沙眼衣原体感染后大鼠输卵管糖蛋白的变化

目的：研究沙眼衣原体（chlamydial trachomatis,CT）感染后,输卵管粘膜的结构及糖蛋白的变化。方法：60只成年Wistar雌性大鼠随机分为实验组和对照组,实验组单侧卵巢囊接种沙眼衣原体E型株,对照组接种2SP代替沙眼衣原体,分别于接种后第0.5、7、14天取材,在光镜下观察输卵管的结构变化,并采用PAS-Alcian blue染色显示输卵管内糖蛋白组分的变化。结果：对照组输卵管粘膜结构和糖蛋白组分无明显变化;实验组输卵管受损部位主要局限于粘膜层,PAS-Alcian blue染色显示沙眼衣原体感染可导致中性糖蛋白分泌减少。结论：沙眼衣原体的感染可使输卵管糖蛋白组分发生改变,这可能与反复感染的宫外孕、输卵管性不孕的发生有关。     

沙眼衣原体感染诱导小鼠生殖道局部促炎性细胞因子的表达情况

建立小鼠生殖道沙眼衣原体感染模型,观察小鼠生殖道局部促炎性细胞因子的表达。将小鼠生物型沙眼衣原体C. muridarum 1＆#215;104 IFU阴道接种于C57B6背景雌性小鼠,取感染后阴道拭子做沙眼衣原体培养,计算IFU,监测小鼠感染和病原体清除情况;80 d后处死小鼠,检测子宫输卵管病理改变;ELISA检测感染过程中小鼠生殖道促炎性细胞因子IL-1α、IL-6、MIP-2和TNF-α产生情况。小鼠感染在第3至第15天维持较高水平,然后病原体被逐渐清除,整个病程约3~5周;病理检测显示子宫输卵有严重炎症、管腔扩张积水,狭窄等;于感染后第3天检测到局部IL-1α、IL-6、MIP-2分泌,第7天达高峰,然后逐渐下降至正常水平（ IL-6于11 d恢复正常,IL-1α和 MIP-2于15 d恢复正常）。 TNF-α仅在第7天检测到高水平表达。相对于TNF-α和IL-6,IL-1α和MIP-2维持时间较长。成功建立沙眼衣原体感染小鼠生殖道模型,沙眼衣原体急性感染可诱导小鼠生殖道局部分泌IL-1α、IL-6、MIP-2和TNF-α。     

小鼠沙眼衣原体肺感染过程中Treg细胞与Th17反应关系

[目的]对沙眼衣原体在BALB/c小鼠肺部感染过程中CD4+ CD25+Foxp3+调节性T细胞(regulatory T cells,Treg)与Th17反应关系进行初步探讨.[方法]取6-8周龄的BALB/c小鼠,鼻腔吸入25 μL含5×103 IFU的沙眼衣原体鼠肺炎菌株(Chlamydia muridarum,Cm),建立沙眼衣原体小鼠肺感染模型.监测感染后不同时期小鼠体重变化;检测肺组织衣原体包涵体形成单位( IFU)及肺组织病理改变;利用流式细胞术检测Cm感染后小鼠体内Treg细胞百分率;ELISA检测肺组织上清液IL-6、TGF-β、IL-17、IL-2细胞因子的的表达;qRT-PCR检测KC( keratinocyte derived chemokine) mRNA和MIP-2( macrophage inflammatory protein-2)mRNA的表达差异.[结果]用5xl03 IFU Cm经鼻腔吸人感染后小鼠发生沙眼衣原体肺炎,表现为体重下降、肺组织大量炎症细胞浸润并可检测到衣原体繁殖.Cm感染后第3天,小鼠体内Treg细胞占CD4 +T细胞的百分比明显降,随后开始恢复,第7天恢复原来水平,一直持续到衣原体清除.TGF-β、IL-2的表达与Treg细胞动态变化一致.与Th17相关细胞因子IL-6、IL-17和Th17相关趋化因子KC、MIP-2的表达于第3天开始升高,至第7天达到最高水平,随后逐渐减少.[结论]在衣原体感染BALB/c小鼠过程中,Treg可能通过提供TGF-β并在IL-6帮助下促进Th17应答产生.     

