Different expression of human herpesvirus-6 (HHV-6) load in whole blood may have a significant impact on the diagnosis of active infection

BackgroundViral load in whole blood is the main virological marker for assessing HHV-6 infection and is used as an indication to begin antiviral therapy. Results are usually expressed as the number of genomic equivalent copies (gec) per mL of blood, although HHV-6 DNA in blood is mainly localized in lymphocytes and polymorphonuclear leukocytes.ObjectivesSince leukocyte counts vary in immunocompromised patients, especially in stem cell transplant recipients, the aim of this study was to compare HHV-6 load expressed as gec per mL with load expressed as gec per million cells (mc), using quantitative real-time PCR for HHV-6 and cell DNA.Study design194 blood samples from 101 patients were analyzed. Leukocyte count was obtained for 142 samples.ResultsThe two modes of expression were incompletely correlated (p < 0.0001; R² = 0.732). To understand this relative discrepancy, samples were classified according to hematological criteria (normal leukocyte count, leukopenia, agranulocytosis, lymphopenia). The expression modes were correlated in all cases except for agranulocytosis (p = 0.21; R² = 0.087). Moreover, the median of ratio between gec per mc and gec per mL ranged from 0.5 when leukocyte count was normal, to 8.2 in cases of agranulocytosis. HHV-6 load follow-up suggested that in agranulocytosis expressing results as gec per mc tended to provide a more representative result.ConclusionsThe different expression of HHV-6 load in whole blood, as either gec per mL or gec per mc resulted in different estimations of infection in the case of agranulocytosis. In this situation, the latter mode of expression is preferred.     

Human herpesvirus-6A and -6B encode viral immunoevasins that downregulate class I MHC molecules

Like all other members of the herpesvirus family, the closely related human herpesviruses-6 and -7 (HHV-6,7) persist in their host throughout life. In so doing, without exception, every member of the herpesvirus family has evolved mechanisms to avoid detection by the immune system. In particular, human cytomegalovirus (HCMV), mouse cytomegalovirus (MCMV), human herpesvirus-8 (HHV-8), and herpes simplex virus (HSV) all encode multiple proteins that interfere with proper MHC class I antigen presentation. The mechanisms employed by these viruses to effect removal of MHC class I from the cell surface vary. The U21 open reading frame from HHV-7 diverts class I MHC molecules to an endolysosomal compartment using an as-yet unknown mechanism. The two variants of HHV-6, HHV-6A and -6B, both possess a U21 open reading frame which contain only approximately 30% amino acid identity to the U21 sequence from HHV-7. Here we describe the characterization of the U21 gene products from HHV-6A and HHV-6B. Like HHV-7 U21, both of the HHV-6 U21 molecules bind to and divert class I MHC molecules to an endolysosomal compartment, effectively removing them from the cell surface, and providing a possible means of escape from immune detection.     

Detection and quantitation of human papillomavirus DNA in peripheral blood mononuclear cells from blood donors

Human papillomavirus (HPV) is the etiological agent of cervical cancer. Also, HPV has been associated with anogenital cancer, oropharyngeal cancer, genital warts, and other dermatological diseases. HPV infects epithelial cells and their replication is closely linked to epithelial differentiation. The presence of HPV DNA in peripheral blood mononuclear cells (PBMC) has been reported in some patients with head and neck cancer, cervical cancer, and other genital diseases. However, the presence of HPV DNA in blood in asymptomatic subjects is still unresolved. The objective of this study was to evaluate the presence of HPV DNA in PBMC from asymptomatic blood donors. Blood samples were collected from 207 healthy Chilean blood donors. Genomic DNA was extracted from PBMC and HPV DNA detection was performed by real-time quantitative polymerase chain reaction assays with GP5+/6+ primers. HPV typing was carried out by genetic sequencing of a 140 to 150 bp fragment of the L1 gene. HPV DNA was detected in 6.8% (14/207) of blood donors. Single HPV infections were detected in seven blood donors. High-risk HPV was found in 6.3% (13/207) of cases: nine blood donors were infected with HPV-16, five with HPV-18, two with HPV-51, and one case was infected with either 32, 33, 45, 59, 66, 70, or 82. The median viral load value was 21.3 copies/mL blood or 13.4 HPV (+) cells per 10 ⁴ PBMC. These results show that HPV DNA is present in PBMC from healthy blood donors and it suggests that blood could be a new route of HPV dissemination.     

