A novel approach to enterovirus typing.

A novel method was developed for typing enteroviruses producing cytopathic effect. Monolayers of primary or secondary rhesus monkey kidney cells were prepared and covered with an agarose overlay. Wells were formed in the agarose, the well bottom being optimally determined to be 3 mm from the monolayer and homotypic enterovirus antiserum, intersecting antiserum pool or antiserum-diluent as control was added. After 2 h at 37 degrees C, the test virus isolate was added to each well. Cultures were incubated at 37 degrees C and were examined daily until cytopathic effect was readily observed in the control well. Monolayers were fixed and stained for macroscopic reading. Enterovirus identity based on the inhibition of cytopathic effect was confirmed with a conventional micro-neutralization method. In all, 51 enterovirus isolates were typed. Included were 21 polioviruses, 9 coxsackieviruses and 21 echoviruses, all of which were correctly identified. This method takes advantage of the ability of enterovirus and antibody to diffuse through agarose. It is simple to perform. It does not require preliminary titration of the test virus isolate and tolerates 1,000 fold fluctuations in virus concentration, thereby offering laboratories a more rapid and efficient means of typing enteroviruses.     

Analysis of the relationship between immunogenicity and immunity for viral subunit vaccines

The prevention of viral infection by vaccination relies on stimulating an appropriate immune response in order to reduce the probability with which a virus can establish an infection. Post-vaccination antibody responses have therefore been associated with reducing the probability with which an individual can be infected (i.e., the vaccine's "impact"). Quantifying this relationship is essential in evaluating new vaccines, especially since comparisons between vaccines, and vaccine licensure, may be dependent on antibody responses alone. In this paper two principal questions are identified which need to be addressed in the evaluation of subunit vaccines: i) how do specific antibody levels relate to complete protection from infection or disease and ii) how do antigenic subunits interact in developing protection when combined together in a single vaccine. The aim is to identify explicitly certain assumptions that are frequently made implicitly in the discussion of vaccine action. First, antibody levels are related to levels of protection through a novel statistical analysis of incidence data from a published hepatitis B vaccine trial. The antibody response observed after influenza A virus infection is discussed in relation to the selection of neutralisation escape variants. Finally, by way of example, a theoretical situation is examined and three simple models of subunit vaccine action are constructed in order to describe how antibody levels may be related to population level phenomena such as the elimination of an infection by mass vaccination.     

HLA and the response of lymphocytes to viral antigens in patients with multiple sclerosis

Serum antiviral antibody titers, presence of lymphocytotoxic antibodies, and lymphoproliferative responses to viral antigens were determined in 44 multiple sclerosis (MS) patients and 25 healthy subjects. These measurements were correlated with the HLA type and the clinical characteristics of the patients. The Dw2/DR2 phenotype, known to be associated with increased MS susceptibility, was also associated with a later onset of MS and more rapid progression of disease. Within the Dw2/DR2 group, the disability status and rate of progression did not correlate with the relative degree of lymphoproliferative response. Patients with the Dw2/DR2 phenotype had similar lymphoproliferative responses to all viral antigens as control subjects possessing or lacking Dw2/DR2. Patients lacking Dw2/DR2 had increased lymphoproliferative responses selectively to measles virus when compared with normal subjects or Dw2/DR2 positive individuals. Absence of the B40 antigen was associated with high antibody titer to measles, and presence of the Dw7/DR7 antigens was associated with high titers against herpes simplex I virus. Both B40 and Dw7/DR7 phenotypes were associated with decreased occurrence of lymphocytotoxic antibodies. The Dw7/DR7 phenotype has been associated in previous studies with a decreased susceptibility to MS. These results, therefore, suggest that both humoral and cellular antiviral immune mechanisms in man are under the influence of HLA-linked genes. Progressive or lack of progression in MS could in turn be somehow related to the differing strength of antiviral immune responses in individuals of the appropriate HLA genotype.     