大鼠输卵管沙眼衣原体感染后体内树突状细胞的变化

目的观察大鼠输卵管沙眼衣原体(CT)感染后体内树突状细胞(DC)的变化.方法选择成年雌性Wistar大鼠,从卵巢囊接种沙眼衣原体E型株.于感染后第1/2d、7d、14d、21d、28d和第35d处死动物取材,显示输卵管和脾内DC的变化.结果 1. 实验1/2d组输卵管未出现S-100 DC,在实验第7d、14d、21d、28d和第35d组输卵管均有S-100 DC出现;2.感染后脾淋巴小结数量增多,体积较大,淋巴小结内S-100 DC密集,动脉周围淋巴鞘内S-100 DC增多.结论输卵管CT感染后,输卵管和脾内S-100 DC增加,提示在体内DC对CT具有抗原提呈和启动机体免疫应答的作用,DC具有作为CT治疗性疫苗基础构建的潜力.     

沙眼衣原体感染后大鼠输卵管与植物凝集素BS-1结合的糖蛋白的变化

目的研究沙眼衣原体感染后输卵管与植物凝集素BS-1结合的糖蛋白的变化.方法取25只成熟Wistar雌性大鼠随机分为实验组和对照组,每组5只.对照组接种2SP代替沙眼衣原体,其余每组大鼠均在卵巢囊接种沙眼衣原体D型株.分别于感染后3,5,7,14d处死动物,取输卵管,观察大鼠输卵管与植物凝集素BS-1结合的糖蛋白在感染后不同天数发生的改变,其变化可通过荧光显微镜观察与植物凝集素BS-1结合后的荧光强度来检测,并采用HPIAS-1000图文分析系统进行定量分析和SPSS11.0统计软件作统计分析.结果输卵管受损部位主要在粘膜层,富含N-乙酰-D-半乳糖胺的糖蛋白随感染的天数不同,其变化有所不同,尤其以输卵管峡部变化明显.图像分析结果显示:感染第7d时其分泌量最低,感染后第14d其分泌量逐渐恢复,且各组间差异有显著性意义(P<0.05).结论输卵管是精子与卵子结合的地方,也是胚胎早期发育的场所.富含N-乙酰-D-半乳糖胺的糖蛋白可通过参与精卵结合、受精卵卵裂和早期胚胎发育等方式,对受精卵及早期胚胎发挥保护作用.     

大鼠输卵管感染沙眼衣原体后IL-18mRNA的表达及介质效应

目的通过大鼠沙眼衣原体(chlamydial trachomatis,CT)感染模型来研究白介素-18(IL-18)在初次感染后不同阶段的表达及其与干扰素-γ(IFN-γ)之间的介质效应.方法选择成年雌性SD大鼠24只,通过手术从一侧卵巢囊接种沙眼衣原体D型株,分别于感染后3d、7d、14d将大鼠处死,取手术侧输卵管以RT-PCR检测感染前后不同时间输卵管局部IL-18 mRNA及IFN-γ mRNA的表达量;用酶联免疫吸附(ELISA)法测定输卵管组织IFN-γ蛋白含量.结果在接种24h后即可检测到IFN-γ mRNA和IL-18 mRNA的表达,并持续升高.在感染后的3 d至7 d内,两种细胞因子的mRNA表达量一直处于高水平状态,大约两周后它们的mRNA表达已明显下降.感染组织内IFN-γ水平与基因表达趋势基本一致.相关分析表明,输卵管组织IL-18 mRNA表达与IFN-γ mRNA、IFN-γ水平均呈显著正相关.结论输卵管组织IL-18 mRNA表达在初次感染后早期即显著增多,并呈逐渐升高的趋势;感染后IL-18 mRNA基因表达对IFN-γ的生成具有重要影响.     