自外周血记忆B细胞体外活化和分化抗原特异性浆细胞的方法研究

目的 建立自人外周血淋巴细胞(PBMCs)中的记忆B细胞活化和分化特异性抗体分泌细胞(如浆细胞)的体外活化方法,为抗体药物研发提供研究基础.方法 采集两名接种过乙型肝炎疫苗3年和25年健康成年志愿者(Z和L)外周血,分离PBMCs,通过白细胞介素(IL)-2、IL-4和Toll样受体诱导剂(CpG、R848)体外诱导活化记忆B细胞.采用酶联免疫吸附试验(ELISA)检测培养上清中总抗体和HBsAg特异性抗体的含量;通过酶联免疫斑点试验(ELISPOT)检测培养细胞中总抗体分泌细胞(ASC)数量的变化和HBsAg特异性抗体细胞数量.结果 活化第6天,对照组和两个活化组[CpG DNA2006联合IL-2(C组)和R848联合IL-2(R组)]细胞培养上清总免疫球蛋白(Ig)G浓度分别为37.06ng/mL、80.87 ng/mL和85.97 ng/mL,两个活化组(C组和R组)均明显高于对照组(t=23.318,60.639,P均＜0.05).ELISPOT检测ASC数量,结果显示,C组和R组数量均多于对照组,并且R组明显多于C组.两种活化方法均能在体外诱导B细胞活化,但R组活化效果更佳,确立R组为最佳活化方法.用该方法活化两名乙型肝炎疫苗接种者PBMCs,ELISA检测活化组特异性抗体浓度,R组显著高于对照组(t=5.031,11.561,P均＜0.05).不同细胞数量诱导的分组,ELISPOT检测HBsAg特异性抗体分泌细胞数量,R组均明显多于对照组.结论 确立诱导剂R848和细胞因子IL-2联合能够有效地诱导外周血记忆B细胞体外活化和分化抗原特异性浆细胞,为今后抗体药物研发提供了研究基础.     

Modulation of in vitro immunoglobulin synthesis of human peripheral blood mononuclear cells by nicotine and cotinine

The influence of nicotine and its main metabolite cotinine on the spontaneous and cytokine-induced immunoglobulin synthesis was studied. The immunoglobulin (G,A) synthesis of peripheral blood mononuclear cells was altered by nicotine donor dependently in the concentration range from 10–6 to 10^–8 M. Cotinine also modulates immunoglobulin (G, A) synthesis. The effective concentration range is about 100 fold higher. Only marginal effects on IgM synthesis were observed. Neither nicotine nor cotinine showed any effect on IgE production or on the IgE class switch. Moreover, both agents induced the production of the cytokines interleukin-1, –2, –3, –4, and –6. Therefore it is suggested that the strongly donor-dependent heterogeneity in the response to nicotine or cotinine is the result of the fine balance of theinduced cytokines.Abbreviations IFN interferon - IL interleukin - PBMC peripheral blood mononuclear cells - TNF tumor necrosis factor Correspondence to: A. Fischer     

Detection of human herpesvirus 6 DNAs in samples from several body sites of patients with exanthem subitum and their mothers by polymerase chain reaction assay

Polymerase chain reaction amplification was used to detect human herpesvirus 6 (HHV-6) DNAs in peripheral blood mononuclear cells (MNCs), plasma, saliva, stool, and urine from three patients with exanthem subitum and in peripheral blood MNCs, plasma, and saliva from their mothers. HHV-6 DNAs were detected in MNCs during and after the disease and were found in plasma only in the acute phase. The virus DNAs were also detected in saliva after recovery from the illness and were found persistently or intermittently in stool but not in urine samples after the onset of the disease. In contrast, one of the three mothers excreted HHV-6 DNAs persistently in saliva. None of the mothers had the virus DNAs in peripheral blood MNCs and plasma nor a significant increase in antibody titers to HHV-6 after possible exposure from their children. These findings suggest systemic replication of HHV-6 during the acute phase in patients with exanthem subitum and persistent infection of the virus in several organs after recovery from the disease. © 1995 Wiley-Liss, Inc.     

