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51.
Mirjam M. J. Jacobs Ben Vosman Vivianne G. A. A. Vleeshouwers Richard G. F. Visser Betty Henken Ronald G. van den Berg 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2010,120(4):785-796
Mapping resistance genes is usually accomplished by phenotyping a segregating population for the resistance trait and genotyping
it using a large number of markers. Most resistance genes are of the NBS-LRR type, of which an increasing number is sequenced.
These genes and their analogs (RGAs) are often organized in clusters. Clusters tend to be rather homogenous, viz. containing
genes that show high sequence similarity with each other. From many of these clusters the map position is known. In this study
we present and test a novel method to quickly identify to which cluster a new resistance gene belongs and to produce markers
that can be used for introgression breeding. We used NBS profiling to identify markers in bulked DNA samples prepared from
resistant and susceptible genotypes of small segregating populations. Markers co-segregating with resistance can be tested
on individual plants and directly used for breeding. To identify the resistance gene cluster a gene belongs to, the fragments
were sequenced and the sequences analyzed using bioinformatics tools. Putative map positions arising from this analysis were
validated using markers mapped in the segregating population. The versatility of the approach is demonstrated with a number
of populations derived from wild Solanum species segregating for P. infestans resistance. Newly identified P. infestans resistance genes originating from S. verrucosum, S. schenckii, and S. capsicibaccatum could be mapped to potato chromosomes 6, 4, and 11, respectively. 相似文献
52.
Diversity, activity, and abundance of sulfate-reducing bacteria in saline and hypersaline soda lakes
Foti M Sorokin DY Lomans B Mussman M Zacharova EE Pimenov NV Kuenen JG Muyzer G 《Applied and environmental microbiology》2007,73(7):2093-2100
Soda lakes are naturally occurring highly alkaline and saline environments. Although the sulfur cycle is one of the most active element cycles in these lakes, little is known about the sulfate-reducing bacteria (SRB). In this study we investigated the diversity, activity, and abundance of SRB in sediment samples and enrichment cultures from a range of (hyper)saline soda lakes of the Kulunda Steppe in southeastern Siberia in Russia. For this purpose, a polyphasic approach was used, including denaturing gradient gel electrophoresis of dsr gene fragments, sulfate reduction rate measurements, serial dilutions, and quantitative real-time PCR (qPCR). Comparative sequence analysis revealed the presence of several novel clusters of SRB, mostly affiliated with members of the order Desulfovibrionales and family Desulfobacteraceae. We detected sulfate reducers and observed substantial sulfate reducing rates (between 12 and 423 micromol/dm(3) day(-1)) for most lakes, even at a salinity of 475 g/liter. Enrichments were obtained at salt saturating conditions (4 M Na(+)), using H(2) or volatile fatty acids as electron donors, and an extremely halophilic SRB, strain ASO3-1, was isolated. Furthermore, a high dsr gene copy number of 10(8) cells per ml was detected in a hypersaline lake by qPCR. Our results indicate the presence of diverse and active SRB communities in these extreme ecosystems. 相似文献
53.
van Dieën JH Spanjaard M Konemann R Bron L Pijnappels M 《Journal of biomechanics》2007,40(16):3641-3649
Stepping down an elevation in ongoing gait is a common task that can cause falls when the level change is unexpected. The aim of this study was to compare expected and unexpected stepping down. We hypothesized that unexpected stepping would lead to loss of control over the movement and potentially falls due to buckling of the leading leg at landing. Ten male subjects repeatedly walked over a platform on which they stepped down an expected 10-cm height difference. In 5 out of 50 trials, the height difference was encountered unexpectedly early. Kinematics and ground reaction forces under both feet were measured during the stride in which the height difference was negotiated. Stepping down involved a substantial increase in forward horizontal and angular momenta (approximately 40 N s and 20 N ms). In expected stepping down, step length was significantly increased (17%), which allowed control of these forward horizontal and angular momenta immediately following landing. In unexpected stepping down, the time between expected ground contact and actual ground contact (110 ms) appeared too short to substantially adjust leg movement and increase step length. Although buckling of the leg did not occur, presumably due to its more vertical orientation at landing, momentum could not be sufficiently attenuated at landing, but a fall was prevented by a rapid step of the trailing limb. The lack of control of momentum might cause a fall, when the capacity to make such a rapid step falls short, as in the elderly, or when the height difference is larger. 相似文献
54.
