被动免疫预防犊牛轮状病毒感染的研究

目的 轮状病毒灭活疫苗免疫孕牛后，研究产下犊牛通过母源抗体获得的被动免疫在预防牛轮状病毒感染中的作用。方法 孕牛产前2月和1月分别接种轮状病毒灭活疫苗，检测产牛后乳汁和犊牛血样中BRV特异性IgG、IgA及中和抗体滴度。犊牛21日龄时口服2mL10^4,59 TCID50／ml的牛轮状病毒，观察犊牛腹泻及排毒情况。结果 免疫组乳清和犊牛血清中产生了高水平的牛轮状病毒特异性IgG、IgA及中和抗体，与对照组差异极显著（P〈0．01）；攻毒后，对照组6头犊牛全部发生腹泻，免疫组6头中有1头腹泻，发病的潜伏期及发病率差异显著。结论 被动免疫可显著提高犊牛血清中牛轮状病毒特异性抗体水平，使犊牛获得一定的免疫保护力抵抗轮状病毒的感染。     

Passive protection against fasciolosis in mice by immunization with a monoclonal antibody (ES-78 MoAb)

Recently, we reported a partial characterization of the epitope recognized by the ES-78 monoclonal antibody (MoAb). This monoclonal antibody was obtained from spleen lymphocytes of a mouse immunized with excretory-secretory antigens of Fasciola hepatica adult worms. In the present study, we report the results obtained in experiments of passive protection using this MoAb in BALB/c mice infected with 15 Fasciola hepatica metacercariae. The monoclonal antibody was able to reduce the parasite burden when administered 24 h before challenge but not when delivered 7 days after challenge. The antibody recognition of digestive tract structures in 3-week-old parasites was demonstrated by immune histochemical techniques. The antigens purified by affinity chromatography using this antibody had molecular weights of 14-20, 25-29 and 36-45 kDa and demonstrated proteinase activity similar to cathepsin L. These results suggest that the antigens carrying the epitope recognized by the ES-78 MoAb may be used as target in the protection against fasciolosis.     

Mucosal immunization with inactivated human immunodeficiency virus plus CpG oligodeoxynucleotides induces genital immune responses and protection against intravaginal challenge

Vaccines capable of protecting against sexually transmitted infections, such as human immunodeficiency virus (HIV), will depend on the induction of potent long-lasting mucosal immune responses in the genital tract. We evaluated vaginal and systemic immune responses and protection from vaginal challenge elicited after intranasal immunization of mice with inactivated glycoprotien 120-depleted HIV-1 immunogen alone or in combination with immunostimulatory CpG oligodeoxynucleotides (ODNs). Mice immunized with HIV-1 immunogen plus CpG ODN had significantly enhanced levels of anti-protein 24 immunoglobulin (Ig) G and IgA antibodies in serum and vaginal washes and increased production of beta-chemokines and interferon-gamma, compared with mice immunized with HIV-1 immunogen alone or with control ODN. Furthermore, mice intranasally immunized with HIV-1 immunogen plus CpG were protected against intravaginal challenge with a recombinant vaccinia virus expressing HIV-1 gag. These results indicate that mucosal immunization with whole-killed HIV-1 plus CpG ODN may be an effective means of inducing local immunity and protection against genital infection.     

Dynamics of reverse cholesterol transport: protection against atherosclerosis

This review considers the antiatherogenic function of high density lipoprotein (HDL) from the point of view of its dynamics within the sequential steps of reverse cholesterol transport (RCT). It is postulated that the efficiency of cholesterol flux through the RCT pathways is clinically more relevant than the HDL cholesterol concentration. The particular role of pre-beta(1)-HDL is reviewed drawing attention to the relationship between its concentration and the flux of cholesterol through the RCT system.     

