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1.
Previous studies have documented that targeting foreign Ags to IgG FcgammaR leads to enhanced Ag-specific responses in vitro and in vivo. However, the ability to overcome immunologic nonresponsiveness by targeting poorly immunogenic Ags to FcgammaR has not been investigated. To address this question in a simple model, we immunized transgenic mice expressing human CD64 (FcgammaRI) and their nontransgenic littermates with Fab' derived from the murine anti-human CD64 mAb m22. The m22 Fab' served as both the targeting molecule and the Ag. We found that only CD64-expressing mice developed anti-Id titers to m22. Furthermore, chemically linked multimers of m22 Fab', which mediated efficient internalization of the human CD64, were significantly more potent than monomeric m22 F(ab')(2) at inducing anti-Id responses. In all cases, the humoral responses were specific for m22 Id and did not react with other murine IgG1 Fab' fragments. Chemical addition of a second murine Fab' (520C9 anti-human HER2/neu) to m22 Fab' multimers demonstrated that IgG1 and IgG2a anti-Id titers could be generated to 520C9 only in the CD64-expressing mice. These results show that targeting to CD64 can overcome immunological nonresponsiveness to a weak immunogen. Therefore, targeting to CD64 may be an effective method to enhance the activity of nonimmunogenic tumor vaccines.  相似文献   

2.
The Japanese encephalitis virus (JEV) is the leading cause of viral encephalitis. Although there are four classes of vaccines against JEV, all of them are administered by s.c or i.m injection. Here, the effectiveness of sublingual (s.l.) administration of a JEV live‐attenuated vaccine or recombinant modified vaccinia virus Ankara (MVA) vaccine, including JEV prM/E, was investigated. The mice were immunized three times i.m. or s.c. One week after the final immunization by both s.l. and i.m. routes, the titers of IgG1 induced by the recombinant MVA vaccine were higher than those induced by the live‐attenuated vaccine, whereas the titers of IgG2a induced by the live‐attenuated vaccine were higher than those induced by the recombinant MVA vaccine. However, both vaccines induced neutralizing antibodies when given by either s.l. or i.m. routes, indicating that both vaccines induce appropriate Th1 and Th2 cell responses through the s.l. and i.m. routes. Moreover, both vaccines protected against induction of proinflammatory cytokines and focal spleen white pulp hyperplasia after viral challenge. Virus‐specific IFN‐γ+ CD4+ and CD8+ T cells appeared to increase in mice immunized via both s.l. and i.m. routes. Interestingly, virus‐specific IL‐17+ CD4+ T cells increased significantly only in the mice immunized via the s.l. route; however, the increased IL‐17 did not affect pathogenicity after viral challenge. These results suggest that s.l. immunization may be as useful as i.m. injection for induction of protective immune responses against JEV by both live‐attenuated and recombinant MVA vaccines.  相似文献   

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He H  Zhao B  Liu L  Zhou K  Qin X  Zhang Q  Li X  Zheng C  Duan M 《DNA and cell biology》2004,23(5):335-339
Cryptosporidiosis, a protozoan disease, is caused by Cryptosporidium parvum in animals and humans. To study the humoral and cellular immune responses induced by DNA vaccine expressing the sporozoite surface protein, CP15/60, of Cryptosporidium parvum, the recombinant plasmid containing the CP15/60 gene was injected into tibialis a interior muscle of BALB/c mice. The mice were subsequently given booster doses twice at 3-week intervals. The humoral and cellular immune responses were detected at different times after immunization. The mice were then challenged by inoculation of 1 x 10(6) oocysts of C. parvum. The experimental results have shown that the recombinant plasmid can induce corresponding specific immune responses and thus protect the mice from challenge of the oocysts, suggesting that the recombinant plasmid could be a potential candidate of DNA vaccine.  相似文献   

5.
Cytomegalovirus is a leading cause of morbidity and mortality among neonatal and immunocompromised patients. The use of vaccine prophylaxis continues to be an effective approach to reducing viral infections and their associated diseases. Murine cytomegalovirus (mCMV) has proven to be a valuable animal model in determining the efficacy of newly developed vaccine strategies in vivo. Live recombinant vesicular stomatitis viruses (rVSV) have successfully been used as vaccine vectors for several viruses to induce strong humoral and cellular immunity. We tested the ability of intranasal immunization with an rVSV expressing the major envelope protein of mCMV, glycoprotein B (gB), to protect against challenge with mCMV in a mouse model. rVSV-gB-infected cells showed strong cytoplasmic and cell surface expression of gB, and neutralizing antibodies to gB were present in mice after a single intranasal vaccination of VSV-gB. After challenge with mCMV, recovery of live virus and viral DNA was significantly reduced in immunized mice. In addition, primed splenocytes produced a CD8+ IFNgamma response to gB. The ability to induce an immune response to a gene product through mucosal vaccination with rVSV-gB represents a potentially effective approach to limiting CMV-induced disease.  相似文献   

