同种异基因骨髓细胞移植诱导嵌合体小鼠生成

采用C57BL/J和BALB/c两种小鼠进行骨髓细胞移植。移植前受体小鼠经 6 0Gy6 0 Coγ射线照射。用细胞染色法和流式细胞术分析了射线对小鼠淋巴细胞的损伤强度和照射后移植了骨髓细胞的小鼠在不同时间内的淋巴细胞亚群变化。结果表明 ,(1 ) 6 0Gyγ射线照射受体鼠 ,能杀伤 95 5 %的外周淋巴细胞 ,但是不影响自身H 2Kb 分子在淋巴细胞表面表达的百分数。残留细胞中CD3+ T细胞、NK1 1 + 淋巴细胞、CD3+ /NK1 1 + 淋巴细胞的阳性率分别由照射前的 40 44%增加到45 30 %、 1 1 3 %增加到 37 41 %和 1 0 7%增加到 5 86 % (P≤ 0 0 1 ) ;(2 )小鼠的淋巴细胞数量从照射后 30d开始恢复 ,到1 90d达到正常值 ;(3 )照射后进行同种异基因骨髓细胞移植后的第 60天 ,受体淋巴细胞表面自身H 2Kb 抗原表达下降 ,CD3+ /NK1 1 + 淋巴细胞百分数增加。随H 2Kb 的抗原表达的恢复 ,CD3+ /NK1 1 + 淋巴细胞百分数下降 ;(4)在细胞移植的第 1 90天 ,受体小鼠 (黑色 )表型呈现出供体鼠 (白色 )颜色特征。在嵌合体小鼠外周淋巴细胞中 ,有 2 5 %为供体H 2Kd 阳性细胞 ,CD3+ /NK1 1 + 淋巴细胞百分数为 1 88% ,明显高于正常值 (P≤ 0 0 1 )。以上结果表明 ,6 0Gy6 0 Coγ射线照射能诱导免疫耐受 ,其耐受性的形成可能与最初保     

20 Gy γ射线不同分割模式头部照射对小鼠学习记忆的影响

目的:探讨20 Gyγ射线不同分割模式头部照射对小鼠学习记忆的影响.方法:48只成年雄性C57BL/6小鼠随机分为对照组(control)、20 Gy单次照射组(20 Gy)、大分割照射组(5 Gy×4 d)和常规分割照射组(2 Gy×10 d),各照射组小鼠均头部接受γ射线照射,总剂量为20 Gy.照后4周采用Mor...     

TLR4在基因突变小鼠C3H/HeJ坐骨神经损伤修复中的作用

目的探究TLR4突变对小鼠坐骨神经损伤修复产生的影响。方法选择TLR4基因突变型C3H/HeJ小鼠和野生型C3H/HeN小鼠作为实验动物,实验设C3H/HeJ夹伤组(HeJ)、C3H/HeN夹伤组(HeN)及C3H/HeN假手术组(control)。在无菌操作条件下,构建小鼠坐骨神经夹伤模型。分别于术后6、12、24和48 h,qPCR检测损伤神经IL-1β、IL-6、TNF-α因子的表达。术后12 h和24 h,Western blot检测损伤神经p75NTR蛋白的表达。术后1周、2周、4周和8周取小鼠坐骨神经,HE染色观察神经恢复情况,免疫组化检测GAP-43、p75NTR蛋白表达情况。坐骨神经功能指数(sciatic functional index,SFI)评价小鼠运动功能恢复情况。结果在6、12和24 h时,与control组相比,HeN组IL-1β和TNF-α的表达量显著升高(P0.01),而HeJ组的变化不明显。HeN组与HeJ组之间TNF-α的表达差异显著(P0.001)。与control组相比,在6 h时HeN组IL-6的表达显著上升(P0.001)。Western blot结果显示,与HeN组相比,坐骨神经损伤后12 h或24 h时HeJ组小鼠p75NTR蛋白表达显著升高(P0.001)。HE染色表明,与HeN组相比,HeJ组小鼠淋巴细胞表达较少,炎性反应较弱。免疫组化结果发现,与HeN组相比,HeJ组小鼠GAP43和p75NTR的表达显著升高(P0.01)。SFI结果显示,与HeN组相比,HeJ组小鼠的SFI评分在术后同期相对较高,神经恢复更好。结论成功构建突变小鼠坐骨神经损伤模型,揭示出TLR4突变可减少炎性因子的释放而加快坐骨神经修复。为临床上治疗周围神经损伤提供了实验理论依据。     