Attenuated expression of profilin-1 confers protection from atherosclerosis in the LDL receptor null mouse

Atherosclerosis-related events are a major cause of morbidity and death worldwide, but the mechanisms underlying atherogenesis are not fully understood. We showed in previous studies that the actin-binding protein profilin-1 (pfn) was upregulated in atherosclerotic plaques and in endothelial cells (ECs) treated with oxidized low-density lipoproteins (oxLDL). The present study addressed the role of pfn in atheroma formation. To this end, mice with heterozygous deficiency of pfn, Pfn(+/-), were crossed with Ldlr(-/-) mice. After 2 months under a 1.25% cholesterol atherogenic diet, Pfn(+/-)Ldlr(-/-) (PfnHet) exhibited a significant reduction in lesion burden compared with Ldlr(-/-) control mice (PfnWT), whereas total cholesterol and triglyceride levels were similar in the 2 groups. Relevant atheroprotective changes were identified in PfnHet. When compared with PfnWT, aortas from PfnHet mice showed preserved endothelial nitric oxide synthase (eNOS) activation and nitric oxide (NO)-dependent signaling, and reduced vascular cell adhesion molecule (VCAM)-1 expression and macrophage accumulation at lesion-prone sites. Similarly, knockdown of pfn in cultured aortic ECs was protective against endothelial dysfunction triggered by oxLDL. Finally, bone marrow-derived macrophages from PfnHet showed blunted internalization of oxLDL and oxLDL-induced inflammation. These studies demonstrate that pfn levels modulate processes critical for early atheroma formation and suggest that pfn heterozygosity confers atheroprotection through combined endothelial- and macrophage-dependent mechanisms.     

Autoantibodies against oxidized low-density lipoprotein (LDL) and carotid atherosclerosis in patients with rheumatoid arthritis

OBJECTIVES: To examine the relationship between autoantibodies against oxidized low-density lipoprotein (oxLDL-Abs) and the progression of carotid atherosclerosis in patients with rheumatoid arthritis (RA). METHODS: Fifty RA patients without evidence of risk factors for atherosclerosis (RA group) and 30 healthy volunteers (normal group) were investigated. The mean intima-media thickness of the common carotid artery (mean CCA-IMT) was measured by high-resolution B-mode ultrasonography. The titer of IgG oxLDL-Abs was measured by enzyme-linked immunosorbent assay. The relationships among mean CCA-IMT, IgG oxLDL-Ab titer and patient factors such as body mass index, systolic blood pressure, diastolic blood pressure, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and serum lipid levels were examined. RESULTS: Mean CCA-IMT, CRP, ESR and titer of IgG oxLDL-Abs were significantly higher in the RA group than in the normal group. Although mean CCA-IMT showed a positive correlation only with age in multivariate analysis, IgG oxLDL-Ab titers in the RA group were positively associated with mean CCA-IMT and independently with age and sex by multiple regression analysis. CONCLUSIONS: IgG oxLDL-Abs appear to be associated with the degree of carotid atherosclerosis in patients with RA, and are independent of traditional risk factors for atherosclerotic diseases. These results suggest a possible link between autoimmune mechanisms and accelerated atherosclerosis in RA.     

An association between an antibody against Chlamydia pneumoniae and common carotid atherosclerosis

OBJECTIVE: Chlamydia pneumoniae (C. pneumoniae) is an important pathogen for infections of the respiratory tract, and there are recently also a number of reports suggesting its relation with atherosclerosis. This study was performed to clarify the relation between C. pneumoniae infection and sclerotic lesions of the common carotid arteries. METHODS AND PATIENTS: We evaluated sclerotic lesions of common carotid arteries by ultrasonography in 147 in-patients (mean age, 70 years; 95% confidence interval, 68-72) in the internal medicine ward, and studied the relation of the known risk factors for atherosclerosis including C. pneumoniae infection. An ultrasonograph and 7.5 MHz linear type B-mode probe were used by a specialist to evaluate sclerotic lesions of common carotid arteries. C. pneumoniae infection was determined by measuring anti-C. pneumoniae IgG specific antibody level (IgG index) using enzyme-linked immunosorbent assay (ELISA) method with serum of fasting blood, which had been preserved at -70 degrees C. RESULTS: IgG index (p=0.0263), from multiple regression analysis using various risk factors as explanatory variables, was a significant independent contributing factor (R2=0.3465, p<0.0001) along with known risk factors such as male (p=0.0289), age (p=0.0007), Brinkman index (p=0.0067), hypertension (p=0.0443) and T-Chol (p=0.0220). CONCLUSION: This study confirmed that the observations of an association between antibody against C. pneumoniae and common carotid atherosclerosis in Western nations is also present in Japan. Our results suggests that C. pneumoniae infection is also an important risk factor for common carotid atherosclerosis.     

