数患有原发性b细胞免疫缺陷的儿童在BTK中存在突变，而少数儿童在b细胞信号转导复合物的成分中存在缺陷。但是，对于病因不明的b细胞免疫缺陷儿童中p110delta的遗传变异知之甚少。来自15个无关家庭和112个正常对照的16名患者进行了序列分析，以鉴定p110delta的遗传变异。还对各组的等位基因频率进行了分析和比较。我们在患者组和对照组中鉴定出五个具有相似等位基因频率的单碱基对多态性核苷酸交换，这对免疫缺陷没有贡献。其中三个是新颖的 (m.953A>G，m.1200C>T和m.1561A>G)，而m.953A>G和m.1561A>G核苷酸交换是非同义的 (分别为N253S和T456A)。在我们对台湾组的研究中，新颖的m.1561A>G与已知的m.873A>G完全处于连锁不平衡状态。此外，在一名具有原发性b细胞免疫缺陷典型临床特征的男孩中鉴定出一个新的单碱基对错义突变m.3256G>A (E1021K)，在其家人或正常对照人群中均找不到。通过氨基酸的原子结构分析以及物种之间的比对比较，它导致负电荷氨基酸E被密码子1021位的正电荷氨基酸K取代，位于高度保守和重要的催化功能域。我们的发现可能有助于进一步了解b细胞免疫缺陷和不同人群中p110delta的多态性。此外，3256G>A错义突变引起了人们的注意，并需要进一步广泛的分析来阐明p110delta在人类免疫缺陷中的作用。

BACKGROUND & AIMS: Rabbits predominantly rearrange the most 3'VH gene (VH1); thus combinatorial diversity is very limited. In man and mouse, the most 3'DH gene, DQ52, is preferentially rearranged early in B-cell development. To test whether this preference for rearranging a DH gene segment based on 3' end proximity exists in rabbit, we cloned and sequenced the rabbit DQ52 gene. The 11 base pair coding region sequence is identical to a published mouse DQ52, and 81.8% similar to the human sequence. It is localized approximately 805 bp upstream of the JH1 gene. However, the 3' recombination signal sequence has an atypical nonamer. We prepared mRNA from 15- to 28-day fetal rabbits and amplified expressed VDJ sequences of mu mRNA by RT-PCR. The PCR products with VDJ rearrangements were cloned and sequenced. As expected, 44 of 45 VDJ sequences reflected use of the 3' VH1a2 gene, but the DQ52 gene was utilized very infrequently, if at all. We found only one VDJ sequence from 28-day fetal liver B-cells with 8 bp that matched the germline DQ52 sequence. Instead of expressing DQ52, another DH gene, Df was frequently expressed. We cloned the genomic Df gene and localized it about 32 kb upstream of the JH region. Thus, in contrast to man and mouse, rabbits preferentially express a DH gene located in the middle of the DH region early in B cell ontogeny. This may correlate with more frequent initial rearrangement of VH to DH in rabbit B cells.

背景与目标： 兔子主要重排最3'VH基因 (VH1); 因此组合多样性非常有限。在人和小鼠中，最3'DH基因DQ52在b细胞发育的早期优先重排。为了测试兔子中是否存在基于3' 末端邻近度重新排列DH基因片段的偏好，我们克隆并测序了兔子DQ52基因。11个碱基对编码区序列与已发表的小鼠DQ52相同，并且81.8% 类似于人序列。它位于JH1基因上游约805 bp。但是，3' 重组信号序列具有非典型的非amer。我们从15至28天的胎兔中制备了mRNA，并通过rt-pcr扩增了mu mRNA的VDJ表达序列。克隆并测序具有VDJ重排的PCR产物。正如预期的那样，在45个VDJ序列中，有44个反映了3'vh1a2基因的使用，但是DQ52基因很少被使用 (如果有的话)。我们从28天的胎儿肝b细胞中发现只有一个VDJ序列，其8 bp与种系DQ52序列匹配。Df不表达另一个DH基因DQ52，而是经常表达。我们克隆了基因组Df基因，并将其定位在JH区域上游约32 kb。因此，与人和小鼠相比，兔子在b细胞个体发育早期优先表达位于DH区域中部的DH基因。这可能与兔b细胞中VH到DH的更频繁的初始重排有关。

BACKGROUND & AIMS: :Long-term cold exposure (5-7 days) is known to induce concomitant increases in the levels of adrenomedullary tyrosine hydroxylase (TH) RNA, protein, and enzyme activity. In this report, we compare the time courses of these changes and investigate the effects of cold exposure on the levels of biopterin, the cofactor required for tyrosine hydroxylation. After only 1 h of cold exposure, TH mRNA abundance increased 71% compared with nonstressed controls. Increases in total cellular TH RNA levels were maximal (threefold over control values) within 3-6 h of cold exposure and remained elevated throughout the duration of the experiment (72 h). TH protein levels increased rapidly after 24 h of cold exposure and reached a maximal value threefold above that of controls at 48-72 h. Despite the relatively rapid and large elevations in TH RNA and protein content, only modest increases in TH activity were detected during the initial 48 h of cold exposure. Adrenomedullary biopterin increased rapidly after the onset of cold exposure, rising to a level approximately twofold that of the nonstressed controls at 24 h, and remained at this level throughout the duration of the stress period. Taken together, the results of this time course study indicate that cold-induced alterations in adrenal TH activity are mediated by multiple cellular control mechanisms, which may include pre- and posttranslational regulation. Our findings also suggest that cold stress-induced increases in the levels of the TH cofactor may represent another key event in the sympathoadrenal system's response to cold stress.

背景与目标： : 已知长期冷暴露 (5-7天) 会引起肾上腺髓质酪氨酸羟化酶 (TH) RNA，蛋白质和酶活性的同时增加。在本报告中，我们比较了这些变化的时间过程，并研究了冷暴露对酪氨酸羟基化所需的辅因子生物蝶呤水平的影响。冷暴露仅1小时后，与无应激对照相比，TH mRNA丰度71% 增加。在冷暴露的3-6小时内，总细胞TH RNA水平的增加最大 (是对照值的三倍)，并且在整个实验期间 (72小时) 保持升高。冷暴露24小时后，TH蛋白水平迅速增加，并在48-72小时达到对照组的三倍的最大值。尽管TH RNA和蛋白质含量的升高相对较快且较大，但在冷暴露的最初48小时内仅检测到TH活性的适度增加。冷暴露开始后，肾上腺髓质生物蝶呤迅速增加，在24小时时升至非应激对照的大约两倍，并在整个应激期内保持在该水平。总之，该时间过程研究的结果表明，冷诱导的肾上腺TH活性的改变是由多种细胞控制机制介导的，其中可能包括翻译前和翻译后的调节。我们的发现还表明，冷应激引起的TH辅因子水平的增加可能是交感肾上腺系统对冷应激反应的另一个关键事件。