Effects of barium chloride adsorbed to polyethylene glycol (PEG) microspheres on co-culture of human blood mononuclear cell and breast cancer cell lines (MCF-7)

This study investigated the effects of BaCl₂ adsorbed to polyethylene glycol (PEG) microspheres on human blood mononuclear cells (MN) co-cultured with breast cancer cell lines (MCF-7). The MCF-7 cells were obtained from the American Type Culture Collection and the blood mononuclear (MN) cells from volunteer donors. MN cells, MCF-7 cells and their co-culture (MN and MCF-7 cells) were pre-incubated for 24?h with or without 25 and 1000?pg?L^?1 BaCl₂ (Ba₂₅ and Ba₁₀₀₀), PEG microspheres or 25 and 1000?pg?L^?1 BaCl₂ adsorbed to PEG microspheres (PEG-Ba₂₅ and PEG-Ba₁₀₀₀). Rheological parameters and apoptosis were determined. Fluorescence microscopy and flow cytometry analyses revealed that BaCl₂ was able to adsorb the PEG microspheres. The blood flow and viscosity curves were similar among the treatments. In general, apoptosis rates increased in co-cultured cells, co-cultured cells incubated with Ba₂₅ and with PEG-Ba₂₅, but the highest rates were observed in co-cultured cells incubated with PEG-Ba₁₀₀₀. In conclusion, BaCl₂ adsorbed to PEG microspheres exhibited dose-dependent antitumor effects against human MCF-7 breast cancer cells co-cultured with MN cells, thereby offering a possible therapeutic alternative for treating this disease provided they are administered at very low concentrations.     

Quantitation of hepatitis C virus in liver and peripheral blood mononuclear cells from patients with chronic hepatitis C virus infection

Since the natural history of hepatitis C virus-associated liver disease and the therapeutic responsiveness might vary according to liver and blood mononuclear cells viral levels, it may be important to quantitate viral RNA in liver, blood mononuclear cells and serum, and to compare these data with genotype, biochemical and histologic data. A polymerase chain reaction-based assay available for serum hepatitis C virus RNA quantitation has been optimized to quantitate viral genomes in liver and peripheral blood mononuclear cells from 47 chronic hepatitis C patients. The procedure permitted hepatitis C virus RNA quantitation in freshly isolated mononuclear cells and in total RNA extracted from frozen mononuclear cells and liver tissue. The intrahepatic viral amount (median: 2.6 × 10³ copies/μg RNA; range: 0 to 3.6 × 10⁴ copies/μg RNA) correlated significantly with the hepatitis C virus RNA concentration in serum (r = 0.76, P < .001) but not in mononuclear cells. Viral RNA concentrations in liver (P < .001), serum (P < 0.01) and PBMC (P < 0.05) were significantly higher in hepatitis C virus genotype 1 patients (essentially type 1b) than in non-1 type cases, but were unrelated to biochemical or histologic indexes of disease activity. In conclusion, the optimized assay permit HCV RNA quantitation in liver and peripheral blood mononuclear cells, suggesting that serum viral level is an accurate measurement of intrahepatic viral burden. J. Med. Virol. 54:265–270, 1998. © 1998 Wiley-Liss, Inc.     