Fcgamma receptor deficiency confers protection against atherosclerosis in apolipoprotein E knockout mice

IgG Fc receptors (FcgammaRs) play a role in activating the immune system and in maintaining peripheral tolerance, but their role in atherosclerosis is unknown. We generated double-knockout (DKO) mice by crossing apolipoprotein E-deficient mice (apoE(-/-)) with FcgammaR gamma chain-deficient mice (gamma(-/-)). The size of atherosclerotic lesions along the aorta was approximately 50% lower in DKO compared with apoE(-/-) control mice, without differences in serum lipid levels. The macrophage and T-cell content of lesions in the DKO were reduced by 49+/-6% and 56+/-8%, respectively, compared with the content in apoE(-/-) lesions. Furthermore, the expression of monocyte chemoattractant protein-1 (MCP-1), RANTES (Regulated on Activated Normal T-cell Expressed and Secreted), and intercellular adhesion molecule-1 (ICAM-1) and the activation of nuclear factor-kappaB (NF-kappaB) were significantly reduced in aortic lesions from DKO mice. In vitro, vascular smooth muscle cells (VSMCs) from both gamma(-/-) and DKO mice failed to respond to immune complexes, as shown by impaired chemokine expression and NF-kappaB activation. ApoE(-/-) mice have higher levels of activating FcgammaRI and FcgammaRIIIA, and inhibitory FcgammaRIIB, compared with wild-type mice. The DKO mice express only the inhibitory FcgammaRIIB receptor. We conclude that FcgammaR deficiency limits development and progression of atherosclerosis. In addition to leukocytes, FcgammaR activation in VSMCs contributes to the inflammatory process, in part, by regulating chemokine expression and leukocyte invasion of the vessel wall. These results underscore the critical role of FcgammaRs in atherogenesis and support the use of immunotherapy in the treatment of this disease.     

弓形虫可溶性抗原联合γ干扰素鼻内免疫小鼠的抗弓形虫感染作用

目的探讨弓形虫可溶性抗原(STAg)和γ干扰素(IFN-γ)联合鼻内免疫对小鼠的保护作用及IFN-γ作为佐剂鼻内免疫抗弓形虫感染的最佳剂量。方法将5~6周龄BALB/c小鼠70只随机分为5组,每组14只,分别用20μgSTAg、20μgSTAg 250UIFNγ-、20μgSTAg 500UIFNγ-、20μgSTAg 1000UIFN-γ和20μgSTAg 2000UIFN-γ鼻内免疫小鼠2次,间隔14d,末次免疫后第10天,用RH株弓形虫速殖子4×104个/只灌胃攻击,逐日观察小鼠健康存活情况。攻击后第29天处死全部小鼠,分离计数脑、肝组织速殖子;计数肠系膜淋巴结(MLN)和脾T淋巴细胞。结果随着佐剂IFN-γ剂量的增加,小鼠存活率有升高趋势,1000UIFN-γ剂量组小鼠存活率最高达93%;肝、脑速殖子数呈下降的趋势,其中STAg 1000UIFN-γ、STAg 2000UIFN-γ组显著低于STAg组;MLN和脾T淋巴细胞发生了增殖性应答,其中STAg 1000UIFNγ-、STAg 2000UIFN-γ组MLN细胞显著高于STAg组。结论STAg 1000UIFNγ-、STAg 2000UIFN-γ鼻内免疫明显优于其它小剂量佐剂及单独抗原免疫,能有效诱导黏膜免疫应答。     