调节性T 细胞在发热结缔组织病患者外周血中的表达及临床意义

目的:研究Treg细胞在发热CTD患者外周血表达对结核感染的诊断价值。方法:对103例发热CTD患者进行T-SPOT.TB试验,将39例阳性者设为实验组-1,进行抗结核治疗,将64例阳性者设为实验组-2,另选取40例健康者作为对照组,检测三组外周血CD4+CD25+Treg细胞、Foxp3基因、IL-10、TGF-β的表达。结果:实验组CD4+CD25+Foxp3 Treg细胞占CD4+T比例高于对照组(P0.05),实验组-1治疗前外周血CD4+CD25+Foxp3 Treg细胞占CD4+T比例高于实验组-1治疗后、实验组-2(P0.05);实验组TGF-β表达量低于对照组(P0.05),实验组-1治疗前低于实验组-1治疗后及实验组-2(P0.05);实验组-1治疗前IL-10表达量低于实验组-1治疗后、实验组-2及对照组(P0.05)。结论:CD4+CD25+Foxp3 Treg细胞在发热CTD伴有结核感染患者外周血中的表达升高,其变化可作为结核感染诊断的辅助性指标。     

沙眼衣原体感染对大鼠早期妊娠的影响

目的检测沙眼衣原体(CT)感染后妊娠大鼠子宫内膜热休克蛋白70(HSP70)和整合素α4β1的表达,探讨CT感染对妊娠的影响.方法取正常未孕大鼠、阴道接种CT后妊娠大鼠和正常妊娠大鼠孕4～8d子宫作切片,采用免疫组织化学方法,研究CT感染对早期妊娠子宫HSP70和整合素α4β1表达的影响.结果 HSP70在未孕及妊娠大鼠子宫均有表达,其主要存在于子宫内膜固有层的基质细胞及蜕膜细胞,整合素α4β1存在于内膜上皮、腺上皮和基质细胞.CT感染后(实验组)妊娠大鼠子宫内膜HSP70的阳性表达在孕4～6d较正常妊娠组(对照组)及未孕组明显增强,差异有显著性(P< 0.01);在孕7～8d与对照组相比无明显差异,但强于未孕组.而整合素α4β1的阳性表达在孕4～6d弱于对照组(孕第5d尤为明显),强于未孕组,差异有显著性(P< 0.01).结论 (1)大鼠生殖道感染CT引起胚泡着床期(4～6d)HSP70的高表达,且主要存在于子宫内膜固有层的基质细胞及蜕膜细胞,内膜上皮、腺上皮中未见表达,推测CT生殖道感染可能影响母体子宫内膜蜕膜细胞的增殖,干扰妊娠,引起不孕或流产.(2)生殖道感染CT引起胚泡着床期整合素α4β1的低表达,并与HSP70表达的变化趋势相反,推测CT生殖道感染可影响孕早期胚泡植入,其不良妊娠结果可能通过HSP70与整合素α4β1的共同作用导致.     