Confirmation of the low clinical effect of human herpesvirus-6 and -7 infections after renal transplantation

Human herpesvirus‐6 and ‐7 (HHV‐6 and HHV‐7) may lead to pathological manifestations in renal transplant recipients. The aim of this study was to investigate beta‐herpesvirus infections in 50 adult kidney transplant recipients after transplantation to examine the effect, interactions, and pathogenic consequences of infection and the effect of immunosuppressive regimens and Human cytomegalovirus (HCMV) prophylaxis with VACV. Beta‐herpesviruses loads in the blood of 50 adult kidney transplant recipients over a 6‐month period after transplantation and 198 blood donors were determined using polymerase chain reaction. The rate of HHV‐6 detection in peripheral mononuclear cells (PBMCs) was higher in patients with end‐stage renal disease and during the post‐transplantation follow‐up than in healthy subjects (33% and 68% vs. 12%, respectively). The detection rate of HHV‐7 in PBMCs was similar between patients, both before grafting and during the follow‐up for transplant recipients (69% and 88%, respectively), and healthy subjects (78%), and correlated with the number of lymphocytes. HCMV in plasma was detected only in patients during the post‐transplant period (24%). VACV prophylaxis had no negative effect on the replication of HHV‐6 or HHV‐7, and univariate analyses demonstrated associations between HHV‐6 infection and acute graft rejection [Odds ratio (OR) = 2.94, 95% confidence interval (CI), 1.05–8.2, P = 0.04], and between HHV‐7 infection and cholestasis [OR = 2.61 (95% CI, 1.08–6.3), P = 0.03]. Immunosuppressive regimens had no effect on beta‐herpesviruses infections. This study revealed the differing behavior of HCMV, HHV‐6, and HHV‐7 in kidney transplant recipients, and confirmed the association of HHV‐6 with graft rejection. J. Med. Virol. 84:450–456, 2012. © 2011 Wiley Periodicals, Inc.     

High- and low-level cytokine induction in human peripheral blood mononuclear cells by different Borrelia burgdorferi strains

In this report we have compared the ability of 14 Borrelia burgdorferi sensu lato isolates to stimulate monocytes. From these isolates, all three human pathogen genospecies were represented. To determine the stimulatory activity of the different strains, interleukin-1β (IL-1β) was measured in the supernatant of monocyte cultures. This was achieved with borrelial strains in a ratio of 10 bacteria to 1 monocyte. In the majority of strains the stimulation induced a release of about 8000 pg/ml IL-1β, whereas four strains (B31, 297, EB3, 1/B29) induced more than 18000 pg/ml IL-1β. We could, therefore, define two groups: low-level inductors and high-level inductors for IL-1β. The strains in the defined groups could not be ascribed to one distinct genospecies or a biological source. Further experiments confirmed the same differential release for tumor necrosis factor-α, but not for IL-6. Studies on IL-1β indicated that high- and low-level release of cytokine was due to differences in protein synthesis. Received: 30 January 1996     

The effects of vitamin A derivatives on in vitro antibody production by peripheral blood mononuclear cells (PBMC) from normal blood donors and patients with common variable immunodeficiency (CVID)

The underlying nature of the defect of CVID is not understood, and the treatment at present is life-long infusion of replacement immunoglobulin. Attempts have been made to use other therapeutic agents, such as IL-2 and retinoic acid (RA), with mixed results. RA is a morphogenetic signalling molecule related to vitamin A and involved in vertebrate development. We report here our in vitro evaluation of the effects of three vitamin A analogues, 9-cis retinal, 13-cis RA and all-trans RA, on antibody production of PBMC from normal donors and patients with CVID. At 10⁻⁵ m, 9-cis retinal strongly augmented IgM production of lymphocytes from normal individuals and to a much lesser extent, mild, non-granulomatous (group C) CVID patients, but IgG production was not affected. In the presence of anti-human IgM and IL-2, 9-cis retinal at 10⁻⁵ m elevated IgM and IgG production by normal PBMC, but the effect on PBMC of mild CVID was minimal. The effect of 9-cis retinal was significantly reduced at 10⁻⁷ and 10⁻⁹ m. Only minimal effects were found using 13-cis RA and all-trans RA under these conditions. No detectable antibody production was found in severe, granulomatous (group A) CVID patients under any conditions tested. Taking all data into account, 9-cis retinal is the most potent stimulator for antibody production compared with 13-cis RA and all-trans RA as tested in this in vitro study.     