Immunization of hamsters with TLCK-killed parasites induces protection against Leishmania infection

Hamsters immunized with N-p-tosyl-L-lysine-chloromethyl ketone TLCK-treated L. brasiliensis brasiliensis (LB) from culture, infected with LB amastigotes presented: a gradual increase in T and B cell responsiveness to mitogens by lymph node lymphocytes, and an increased response to concanavalin A with no changes for dextran sulphate and pokeweed mitogen in splenocytes. Absence of parasites in lymph nodes after 6 weeks post-infection and a nodule 4 times smaller than that of infected control animals. The nodule was undetectable after 70 days of infection. Hamsters preimmunized with TLCK-treated L. donovani (LD) from culture did not show suppression of the blastogenic response to mitogens of spleen and lymph node cells after infection with LD amastigotes and survived for more than one year, whereas infected, unimmunized animals died five months after infection. Animals preimmunized with culture parasites (LB or LD) treated with phenyl-methyl-sulphonyl-fluoride (PMSF) and infected with LB or LD amastigotes did not show any protective effect.     

Vaccination of monoglycosylated hemagglutinin induces cross-strain protection against influenza virus infections

The 2009 H1N1 pandemic and recent human cases of H5N1, H7N9, and H6N1 in Asia highlight the need for a universal influenza vaccine that can provide cross-strain or even cross-subtype protection. Here, we show that recombinant monoglycosylated hemagglutinin (HA_mg) with an intact protein structure from either seasonal or pandemic H1N1 can be used as a vaccine for cross-strain protection against various H1N1 viruses in circulation from 1933 to 2009 in mice and ferrets. In the HA_mg vaccine, highly conserved sequences that were originally covered by glycans in the fully glycosylated HA (HA_fg) are exposed and thus, are better engulfed by dendritic cells (DCs), stimulated better DC maturation, and induced more CD8+ memory T cells and IgG-secreting plasma cells. Single B-cell RT-PCR followed by sequence analysis revealed that the HA_mg vaccine activated more diverse B-cell repertoires than the HA_fg vaccine and produced antibodies with cross-strain binding ability. In summary, the HA_mg vaccine elicits cross-strain immune responses that may mitigate the current need for yearly reformulation of strain-specific inactivated vaccines. This strategy may also map a new direction for universal vaccine design.HA glycoprotein on the surface of influenza virus is a major target for infectivity-neutralizing antibodies. However, the antigenic drift and shift of this protein mean that influenza vaccines must be reformulated annually to include HA proteins of the viral strains predicted for the upcoming flu season (1). This time-consuming annual reconfiguration process has led to efforts to develop new strategies and identify conserved epitopes recognized by broadly neutralizing antibodies as the basis for designing universal vaccines to elicit antibodies with a broad protection against various strains of influenza infection (2–6). Previous studies have shown that the stem region of HA is more conserved and able to induce cross-reactive and broadly neutralizing antibodies (7–9) to prevent the critical fusion of viral and endosomal membranes in the influenza lifecycle (10–14). Other broadly neutralizing antibodies have been found to bind regions near the receptor binding site of the globular domain, although these antibodies are fewer in number (15, 16).Posttranslational glycosylation of HA plays an important role in the lifecycle of the influenza virus and also contributes to the structural integrity of HA and the poor immune response of the infected hosts. Previously, we trimmed down the size of glycans on avian influenza H5N1 HA with enzymes and showed that H5N1 HA with a single N-linked GlcNAc at each glycosylation site [monoglycosylated HA (HA_mg)] produces a superior vaccine with more enhanced antibody response and neutralization activity against the homologous influenza virus than the fully glycosylated HA (HA_fg) (17). Here, to test whether the removal of glycans from HA contributes to better immune responses and possibly protects against heterologous strains of influenza viruses, we compared and evaluated the efficacy of HA glycoproteins with various lengths of glycans as potential vaccine candidates.