TLR2、TLR4 及 MyD88 高表达与 Cm 呼吸道感染肺组织炎症相关

目的:探讨沙眼衣原体呼吸道感染过程中C3H/ HeN(C3H)小鼠过度炎症反应的机制。方法:C3H 与C57BL/6(C57)小鼠鼻腔吸入1伊103 IFU 沙眼衣原体小鼠肺炎菌株(Cm),建立沙眼衣原体小鼠肺炎模型,使用RT-PCR 检测感染后不同时间点小鼠肺组织Toll 样受体TLR2、TLR4 及转导蛋白MyD88 mRNA 的表达。结果:使用1伊103 IFU 的Cm 呼吸道感染C3H与C57BL/6(C57)诱导小鼠衣原体肺炎,Cm 感染在高易感性的C3H 小鼠及低易感的C57 小鼠均诱导Toll 样受体的表达,但在感染后第7 天及第14 天,高易感的C3H 小鼠肺组织中TLR2 和TLR4 mRNA 的表达均显著高于C57 小鼠,尤其TLR2(P<0.001 或P<0.05),进一步研究发现Cm 呼吸道感染C3H 小鼠肺组织MyD88mRNA 的表达也显著高于C57 小鼠,并在感染后第14 天仍维持高表达。结论:Cm 呼吸道感染诱导TLR2、TLR4 及MyD88 在高易感的C3H 小鼠肺组织高表达,可能与C3H 小鼠肺组织过度炎症反应相关。     

安脑片对aGVHD小鼠Th1/Th2细胞的调节作用

目的:观察中药安脑片对aGVHD小鼠的Th1/Th2细胞的调节作用。方法:清洁级BALB/c雄性小鼠作为供鼠,以清洁级C57BL/6雌性小鼠为受鼠,建立aGVHD模型;C57BL/6小鼠在移植前进行60Co全身照射,剂量为9.0 Gy,照射后4小时内尾静脉输注BALB/c雄性小鼠的骨髓细胞8×107个/只+脾细胞8×107个/只。造模成功后,随机分为安脑片组和空白组。移植后第30天杀鼠取材,取眶静脉血并制备肝脏标本,ELISA法检测小鼠血清IFN-γ及IL-10水平,免疫组化法检测肝脏组织IFN-γ及IL-10的阳性表达。结果:安脑片组小鼠血清IFN-γ的表达治疗前为(9.67±0.88)pg/ml,治疗后降至(4.81±0.87)pg/ml,IL-10的表达在治疗前为(3.81±0.55)pg/ml,治疗后升至(8.16±0.92)pg/ml。免疫组化的结果也显示小鼠肝脏组织IFN-γ及IL-10的表达改善明显,治疗后小鼠IFN-γ的表达评分降为1.27±0.46,IL-10的表达评分升至3.73±0.46,与治疗前相比差异显著(P=0.000)。结论:安脑片可有效改善小鼠aGVHD效应并调节Th1/Th2细胞因子的平衡。     