55.
Mirjam?S. de?Pagter Markus?J. van?Roosmalen Annette?F. Baas Ivo Renkens Karen?J. Duran Ellen van?Binsbergen Masoumeh Tavakoli-Yaraki Ron Hochstenbach Lars?T. van?der?Veken Edwin Cuppen Wigard?P. Kloosterman 《American journal of human genetics》2015,96(4):651-656
Chromothripsis represents an extreme class of complex chromosome rearrangements (CCRs) with major effects on chromosomal architecture. Although recent studies have associated chromothripsis with congenital abnormalities, the incidence and pathogenic effects of this phenomenon require further investigation. Here, we analyzed the genomes of three families in which chromothripsis rearrangements were transmitted from a mother to her child. The chromothripsis in the mothers resulted in completely balanced rearrangements involving 8–23 breakpoint junctions across three to five chromosomes. Two mothers did not show any phenotypic abnormalities, although 3–13 protein-coding genes were affected by breakpoints. Unbalanced but stable transmission of a subset of the derivative chromosomes caused apparently de novo complex copy-number changes in two children. This resulted in gene-dosage changes, which are probably responsible for the severe congenital phenotypes of these two children. In contrast, the third child, who has a severe congenital disease, harbored all three chromothripsis chromosomes from his healthy mother, but one of the chromosomes acquired de novo rearrangements leading to copy-number changes. These results show that the human genome can tolerate extreme reshuffling of chromosomal architecture, including breakage of multiple protein-coding genes, without noticeable phenotypic effects. The presence of chromothripsis in healthy individuals affects reproduction and is expected to substantially increase the risk of miscarriages, abortions, and severe congenital disease. 相似文献
56.
Anna Stincone Alessandro Prigione Thorsten Cramer Mirjam M. C. Wamelink Kate Campbell Eric Cheung Viridiana Olin‐Sandoval Nana‐Maria Grüning Antje Krüger Mohammad Tauqeer Alam Markus A. Keller Michael Breitenbach Kevin M. Brindle Joshua D. Rabinowitz Markus Ralser 《Biological reviews of the Cambridge Philosophical Society》2015,90(3):927-963
57.
Lupberger J Zeisel MB Xiao F Thumann C Fofana I Zona L Davis C Mee CJ Turek M Gorke S Royer C Fischer B Zahid MN Lavillette D Fresquet J Cosset FL Rothenberg SM Pietschmann T Patel AH Pessaux P Doffoël M Raffelsberger W Poch O McKeating JA Brino L Baumert TF 《Nature medicine》2011,17(5):589-595
Hepatitis C virus (HCV) is a major cause of liver disease, but therapeutic options are limited and there are no prevention strategies. Viral entry is the first step of infection and requires the cooperative interaction of several host cell factors. Using a functional RNAi kinase screen, we identified epidermal growth factor receptor and ephrin receptor A2 as host cofactors for HCV entry. Blocking receptor kinase activity by approved inhibitors broadly impaired infection by all major HCV genotypes and viral escape variants in cell culture and in a human liver chimeric mouse model in vivo. The identified receptor tyrosine kinases (RTKs) mediate HCV entry by regulating CD81-claudin-1 co-receptor associations and viral glycoprotein-dependent membrane fusion. These results identify RTKs as previously unknown HCV entry cofactors and show that tyrosine kinase inhibitors have substantial antiviral activity. Inhibition of RTK function may constitute a new approach for prevention and treatment of HCV infection. 相似文献
58.
