Effects of venom immunotherapy on serum level of CCL5/RANTES in patients with Hymenoptera venom allergy

Abstract

Hymenoptera venoms are known to cause life-threatening IgE-mediated anaphylactic reactions in allergic individuals. Venom immunotherapy is a recommended treatment of insect allergy with still the mechanism not being completely understood. We decided to assess the serum CCL5/RANTES level in patients who experienced severe anaphylactic reaction to Hymenoptera venom and to find out changes in the course of immunotherapy. Twenty patients (9 men, 11 women, mean age: 31.91?±?7.63 years) with history of anaphylactic reaction after insect sting were included into the study. Diagnosis was made according to sIgE and skin tests. All of them were enrolled into rush venom immunotherapy with bee or wasp venom extracts (Pharmalgen, ALK-Abello, Horsholm, Denmark). Serum levels of CCL5/RANTES were measured using a commercially available ELISA kit (R&D Systems, Minneapolis, MN). CCL5/RANTES serum concentration are higher in insect venom allergic patients than in healthy controls (887.5?±?322.77 versus 387.27?±?85.11?pg/ml). Serum concentration of CCL5/RANTES in insect venom allergic patient was significantly reduced in the course of allergen immunotherapy already after 6 days of vaccination (887.5?±?322.77 versus 567.32?±?92.16?pg/ml). CCL5/RANTES serum doesn’t correlate with specific IgE. Chemokine CCL5/RANTES participates in allergic inflammation induced by Hymenoptera venom allergens. Specific immunotherapy reduces chemokine CCL5/RANTES serum level already after initial days of venom immunotherapy.     

Increased replication of respiratory syncytial virus in the presence of cytokeratin 8 and 18

Previously, it was reported that productive viral infection, viral protein synthesis, and viral RNA replication of respiratory syncytial virus (RSV) operated efficiently in two human epithelial cell lines (HEp-2 and A549), but not in a human mast-cell line, HMC-1. Based on these observations, it was hypothesized that HMC-1 cells lack the machinery required for RSV replication. To identify the host factors required for RSV replication, cDNA subtraction using A549, HEp-2, and HMC-1 cells was performed, and cytokeratin 18 (C18) was identified as a candidate host factor. Because C18 is generally expressed in simple epithelia with cytokeratin 8 (C8), HMC-1 cells that constitutively express C18 and C8 (HMC-1-C8/18) were established to evaluate the role of C8/18 in RSV replication. In HMC-1-C8/18 cells, RSV RNA replication was increased, and the amount of infective virus produced was also increased in the cellular fraction after RSV spinoculation, whereas RSV production was decreased in A549 cells in which C18 expression was knocked down. These data suggest that the replication of RSV increases in the presence of C8/18.     

Experimental respiratory syncytial virus infection of four species of primates.

Four species of nonhuman primates were inoculated intranasally with 10(3.1) to 10(3.7) plaque forming units (pfu) of respiratory syncytial (RS) virus. Adults squirrel monkeys and newborn rhesus monkeys became infected and shed small quantities (peak titer 10(2.0) pfu/ml of nasopharyngeal swab specimen) of virus, but illness did not develop. Infant cebus monkeys aged 2 months became infected, shed 10(2.3) to 10(3.8) pfu/ml of nasopharyngeal swab specimen, but did not become ill. Chimpanzees aged 15 to 18 months shed a large quantity of virus, up to 10(6.0) pfu/ml of nasopharyngeal swab specimen and developed an upper respiratory illness. Chimpanzees are proposed as a possible animal model for future study of the immunopathology of RS virus disease and for in vivo evaluation of attenuated live virus vaccine candidates.     

Expression of CTLA-4 (CD152) in peripheral blood T cells of children with influenza virus infection including encephalopathy in comparison with respiratory syncytial virus infection