Increased beta2-microglobulin-free HLA class I heavy chain serum levels in the course of immune responses to viral antigens and to mismatched HLA antigens

Besides being present in serum in association with beta2-mu, HLA class I heavy chains are also present in serum as beta2-micro-free moieties. The increase in serum levels of beta2-micro-associated HLA class I heavy chains in conditions associated with an activation of the immune system have prompted us to measure the serum levels of beta2-mu-free HLA class I heavy chains in the course of immune responses to viral antigens and to mismatched histocompatibility antigens. The serum level of beta2-mu-free HLA class I heavy chains, like that of beta2-mu-associated HLA class I heavy chains was significantly increased in patients affected by advanced HIV-1 infection or by chronic hepatitis C (CHC). In the latter group of patients an association was found between a reduction in the beta2-mu-free HLA class I heavy chain serum level and response to therapy with interferon alpha and ribavirin. Moreover, the beta2-mu-free HLA class I heavy chain serum level was increased more than that of beta2-mu-associated HLA class I heavy chains during episodes of liver ischemia following liver transplantation and in the course of acute graft rejection and of acute graft-versus-host-disease (GVHD) after allogeneic bone marrow transplantation (BMT). These results suggest that the serum levels of beta2-mu-free and beta2-mu-associated HLA class I heavy chains are independently regulated. Furthermore, beta2-mu-free HLA class I heavy chain serum level may be a useful marker to monitor response to therapy in CHC patients and the clinical course of liver and bone marrow grafts.     

甲型H1N1流感病毒亚单位疫苗对小鼠的免疫原性观察

目的:观察国产甲型H1N1流感病毒亚单位疫苗对小鼠的免疫原性.方法:将不同血凝素含量(20、30、40 μg/ml)各3批甲型H1N1流感病毒亚单位疫苗分别免疫小鼠,腹腔注射0.5 ml/只,每批疫苗又分为1针组、2针组,每组10只,2针间隔1周,同时设对照组.首针免疫后21天,分别采血,分离血清,检测血凝抑制抗体效价和中和抗体效价,观察疫苗的免疫原性.结果:血凝素含量为20 μg/ml的甲型H1N1流感病毒亚单位疫苗1针组、2针组血凝抑制抗体效价均小于1:40,中和抗体效价均小于1∶200;血凝素含量为30、40 μg/ml的甲型H1N1流感病毒亚单位疫苗1针组、2针组的血凝抑制抗体效价均大于1∶40,中和抗体效价均大于1∶200;血凝素含量为30、40 μg/ml的甲型H1N1流感病毒亚单位疫苗1针组和2针组的血凝抑制抗体和中和抗体效价比较,差异均无统计学意义.结论:血凝素含量为30 μg/ml的甲型H1N1流感病毒亚单位疫苗接种1针即可达到理想的免疫效果.     

Studies using a viral challenge and CD8 T cell depletions on the roles of cellular and humoral immunity in the control of an SHIV-89.6P challenge in DNA/MVA-vaccinated macaques

Here, we study immune responses in four DNA/MVA-vaccinated macaques following an SHIV-89.6P challenge and a subsequent CD8 cell depletion. Both post-challenge and post-depletion peaks of viremia contracted with the expansion, or re-emergence, of CD8 T cells. Post-depletion, CD8 cells expanded in the presence of higher levels of neutralizing Ab and CD4 help than post-challenge and had superior maturational characteristics as measured by expression of the anti-apoptotic protein Bcl-2, the IL-7 receptor CD127 and co-production of IFN-gamma and IL-2. Pre-challenge and pre-depletion titers of neutralizing Ab correlated inversely with peaks of viremia and directly with peaks for anti-viral CD4 cells. Thus, our results reveal CD8 cells playing a central role, and neutralizing Ab, a supporting role in SHIV-89.6P control. They also suggest a dynamic relationship between neutralizing Ab, antigen load and anti-viral CD4 cells in the maturation of high-quality anti-viral CD8 T cells.     

Clinical utility of bronchoalveolar lavage cytomegalovirus viral loads in the diagnosis of cytomegalovirus pneumonitis in infants