Correlation between the detection of viral DNA by the polymerase chain reaction in peripheral blood leukocytes and serological responses to human herpesvirus 6, human herpesvirus 7, and cytomegalovirus in renal allograft recipients

Diagnosis of significant infections by human herpesvirus 6 (HHV6) and 7 (HHV7) in transplant patients has proved difficult because both viruses are ubiquitous and can cause persistent infections in their hosts. The significance of viral DNA detected in peripheral blood leukocytes (PBLs; DNAemia) by PCR is therefore unclear. The interpretation of serological results is complicated by the fact that both primary and secondary infections with other herpesviruses may be associated with a concurrent antibody response to HHV6. Fifty-four renal allograft recipients were studied prospectively and their serological response to HHV6, HHV7 and CMV were compared with the detection of viral DNAemia from the homologous and heterologous viruses. Serum and heparinised blood samples were collected prospectively from 54 renal allograft recipients. DNA was extracted from PBLs and tested for the presence of HHV6, HHV7 and CMV DNA by PCR. Antibodies to HHV6 and HHV7 were measured by an indirect immunofluorescence test and to CMV by an anticomplement immunofluorescence (ACIF) test. CMV IgM antibodies were detected by a commercial enzyme immunoassay. CMV and HHV7 DNAemia were each significantly associated with serological responses to the homologous virus but no such association was found for HHV6 DNAemia. However, patients with consecutively positive DNAemia to any of the viruses (including HHV6) were more likely to have a homologous serological response. Patients who had detectable CMV IgM without a concurrent rise in CMV antibodies were significantly less likely to have CMV DNAemia (odds ratio = 0.16; 95% CI 0.02–0.9). CMV IgM antibodies may be associated with HHV6 or HHV7 DNAemia (odds ratio 2.3; 95% CI 0.5–15). This serological profile may reflect a cross-reactive response to HHV6, HHV7 or other herpesviruses. CMV IgM should not be used in isolation for the diagnosis of CMV infection or disease in this group of patients. J. Med. Virol. 53:288–294, 1997. © 1997 Wiley-Liss, Inc.     

Effect of IL-4 and interferon-gamma (IFN-gamma) on IL-3- and IL-5-induced eosinophil differentiation from human cord blood mononuclear cells.

IL-4 and IFN-gamma positively and negatively regulate allergic inflammation. To determine the regulatory mechanisms of eosinopoiesis by cytokines, we examined the effect of recombinant IL-4 and IFN-gamma and of anti-IL-4 and anti-IFN-gamma antibodies on IL-3- and IL-5-induced eosinophil differentiation from human umbilical cord blood mononuclear cells. rhIL-4 (10-300 U/ml) inhibited IL-3- and IL-5-induced eosinophil differentiation from cord blood mononuclear cells on day 28 of culture by 62-81% in a concentration-dependent manner. rhIFN-gamma (5-500 U/ml) also inhibited IL-3- and IL-5-induced eosinophil differentiation by 80-99% in a concentration-dependent manner. The inhibitory effect of rhIL-4 and rhIFN-gamma was observed only when rhIL-4 or rhIFN-gamma were present in the culture from day 0 to day 14, but not from day 15 to day 28. Addition of anti-IL-4 antibody to the culture enhanced IL-3- and IL-5-induced eosinophil differentiation on day 28 of culture by 30%, whereas anti-IL-2 MoAb and anti-IFN-gamma MoAb had no significant effect. These results indicate that IL-4 and IFN-gamma have inhibitory effects on IL-3- and IL-5-induced eosinophil differentiation from its progenitor cells.     