van Zuiden M Heijnen CJ van de Schoot R Amarouchi K Maas M Vermetten E Geuze E Kavelaars A 《PloS one》2011,6(12):e29142
Major depressive disorder (MDD) is frequently diagnosed in military personnel returning from deployment. Literature suggests that MDD is associated with a pro-inflammatory state. To the best of our knowledge, no prospective, longitudinal studies on the association between development of depressive symptomatology and cytokine production by peripheral blood leukocytes have been published. The aim of this study was to investigate whether the presence of depressive symptomatology six months after military deployment is associated with the capacity to produce cytokines, as assessed before and after deployment. 1023 military personnel were included before deployment. Depressive symptoms and LPS- and T-cell mitogen-induced production of 16 cytokines and chemokines in whole blood cultures were measured before (T0), 1 (T1), and 6 (T2) months after return from deployment. Exploratory structural equation modeling (ESEM) was used for data reduction into cytokine patterns. Multiple group latent growth modeling was used to investigate differences in the longitudinal course of cytokine production between individuals with (n = 68) and without (n = 665) depressive symptoms at T2. Individuals with depressive symptoms after deployment showed higher T-cell cytokine production before deployment. Moreover, pre-deployment T-cell cytokine production significantly predicted the presence of depressive symptomatology 6 months after return. There was an increase in T-cell cytokine production over time, but this increase was significantly smaller in individuals developing depressive symptoms. T-cell chemokine and LPS-induced innate cytokine production decreased over time and were not associated with depressive symptoms. These results indicate that increased T-cell mitogen-induced cytokine production before deployment may be a vulnerability factor for development of depressive symptomatology in response to deployment to a combat-zone. In addition, deployment to a combat-zone affects the capacity of T-cells and monocytes to produce cytokines and chemokines until at least 6 months after return. 相似文献
59.
Identification of Varicella-Zoster Virus-Specific CD8 T Cells in Patients after T-Cell-Depleted Allogeneic Stem Cell Transplantation
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Pim L. J. van der Heiden Renate de Boer Dirk M. van der Steen Michel G. D. Kester Menno W. A. G. van der Hoorn Wilmy M. E. Haarman Helen E. Barnby-Porritt Jeremy W. Fry C. E. Napper Erik W. A. Marijt Roel Willemze J. H. Frederik Falkenburg Mirjam H. M. Heemskerk 《Journal of virology》2009,83(14):7361-7364
To study the role of CD8 T cells in the control of varicella-zoster virus (VZV) reactivation, we developed multimeric major histocompatibility complexes to identify VZV-specific CD8 T cells. Potential HLA-A2 binding peptides from the putative immediate-early 62 protein (IE62) of VZV were tested for binding, and peptides with sufficient binding capacity were used to generate pentamers. Patients with VZV reactivation following stem cell transplantation were screened with these pentamers, leading to the identification of the first validated class I-restricted epitope of VZV. In 42% of HLA-A2 patients following VZV reactivation, these IE62-ALW-A2 T cells could be detected ex vivo.Varicella-zoster virus (VZV) infects about 95% of the population, persists throughout life, and may lead to herpes zoster when the virus reactivates. After T-cell-depleted allogeneic stem cell transplantation (TCD alloSCT), reactivation of the virus leads to considerable morbidity (10). Primary infection elicits both humoral and cellular responses, but cellular immunity is essential for preventing herpes zoster. The VZV genome comprises more than 70 unique open reading frames that encode proteins that are coordinately expressed during replication. The product of open reading frame 62, the immediate-early 62 (IE62) protein, is required for the initiation of VZV replication (9) and is expressed at high levels before viral replication has occurred (8). Previous research has demonstrated that IE62-specific T cells were detected after primary VZV infection and in immune subjects (2, 4). In addition, T cells recognizing various other IE proteins and glycoproteins of VZV, as demonstrated by gamma interferon (IFN-γ) production upon stimulation with peptides or lysate derived from these