Hepatitis B virus(HBV) is classically considered to be hepatotropic, but accumulating evidences strongly support its extra-hepatotropic nature too. HBV nucleicacids and proteins have long been reported in a variety of...Hepatitis B virus(HBV) is classically considered to be hepatotropic, but accumulating evidences strongly support its extra-hepatotropic nature too. HBV nucleicacids and proteins have long been reported in a variety of extra-hepatic tissues. Of these, HBV has been studied in details in the peripheral blood mononuclear cells(PBMCs), due to its accessibility. From these studies, it is now well established that PBMCs are permissive to HBV infection, replication, transcription and production of infective virions. Furthermore, molecular evolutionary studies have provided definite evidences towards evolution of HBV genome in PBMCs, which is independent of evolution occurring in the liver, leading to the emergence and selection of compartment specific escape variants or drug resistant strains. These variants/resistant strains of HBV remain restricted within the PBMCs and are rarely detected in the serum/plasma. In addition, HBV infected PBMCs have been reported to be directly transmitted through intrauterine modes, and this infection does not correlate significantly with serum HBV surface antigen or HBV DNA markers. This editorial briefly reviews the current knowledge on this topic, emphasizes and delineates the gaps that are required to be filled to properly understand the biological and clinical relevance of extrahepatic tropism of HBV.展开更多
Aim To determine the effect of VIR576, a dimeric 20-mer peptide potently inhibits HIV-1 entry, on antigen-specific T cell and non-antigen-specific T cell activation. Methods In vitro T-cell proliferation assays were e...Aim To determine the effect of VIR576, a dimeric 20-mer peptide potently inhibits HIV-1 entry, on antigen-specific T cell and non-antigen-specific T cell activation. Methods In vitro T-cell proliferation assays were estalished to investigate the potential effect of FP16, VIR576 on the proliferation of A2b cells in response to MOG35-55. A fluorescence-based binding assay using Rhodamine (Rho)-conjugated VIR576 was estalished to e- valuate the potential interaction between VIR576 and TCR-TMD. Fluorescence confocal microscopy was used to to study whether VIR576 could colocalize with CD4 molecule in the CD4 + T cell membrane to interact with TCR. Re- suits The effects of VIR576 on the proliferation of MOG-specific A2b T cells in response to the stimulation of MOG 35 -55 peptide wasevaluated. VIR576 itself could directly inhibit antigen-specific T-cell activation. Further studies confirmed that VIR576 also inhibited the proliferation of splenocytes and primary CD4 + CD25- T cells iso- lated from the spleens of DOll. 10 OVA Tg mice in response to OVA stimulation in vitro. However, VIR576 had no effect on the proliferation of normal mouse splenocytes and T lymphocytes stimulated with Con A or anti-CD3 anti- body. The FRET assay confirmed that VIR576 effectively binds to the core peptide (CP) , corresponding to the N- terminal 9-residue region of TCR-TMD. Confocal microscopy revealed that VIR576 colocalizes with CD4 on the ac- tivated CD4 + T-cell membrane, particularly within the activation cluster including re-assembled CD4 and TCR mol- ecules. Conclusion These results suggest that VIR576 is effective in suppressing antigen-specific T-cell activa- tion, but it has no effect on non-specific T-cell proliferation, and VIR576 has the ability to down-regulate antigen- specific T-cell activation by interaction with TCR transmembrane domain.展开更多