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Human infections with EHEC such as O157:H7 have been a great concern for worldwide food-industry surveillance. This pathogen is commonly associated with bloody diarrhea that can evolve to the life-threatening hemolytic uremic syndrome. Animals are the natural reservoir where this pathogen remains asymptomatically, in steps of ingestion and colonization of the bowel. The bacterium is shed in the feces, contaminating the surroundings, including water and food that are directed for human consumption. A major player in this colonization process is intimin, an outer membrane adhesion molecule encoded by the E. coli attachment and effacement (eae) gene that has been shown to be essential for intimate bacterial attachment to eukaryotic host cells. In an attempt to reduce the colonization of animal reservoirs with EHEC O157:H7, we designed a vaccine model to induce an immune response against intimin gamma. The model is based on its recombinant expression in attenuated Salmonella, used as a suitable vaccine vector because of its recognized ability to deliver recombinant antigens and to elicit all forms of immunity: mucosal, systemic, and humoral responses. To test this model, mice were orally immunized with a S. enterica serovar Typhimurium strain carrying the pYA3137eaeA vector, and challenged with E. coli O157:H7. Here we show that immunization induced the production of high levels of specific IgG and IgA antibodies and promoted reduction in the fecal shedding of EHEC after challenge. The live recombinant vaccine reported herein may contribute to the efforts of reducing animal intestinal mucosa colonization.  相似文献   

8.
This paper appeared in the February issue, occupying pp. 150‐159. It was a duplicate of JGM 1271, which appears on pp. 57‐65 of the January issue. It has therefore been withdrawn from Wiley InterScience. The publisher apologies to the authors for the error. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

9.
目的探讨脑梗死患者的细胞免疫功能与体液免疫功能的变化规律。 方法2016年5月~ 2017年5月期间广东省佛山市禅城区中心医院收治的脑梗死患者120例设为观察组,观察组患者按照脑梗死的面积分为轻症组(大脑中动脉区域脑梗,脑梗范围的直径≤5 cm者,60例)和中重症组(大脑中动脉区域脑梗,脑梗范围的直径> 5 cm者,60例);选择120例健康体检者设为对照组。采用流式细胞仪和速率散射免疫透射比浊法测定各组血免疫球蛋白IgA、IgM、IgG、补体C3、C4水平来反应体液免疫功能;用试剂盒、外周血中T淋巴细胞亚群CD3+、CD4+、CD8+、NK细胞、B细胞和CD4+/CD8+百分率水平的测定;对抗心磷脂抗体(ACA)浓度进行测定;通过ACA浓度反映的颈动脉粥样硬化(CAS)中生化指标的变化分析脑梗死患者的细胞免疫功能与体液免疫功能的关联。多组间比较采用单因素方差分析;患者性别比例采用χ2分析;通过直线相关分析细胞免疫与体液免疫的相关性。 结果脑梗死中重症组T淋巴细胞含量低于脑梗死轻症组和对照组,差异具有统计学意义(P < 0.05),CD8+细胞百分率(27.91%±2.97%)T淋巴细胞含量高于脑梗死轻症组和对照组,CD4+/CD8+比值(1.98±0.03)水平高于脑梗死轻症组和对照组(P < 0.05);与脑梗死轻症组和对照组比较,脑梗死中重症组NK细胞(12.29%±1.58%)和B细胞(12.76%±2.00%)均下降(P < 0.05)。与脑梗死轻症组和对照组比较,脑梗死中重症组血清中血球免疫球蛋白IgG(10.60±1.06)IU/ml水平降低(P < 0.05);血球免疫球蛋白IgA(4.01±0.35)IU/ml、补体C3(2.13±0.04)IU/ml和补体C4(0.39±0.01)IU/ml的水平升高(P < 0.05),而IgM(2.60±0.05)IU/ml无明显变化,差异无统计学意义(P > 0.05)。与脑梗死轻症组(14.11±2.09)PLU/ml和对照组(7.82±1.15)PLU/ml比较,脑梗死中重症组(16.88±2.50)PLU/ml血清ACA浓度提高,差异具有统计学意义(t = 9.153,P < 0.01)。与脑梗死轻症组和对照组比较,脑梗死中重症组总胆固醇[(1.75±0.03)mmol/L]和甘油三酯[(2.42±0.33)mmol/L]含量增加;高密度脂蛋白胆固醇[(0.41±0.03)mmol/L]含量降低;与对照组比较,脑梗死中重症组低密度脂蛋白胆固醇[(1.55±0.21)mmol/L]含量升高(P < 0.05)。通过细胞免疫参数与体液免疫参数之间的相关性分析显示呈负相关,且相关性曲线陡峭(P < 0.05)。 结论脑梗死患者的细胞免疫与体液免疫的变化规律可指导脑梗死治疗和预后。  相似文献   