rhG-CSF 动员对供者CD4+ T 细胞免疫表型和功能影响

目的:研究重组人粒细胞集落刺激因子(rhG-CSF)动员对供者CD4+T细胞表面分子淋巴细胞功能相关抗原-1(LFA-1)、细胞间黏附分子-1(ICAM-1)、L-选择素(LAM-1)和人整合素-4(VLA-4)的表达及其介导的CD4+T细胞功能的影响,探讨外周血干细胞移植过程中CD4+T细胞免疫耐受机制。方法:使用三色荧光标记检测动员前及动员后第5天供者外周血LFA-1、ICAM-1、LAM-1和VLA-4的表达率,ELISA方法检测动员前后CD4+T细胞分泌IFN-γ和IL-4能力,免疫磁性分选法分离纯化CD4+T细胞,检测动员前后CD4+T细胞对基质细胞衍生因子-1α(SDF-1α)的迁移能力和对ICAM-1的黏附能力。结果:动员前后CD4+T细胞LFA-1(CD11a)和VLA-4(CD49d)表达率差异无统计学意义(P>0.01),动员前后CD4+T细胞LAM-1(CD62L)和ICAM-1(CD54)的表达率差异均有统计学意义,动员前显著高于动员后(P<0.01);动员前后CD4+T淋巴细胞向SDF-1α的迁移率差异无统计学意义(P>0.01);动员后CD4+T细胞对ICAM-1的黏附率降低(P<0.01);动员后IL-4和IFN-γ两个细胞因子在外周血血清的浓度均降低(P<0.01)。结论:rhG-CSF动员不影响CD4+T细胞LFA-1和VLA-4表达及CD4+T细胞迁移,但影响CD4+T细胞ICAM-1和LAM-1表达以及CD4+T细胞通过LFA-1对ICAM-1的黏附能力影响,并可能影响CD4+T细胞分泌细胞因子IL-4及IFN-γ的功能。     

沙眼衣原体感染对大鼠着床期间子宫内膜E-cadherin的影响

目的 研究沙眼衣原体（Chlamydia trachomatis,CT）感染后大鼠着床期间子宫内膜上皮钙粘蛋白（E-cad-herin,E-cad）的变化。方法 大鼠雌雄合笼建立早孕模型,取正常和CT感染后妊娠4-7d的子宫组织,免疫组化SP法检测E-cad的表达。结果 正常和感染后妊娠组E-cad的表达均存在先上升后下降的趋势,表达峰值均在妊娠第6d,CT感染组低于正常组,且存在显著性差异（P〈0.05）;其表达部位在子宫内膜上皮细胞的胞膜或/和胞浆,蜕膜细胞无或少量表达。结论 沙眼衣原体感染后可能通过影响子宫内膜黏附分子E-cad的表达,破坏子宫内膜微环境,进而干扰早期妊娠。     

Proinflammatory and Th2-derived cytokines modulate CD40-mediated expression of inflammatory mediators in airway epithelia: implications for the role of epithelial CD40 in airway inflammation

Cytokines produced by activated macrophages and Th2 cells within the lung play a key role in asthma-associated airway inflammation. Additionally, recent studies suggest that the molecule CD40 modulates lung immune responses. Because airway epithelial cells can act as immune effector cells through the expression of inflammatory mediators, the epithelium is now considered important in the generation of asthma-associated inflammation. Therefore, the goal of the present study was to examine the effects of proinflammatory and Th2-derived cytokines on the function of CD40 in airway epithelia. The results show that airway epithelial cells express CD40 and that engagement of epithelial CD40 induces a significant increase in expression of the chemokines RANTES, monocyte chemoattractant protein (MCP-1), and IL-8 and the adhesion molecule ICAM-1. Cross-linking epithelial CD40 had no effect on expression of the adhesion molecule VCAM-1. The proinflammatory cytokines TNF-alpha and IL-1beta and the Th2-derived cytokines IL-4 and IL-13 modulated the positive effects of CD40 engagement on inflammatory mediator expression in airway epithelial cells. Importantly, CD40 ligation enhanced the sensitivity of airway epithelial cells to the effects of TNF-alpha and/or IL-1beta on expression of RANTES, MCP-1, IL-8, and VCAM-1. In contrast, neither IL-4 nor IL-13 modified the effects of CD40 engagement on the expression of RANTES, MCP-1, IL-8, or VCAM-1; however, both IL-4 and IL-13 attenuated the effects of CD40 cross-linking on ICAM-1 expression. Together, these findings suggest that interactions between CD40-responsive airway epithelial cells and CD40 ligand+ leukocytes, such as activated T cells, eosinophils, and mast cells, modulate asthma-associated airway inflammation.     