三氧化二砷对MRL/lpr狼疮鼠T-bet/GATA3信号通路的影响

目的:本文旨在探讨三氧化二砷(arsenic trioxide,ATO)对MRL/lpr狼疮鼠T-bet/GATA3信号通路的影响及其作用机制。方法:将20周龄MRL/lpr狼疮鼠和正常C57BL/6J小鼠随机分组,分别接受ATO(0.4mg·kg~(-1)·d~(-1))和同体积生理盐水(NS)治疗2个月,分离脾脏淋巴细胞,然后用实时荧光定量PCR法检测T-bet、GATA3、IFN-γ、IL-4的mRNA水平及T-bet/GATA3 mRNA的比值,Western blot法检测T-bet和GATA3的蛋白表达,ELISA法检测血清中IFN-γ和IL-4的浓度。结果:(1)MRL/lpr狼疮鼠NS组T-bet、IFN-γ的mRNA及蛋白表达、Tbet/GATA3 mRNA比值均高于C57BL/6J小鼠NS组(P0.05),而GATA3、IL-4的mRNA及其蛋白表达均低于C57BL/6J小鼠NS组(P0.05);(2)在MRL/lpr狼疮鼠中,与NS组相比,ATO组T-bet、IFN-γ的mRNA及蛋白表达、T-bet/GATA3 mRNA比值均下降(P0.05),而2组中GATA3、IL-4的mRNA及蛋白表达无明显差异;(3)在C57BL/6J小鼠中,NS组和ATO组之间以上指标均无显著性差异。结论:ATO可能通过影响MRL/lpr狼疮鼠Tbet/GATA3信号通路,降低T-bet表达,从而减少Th1型细胞因子IFN-γ的表达和分泌。     

C57BL/6J×129/J杂交小鼠ES细胞系的建株(英)

 目的：建立C57BL/6J×129/J杂交小鼠ES细胞系。 方法： 收集3.5 d.p.c.的囊胚，培养在预先铺有小鼠成纤维细胞（MEFs）的高糖DMEM培养液中。3-4 d后，挑出内细胞团（ICM），消化后重新种到新鲜的有MEFS培养液中。等到有典型的ES样集落长出，即传代以得到永久ES细胞系。通过分析碱性磷酸酶活性，SSEA-1，Oct-4的表达和形成畸胎瘤的能力来鉴定ES细胞的多向分化能力。 结果： 获得的两个C57BL/6J×129/J杂交小鼠ES细胞系绝大多数细胞具有正常的核型（40，XY），碱性磷酸酶染色阳性，SSEA-1，Oct-4表达阳性， ES细胞注入SCID鼠后可获得来自3个胚层的组织。 结论： 建立了两株具有长期自我更新能力和多向分化潜能的C57BL/6J×129/J杂交小鼠ES细胞系。     

肺炎衣原体对C57BL/6J小鼠腹膜巨噬细胞泡沫化的影响

目的:探讨肺炎衣原体在C57BL/6J小鼠腹膜巨噬细胞泡沫化过程中的作用。方法:将肺炎衣原体与C57BL/6J小鼠腹膜巨噬细胞培养72h后用油红O方法染色观察细胞的形态变化并测定细胞内胆固醇的含量。结果:肺炎衣原体能使C57BL/6J小鼠腹膜巨噬细胞胞浆内脂质颗粒增多,胆固醇酯占总胆固醇的比例增加。结论:肺炎衣原体能促进C57BL/6J小鼠腹膜巨噬细胞泡沫化。     

C57BL/6J小鼠主要器官的组织学数据库的建立

目的建立C57BL/6J小鼠主要器官的组织学数据库。方法选取C57BL/6J小鼠雌性10只,雄性10只,将其麻醉致死,解剖切取心、肝、脾、肺、肾、胃等45个器官和组织,用10%的中性缓冲福尔马林固定,石蜡切片,常规HE染色,用显微镜观察,图像采集,用计算机对图像进行标注。采用SQLSEVER2000数据库管理系统,C#编程语言,B/S（浏览器/服务器）为系统构架。结果解剖20只C57BL/6J小鼠主要器官和组织,制做了1 589张切片,观察采集了13 578张图片,对1 563张图片进行了标注,建立了容量达7.85 GB的C57BL/6J小鼠主要器官的组织学数据库。结论构建可查询的C57BL/6J小鼠主要器官的形态学数据库,是研究疾病模型小鼠方便快捷的对照图库。     