Four rice (Oryza satia L. cv. IR72) signal factors with the functions of inducing Agrobaterium tumefaciens (Smith et Townsend) Conn vir genes were constructed. They were 5, 7, 4’-trihydroxy-3’, 5’-dimethoxy-flavone...Four rice (Oryza satia L. cv. IR72) signal factors with the functions of inducing Agrobaterium tumefaciens (Smith et Townsend) Conn vir genes were constructed. They were 5, 7, 4’-trihydroxy-3’, 5’-dimethoxy-flavone (F1) and its structure analogues F2, F3 and F4. These four signal fartors were detected by Agrobacterium vir:: lzcZ fusion gene system as to compare their functions of inducing virA, virB, virC,virD, virE and virG genes. The structure characters and structure-activity relationship of these signal factors with the best inducing effects to Agrobacterium exogenous gene transformation system were defined which may provide some basic information for foreign gene transformation in rice.展开更多
目的为快速、高效、准确地检出羊口疮病毒(ORFV),并进一步明确皖北地区羊群ORFV流行毒株的遗传变异情况。方法本研究基于ORFV F1L基因建立SYBR Green I实时荧光定量PCR(qPCR)方法,对皖北地区羊场开展ORFV检测,并从阳性病料中PCR扩增ORF...目的为快速、高效、准确地检出羊口疮病毒(ORFV),并进一步明确皖北地区羊群ORFV流行毒株的遗传变异情况。方法本研究基于ORFV F1L基因建立SYBR Green I实时荧光定量PCR(qPCR)方法,对皖北地区羊场开展ORFV检测,并从阳性病料中PCR扩增ORFV的完整VIR基因,直接测序后进行遗传演化分析。结果所建立ORFV SYBR Green I qPCR方法的线性关系良好,R 2=0.994;扩增效率高,E%=95.62%;检测速度快,理论反应时间约15 min;灵敏度较高,检测下限为10 copies/μL,是普通PCR法的100倍;重复性良好,组内和组间变异系数分别为0.44%~1.14%和2.82%~3.16%。用该qPCR方法对采集自皖北地区的168份羊临床样本进行检测,其ORFV阳性率为37.5%(63/168)。PCR扩增阳性样本中ORFV的完整VIR基因并直接测序,共获得52条全长VIR基因序列,其中21条来源于山羊,31条来源于绵羊。52条VIR基因间核苷酸序列及氨基酸序列的一致性分别为95.8%~100.0%和93.5%~100.0%,与参考毒株VIR基因核苷酸序列及氨基酸序列的一致性分别为95.1%~100.0%和91.3%~100.0%。基于ORFV VIR基因的遗传进化树分析显示,本次检测的21株山羊源ORFV毒株与8株国内外山羊源参考毒株和1株人源hChi17.2017参考毒株位于同一大分支,而本次检测的31株绵羊源ORFV毒株与7株国内外绵羊源参考毒株、1株人源hMbu15参考毒株及1株OV-V疫苗毒株位于遗传距离较远的另一大分支。结论建立了用于检测ORFV的高效、快捷、特异、灵敏、稳定的SYBR Green I qPCR方法。从临床样本中检测到的不同宿主来源ORFV的VIR基因间存在较大遗传差异。该研究结果可为ORFV的临床监测、检测、诊断及防控提供参考和指导。展开更多
Some properties of mass transfer within a semi-detached binary system are discussed based on an example of VV Vir. The observations and analysis of VV Vir show that it is a semi-detached binary system with the less ma...Some properties of mass transfer within a semi-detached binary system are discussed based on an example of VV Vir. The observations and analysis of VV Vir show that it is a semi-detached binary system with the less massive cooler component filling its Roche lobe, which is also called an Algol-type binary system. Based on the parameters of this semi-detached binary, a theoretical study on the mass flow is carded out, including the trajectory of the mass flow, the position, radius and temperature of the impact spot caused by the mass flow, the inconsistent form of the mass flow and the possibly huge rate of energy transfer carried by the mass flow. Humps and distortions in light curves of VV Vir are deemed to be weak evidence for the theoretical results.展开更多
We present multi-color photometric observations and a one-dimensional spectrum, acquired from March 2016 to May 2017, for the short-period eclipsing binary PS Vir, by using the 2.16-m, 85-cm and 60-cm telescopes at Xi...We present multi-color photometric observations and a one-dimensional spectrum, acquired from March 2016 to May 2017, for the short-period eclipsing binary PS Vir, by using the 2.16-m, 85-cm and 60-cm telescopes at Xinglong station, which is administered by National Astronomical Observatories, Chinese Academy of Sciences. The spectral type was determined as G2V from the one-dimensional spectrum. The photometric solution was reduced from BVRc light curves. The results imply that PS Vir is a W-subtype contact binary with a mass ratio of q - 0.305(zk0.008) and a fill-out factor of f = 14.4(+1.8)%. The orbital period may be undergoing a cyclic oscillation with an ampli-tude of A = 0.0027(~0.0001)d and a modulated period of 11.7(4-0.2) yr, which may result from the light-time effect due to a third body. The lower limit on mass for the assumed component is 0.12 Me. Moreover, the more massive component of PS Vir may be a bit more evolved star as determined from the mass-luminosity diagram.展开更多
基金Supported by The Defence Research and Development Organi-zation(DRDO),Ministry of Defence,Government of India