Foxp3-expressing T regulatory cells and mast cells in acute graft-versus-host disease of the skin

Acute graft-versus-host disease (aGVHD) limits the effectiveness of allogeneic hematopoietic stem cell transplantation. Foxp3 is required for the development and function of CD4+/CD25+ regulatory T cells (T-regs). Foxp3-expressing T-regs are thought to protect against GVHD. Mast cells are thought to be essential in CD4+/CD25+ regulatory T cell-dependent peripheral tolerance. Twenty biopsies of skin with grades I-III aGVHD were stained for Foxp3 and CD117. Inflammation was quantified by a 4 point scale, 0=no inflammation, 1=50%. T-regs and mast cells were quantified by a 4 point scale, 0=no cells per 20x field, 1=10 cells. T-regs were positively correlated with both inflammation and aGVHD grade. Twelve cases with low T-regs had mild inflammation and lower grades of aGVHD and 6 cases with high T-regs had dense inflammatory infiltrate and higher grades of aGVHD. The number of T-regs, mast cells and density of the inflammatory infiltrate were positively correlated only in cases with mild inflammation. In aGVHD of the skin, T-regs increased with the degree of inflammation and GVHD grade. Mast cells were present at the same density whether aGVHD was of lower or higher grade.     

Antigen-specific CD4+ T cells produce sufficient IFN-gamma to mediate robust protective immunity against genital Chlamydia muridarum infection

Chlamydia has been shown to evade host-specific IFN-gamma-mediated bacterial killing; however, IFN-gamma-deficient mice exhibit suboptimal late phase vaginal Chlamydia muridarum clearance, greater dissemination, and oviduct pathology. These findings introduce constraints in understanding results from murine chlamydial vaccination studies in context of potential implications to humans. In this study, we used mice deficient in either IFN-gamma or the IFN-gamma receptor for intranasal vaccination with a defined secreted chlamydial Ag, chlamydial protease-like activity factor (CPAF), plus CpG and examined the role of IFN-gamma derived from adoptively transferred Ag-specific CD4+ T cells in protective immunity against genital C. muridarum infection. We found that early Ag-specific IFN-gamma induction and CD4+ T cell infiltration correlates with the onset of genital chlamydial clearance. Adoptively transferred IFN-gamma competent CPAF-specific CD4+ T cells failed to enhance the resolution of genital chlamydial infection within recipient IFN-gamma receptor-deficient mice. Conversely, IFN-gamma production from adoptively transferred CPAF-specific CD4+ T cells was sufficient in IFN-gamma-deficient mice to induce early resolution of infection and reduction of subsequent pathology. These results provide the first direct evidence that enhanced anti-C. muridarum protective immunity induced by Ag-specific CD4+ T cells is dependent upon IFN-gamma signaling and that such cells produce sufficient IFN-gamma to mediate the protective effects. Additionally, MHC class II pathway was sufficient for induction of robust protective anti-C. muridarum immunity. Thus, targeting soluble candidate Ags via MHC class II to CD4+ T cells may be a viable vaccine strategy to induce optimal IFN-gamma production for effective protective immunity against human genital chlamydial infection.     

The protective efficacy of chlamydial protease-like activity factor vaccination is dependent upon CD4+ T cells

We have previously determined the protective efficacy of intranasal vaccination with chlamydial protease-like activity factor (CPAF) against genital chlamydial infection. Since T-helper 1 (Th1) responses are important for anti-chlamydial immunity, we examined the contribution of CD4(+) T cells in CPAF mediated immunity against intravaginal (i.vag.) Chlamydia muridarum infection in C57BL/6 mice. CPAF+IL-12 vaccination induced antigen-specific CD4(+) T cells that secreted elevated levels of IFN-gamma, and generated strong humoral responses. The protective effects of CPAF vaccination against genital chlamydial challenge were abrogated by anti-CD4 neutralizing antibody treatment. Moreover, anti-chlamydial immunity could be adoptively transferred to na?ve recipients using CPAF-specific CD4(+) T cells. Therefore, CPAF mediated anti-chlamydial immunity is highly dependent upon antigen-specific CD4(+) T cells.     