饥饿、糖尿病和肥胖状态对小鼠肝脏SOCS2基因表达的影响

目的确定小鼠肝脏SOCS2基因在饥饿、糖尿病和肥胖状态下的表达水平,并初步研究SOCS2对糖异生的影响。方法动物分3组:C57BL/6J小鼠、对照组(饱食)和实验组(饥饿24 h);糖尿病模型小鼠db/db及对照小鼠db/m饱食;肥胖模型小鼠ob/ob及其对照C57BL/6J小鼠(饱食)。处死小鼠后提取肝脏RNA做反转录PCR,荧光实时定量PCR检测小鼠肝脏SOCS2及糖异生相关基因在3组小鼠中的表达水平;使用腺病毒表达系统在C57BL/6J小鼠原代肝细胞中过表达SOCS2,Western blot检测SOCS2蛋白的表达,葡萄糖生成实验检测糖输出。结果饥饿使C57BL/6J小鼠肝脏中SOCS2 mRNA水平下调,db/db和ob/ob小鼠肝脏SOCS2基因表达比其对照小鼠均明显下降(P0.05),调节糖异生的关键基因PGC-1α、PEPCK和G6Pase的mRNA水平均上升。在C57BL/6J小鼠原代肝细胞中过表达SOCS2,得到大小为Mr 23 000的蛋白,糖输出受到明显抑制。结论初步认定SOCS2可抑制C57BL/6J小鼠原代肝细胞糖异生,可能是治疗糖尿病的一个新靶点。     

Pulmonary clearance of Mycoplasma pulmonis in C57BL/6N and C3H/HeN mice.

In C57BL/6N and C3H/HeN mice known to be free of all murine pathogens and matched for age, sex, and environmental factors, pulmonary clearance was measured over a 72-h time period after exposure to infectious aerosols of 35S-labeled Mycoplasma pulmonis. Reduced clearance of M. pulmonis in C3H/HeN mice relative to C57BL/6N mice was primarily due to impaired mycoplasmacidal activity in the lungs of the C3H/HeN mice. The C3H/HeN mice also had a slightly slower rate of mechanical transport of radiolabel from the lungs in the first 4 h after infection relative to the C57BL/6N mice but not at any later times. By 72 h after infection (relative to 0 h, C3H/HeN mice had an over 4,000% (1.75 X 10(7) versus 4.30 X 10(5] increase in neutrophils and an over 18,000% (more than 2 orders of magnitude) increase in numbers of M. pulmonis recovered from mechanically disaggregated lungs. In contrast, C57BL/6N mice reduced the number of M. pulmonis present by over 83% (nearly 2 orders of magnitude) before any increase in inflammatory cells, which was only a slight increase in lymphocytes and macrophages at 24 h after infection. These results directly link decreased mycoplasmal pulmonary clearance in C3H/HeN mice with the increased susceptibility to, and severity of, murine respiratory mycoplasmosis observed in this strain. The resistance of C57BL/6N mice appears to be related to nonspecific host defense mechanisms responsible for limiting the extent of infection.     

Immunopathological response of C57BL/6 and C3H/HeN mice to Aspergillus fumigatus antigens