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Serum IgA, IgM and IgG as well as percentage of lymphocytes T and B in peripheral blood were determined in 50 children aged between 6 months and 3 years with iron deficiency anaemia. A significant decrease in lymphocyte T number in these children was found in comparison with control group of healthy children. Lymphocyte T count positively correlated with serum iron concentration. Moreover, a decrease in serum IgA and IgG was found in children with iron deficit.  相似文献   

12.
 In the present study we describe a novel murine tumor model in which the highly malignant murine B cell lymphoma 38C13 has been transduced with the cDNA encoding human tumor-associated antigen HER2/neu. This new cell line (38C13-HER2/neu) showed stable surface expression but not secretion of human HER2/neu. It also maintained expression of the idiotype (Id) of the surface immunoglobulin of 38C13, which serves as another tumor-associated antigen. Surprisingly, spontaneous tumor regression was observed following s.c. but not i.v. injection of 38C13-HER2/neu cells in immunocompetent syngeneic mice. Regression was more frequently observed with larger tumor cell challenges and was mediated through immunological mechanisms because it was not observed in syngeneic immunodeficient mice. Mice that showed complete tumor regression were immune to challenge with the parental cell line 38C13 and V1, a variant of 38C13 that does not express the Id. Immunity could be transferred with sera, suggesting that an antibody response mediated rejection and immunity. Continuously growing s.c. tumors as well as metastatic tumors obtained after the i.v. injection of 38C13-HER2/neu maintained expression of human HER2/neu, which can serve as a target for active immunotherapy. As spontaneous tumor regression has not been observed in other human murine models expressing human HER2/neu, our results illustrate the enormous differences that can exist among different murine tumors expressing the same antigen. The present model provides a useful tool for the study of the mechanisms of protective immunity to B cell lymphoma and for the evaluation of different therapeutic approaches based on the stimulation or suppression of the immune response. Received: 2 August 2000 / Accepted: 20 September 2000  相似文献   

13.
Our previous study showed that a combination of a plasmid-expressing Flt3 ligand (pFL) and CpG oligodeoxynucleotides (CpG ODN) as a combined nasal adjuvant elicited mucosal immune responses in aged (2-y-old) mice. In this study, we investigated whether a combination of pFL and CpG ODN as a nasal adjuvant for a pneumococcal surface protein A (PspA) would enhance PspA-specific secretory-IgA Ab responses, which could provide protective mucosal immunity against Streptococcus pneumoniae infection in aged mice. Nasal immunization with PspA plus a combination of pFL and CpG ODN elicited elevated levels of PspA-specific secretory-IgA Ab responses in external secretions and plasma in both young adult and aged mice. Significant levels of PspA-specific CD4(+) T cell proliferative and PspA-induced Th1- and Th2- type cytokine responses were noted in nasopharyngeal-associated lymphoreticular tissue, cervical lymph nodes, and spleen of aged mice, which were equivalent to those in young adult mice. Additionally, increased numbers of mature-type CD8, CD11b-expressing dendritic cells were detected in mucosal inductive and effector lymphoid tissues of aged mice. Importantly, aged mice given PspA plus a combination of pFL and CpG ODN showed protective immunity against nasal S. pneumoniae colonization. These results demonstrate that nasal delivery of a combined DNA adjuvant offers an attractive possibility for protection against S. pneumoniae in the elderly.  相似文献   

14.
The emergence of SARS-CoV-2 variants and potentially other highly pathogenic sarbecoviruses in the future highlights the need for pan-sarbecovirus vaccines.Here...  相似文献   

15.
The article deals with the comparative study of the state of phagocytosis, as manifested by the ingestion of bacterial cells and by the results of the specific lupus erythematosus test, in 65 patients with acute viral hepatitis A and 45 patients with acute viral hepatitis B; these patients were also compared with respect to the presence of the markers of antigenemia and the state of their nonspecific immunity, determined by the level of serum immunoglobulins.  相似文献   

