Vaccination against transplacental cytomegalovirus transmission: vaccine reactivation and efficacy in guinea pigs

The guinea-pig model of cytomegalovirus (CMV) infection was used in continuing studies of experimental CMV vaccines for prevention of congenital CMV infection. Low-passage guinea-pig cytomegalovirus (GPCMV) vaccine, which has been shown to be effective in preventing transplacental CMV transmission, was tested for reactivation during pregnancy. In Hartley strain guinea pigs intraperitoneally given 10(5.5) 50% tissue culture infective doses (TCID50) of low-passage vaccine, 27 (41%) of 66 throat swabs obtained during subsequent pregnancies showed CMV, in contrast to 28 (24%) of 115 throat swabs obtained from nonpregnant control animals. High-passage GPCMV vaccine (approximately 5 X 10(3) TCID50) did not cause acute viremia, detectable generalized infection, or GPCMV reactivation during subsequent pregnancies. Immune pregnant animals and their fetuses were protected against generalized CMV infection when challenged with virulent GPCMV. In contrast, nonimmune pregnant controls developed generalized maternal, placental, and fetal infection. Experimental low-dose, high-passage GPCMV vaccine can protect against transplacental CMV transmission without apparent vaccine reactivation during pregnancy.     

Rifampin in the treatment of experimental brucellosis in mice and guinea pigs.

Rifampin, a broad-spectrum antibiotic able to penetrate intracellularly, was used for treatment of infections with Brucella melitensis in mice and Brucella abortus in guinea pigs. Treatments were administered for seven, 14, or 21 days; mice were given 25 mg of rifampin/kg per day, and guinea pigs 100 mg/kg per day. Efficacy of the drug was determined by comparison of rifampin-treated animals with saline-treated controls and with tetracycline-treated mice (200 mg/kg per day) according to the following criteria: (1) primary infections of the spleen and (in guinea pigs) of the lymph nodes; (2) residual infections of the spleen, i.e., infections shown after complementary treatment with suspensions of killed Corynebacterium parvum or with cortisone; (3) splenomegaly; and (4) serological response (in guinea pigs). Treatment with rifampin, even for one or two weeks, drastically reduced the number of infections by all of these criteris, and treatment for three weeks cured nearly all mice; the incidences of primary and residual infections in rifampin-treated mice after three weeks were 0 and 8.5%, respectively, as compared with 70.3% and 73.5%, respectively, in tetracycline-treated mice. Of 25 guinea pigs treated with rifampin for three weeks, spleen infection was shown in one, and lymph node infections in 10.     

Asia1型口蹄疫新型多表位疫苗免疫豚鼠的效力试验

目的 评价一种改进型Asia 1型口蹄疫多表位重组疫苗的免疫效能。方法 根据Asia 1型口蹄疫病毒的基因序列设计多表位基因,构建重组表达质粒(pRE-oIgG)。用大肠杆菌细胞分别表达靶标蛋白RE-oIgG和口蹄疫病毒3D蛋白,并用组氨酸亲和层析柱纯化。纯化的RE-oIgG,3D和RE-oIgG与3D的混合物分别经油性佐剂IAS206乳化后配制成相应的疫苗。25只雌性豚鼠被随机分成5组,每组5只豚鼠,经肌肉途径分别注射RE-oIgG、3D、RE-oIgG与3D的混合物、Asia 1口蹄疫灭活疫苗和PBS,所有动物进行两次免疫。采用ELISA、病毒微量中和试验、攻毒试验和流式细胞术分别测定免疫前后抗口蹄疫特异性抗体、中和抗体、保护率以及淋巴细胞增殖反应。结果 RE-oIgG与3D的混合物能够诱导高效价的抗Asia 1型口蹄疫病毒的特异性抗体,与RE-oIgG单独免疫豚鼠相比较具有明显的差异性(P<0.05)。除了阴性对照组PBS外,来自所有免疫动物的外周血淋巴细胞经过体外培养刺激后均产生了明显的淋巴细胞增殖反应。单独免疫3D蛋白和安慰剂PBS实验组既没有测到抗口蹄疫病毒特异性抗体,也没有测到中和抗体。而RE-oIgG与3D的混合物不仅诱导机体产生了高水平的保护性中和抗体,而且诱发了明显的淋巴细胞增殖反应。更为重要的是,该蛋白质混合物针对1 000 GPID₅₀强毒攻击后,所有动物没有出现症状完全保护。值得一提的是,单独免疫3D蛋白的5只豚鼠中,其中2只完全保护;另外3只虽然出现了临床症状,但相对PBS对照组来说发病时间大约推迟2～3 d。因此,笔者认为RE-oIgG与3D的混合物不仅能够诱导体液免疫反应,而且能够诱发细胞免疫反应,是一种高效能的新型疫苗,将来可用于我国口蹄疫的防控。     

Macrophage depletion test in guinea pigs]

In the present investigations heterologous lymphokine-containing fluids were examined in albino guinea pigs for their macrophage depletion activity. Cell-free ascites from Ehrlich ascites tumor and leukemia L 1210 of mice as well as supernatants of PHA-stimulated peripheral blood lymphocyte cultures were used. Ascites of Ehrlich's ascitic tumor and Leukemia L 1210 led to a significant depletion of macrophages. The application of supernatants of PHA-stimulated human lymphocyte cultures resulted in a dose-dependent reduction of peritoneal macrophages. On the other hand, a stimulation of the number of peritoneal macrophages by control supernatants of non-stimulated lymphocyte cultures was observed. The findings indicate the existence of two lymphokines having opposite effects.     