proteins, have been described (1, 6, 13). The VZV-specific memory T cells found in these studies were predominantly CD4 T cells, while no VZV-specific CD8 T cells were demonstrated without prior in vitro expansion, possibly due to the low frequency of VZV-specific CD8 T cells or to the low sensitivity of the screening methods used to detect CD8 T cells by IFN-γ production upon stimulation. Frey et al. described CD8 epitopes of IE62 detected following in vitro restimulation. However, the HLA restriction and specificity of these T cells were not confirmed (4). Due to the lack of validated VZV-derived immunodominant peptides for major histocompatibility complex (MHC) class I, the analysis of VZV-specific CD8 T-cell responses is hampered (14). To be able to analyze the role of CD8 T cells in VZV reactivation, we therefore set out to identify epitopes for VZV by using VZV-IE62-specific MHC class I peptide complexes.The predictive algorithms BIMAS (11) and SYFPEITHI (12) were used to select potential HLA-A2 binding peptides from the IE62 protein. Peptides with a score of ≥3 (BIMAS) or ≥20 (SYFPEITHI) were considered to have potentially significant binding affinity. The 81 resulting 9-mer peptides were synthesized and tested for binding affinity with the REVEAL MHC-peptide binding assay (ProImmune, Oxford, United Kingdom). HLA-A2 binding affinity was determined by the ability of the peptides to stabilize the HLA-peptide complex. Based on the binding affinity measurements, 34 high- to medium-affinity HLA-A2 binding peptides were selected and used to generate ProVE MHC pentamers (ProImmune, Oxford, United Kingdom). To enable screening of this large number of pentamers, the pentamers were divided into five pools, each containing six or seven pentamers. In the initial screening with pooled pentamers, four HLA-A2-positive patients were screened after a clinical diagnosis of VZV reactivation after TCD alloSCT. The presence of viral DNA in plasma at the time of clinical observations of VZV reactivation was confirmed by real-time PCR on plasma samples as previously described (7). After informed consent was obtained, peripheral blood mononuclear cells (PBMCs) were cryopreserved and thawed and 0.5 × 106 cells were incubated with pentamers at a concentration of 0.03 mg/ml for 10 min at room temperature in RPMI medium supplemented with 2% fetal bovine serum. After the cells were washed twice, 8 μl of FluoroTag-phycoerythrin (PE) was added for 20 min of incubation at 4°C and the cells were counterstained with CD4, CD40, and CD19-fluorescein isothiocyanate (FITC). Flow cytometric analysis was performed on a FACScalibur fluorescence-activated cell sorter (FACS; Becton-Dickinson [BD], San Jose, CA). In one of four patients, pentamer pool 6, containing pentamers 61, 62, 64, 65, 66, and 67, was positive (0.06% of CD8 T cells); no other positive signals were observed. Staining with the individual pentamers revealed that pentamer 66, containing the epitope ALWALPHAA derived from the IE62 protein of VZV (IE62-ALW-A2) was responsible for the positive signal (0.06% of CD8 T cells, Fig. Fig.1B1B).Open in a separate windowFIG. 1.Screening with pentamers containing VZV-derived immunogenic epitopes. PBMCs of a patient after VZV reactivation following TCD alloSCT were incubated with pentamers and then stained with FluoroTag-PE to detect the pentamer-positive cells (A and B) and counterstained with CD4-, CD40-, and CD19-FITC. Pentamer staining of the CD4-, CD40-, and CD19-negative cells is shown. (A) PBMCs stained with pentamer 67 containing the epitope ALPHAAAAV, showing no specific staining. (B) PBMCs stained with pentamer 66 containing the epitope ALWALPHAA, showing specific staining. IE62-ALW-A2-specific T-cell clones were sorted into a single cell per well and expanded nonspecifically. The clones were stained with an irrelevant tetramer (C) and the IE62-ALW-A2 tetramer (D) in combination with CD8-FITC. Clones 1 and 2 were stained with a Vβ kit (BD) to demonstrate that clone 1 (E) and clone 2 (F) express different T-cell receptors. The results demonstrate that we isolated different T-cell clones that specifically stain with the IE62-ALW-A2 tetramer.To confirm the specificity of the IE62-ALW-A2-specific T cells, the pentamer-positive T cells were sorted into a single cell per well with a FACSDiva (BD) and expanded as previously described (5). The expanded T-cell clones were labeled specifically with the IE62-ALW-A2 PE-conjugated tetramer that was constructed as previously described (3) (Fig. (Fig.1D),1D), and Vβ analysis with the T-cell receptor Vβ repertoire kit (BD) showed that at least two different T-cell clones were isolated, demonstrating the oligoclonal origin of IE62-ALW-A2-positive T cells (Fig. 1E and F). To assess the cytolytic capacity of IE62-ALW-A2 T cells, chromium release assays were performed as described earlier (5). 