Influenza virus and respiratory syncytial virus (RSV) are the most common causes of acute severe respiratory infection in children during the winter. There have been few reports about peripheral blood T cell activation in vivo in influenza virus infection and conflicting results concerning peripheral blood T cells activation in RSV infection. Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4, CD152) is a receptor present on T cells that plays a critical role in the down-regulation of antigen-activated immune responses. To clarify the status of peripheral blood T cells, we investigated intracellular CTLA-4 expression in T cells in patients with influenza virus and RSV infection. We collected blood samples from 15 patients with influenza virus infection, including three with complications of influenza virus-associated encephalopathy and 18 patients with RSV infection, as well as 44 healthy children. We determined the intracellular expression of CTLA-4 in CD4+ and CD8+ T cells by flow cytometry. There were no significant differences in the percentages of intracellular CTLA-4-positive CD4+ T cells and CD8+ T cells by age. The percentages of intracellular CTLA-4-positive CD4+ T cells in the patients with influenza virus infection were significantly higher than those in healthy children (P < 0.01). In particular, the patients with influenza virus-associated encephalopathy had sevenfold higher percentages of CTLA-4-positive CD4+ T cells than influenza patients without encephalopathy (P < 0.05). The patients with influenza virus-associated encephalopathy had increased percentages of CTLA-4-positive CD8+ cells at the acute stage in comparison with the convalescent stage and in control subjects (P < 0.01, respectively). RSV patients showed no increase in CTLA-4-positive CD4+ T cells or CD8+ T cells. The immunological status of peripheral T cell activation is substantially different in influenza virus infection and RSV infection. The patients with RSV infection did not show any increase in CTLA-4-positive peripheral blood T cells. There was a remarkable increase in intracellular CTLA-4 in CD4+ and CD8+ T cells in influenza virus-associated encephalopathy. Down-regulation of antigen-activated peripheral blood T cell activation might play an important role in the pathogenesis of influenza virus-associated encephalopathy and host defence against influenza virus infection.     

Increased number of T cells committed to IL-5 production after respiratory syncytial virus (RSV) infection of human mononuclear cells in vitro

We examined changes in the cytokine profile of T cells induced by in vitro infection with RSV. Isolated mononuclear cells from 27 healthy adults and six infants were infected with RSV at a concentration of 3 MOI (multiplicity of infection). After 48 h cells were restimulated with phorbol ester and ionomycin in the presence of monensin for 5 h. The intracellular expression of viral antigen, the cytokines IL-2, IL-4, IL-5, interferon-gamma (IFN-γ), and the expression of surface markers were assessed by immunofluorescent staining and flow cytometry. There was a significant (P < 0.001) rise of IL-5 expression in RSV-infected cultures in comparison with uninfected cultures from the same individuals, whereas there were no changes in the expression of the other lymphokines. The increase in IL-5 generation depended on viable infectious RSV rather than inactivated virus. RSV infection as well as IL-5 production in T cells were confined to the CD8 subpopulation. However, there was no simultaneous expression of RSV antigen and IL-5. Purified T cells did not show any increase in IL-5 generation. However, when the rate of RSV infection was enhanced in monocytes by means of a specific monoclonal antibody, co-cultured T cells displayed an increase of IL-5 production compared with samples with ordinary low rate RSV infection. It is therefore likely that the increased commitment of lymphocytes to produce IL-5 after RSV infection in vitro is mediated by monocytes or other antigen-presenting cells.     

Primary respiratory syncytial virus infection in mice

A mouse model of respiratory syncytial virus (RSV) infection is described. A high-titered, large-volume inoculum results in replication of RSV to a high titer in lungs of BALB/c mice. Mice older than 15 weeks of age are more susceptible to RSV infection. Titers up to 10(6.9) plaque-forming units (pfu)/gram lung can be attained in 32-week-old mice. Older mice experience a clinical illness manifested by ruffled fur, reduced activity, and weight loss. Lung histology of older mice infected with RSV shows bronchiolitis and increased number of lymphocytes and macrophages in alveolar spaces compared with that of mice less than 8 weeks old. This model will serve as the basis for investigating immunodeterminants of recovery and protection from RSV infection.     

Decreased interferon-gamma response in respiratory syncytial virus compared to other respiratory viral infections in infants

An inappropriate interferon-gamma response has been implicated in the pathogenesis of severe respiratory syncytial virus (RSV) lower respiratory tract illness (LRTI). To assess whether this is unique for RSV primary LRTI compared to a first non-RSV LRTI, intracellular interferon-gamma was determined by flow cytometry in peripheral blood mononuclear cells from 32 infants with a primary RSV infection, 28 with a first non-RSV LRTI due to adenoviral, parainfluenzaviral and rhinoviral infection and 13 healthy infants. Interferon-gamma responses were increased significantly during adenoviral, parainfluenzaviral and the majority of the rhinoviral infections, but remained low during RSV and severe rhinoviral infection. Low interferon-gamma responses were associated with a more severe clinical course of LRTI. This indicates that depending on the nature of the viral pathogen, respiratory virus infections in infants differ significantly with regard to the quantity of the interferon-gamma production and that this may contribute to the clinical course of the disease.     