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Orf virus (ORFV; Parapoxvirus ovis) was used to develop a novel vector system for the generation of effective and safe live vaccines. Based on the attenuated ORFV strain D1701-V, recombinants were produced that express the glycoproteins gC (D1701-VrVgC) or gD (D1701-VrVgD) of the alphaherpesvirus of swine, pseudorabies virus (PRV). Expression of gC and gD was also demonstrated on the surface of recombinant virus-infected murine cells that do not produce infectious ORFV. Single or combined immunization with the ORFV recombinants protected different mouse strains of a host species nonpermissive for ORFV against a fulminant, lethal PRV challenge infection equal to immunization with PRV live vaccine. Most notably, even a single immunization with D1701-VrVgC was protective, whereas two applications of D1701-VrVgD were required for immune protection. The higher protective capacity of D1701-VrVgC correlated with the induction of a strong specific humoral immune response. This suggestion was supported by transfer experiments using sera from recombinant-immunized mice, which resulted in partial gC but not gD antibody-mediated protection of the na?ve recipients. Remarkably, immunization of different immune-deficient mice demonstrated that the application of the PRV gC-expressing recombinant controlled the challenge infection in the absence of either CD4(+) or CD8(+) T cells, B cells, or an intact perforin pathway. In contrast, D1701-VrVgD-immunized mice lacking CD4(+) T cells exhibited reduced protection, whereas animals lacking CD8(+) T cells, B cells, or perforin resisted the challenge infection. The present study demonstrates the potential of these new vector vaccines to efficiently prime both protective humoral and cell-mediated immune mechanisms in a host species nonpermissive for the vector virus.  相似文献   

18.
Formation of antigenic peptides by the multicatalytic proteinase complex (MPC, proteasome) is facilitated by incorporation of three subunits (LMP2, LMP7 and LMP10) that are inducible by IFN-gamma and TNF-alpha. These cytokines, or their functional homologues (e.g. TNF-beta), are released from many cells including Th(1)lymphocytes. To learn more about the relationship between control of cellular immunity and expression of LMP subunits, we measured LMP7 levels in human umbilical vein endothelial cells of cytokines promoting cellular immunity (IL-12, IFN-gamma, TNF-alpha) or humoral immunity (IL-10, IL-6). Little or no effect was seen when cells were exposed to IL-6, IL-10 or IL-12 alone. IFN-gamma upregulated LMP7 levels, as did TNF-alpha to a lesser extent. IL-10 downregulated IFN-gamma-induced increases in LMP7 levels, as did IL-12. The findings indicate that regulation of levels of LMP7 is similar to and may be coupled with that of other molecules required for MHC class I-dependent immunity, and depends primarily on cytokines released by Th(1)helper lymphocytes.  相似文献   

19.
The lymphocyte activation gene-3 (LAG-3) product is a MHC class II ligand that has been used in vivo to stimulate MHC class II+ APCs to increase tumor-specific immune responses. We investigated whether LAG-3 could also play an adjuvant role in vivo for the induction of humoral and CD4 or CD8 cell-mediated immune responses when immunizing mice with a particulate (hepatitis B surface Ag) or soluble (OVA) Ag. In both cases, coadministration of 1 microg of a soluble fusion protein between murine LAG-3 and the Fc fraction of a murine IgG2a mAb (mLAG-3Ig) as a vaccine adjuvant induced or increased CTL responses to the corresponding MHC class I-restricted peptide. In addition, splenocytes of mice vaccinated with either the particulate or soluble Ag plus mLAG-3Ig exhibited a significantly greater proliferative response than did splenocytes of mice immunized with Ag and a control Ig molecule. Similarly, these splenocytes had a greater Th1- but not Th2-type cytokine response. Finally, mice immunized with Ag plus mLAG-3Ig produced higher titers of Abs than mice immunized with Ag and a control Ig molecule. Thus, these data provide evidence of a novel means of improving the immunogenicity of subunit vaccines.  相似文献   

20.
Adjuvants play an important role in vaccine formulations by increasing their immunogenicity. In this study, the phenolic compound-rich J fraction (JFR) of a Brazilian green propolis methanolic extract stimulated cellular and humoral immune responses when co-administered with an inactivated vaccine against swine herpesvirus type 1 (SuHV-1). When compared to control vaccines that used aluminium hydroxide as an adjuvant, the use of 10 mg/dose of JFR significantly increased (p < 0.05) neutralizing antibody titres against SuHV-1, as well as the percentage of protected animals following SuHV-1 challenge (p < 0.01). Furthermore, addition of phenolic compounds potentiated the performance of the control vaccine, leading to increased cellular and humoral immune responses and enhanced protection of animals after SuHV-1 challenge (p < 0.05). Prenylated compounds such as Artepillin C that are found in large quantities in JFR are likely to be the substances that are responsible for the adjuvant activity.  相似文献   

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