51Cr-labeled Epstein-Barr virus (EBV) lymphoblastoid cell lines (LCLs) loaded with the IE62-ALW peptide were incubated with IE62-ALW-A2 T cells for 4 h. As demonstrated in Fig. Fig.2A,2A, HLA-A2-positive EBV LCLs loaded with the IE62-ALW-A2 peptide were lysed by both T-cell clones, whereas unloaded EBV LCLs were not lysed. To determine the avidity of the T-cell clones, the IE62-ALW-A2 peptide was titrated on EBV LCLs, and after 24 h of coculture, supernatants were harvested and used to determine the IFN-γ production of the stimulated T cells by standard enzyme-linked immunosorbent assay. Half-maximum IFN-γ production of the T-cell clones was observed when the stimulator cells were loaded with 10 ng/ml peptide, indicative of high-avidity T-cell clones (Fig. (Fig.2B).2B). To determine whether the T cells recognized cells endogenously expressing the IE-62-encoding gene, COS-A2 cells were transfected with Lipofectamine (Invitrogen, Carlsbad, CA) by using pcDNA vectors coding for different VZV genes, which were kindly provided by E. Wiertz (Department of Medical Microbiology, Leiden University Medical Center, Leiden, The Netherlands). The transfected COS-A2 cells were used 24 h after transfection as stimulator cells in this assay. After 24 h of coculture, supernatants were harvested and used to determine the IFN-γ production of the stimulated T cells. IE62-ALW-A2 T-cell clones produced IFN-γ in response to COS-A2 cells endogenously expressing the IE62 protein, as well as COS-A2 cells pulsed with the IE62-ALW-A2 peptide. No IFN-γ was produced when the COS-A2 cells were transfected with the IE63-encoding gene of VZV or pulsed with an irrelevant peptide (Fig. (Fig.2C2C).Open in a separate windowFIG. 2.IE62-ALW-A2 T cells recognize IE62-ALW-A2 peptide-loaded target cells and target cells endogenously expressing IE62. (A) The cytolytic activity of IE62-ALW-A2-positive T-cell clones 1 and 2 was analyzed with the 51Cr release assay. T cells were incubated for 4 h with IE62-ALW-A2 peptide (pep)-loaded or unloaded, HLA-A2-positive EBV LCLs at an effector-to-target ratio of 10:1. (B) IE62-ALW-A2 T-cell clone 1 was stimulated with HLA-A2-positive EBV LCLs loaded with different concentrations of the IE62-ALW-A2 peptide. Release of IFN-γ (pg/ml) after 24 h of stimulation is shown. (C) IE62-ALW-A2 T-cell clones 1 and 2 were stimulated with HLA-A2-positive COS-A2 cells, left untreated, or loaded with the IE62-ALW-A2 peptide or with the IE4-ALR-B8 peptide as an irrelevant peptide or transfected with the IE63-encoding gene (COS-A2-IE63) or the IE62-encoding gene (COS-A2-IE62). Release of IFN-γ (picograms per milliliter) after 24 h of stimulation is shown.To determine whether IE62-ALW-A2-specific T cells were present in healthy individuals, cryopreserved PBMCs from 18 healthy, VZV-seropositive, HLA-A2-positive individuals were screened with the PE-conjugated VZV tetramer. PBMCs were labeled with tetramers for 15 min at 37°C in RPMI medium without phenol supplemented with 2% fetal bovine serum, washed, and analyzed with a FACScalibur. In 3 of these 18 serologically VZV-positive individuals, IE62-ALW-A2 tetramer-positive T cells could be detected (range, 0.01 to 0.02% of CD8 T cells). These data demonstrate that IE62-ALW-A2-specific T cells can be observed and that the frequency of these T cells is low under steady-state conditions in immunocompetent persons.To assess the frequency of IE62-ALW-A2-specific T cells in a cohort of patient who suffered from VZV reactivation following TCD alloSCT, 19 HLA-A2-positive patients after VZV reactivation following TCD alloSCT were screened by using the IE62-ALW-A2 tetramer. We screened these patients at a median of 47 days after the clinical diagnosis of VZV reactivation. In 8 of these 19 patients, IE62-ALW-A2-specific T cells could be directly detected ex vivo (mean, 0.04% [range, 0.01 to 0.11%] of CD8 T cells), indicating that this epitope is recognized in 42% of the HLA-A2-positive patients during VZV reactivation (Table (Table1).1). In VZV-seronegative patients (six screened), no IE62-ALW-A2 tetramer-positive cells could be detected.