重庆地区急性呼吸道感染患儿呼吸道合胞病毒流行特征及其G基因序列分析

目的 分析重庆地区2008-2009年度急性呼吸道感染住院患儿呼吸道合胞病毒(respiratory syncytial virus,RSV)的亚型流行情况,并了解优势流行株BA株的G蛋白基因特征.方法 采集2008年4月-2009年3月全年于重庆医科大学附属儿童医院因急性呼吸道感染住院的508例患儿鼻咽深部分泌物,用RT-PCR方法检测RSV并进行亚型鉴定,选取29例B亚型和10例A亚型RSV阳性标本,用RT-PCR的方法扩增全长G蛋白并测序.结果 在508例标本中,RSV阳性126例(24.8%),其中检测出A亚型43例(34.1%),B亚型80例(63.5%),A、B亚型混合感染3例(2.4%).所测的10株A亚型的G基因与标准株A2的核苷酸同源性为91.4%～92.0%,均属GA2基因型;29株B亚型的G基因与标准株CH18537的核苷酸同源性为92.0%～93.0%,其中19株均为具有60个高度重复核苷酸插入的BA株.B亚型流行株与CH18537标准株相比,G基因有多种核苷酸变异如缺失、插入等,尤其在G蛋白近C端1/3处的高变区.结论 2008-2009年RSV仍是重庆地区儿童急性呼吸道感染的主要病原,与既往两年A亚型优势流行不同,2008-2009年度B亚型毒株流行占优;近年新发现的BA株可能已成为本地区优势流行株,BA株G基因变异是否导致G蛋白功能增强,进而促进其优势流行尚有待研究.     

Immunoprophylaxis and immunotherapy of respiratory syncytial virus infection in the cotton rat

Human convalescent antiserum to respiratory syncytial virus (RSV) administered intraperitoneally to cotton rats prior to RSV challenge provided near-complete protection from pulmonary infection. Antiserum given subsequent to viral challenge reduced pulmonary viral titers 100-fold or greater within 24 h. Sandoglobulin, a preparation of purified human IgG with high titer of anti-RSV neutralizing activity, produced the same effects as convalescent antiserum. Sandoglobulin was absorbed rapidly and produced a significant therapeutic reduction in virus titer within 3 h. The level of virus reduction in pulmonary and nasal tissues was directly proportional to the neutralizing antibody titer in the cotton rat serum, and was always greater in the lungs than the nose. Animals treated therapeutically with Sandoglobulin had a depressed primary antibody response to infection, but were completely resistant to reinfection with RSV. Histologic examination of pulmonary tissues from Sandoglobulin-treated animals showed no pathologic changes.     

Prevalence and clinical characteristics of human respiratory syncytial virus in Chinese adults with acute respiratory tract infection

Respiratory syncytial virus (RSV) is a leading cause of respiratory tract illnesses worldwide. Although the prevalence and clinical manifestations of the two subtypes, RSV‐A and RSV‐B, have been studied in some detail in infants and young children, they have not been determined in adults. To evaluate the prevalence of the RSV subtypes and disease severity between RSV‐A and RSV‐B infections in adults, nasal and throat swabs that were collected from patients ≥15 years old who sought medical care for acute respiratory infections at the Fever Clinic of the Peking Union Medical College Hospital in Beijing, China between May 2005 and April 2010. The samples were tested for RSV infection using PCR and sequencing analysis. RSV was detected in 95 (1%) of the adult patients, of whom 53 (55.8%) were positive for RSV‐A and 42 (44.2%) for RSV‐B. The incidence of RSV infections increased with age (χ² = 37.17, P = 1.66E?07). Demographic data and clinical manifestations of RSV‐A were similar to those of RSV‐B. Although RSV‐A and RSV‐B co‐circulated during the 2005–2006 and 2008–2009 seasons, RSV‐A was predominant in the 2006–2008 seasons, whereas RSV‐B was predominant in the 2009–2010 season. Upper respiratory tract infections were diagnosed in most RSV‐infected patients (n = 80, 84.2%), and three patients suffered from pulmonary infection. This is the first study to provide data on the prevalence and clinical manifestations of RSV subgroups among Chinese adults with fever and acute illness, over five successive epidemic seasons. J. Med. Virol. 85:348–353, 2013. © 2012 Wiley Periodicals, Inc.     