Aspergillus fumigatus generates an enhanced Th2-biased immune response in mice with defective cystic fibrosis transmembrane conductance regulator

Cystic fibrosis (CF) lung disease is characterized by persistent airway inflammation and airway infection that ultimately leads to respiratory failure. Aspergillus sp. are present in the airways of 20-40% of CF patients and are of unclear clinical significance. In this study, we demonstrate that CF transmembrane conductance regulator (CFTR)-deficient (CFTR knockout, Cftr(tm1Unc-)TgN(fatty acid-binding protein)CFTR) and mutant (DeltaF508) mice develop profound lung inflammation in response to Aspergillus fumigatus hyphal Ag exposure. CFTR-deficient mice also develop an enhanced Th2 inflammatory response to A. fumigatus, characterized by elevated IL-4 in the lung and IgE and IgG1 in serum. In contrast, CFTR deficiency does not promote a Th1 immune response. Furthermore, we demonstrate that CD4+ T cells from naive CFTR-deficient mice produce higher levels of IL-4 in response to TCR ligation than wild-type CD4+ T cells. The Th2 bias of CD4+ T cells in the absence of functional CFTR correlates with elevated nuclear levels of NFAT. Thus, CFTR is important to maintain the Th1/Th2 balance in CD4+ T cells.     

Chlamydia muridarum infection subverts dendritic cell function to promote Th2 immunity and airways hyperreactivity

There is strong epidemiological evidence that Chlamydia infection can lead to exacerbation of asthma. However, the mechanism(s) whereby chlamydial infection, which normally elicits a strong Th type 1 (Th1) immune response, can exacerbate asthma, a disease characterized by dominant Th type 2 (Th2) immune responses, remains unclear. In the present study, we show that Chlamydia muridarum infection of murine bone marrow-derived dendritic cells (BMDC) modulates the phenotype, cytokine secretion profile, and Ag-presenting capability of these BMDC. Chlamydia-infected BMDC express lower levels of CD80 and increased CD86 compared with noninfected BMDC. When infected with Chlamydia, BMDC secrete increased TNF-alpha, IL-6, IL-10, IL-12, and IL-13. OVA peptide-pulsed infected BMDC induced significant proliferation of transgenic CD4(+) DO11.10 (D10) T cells, strongly inhibited IFN-gamma secretion by D10 cells, and promoted a Th2 phenotype. Intratracheal transfer of infected, but not control noninfected, OVA peptide-pulsed BMDC to naive BALB/c mice, which had been i.v. infused with naive D10 T cells, resulted in increased levels of IL-10 and IL-13 in bronchoalveolar lavage fluid. Recipients of these infected BMDC showed significant increases in airways resistance and decreased airways compliance compared with mice that had received noninfected BMDC, indicative of the development of airways hyperreactivity. Collectively, these data suggest that Chlamydia infection of DCs allows the pathogen to deviate the induced immune response from a protective Th1 to a nonprotective Th2 response that could permit ongoing chronic infection. In the setting of allergic airways inflammation, this infection may then contribute to exacerbation of the asthmatic phenotype.     

Demonstration of the origin of human mast cells from CD34+ bone marrow progenitor cells.