Open in a separate windowaMean percentages of IE62-ALW-A2 tetramer-positive cells of CD8 T cells of three tetramer stainings performed on different days are shown.bPBMCs were in vitro stimulated (IVS) for 7 days with IE62-ALW-A2 peptide, and the mean percentages of tetramer-positive cells of three to six stimulations are shown. A negative result was defined as <0.01% of CD8+ T cells.cND, no PBMCs were available to do the analysis.To verify the presence of the IE62-ALW-A2-specific T cells in the patient and donor cohort and to investigate whether individuals negative for IE62-ALW-A2-specific T cells were unable to mount a response against the epitope or whether the frequency of IE62-ALW-A2-specific T cells was too low to detect by FACS, the presence of these T cells was further measured after in vitro stimulation. PBMCs were cultured at a concentration of 1 × 106/ml in 24-well plates in Iscove''s modified Dulbecco''s medium supplemented with 10% human serum in the presence of IE62-ALW peptide (1 μg/ml), interleukin-2 (IL-2; 50 IU/ml), and IL-15 (10 ng/ml). After stimulation for 7 days, the presence of IE62-ALW-A2-specific T cells was reassessed by tetramer labeling. These in vitro stimulations demonstrated that IE62-ALW-A2 CD8 T cells were detectable in another four patients and confirmed the presence of IE62-ALW-A2-specific T cells in eight patients and three healthy, VZV-seropositive individuals with ex vivo-detectable IE62-ALW-A2-specific T cells (Table (Table1;1; Fig. 3A to D). Thus, in 12 (63%) of 19 patients, IE62-ALW-A2 CD8 T cells could be detected either by direct tetramer labeling or after in vitro expansion, indicating that this HLA-A2-restricted epitope is commonly used in HLA-A2-positive individuals.Open in a separate windowFIG. 3.Detection and kinetics of IE62-ALW-A2-specific T cells. PBMCs with detectable IE62-ALW-A2 T cells (A, left side), a low level of detectable tetramer-positive cells (B, left side), or no detectable tetramer-positive cells (C and D, left side) were in vitro stimulated for 7 days with IE62-ALW-A2 peptide (I μg/ml) in the presence of IL-2 and IL-15 (A to D, right side). Cells were stained with CD4-FITC, CD40-FITC, and IE62-ALW-A2 tetramer, and the percentages of CD8+ T cells that were IE62-ALW-A2 tetramer positive are indicated. CD8+ T cells are defined as CD4− CD40− lymphocytes. (E) PBMCs of a patient during the course of VZV reactivation following TCD alloSCT were stained with the IE62-ALW-A2 tetramer in combination with CD8-FITC. The percentages of IE62-ALW-A2-specific CD8 T cells before, during, and after VZV reactivation are shown. In the box, the presence of viral DNA in peripheral blood is shown as measured by real-time PCR at various time points. The bold line illustrates the use of valaciclovir to treat the VZV reactivation.To study whether the immune response against the IE62-ALW-A2 epitope correlated with clinical reactivation, the percentage of IE62-ALW-A2-positive T cells was analyzed during the course of VZV reactivation in one patient. To determine the presence of viral DNA in plasma before and during the course of VZV reactivation, real-time PCR was performed on plasma samples derived at different time points. Six days prior to clinical signs of VZV reactivation, only 0.03% of the CD8 T cells were IE62-ALW-A2 specific. At 42 days after the onset of VZV reactivation, 0.23% of the CD8 T cells were IE62-ALW-A2 specific. After the VZV infection resolved, the percentage of IE62-ALW-A2-specific CD8 T cells declined to 0.09% at