C3H/HeN and C57BL/6 mice were exposed to culture filtrate (CF) and mycelial extracts (ME) of Aspergillus fumigatus (Af) intranasally. Animals received 6, 8 or 10 biweekly doses and were sacrificed 2 weeks after the last dose was administered. Specific antibodies against Af were detected in their sera by biotin-avidin-linked immunosorbent assay (BALISA). Antibodies against Af belonging to all isotypes showed an increase in both strains of mice. A progressive increase in IgG and IgA antibody isotypes against both CF and ME antigens was detected in C3H/HeN mice during the entire experimental period, whereas most antibody levels peaked after the 8th dose and remained steady or decreased slightly in the C57BL/6 strain. Lung lavage studies showed a relative decrease in the number of macrophages and an increase in the number of lymphocytes after the 6th and 8th instillation of Af antigens in both strains of mice. Histology of the lung demonstrated a progressive inflammatory reaction in C57BL/6 mice during the experimental period. On the other hand, the C3H/HeN mice showed a negligible inflammatory pulmonary reaction. The antibody responses and inflammatory changes detected in the lungs of mice exposed to Af antigens are comparable to allergic bronchopulmonary aspergillosis (ABPA) in humans and hence this model will be of value in understanding the disease mechanism in ABPA and related diseases.     

Rapid killing of actinomycin D-treated tumour cells by mononuclear phagocytes: reactivity in mouse strains with defective classical tumour cytotoxicity

In confirmation of previous data, macrophages from C3H/HeJ, C57BL/10ScCR and A/J mice, exposed in vivo to BCG or in vitro to lymphokines, had little tumoricidal activity, as assessed in a 48-hr [3H]thymidine release assay against TU5 tumour cells, compared to macrophages from C3H/HeN, C57BL/6 and (BALB/c X DBA/2)F1 mice. Macrophages from these mouse strains were examined for their capacity to kill actinomycin D-pretreated WEHI 164 sarcoma cells in a 6-hr 51chromium release assay (drug-dependent cellular cytotoxicity, DDCC). Peptone-elicited macrophages from C3H/HeN, C57BL/6, (BALB/c X DBA/2)F1, C57BL/10ScCR and A/J mice had high DDCC activity, whereas C3H/HeJ macrophages expressed little cytotoxicity against actinomycin D-pretreated WEHI 164 cells. In vivo exposure to BCG or inactivated streptococci caused a modest augmentation of the DDCC effector function of C3H/HeJ macrophages, but levels of reactivity remained 20-fold less than those of similarly treated normal mice. Thus, C57BL/10ScCR and A/J macrophages have defective classical direct cytotoxicity but mediate DDCC efficiently, whereas C3H/HeJ macrophages are defective in both effector functions.     

Acute restraint stress reduces protein kinase C gamma in the hippocampus of C57BL/6 but not DBA/2 mice

Protein kinase C gamma (PKC gamma) is highly expressed in the rodent hippocampus and has been implicated in long-term alterations in synaptic efficacy. Acute stress has been shown to negatively affect hippocampal synaptic plasticity, and the present study examined the effect of acute stress on PKC gamma expression/subcellular distribution by quantitative western blotting in two inbred mouse strains (C57BL/6J versus DBA/2J) with established differences in hippocampal plasticity. It was found that both DBA/2J and C57BL/6J strains exhibited similar basal, stress-induced elevations, and recovery of serum corticosterone levels. Acute stress produced a significant reduction in both membrane and cytosolic PKC gamma expression in the hippocampus of C57BL/6J mice compared to no-stress controls, but did not alter either membrane or cytosolic PKC gamma expression in the hippocampus of DBA/2J mice compared to no-stress controls. These data provide direct evidence that PKC gamma is differentially regulated in the hippocampus of C57BL/6J and DBA/2J mice by acute stress. The role of stress-induced regulation of hippocampal PKC gamma expression in hippocampal synaptic plasticity is discussed.     

Distinct granuloma responses in C57BL/6J and BALB/cByJ mice in response to pristane