文摘Hepatitis B virus(HBV) is classically considered to be hepatotropic, but accumulating evidences strongly support its extra-hepatotropic nature too. HBV nucleicacids and proteins have long been reported in a variety of extra-hepatic tissues. Of these, HBV has been studied in details in the peripheral blood mononuclear cells(PBMCs), due to its accessibility. From these studies, it is now well established that PBMCs are permissive to HBV infection, replication, transcription and production of infective virions. Furthermore, molecular evolutionary studies have provided definite evidences towards evolution of HBV genome in PBMCs, which is independent of evolution occurring in the liver, leading to the emergence and selection of compartment specific escape variants or drug resistant strains. These variants/resistant strains of HBV remain restricted within the PBMCs and are rarely detected in the serum/plasma. In addition, HBV infected PBMCs have been reported to be directly transmitted through intrauterine modes, and this infection does not correlate significantly with serum HBV surface antigen or HBV DNA markers. This editorial briefly reviews the current knowledge on this topic, emphasizes and delineates the gaps that are required to be filled to properly understand the biological and clinical relevance of extrahepatic tropism of HBV.
文摘Aim To determine the effect of VIR576, a dimeric 20-mer peptide potently inhibits HIV-1 entry, on antigen-specific T cell and non-antigen-specific T cell activation. Methods In vitro T-cell proliferation assays were estalished to investigate the potential effect of FP16, VIR576 on the proliferation of A2b cells in response to MOG35-55. A fluorescence-based binding assay using Rhodamine (Rho)-conjugated VIR576 was estalished to e- valuate the potential interaction between VIR576 and TCR-TMD. Fluorescence confocal microscopy was used to to study whether VIR576 could colocalize with CD4 molecule in the CD4 + T cell membrane to interact with TCR. Re- suits The effects of VIR576 on the proliferation of MOG-specific A2b T cells in response to the stimulation of MOG 35 -55 peptide wasevaluated. VIR576 itself could directly inhibit antigen-specific T-cell activation. Further studies confirmed that VIR576 also inhibited the proliferation of splenocytes and primary CD4 + CD25- T cells iso- lated from the spleens of DOll. 10 OVA Tg mice in response to OVA stimulation in vitro. However, VIR576 had no effect on the proliferation of normal mouse splenocytes and T lymphocytes stimulated with Con A or anti-CD3 anti- body. The FRET assay confirmed that VIR576 effectively binds to the core peptide (CP) , corresponding to the N- terminal 9-residue region of TCR-TMD. Confocal microscopy revealed that VIR576 colocalizes with CD4 on the ac- tivated CD4 + T-cell membrane, particularly within the activation cluster including re-assembled CD4 and TCR mol- ecules. Conclusion These results suggest that VIR576 is effective in suppressing antigen-specific T-cell activa- tion, but it has no effect on non-specific T-cell proliferation, and VIR576 has the ability to down-regulate antigen- specific T-cell activation by interaction with TCR transmembrane domain.
文摘Four rice (Oryza satia L. cv. IR72) signal factors with the functions of inducing Agrobaterium tumefaciens (Smith et Townsend) Conn vir genes were constructed. They were 5, 7, 4’-trihydroxy-3’, 5’-dimethoxy-flavone (F1) and its structure analogues F2, F3 and F4. These four signal fartors were detected by Agrobacterium vir:: lzcZ fusion gene system as to compare their functions of inducing virA, virB, virC,virD, virE and virG genes. The structure characters and structure-activity relationship of these signal factors with the best inducing effects to Agrobacterium exogenous gene transformation system were defined which may provide some basic information for foreign gene transformation in rice.