Cytomegalovirus (CMV) pneumonitis is a significant cause of morbidity and mortality of children in Africa. The current practice for diagnosing CMV pneumonitis in this setting is based on interpretation of clinical, laboratory, and radiological findings. There is a need for a sensitive and specific laboratory test to objectively distinguish between patients with CMV pneumonitis and those with CMV infection, and non‐CMV pneumonia. In this study, we compared plasma and non‐bronchoscopic bronchoalveolar lavage (NBBAL) CMV viral loads in patients with CMV pneumonitis and those with CMV infection and non‐CMV pneumonia. Receiver operator characteristic curve analysis was used to establish a threshold and assess utility of viral loads in the diagnosis of CMV pneumonitis. We assessed the urea dilution method, and expression of viral loads relative to the total amount of extracted nucleic acids in correcting for NBBAL dilution. CMV quantification in NBBAL specimens was more predictive of CMV pneumonitis than blood CMV quantification. The threshold of 4.03 log IU/ml in NBBAL specimens has good predictive value and can be used to guide management of infants with suspected CMV pneumonitis. Adjusting for dilution of NBBAL specimens by using the urea dilution method or by expressing the viral load relative to the total nucleic acids extracted did not provide additional analytical benefits. J. Med. Virol. 89:1080–1087, 2017 . © 2016 Wiley Periodicals, Inc.

     

Single dose inactivated hepatitis A vaccine: Rationale and clinical assessment of the safety and immunogenicity

In comparison with the classical immunisation schedules (0-1-6 or 0-1-12 months) for hepatitis A, a 0- and 12- or a 0- and 6-month schedule would have important advantages by reducing the number of injections and discomfort and increasing scheduling convenience and patient compliance. It would be convenient if a single dose with enough antigen could protect both rapidly and for at least 12 months, when the booster dose would be given. Several clinical trials have been carried out with an inactivated hepatitis A vaccine containing 1,440 ELU. (1 ml), according to a 0–12 and a 0–6 vaccination schedule. This hepatitis A vaccine is safe and well tolerated. It offers a rapid seroresponse: 14 days after a single dose the seroconversion is 88% (95% C.I.: 84.6–90.9). The 0–12 schedule study showed good persistence of hepatitis A virus (HAV) antibodies with a seroconversion rate of almost 95% at month 12. Booster doses given at 6 or 12 months result in a substantial rise in antibody levels; according to these antibody litres, the 1,440 EL. U. vaccine can be expected to confer comparable duration of protection as the 720 EL. U. vaccine, i.e., 10–20 years. Preliminary data show that tinning of the booster may not be critical for the antibody response. In conclusion, the 1,440 EL. U. hepatitis A vaccine is safe, offers rapid seroconversion, and is highly immunogenic. The persistence of HAV antibodies until month 12 allows a certain flexibility in the administration of the booster: month 6 or 12, and a 0–12 or 0–6 schedule can increase the vaccination compliance. copy; 1994 Wiiey-Liss, inc.     

小鼠B7-1基因转染的黑色素瘤细胞免疫原性探讨

目的 探讨Ｂ７－１分子对肿瘤细胞免疫原性的影响。方法 将小鼠Ｂ７－１基因转染的黑色素瘤细胞（Ｂ１６－ｍＢ７．１）与野 生型及空载体转染细胞（Ｂ１６－ｗｔ和Ｂ１６－ｎｅｏ）的免疫原性在体内外进行了比较。同源淋巴细胞肿瘤细胞混合培养（ＭＴＬＣＳ）后测定淋巴增殖指数和ＣＴＬＳ活性,将Ｂ１６－ｎｅｏｐ和Ｂ１６－ｍＢ７．１细胞接种于小鼠皮下,观察肿瘤生长速度。结果 Ｂ１６ｍＢ７．１在体外刺激淋巴细胞增殖和诱     