Granuloma formation is an inflammatory response of the host against invading pathogens or indigestible substances. We generated mesenteric oil granulomas by injecting pristane into the peritoneal cavity (PC) of mice, and compared oil granuloma formation in the C57BL/6J and BALB/cByJ strains of mice. The formation and kinetics of oil granulomas were distinct between the two strains. In C57BL/6J mice, injected pristane induced oil granuloma formation at both the mesenteric centers (MG) and margins (SG). MG was resolving by 11 weeks, and SG persisted. In BALB/cByJ mice, MG developed slower but persisted longer than in C57BL/6J mice, and SG resolved sooner than in C57BL/6J mice. Injection of India ink revealed that phagocytes were localised mainly to the SG in C57BL/6J mice, but were located diffusely in both MG and SG of BALB/cByJ mice. SG cells expressed more monocyte chemotactic protein‐1 (MCP‐1) mRNA than MG cells in C57BL/6J mice, but there was no difference in MCP‐1 expression between the MG and SG in BALB/cByJ mice. These observations suggest that the recruitment of inflammatory leucocytes under the direction of chemokines differentiates the patterns of granuloma responses to pristane in C57BL/6J and BALB/cByJ mice.     

C57BL/6J mice exhibit reduced dopamine D3 receptor-mediated locomotor-inhibitory function relative to DBA/2J mice

Previous reports have identified greater sensitivity to the locomotor-stimulating, sensitizing, and reinforcing effects of amphetamine in inbred C57BL/6J mice relative to inbred DBA/2J mice. The dopamine D3 receptor (D3R) plays an inhibitory role in the regulation of rodent locomotor activity, and exerts inhibitory opposition to D1 receptor (D1R)-mediated signaling. Based on these observations, we investigated D3R expression and D3R-mediated locomotor-inhibitory function, as well as D1R binding and D1R-mediated locomotor-stimulating function, in C57BL/6J and DBA/2J mice. C57BL/6J mice exhibited lower D3R binding density (-32%) in the ventral striatum (nucleus accumbens/islands of Calleja), lower D3R mRNA expression (-26%) in the substantia nigra/ventral tegmentum, and greater D3R mRNA expression (+40%) in the hippocampus, relative to DBA/2J mice. There were no strain differences in DR3 mRNA expression in the ventral striatum or prefrontal cortex, nor were there differences in D1R binding in the ventral striatum. Behaviorally, C57BL/6J mice were less sensitive to the locomotor-inhibitory effect of the D3R agonist PD128907 (10 microg/kg), and more sensitive to the locomotor-stimulating effects of novelty, amphetamine (1 mg/kg), and the D1R-like agonist +/- -1-phenyl-2,3,4,5-tetrahydro-(1H)-3-benzazepine-7,8,-diol hydrochloride (SKF38393) (5-20 mg/kg) than DBA/2J mice. While the selective D3R antagonist N-(4-[4-{2,3-dichlorphenyl}-1 piperazinyl]butyl)-2-fluorenylcarboxamide (NGB 2904) (0.01-1.0 mg/kg) augmented novelty-, amphetamine-, and SKF38393-induced locomotor activity in DBA/2J mice, it reduced novelty-induced locomotor activity in C57BL/6J mice. Collectively, these results demonstrate that C57BL/6J mice exhibit less D3R-mediated inhibitory function relative to DBA/2J mice, and suggest that reduced D3R-mediated inhibitory function may contribute to heightened sensitivity to the locomotor-stimulating effects of amphetamine in the C57BL/6J mouse strain. Furthermore, these data demonstrate that comparisons between C57BL/6J and DBA/2J mouse strains provide a model for elucidating the molecular determinants of genetic influence on D3R function.     

Comparative phenotypic assessment of cardiac pathology, physiology, and gene expression in C3H/HeJ, C57BL/6J, and B6C3F1/J mice