Cell-mediated immunity in respiratory syncytial virus disease

Systemic cell-mediated responses to respiratory syncytial (RS) virus were detected, using a whole blood transformation assay, in 10 of 28 infants and children with RS virus infections during the period 1–14 days postadmission. Cell-mediated responses were unrelated to the age of the patient or the severity of illness. No correlation was found between cellular responses and fourfold or greater rises in antibody titre to RS virus, as determined by a membrane immunofluorescence technique. Patients under 6 months of age had significantly lower levels of IgA and IgG antibody to RS virus compared to older patients, although cell-mediated responses were similar in both groups. The presence of cell-mediated reactivity to RS virus was also demonstrated in 5 of 95 samples of cord blood examined, and cellular responses failed to correlate with the levels of IgG antibody to RS virus.     

RANTES (CCL5) production during primary respiratory syncytial virus infection exacerbates airway disease

Respiratory syncytial virus (RSV) is a respiratory pathogen that causes significant morbidity in infants and young children. The importance of chemokines during RSV infection for respiratory symptoms has not been fully elucidated. The current study examined the effect of RANTES (CCL5) on airway pathophysiology after RSV infection. BALB/c mice produce RANTES (CCL5) after RSV infection that correlates with the changes in pathophysiology. Animals treated with anti-RANTES (CCL5) antibody demonstrated significant decreases in airway hyperreactivity (AHR). Delayed treatment with anti-RANTES (CCL5) at day 5 of infection also significantly reduced development of AHR on day 9 of infection, suggesting that RANTES (CCL5) may be a target in established disease. Determination of Th1/Th2-associated cytokine patterns indicated that anti-RANTES (CCL5) treatment increased IL-12 production, thus altering the lung environment. The assessment of RANTES (CCL5) production in vitro and in vivo demonstrated that it was regulated by IL-13, a cytokine that is related to RSV-induced AHR in this mouse model. These data show that RANTES (CCL5) is an important mediator of the pathophysiological responses seen in RSV infection.     

呼吸道合胞病毒感染的研究进展

呼吸道合胞病毒是在世界范围内引起婴幼儿呼吸道感染的最常见病原微生物,它不仅可以引起呼吸系统的一些常见症状和体征,而且在肺外器官如中枢神经系统、心血管系统、内分泌系统等各器官也可引起一些尚未被人们普遍认识的肺外表现,而这些临床特点的重要性也愈来愈受到人们的重视.     

Type I interferon induces CX3CL1 (fractalkine) and CCL5 (RANTES) production in human pulmonary vascular endothelial cells

Type I interferon (IFN) medications cause various adverse reactions, including vascular diseases. Although an association between chemokines and vascular diseases has also been reported, the relationship between type I IFN and chemokines in vascular endothelial cells (VEC) remains unclear. To provide clues to pathogenesis of the diseases, we analysed the effects of type I IFN on chemokine production in human VEC. Type I IFN induced higher CX3CL1 (fractalkine) mRNA expression and protein secretion in pulmonary arterial VEC than in umbilical vein VEC. Type I IFN also induced CCL5 [regulated upon activation normal T cell expressed and secreted (RANTES)] production in VEC, especially in lung micro-VEC. IFN-β induced much higher chemokine production than IFN-α, and Janus protein tyrosine kinase (JAK) inhibitor I prevented type I IFN-induced chemokine secretion. Type I IFN-induced chemokines may be involved in the pathophysiology of pulmonary vascular diseases, and the JAK inhibitor may serve as a therapeutic option for these diseases.     

Shedding of infectious virus and virus antigen during acute infection with respiratory syncytial virus.

Shedding of respiratory syncytial virus (RSV) in nasopharyngeal aspirates (NPA) of hospitalized children with acute respiratory infection was studied using direct antigen detection by time-resolved fluoroimmunoassay, rapid identification of infectious virus in centrifugally inoculated cell cultures by immunoperoxidase staining and conventional virus culture. Sequential NPAs, in which also local RSV-specific IgA response was measured, were collected from children with proven RSV infection. The shedding pattern was similar for both infectious virus and viral antigen. The overall agreement of the three methods was good (81%) in diagnostic specimens collected on admission, but markedly reduced (46%) in follow-up specimens. Secretory IgA was abundant in specimens giving discrepant or negative results only. The proportion of patients who shed RSV was high (> or = 87%) in the first week after onset of symptoms, and decreased sharply in the second week. An opposite temporal pattern was found in the proportion of patients with detectable RSV-IgA in their secretions. Sequentially isolated strains were antigenically stable as determined by their reactivity with a large panel of monoclonal antibodies. The findings suggest that RSV shedding should be monitored by using more than one method for virus detection.