新型佐剂SWZY对弱免疫原性小鼠黑色素瘤瘤苗的免疫增强作用

目的:评价佐剂SWZY对弱免疫原性黑色素瘤瘤苗的免疫增强作用。方法:C57BL/6小鼠分为6组,实验组分别用5种不同配方的佐剂(FCA,FCA IL-2 GM-CSF,FIA IL-2 GM-CSF,FIA SWZY,FIA SWZY IL-2 GM-CSF)和照射灭活的小鼠黑色素瘤细胞株D5制成瘤苗免疫小鼠,对照组免疫用不加任何佐剂的灭活D5黑色素瘤细胞。末次免疫后3d各组取半数动物检测DTH反应、脾细胞的杀伤活性以及免疫小鼠血清及脾细胞培养上清中IFN-γ和IL-10的水平,剩余半数动物接种未灭活的D5黑色素瘤细胞,3周后再次检测上述各免疫学参数。结果:与对照组小鼠比较,各实验组小鼠的DTH反应及脾细胞的杀伤活性均明显升高(P<0.05),但成瘤后随着肿瘤的增大,则呈下降趋势。成瘤前各实验组小鼠血清及脾细胞培养上清中IFN-γ的水平均高于对照组小鼠(P<0.05),但IL-10的水平均低于对照组小鼠。成瘤后各实验组及对照组小鼠血清及脾细胞培养上清中IFN-γ的水平均下降,而IL-10的水平均明显上升,其中FCA瘤苗组和FIA SWZY瘤苗组免疫小鼠的血清及脾细胞培养上清中IFN-γ的水平仍高于对照组小鼠(P<0.05),IL-10的水平仍低于对照组小鼠(P<0.05)。结论:用5种佐剂配方制成的瘤苗免疫小鼠均能诱导对弱免疫原性肿瘤的细胞免疫应答,并增强Th1型细胞免疫的应答,但随着肿瘤的形成和逐渐进展,细胞免疫应答的效应逐渐减弱。其中佐剂SWZY与FCA的作用相当,但前者的毒副作用较小,有可能成为一种新型的人用肿瘤疫苗的佐剂。     

The contribution of HLA class I antigens in immune status following two doses of rubella vaccination

The variability of humoral and cellular immune responses modulated by human leukocyte antigen (HLA) genes is a significant factor in the protective effect of rubella vaccines. We performed HLA class I typing in a group of 346 healthy schoolchildren and young adults who previously received two doses of measles-mumps-rubella-II vaccine. Rubella virus–specific humoral (serum antibody) immunity and cell-mediated immunity (lymphocyte proliferation) were assessed. Median values for antibody levels and stimulation indices (SI) were 38.63 IU/ml and 2.29 IU/ml, respectively. The alleles that provided suggestive, but not conclusive, evidence of HLA association with rubella seropositivity were HLA-B*2705 (median, 24.68 IU/ml; p = 0.160), B*4501 (median, 61.22 IU/ml; p = 0.098), Cw*0303 (median, 30.34 IU/ml; p = 0.102) and Cw*0704 (median, 26.58 IU/ml; p = 0.144). These alleles approach, but do not achieve, statistical significance. Of all the alleles analyzed, HLA-B*3503 (median SI, 3.00; p = 0.031) and HLA-Cw*1502 (median SI, 3.19; p = 0.035) were positively associated with lymphoproliferative responses to rubella virus antigens, whereas the HLA-B*3901 (SI, 1.34; p = 0.066) allele was negatively associated. This suggests that class I HLA alleles may have limited associations with humoral and cellular immune responses to rubella vaccine. These data may facilitate our understanding of immune response variation in a genetically outbred heterogeneous population.     

A numerical approach to evaluate the fatigue life of monolimb

Monolimb refers to a transtibial prosthesis with the prosthetic socket and the shank being molded into one piece of thermoplastic material. Shank flexibility of a monolimb can improve gait and comfort. However, fatigue failure of monolimbs under cyclic walking load is an important concern. This study is to evaluate the fatigue life of a monolimb designed for a transtibial amputee, based on finite element analysis, the statistical Miner's rule and reliability analysis. Stress uncertainty due to modeling error and the scatter in fatigue test data were considered. Results indicated that the accuracy of fatigue life evaluation of monolimb depends significantly on the precision of stress estimation. In addition, relationship between fatigue failure probability and the number of walking steps was suggested providing a reference for clinicians to determine the interval of the inspection for the monolimb.     

A bioinformatics approach to ascertaining the rarity of HLA alleles

A project of the 15th International Histocompatibility Workshop examined the rarity of human leukocyte antigen (HLA) alleles. A section was constructed in the website, www.allelefrequencies.net to contain this data from different sources. A mechanism to search the data was implemented for use by any individual.     

Real-time PCR versus viral culture on urine as a gold standard in the diagnosis of congenital cytomegalovirus infection

Background

Cytomegalovirus (CMV) infection is the most common cause of congenital infection. Whereas CMV PCR has replaced viral culture and antigen detection in immunocompromised patients because of higher sensitivity, viral culture of neonatal urine is still referred to as the gold standard in the diagnosis of congenital CMV infection.

Objective

To compare real-time CMV PCR with shell vial culture on urine in the diagnosis of congenital CMV, in a multicenter design.