Human cardiomyopathies often lead to heart failure, a major cause of morbidity and mortality in industrialized nations. Described here is a phenotypic characterization of cardiac function and genome-wide expression from C3H/HeJ, C57BL/6J, and B6C3F1/J male mice. Histopathologic analysis identified a low-grade background cardiomyopathy (murine progressive cardiomyopathy) in eight of nine male C3H/HeJ mice (age nine to ten weeks), but not in male C57BL/6J and in only of ten male B6C3F1/J mice. The C3H/HeJ mouse had an increased heart rate and a shorter RR interval compared to the B6C3F1/J and C57BL/6J mice. Cardiac genomic studies indicated the B6C3F1/J mice exhibited an intermediate gene expression phenotype relative to the 2 parental strains. Disease-centric enrichment analysis indicated a number of cardiomyopathy-associated genes were induced in B6C3F1/J and C3H/HeJ mice, including Myh7, My14, and Lmna and also indicated differential expression of genes associated with metabolic (e.g., Pdk2) and hypoxic stress (e.g. Hif1a). A novel coexpression and integrated pathway network analysis indicated Prkaa2, Pdk2, Rhoj, and Sgcb are likely to play a central role in the pathophysiology of murine progressive cardiomyopathy in C3H/HeJ mice. Our studies indicate that genetically determined baseline differences in cardiac phenotype have the potential to influence the results of cardiotoxicity studies.     

Dual Role of Interleukin-10 in Murine Lyme Disease: Regulation of Arthritis Severity and Host Defense

In the murine model of Lyme disease, C3H/He mice exhibit severe arthritis while C57BL/6N mice exhibit mild lesions when infected with Borrelia burgdorferi. Joint tissues from these two strains of mice harbor similar concentrations of B. burgdorferi, suggesting that the difference in disease severity reflects differences in the magnitude of the inflammatory response to B. burgdorferi lipoproteins. Stimulation of bone marrow macrophages from C3H/HeN mice with the B. burgdorferi lipoprotein OspA resulted in higher-level production of the inflammatory mediators tumor necrosis factor alpha, nitric oxide, and interleukin-6 (IL-6) than that of macrophages from C57BL/6N mice. In contrast, macrophages from C57BL/6N mice consistently produced larger amounts of the anti-inflammatory cytokine IL-10 than did C3H/HeN macrophages. Addition of recombinant IL-10 suppressed the production of inflammatory mediators by macrophages from both strains. IL-10 was found to modulate B. burgdorferi-induced inflammation in vivo, since C57BL/6J mice deficient in IL-10 (IL-10-/-) developed more severe arthritis than wild-type C57BL/6J mice. The increase in arthritis severity was associated with a 10-fold decrease in the number of B. burgdorferi organisms present in ankle tissues from IL-10-/- mice. These findings suggest that in C57BL/6 mice, IL-10-dependent regulation of arthritis severity occurs at the expense of effective control of bacterial numbers.     

Early local cytokine profiles in strains of mice with different outcomes from chlamydial genital tract infection

In this study, we expand on the examination of genetically determined differences in host responses that correlate with clearance of Chlamydia trachomatis from the genital tract. We infected C57BL/6, BALB/c, and C3H/HeN mice with the mouse pneumonitis agent of C. trachomatis (MoPn). C57BL/6 mice had the shortest course of infection (22 days) and the lowest incidence of severe hydrosalpinx. BALB/c mice also had a short course of infection (25 days), but all developed hydrosalpinx. C3H/HeN mice had the longest course of infection (38 days), and all developed severe hydrosalpinx. Determination of local cytokine responses by enzyme-linked immunosorbent assay (ELISA) of genital tract secretions revealed that the levels of the proinflammatory cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) were significantly increased in the C57BL/6 and BALB/c strains compared to those in the C3H/HeN strain whereas the level of IL-6 was not different. The level of the neutrophil chemokine macrophage inflammatory protein 2 (MIP-2) was increased during the first week of infection in all three strains but was significantly higher in the BALB/c strain, the strain with the most rapid influx of neutrophils into the genital tract. Prolonged detection of MIP-2 in C3H/HeN mice was associated with a protracted presence of neutrophils in the genital tract. Early increases in the levels of the proinflammatory cytokines TNF-alpha and IL-1beta are associated with earlier eradication of infection in the C57BL/6 and BALB/c strains than in the C3H/HeN strain. Increased levels of MIP-2 and neutrophils in BALB/c and C3H/HeN mice relative to C57BL/6 mice suggest that these responses may contribute to pathology.