Protection against congenital cytomegalovirus infection and disease in guinea pigs, conferred by a purified recombinant glycoprotein B vaccine

Glycoprotein B (gB) has emerged as a subunit-vaccine candidate for congenital cytomegalovirus (CMV) infection, a major public health problem. The present study evaluated a cloned, recombinant gB vaccine in the guinea pig cytomegalovirus (GPCMV) model of congenital infection. Guinea pigs were immunized with gB, which was coadministered with either Freund's adjuvant or alum. All gB-immunized dams had enzyme-linked immunosorbent-assay and neutralizing-antibody responses, with significantly higher titers in the gB/Freund's group. Pregnant dams were challenged with GPCMV subcutaneously during the 3rd trimester. Maternal DNAemia on day 10 after infection trended lower in gB-immunized dams than in control animals, with significant reductions in the gB/Freund's group. Vaccination resulted in a highly significant reduction in pup mortality. For the gB-vaccine groups, pup mortality was significantly lower, and reduced rates of GPCMV transmission were noted, for dams immunized with gB and Freund's adjuvant, compared with dams immunized with gB and alum. These are the first data indicating that a recombinant gB vaccine protects against congenital CMV infection and disease.     

细胞间粘附分子1mRNA在哮喘豚鼠支气管组织中的原位表达

为了解哮喘豚鼠支气管组织中的细胞间粘附分子１（ＩＣＡＭ－１）ｍＲＮＡ表达情况，将实验豚鼠随机分为正常对照组、氟美松组和哮喘组，采用原位杂交方法显示ＩＣＡＭ－１ｍＲＮＡ的表达变化，用ＨＥ染色方法来测定炎细胞在支气管粘膜中的浸润程度。原位杂交结果显示，ＩＣＡＭ－１ｍＲＮＡ主要在支气管粘膜下的小血管、毛细血管内皮细胞以及支气管上皮细胞的胞浆内表达。定量分析结果表明，哮喘组豚鼠支气管组织表达ＩＣＡＭ－１ｍＲＮＡ较正常对照组及氟美松组显著增加（Ｐ＜０．０２，Ｐ＜０．０５），哮喘豚鼠支气管组织ＩＣＡＭ－１ｍＲＮＡ的表达量与炎细胞总数之间显著相关（Ｐ＜０．０５）。提示支气管粘膜组织ＩＣＡＭ－１ｍＲＮＡ表达与哮喘支气管粘膜嗜酸细胞为主的炎细胞浸润有关，糖皮质激素能够抑制细胞粘附分子的表达。     

Development of embryos in superovulated guinea pigs following active immunization against the inhibin alpha-subunit

Embryo recovery and subsequent embryonic development from guinea pigs treated with or without inhibin vaccines were compared to determine the effect of active immunization against the inhibin alpha-subunit. Twenty female guinea pigs of the Hartley strain were injected 3 times either with 1 ml inhibin vaccine (recombinant ovine inhibin a-subunit in oil emulsion: 50 microg/ml, inhibin-immunized group), or 1 ml placebo (saline in oil emulsion; control group) at 4 week intervals. After one estrous cycle following the last injection, females were naturally mated and embryos were collected at 11:00 hr of day 6 of pregnancy (Day 1: sperm in the vaginal smear) for culture in vitro. Active immunization increased the number of corpora lutea (12.6+/-3.0 vs. 4.6+/-0.2, P<0.05), recovered embryos (9.8+/-1.9 vs. 3.6+/-0.4, P<0.01) and normal embryos (7.8+/-1.4 vs. 3.6+/-0.4, P<0.05), although estrous cycle length was not affected (P>0.05). During subsequent 8 day culture in vitro, most of the recovered embryos formed trophoblast outgrowth; 100% (14/14) and 88.2% (15/17) in control and immunized groups, respectively. High levels of inhibin antibody titers were sustained in the inhibin-immunized guinea pigs at least for 5 months after the last injection while no antibody titer was detected in the control animals. These results indicate that active immunization against the inhibin a-subunit is a long-acting and efficient method to induce superovulation with normal embryonic development in the guinea pig.     

A new candidate vaccine for human brucellosis based on influenza viral vectors: a preliminary investigation for the development of an immunization schedule in a guinea pig model

Background::A new candidate vector vaccine against human brucellosis based on recombinant influenza viral vectors (rIVV) subtypes H5N1 expressing Brucell...     

Bronchial hyperresponsiveness to acetylcholine during acute pulmonary congestion in guinea pigs]

To understand the precise mechanism of bronchial hyperresponsiveness in patients with congestive heart failure, we studied the effect of mild pulmonary congestion on bronchial responsiveness to inhaled acetylcholine (ACh) in guinea pigs. We induced mild pulmonary congestion by inflation of a balloon placed in the left atrium, and maintained the left atrial pressure (Pla) at 10 mmHg for 30 minutes with continuous monitoring of lung resistance (RL) and dynamic compliance (Cdyn). Furthermore, we determined the provocative concentration of ACh producing 100% increase in RL (PC100-ACh), before and during balloon inflation. In animals with propranolol pretreatment, but not in animals without propranolol pretreatment, mild pulmonary congestion caused slight increase in RL (N.S.) and significant decrease in Cdyn (p less than 0.01) and PC 100-ACh (p less than 0.01). Cutting of bilateral vagal nerves partially inhibited the decrease of PC100-ACh, but pretreatment with either phenoxybenzamine, indomethacin, AA-861 or OKY-046 had not effect. These results suggest that blockade of beta-adrenergic receptors and the vagal reflex, but not of alpha-adrenergic receptors or arachidonates, contributes to bronchial hyperresponsiveness during acute pulmonary congestion.