Study design

A series of neonatal urines (n = 340), received for congenital CMV diagnostics and routinely assessed with shell vial CMV culture, was retrospectively tested by real-time CMV PCR.

Results

The proportion of newborns found to be congenitally infected by real-time CMV PCR was 8.2% (28/340, 95%CI 5.6-11.8%), and 7.4% (25/340, 95%CI 4.9-10.8%) by rapid culture. When considering rapid culture as reference, real-time PCR was highly sensitive (100%), whereas sensitivity of rapid culture was 89.3% when considering real-time PCR as reference.

Conclusions

Our results, supported by analytical and clinical data on CMV DNA detection in neonatal urine, suggest enhanced sensitivity of recent PCR techniques when compared to viral culture. There is considerable rationale to favor real-time CMV PCR as a gold standard in the diagnosis of congenital CMV infection. A large-scale study combining both laboratory and clinical data is required to determine the exact time frame for sampling of neonatal urine when using real-time PCR.     

New revelations in susceptibility to autoimmune thyroiditis by the use of H2 and HLA class II transgenic models

H2 and HLA transgenes were utilized to clarify the role of class II genes in susceptibility to experimental autoimmune thyroiditis (EAT), a model for Hashimoto's thyroiditis (HT). Susceptibility was transferred by H2 class II transgenes to a resistant haplotype and by HLA-DRA/DRB1*0301 (DR3) transgene into class II-negative Ab0 mice. Mice with a HLA-DRB1*1502 (DR2) transgene remain resistant to mouse thyroglobulin (mTg)-induced EAT, illustrating the role of HLA-DRB1 polymorphism. A role for HLA-DQ polymorphism was shown with hTg-induced EAT in HLA-DQ*0301/DQB1*0302 (DQ8), but not HLA-DQ*0103/DQB1*0601 (DQ6), transgenic mice. Yet, both DQ8+ and DQ6+ mice were unresponsive to mTg. Single transgenes obviate the problems from DR/DQ linkage disequilibrium and may distinguish the degree of susceptibility and the response to shared or specific epitopes. The introduction of conserved Eak transgene into Ab0 mice reveals a new role for H2E molecules in EAT. Without H2A molecules, EalphaEbetab molecules and T cells respond to hTg or pTg with severe thyroiditis, but not to mTg, thus distinguishing self from nonself. However, IAb genes in resistant mice ameliorate Eak transgene-mediated thyroiditis, similar to the effect of Eak transgene on IAs-mediated EAT. Studies in HLA DQ/DR double transgenic mice simulating human haplotypes could reveal HLA class II gene interactions in HT.     

A novel approach to regulate experimental visceral leishmaniasis in murine macrophages using CCR5 siRNA

Early infection with Leishmania donovani during visceral leishmaniasis (VL) results in the enhanced expression of C-C chemokine receptor 5 (CCR5) in macrophages. CCR5 expression at different time points of infection revealed increased expression at protein and mRNA level from 3 to 24 h and beyond 24 h expression of CCR5 is downregulated. To better understand the functional role of CCR5 during leishmania infection, RNA interference strategy has been used to modulate macrophage function by targeting the expression of CCR5 gene. We found that silencing of CCR5 receptor expression by transfection of CCR5-specific small interfering RNA (siRNA) in murine peritoneal macrophages restricted the parasitic burden up to 70% during early hours of infection . In addition, gene silencing of CCR5 prior to L. donovani infection enhanced the pro-inflammatory response of the host macrophages in comparison with infection alone as shown by high nitric oxide generation and the TNF-α:IL-10 ratio. These findings suggest that CCR5 receptor plays a significant role in the entry and establishment of L. donovani in murine macrophages and CCR5 gene silencing would be a potent therapeutic approach to control VL by restricting parasite entry.     

HLA antigens and different clinical forms of 21-hydroxylase deficiency in the French population

HLA associations with 21-OH deficiency were studied on respectively 109 and 60 congenital and late onset French index cases. Significant negative associations were found with antigens B8: congenital forms; B5, DR3: late onset. Significant positive associations were observed with A3, Bw47 (A3 Cw6 Bw47 DR7): congenital forms; B40: salt-wasting form; B5: simple virilizing form; Aw33, B14, DR1, DR2, DRw6 (Aw33 B14 DR1): late onset form. Among late onset patients not bearing B14 antigens significant positive associations were observed with B12 and B35.