It has been established that murine mast cells are derived from a pluripotent bone marrow stem cell. In humans, the corresponding pluripotent cell is included in the CD34+ bone marrow population. To determine whether human mast cells arise from CD34+ human progenitor cells, enriched CD34+ cells were cultured over agarose surfaces (interphase cultures) or cocultured with mouse 3T3 fibroblasts in the presence of recombinant human (rh) IL-3. The presence of both mast cells and basophils was determined using a variety of histochemical and immunohistologic techniques, including immunogold labeling for IgE receptors and mast cell tryptase. Mast cells and basophils continued to appear in cultures when T cell, B cell, macrophage, and eosinophil committed progenitor cells were removed, but were not seen in cultures from which CD34+ cells were removed. CD34+ cells layered over agarose in the presence of rhIL-3 were shown to give rise to cultures that contained mast cells (1 to 5%) and basophils (25 to 40%). Cultures supplemented with rhIL-4 showed no additional increase in mast cells or basophils. CD34+ cells cocultured with 3T3 fibroblasts in the presence of rhIL-3 gave rise to mast cells within the fibroblast monolayer, which by 6 wk comprised up to 46% of the monolayer. CD34-cells on 3T3 fibroblasts gave rise to few mast cells (2% of the monolayer). Mast cell granules from interphase cultures contained homogeneous electron-dense material. In contrast, mast cells within 3T3 monolayers at 6 wk contained a variety of granule morphologies, including scroll, mixed, reticular, dense core, or homogeneous patterns. We conclude that both human mast cells and basophils arise from CD34+ human progenitor cells.     

Regulatory T cells dampen pulmonary inflammation and lung injury in an animal model of pneumocystis pneumonia

CD4+CD25+FoxP3+ regulatory T cells are decreased in patients infected with HIV and have been shown to be critical in mediating Ag tolerance in the lung. Because a subset of Pneumocystis-infected individuals develop substantial lung injury, which can be modeled in immune reconstituted scid mice, we used mouse models of Pneumocystis carinii to investigate the role of regulatory T cells in opportunistic infection and immune reconstitution. In this study, we show that CD4+CD25+FoxP3+ cells are part of the host response to Pneumocystis in CD4+ T cell-intact mice. Moreover, lung injury and proinflammatory Th1 and Th2 cytokine levels in the bronchoalveolar lavage fluid and lung homogenate were increased following CD4+CD25- immune reconstitution in Pneumocystis-infected SCID mice but not in CD4+CD25+ T cell-reconstituted animals. The ability of CD4+CD25+ T cells to control inflammation and injury during the course of Pneumocystis was confirmed by treatment of wild-type C57BL/6 mice with anti-CD25 mAb. These data show that CD4+CD25+ T cells control pulmonary inflammation and lung injury associated with Pneumocystis infection both in the setting of immune reconstitution as well as new acquisition of infection.     

Differential Th1 and Th2 cell responses in male and female BALB/c mice infected with coxsackievirus group B type 3.

Male and female BALB/c mice differ dramatically in susceptibility to myocarditis subsequent to coxsackievirus B3 (CVB3) infection. CVB3 infection of male mice results in substantial inflammatory cell infiltration of the myocardium, and virus-immune lymphocytes from these animals give predominantly a Th1 cell phenotypic response, as determined by predominant immunoglobulin G2a isotypic antibody production and elevated numbers of gamma interferon and interleukin-2 (IL-2)-producing CD4+ T lymphocytes. Females infected with the same virus give predominantly a Th2 cell phenotypic response, as determined by preferential immunoglobulin G1 antibody isotypic responses and increased precursor frequencies of IL-4- and IL-5-producing CD4+ T cells. Treatment of females with testosterone or males with estradiol prior to infection alters subsequent Th subset differentiation, suggesting that the sex-associated hormones have either a direct or indirect effect on CD4+ lymphocyte responses in this model. Treatment of females with 0.1 mg of monoclonal antibody to IL-4 reduces precursor frequencies of IL-4-producing CD4+ T cells and increases frequencies of gamma interferon-producing cells. This treatment also enhances myocardial inflammation, indicating a correlation between Th1-like cell responses and pathogenicity in CVB3 infection. The Th2-like cell may regulate Th1 cell activation. Adoptive transfer of T lymphocytes from CVB3-infected female mice into male animals suppresses the development of myocarditis in the recipients. Treatment of the female donors with monoclonal antibodies to either CD3, CD4, or IL-4 molecules abrogates suppression.