B7H6 is a functional ligand for NKp30 in rat and cattle and determines NKp30 reactivity toward human cancer cell lines

NK cells kill cancer cells and infected cells upon activation by cell surface receptors. Human NKp30 is an activating receptor expressed by all mature NK cells. The B7 family member B7H6 has been identified as one ligand for NKp30. Several alternative ligands have also been reported, and the field remains unsettled. To this end, we have identified full‐length functional B7H6 orthologs in rat and cattle, demonstrated by phylogenetic analysis and transfection experiments. In cell–cell contact‐dependent assays, chimeric NKp30 reporter cells responded strongly to B7H6 in rat and cattle. Likewise, rat NKp30 expressing target cells induced strong activation of B7H6 reporter cells. Together, these observations demonstrate that B7H6 is conserved as a functional ligand for NKp30 in mammalian species separated by more than 100 million years of evolution. B7H6 and NKp30 are pseudogenes in laboratory mice. The rat thus represents an attractive experimental animal model to study the NKp30‐B7H6 interaction in vivo. B7H6 was widely expressed among human cancer cell lines, and the expression level correlated strongly with the activation of human NKp30 reporter cells. Furthermore, siRNA knockdown of B7H6 abolished NKp30 reporter responses, suggesting that B7H6 is the major functionally relevant expressed ligand for NKp30 on these cancer cell lines.     

B7-H3在人肝癌细胞株HepG2对外周血CD8+T细胞活化、周期及分泌IL-17调节中的作用

目的 研究B7-H3在人肝癌细胞株HepG2对人外周血CD8+T细胞活化、周期及IL-17分泌等调节中的作用.方法 RT-PCR及FCM检测B7-H3在HepG2细胞上的表达;应用脂质体法将PGPU6/GFP/neo-B7-H3shRNA质粒转入肝癌细胞株HepG2,阻断B7-H3的表达;免疫磁珠分选健康人外周血CD8+T细胞;FCM分析B7-H3分子在HepG2细胞对PHA刺激下CD8+T细胞活化、周期及PMA刺激下CD8+T细胞分泌IL-17调节中的作用.结果 肝癌细胞株HepG2高表达B7-H3分子,PGPU6/GFP/neo-B7-H3 shRNA质粒能有效阻断B7-H3在HepG2细胞上的表达;FCM分析结果显示,肝癌细胞株HepG2对CD8+T细胞活化及周期均有抑制作用;阻断B7-H3的表达后,明显减弱HepG2细胞对CD8+T细胞早期活化表型CD69表达的抑制作用,且能够通过下调CD8+T细胞Go/G1期细胞数量,上调S期细胞数量逆转HepG2细胞对CD8+T细胞周期的阻滞作用;在HepG2存在条件下,CD8+T细胞对IL-17的分泌明显增加,阻断B7-H3的表达后,IL-17的分泌被进一步上调.结论 HepG2细胞高表达B7-H3分子;B7-H3能够协同HepG2细胞对CD8+T细胞活化表型CD69的表达及细胞周期的抑制作用;HepG2细胞上调CD8+T细胞对IL-17的分泌作用,但B7-H3可抑制该上调作用.     

Seroepidemiological study of human herpesvirus-6 and -7 in children of different ages and detection of these two viruses in throat swabs by polymerase chain reaction

The presence of human herpesvirus 6 (HHV-6) and human herpesvirus 7 (HHV-7) in throat swabs of 62 children of different age groups (group I, ages 0–5 month; group II, ages 6–11 months, group III, ages 12–23 months, group IV, age 2–8 years) and 28 adults was detected by polymerase chain reaction. The detection rate of HHV-6 DNA was the highest (87%) in children aged 1-year-old and decreased with age, whereas the detection rate of HHV-7 increased with age and reached a maximum in adults. HHV-6B was detected in almost all samples except for two children who secreted only HHV-6A. When the antibody prevalence was determined in the four groups of children, HHV-6 antibody was detected in 8/12 (66.7%), 10/12 (83.3%), 15/16 (93.8%), and 13/14 (92.9%), respectively. Antibody to HHV-7 in these groups was detected in 6/12 (50.0%), 4/12 (33.3%), 12/16 (75.0%), and 13/14 (92.9%), respectively. Detection of HHV-6 DNA in throat swabs of triplets who had the sequential onset of exanthem subitum was attempted by using samples sequentially collected from these children after the onset of the disease in the first patient. HHV-6 DNA with high copy numbers was detectable during the acute and convalescent phases of the disease in all patients, but no DNA was detected in samples collected before the onset of disease. © 1996 Wiley-Liss, Inc.