day 49 and 0.03% at day 145 after reactivation (Fig. (Fig.3D).3D). The T cells present at the peak of the response were predominantly HLA-DR positive, CD45RA negative, CCR7 negative, CD28 negative, and CD27 positive, consistent with an activated effector memory phenotype.In this study, we demonstrate that CD8 T cells specific for VZV are detectable without prior in vitro stimulation in patients with VZV reactivation following TCD alloSCT. We identified the ALWALPHAA peptide derived from the IE62-encoding gene of VZV as the first validated VZV-specific HLA class I-restricted immunogenic epitope by a pentamer-based epitope discovery method. The detection of the IE62-ALW peptide as an immunogenic peptide for VZV-specific CD8 T cells demonstrates the usefulness of this procedure for discovering new immunogenic virus- or tumor-specific epitopes. We demonstrated that, despite the low frequency, it is possible to detect VZV-specific CD8 T cells, allowing ex vivo analysis of the immune response to VZV infection, reactivation, and possibly VZV vaccination. 相似文献
TABLE 1.
Presence of IE62-ALW-A2-specific T cells in HLA-A2 patients after VZV reactivation following TCD alloSCTPatient | No. of days after:
| % IE62-ALW-A2+ T cells (SD)
| ||
---|---|---|---|---|
TCD alloSCT | VZV reactivation | Before IVSa | After IVSb | |
1 | 180 | 46 | Negative | 0.22 (0.15) |
2 | 190 | 38 | 0.03 (0.01) | 0.51 (0.21) |
3 | 545 | 31 | Negative | Negative |
4 | 294 | 52 | Negative | 0.12 (0.06) |
5 | 82 | 38 | Negative | Negative |
6 | 183 | 16 | Negative | 0.01 (0.01) |
7 | 176 | 81 | 0.02 (0.01) | 0.44 (0.06) |
8 | 99 | 35 | 0.11 (0.02) | 0.22 (0.04) |
9 | 601 | 88 | Negative | 0.01 (0.01) |
10 | 95 | 63 | Negative | Negative |
11 | 90 | 83 | Negative | Negative |
12 | 179 | 48 | Negative | Negative |
13 | 1,224 | 62 | Negative | Negative |
14 | 173 | 20 | 0.03 (0.01) | 0.22 (0.12) |
15 | 514 | 21 | 0.03 (0.01) | NDc |
16 | 635 | 40 | 0.02 (0.01) | ND |
17 | 161 | 8 | Negative | Negative |
18 | 174 | 48 | 0.01 (0.00) | 0.02 (0.01) |
19 | 92 | 49 | 0.04 (0.01) | 0.06 (0.02) |
60.
The purple photosynthetic bacterium Rubrivivax gelatinosus has, at least, four periplasmic electron carriers, i.e., HiPIP, two cytochromes c?with low- and high-midpoint potentials, and cytochrome c? as electron donors to the photochemical reaction center. The quadruple mutant lacking all four electron carrier proteins showed extremely slow photosynthetic growth. During the long-term cultivation of this mutant under photosynthetic conditions, a suppressor strain recovering the wild-type growth level appeared. In the cells of the suppressor strain, we found significant accumulation of a soluble c-type cytochrome that has not been detected in wild-type cells. This cytochrome c has a redox midpoint potential of about +280 mV and could function as an electron donor to the photochemical reaction center in vitro. The amino acid sequence of this cytochrome c was 65% identical to that of the high-potential cytochrome c?of this bacterium. The gene for this cytochrome c was identified as nirM on the basis of its location in the newly identified nir operon, which includes a gene coding cytochrome cd?-type nitrite reductase. Phylogenetic analysis and the well-conserved nir operon gene arrangement suggest that the origin of the three cytochromes c? in this bacterium is NirM. The two other cytochromes c?, of high and low potentials, proposed to be generated by gene duplication from NirM, have evolved to function in distinct pathways. 相似文献