基金Supported by National Natural Science Foundation of China(30672496 and 30801413)Guangdong Medical Research Grant(A201032)Guangdong International Cooperation Grant(2011B050200006)~~
文摘目的为快速、高效、准确地检出羊口疮病毒(ORFV),并进一步明确皖北地区羊群ORFV流行毒株的遗传变异情况。方法本研究基于ORFV F1L基因建立SYBR Green I实时荧光定量PCR(qPCR)方法,对皖北地区羊场开展ORFV检测,并从阳性病料中PCR扩增ORFV的完整VIR基因,直接测序后进行遗传演化分析。结果所建立ORFV SYBR Green I qPCR方法的线性关系良好,R 2=0.994;扩增效率高,E%=95.62%;检测速度快,理论反应时间约15 min;灵敏度较高,检测下限为10 copies/μL,是普通PCR法的100倍;重复性良好,组内和组间变异系数分别为0.44%~1.14%和2.82%~3.16%。用该qPCR方法对采集自皖北地区的168份羊临床样本进行检测,其ORFV阳性率为37.5%(63/168)。PCR扩增阳性样本中ORFV的完整VIR基因并直接测序,共获得52条全长VIR基因序列,其中21条来源于山羊,31条来源于绵羊。52条VIR基因间核苷酸序列及氨基酸序列的一致性分别为95.8%~100.0%和93.5%~100.0%,与参考毒株VIR基因核苷酸序列及氨基酸序列的一致性分别为95.1%~100.0%和91.3%~100.0%。基于ORFV VIR基因的遗传进化树分析显示,本次检测的21株山羊源ORFV毒株与8株国内外山羊源参考毒株和1株人源hChi17.2017参考毒株位于同一大分支,而本次检测的31株绵羊源ORFV毒株与7株国内外绵羊源参考毒株、1株人源hMbu15参考毒株及1株OV-V疫苗毒株位于遗传距离较远的另一大分支。结论建立了用于检测ORFV的高效、快捷、特异、灵敏、稳定的SYBR Green I qPCR方法。从临床样本中检测到的不同宿主来源ORFV的VIR基因间存在较大遗传差异。该研究结果可为ORFV的临床监测、检测、诊断及防控提供参考和指导。
基金Supported by the National Natural Science Foundation of China
文摘Some properties of mass transfer within a semi-detached binary system are discussed based on an example of VV Vir. The observations and analysis of VV Vir show that it is a semi-detached binary system with the less massive cooler component filling its Roche lobe, which is also called an Algol-type binary system. Based on the parameters of this semi-detached binary, a theoretical study on the mass flow is carded out, including the trajectory of the mass flow, the position, radius and temperature of the impact spot caused by the mass flow, the inconsistent form of the mass flow and the possibly huge rate of energy transfer carried by the mass flow. Humps and distortions in light curves of VV Vir are deemed to be weak evidence for the theoretical results.
基金funding from the National Natural Science Foundation of China(Nos.11473009 and U1231102)the Outstanding Young Talents Program of the Education Department of Anhui Province (No.gxyq2018161)supported by the Open Project Program of the Key Laboratory of Optical Astronomy,National Astronomical Observatories,Chinese Academy of Sciences
文摘We present multi-color photometric observations and a one-dimensional spectrum, acquired from March 2016 to May 2017, for the short-period eclipsing binary PS Vir, by using the 2.16-m, 85-cm and 60-cm telescopes at Xinglong station, which is administered by National Astronomical Observatories, Chinese Academy of Sciences. The spectral type was determined as G2V from the one-dimensional spectrum. The photometric solution was reduced from BVRc light curves. The results imply that PS Vir is a W-subtype contact binary with a mass ratio of q - 0.305(zk0.008) and a fill-out factor of f = 14.4(+1.8)%. The orbital period may be undergoing a cyclic oscillation with an ampli-tude of A = 0.0027(~0.0001)d and a modulated period of 11.7(4-0.2) yr, which may result from the light-time effect due to a third body. The lower limit on mass for the assumed component is 0.12 Me. Moreover, the more massive component of PS Vir may be a bit more evolved star as determined from the mass-luminosity diagram.