Binding of HIV-1 virions to α_4β_7 expressing cells and impact of antagonizing α_4β_7 on HIV-1 infection of primary CD4^+ T cells

HIV-1 envelope glycoprotein is reported to interact with α4β7, an integrin mediating the homing of lymphocytes to gut-associated lymphoid tissue, but the significance of α4β7 in HIV-1 infection remains controversial. Here, using HIV-1 strain Ba L, the gp120 of which was previously shown to be capable of interacting with α4β7, we demonstrated that α4β7 can mediate the binding of whole HIV-1 virions to α4β7-expressing transfectants. We further constructed a cell line stably expressing α4β7 and confirmed the α4β7-mediated HIV-1 binding. In primary lymphocytes with activated α4β7 expression, we also observed significant virus binding which can be inhibited by an anti-α4β7 antibody. Moreover, we investigated the impact of antagonizing α4β7 on HIV-1 infection of primary CD4+ T cells. In α4β7-activated CD4+ T cells, both anti-α4β7 antibodies and introduction of shorthairpin RNAs specifically targeting α4β7 resulted in a decreased HIV-1 infection. Our findings indicate that α4β7 may serve as an attachment factor at least for some HIV-1 strains. The established approach provides a promising means for the investigation of other viral strains to understand the potential roles of α4β7 in HIV-1 infection.

Trizivir (Abacavir/Lamivudine/Zidovudine) plus Lopinavir/Ritonavir Induction Therapy Followed by Trizivir-Alone Maintenance for HIV-1-Infected Patients: A 96-Week Pilot Treatment Simplification Study

Objective: The purpose of this study was to investigate whether switching HIV-infected patients stabilized on Trizivir (abacavir 300 mg/lamivudine 150 mg/zidovudine 300 mg) plus lopinavir/ritonavir 400 mg/100mg twice daily to Trizivir alone affects clinical efficacy and tolerability. Methods: This phase 4, open-label, pilot study was conducted over 96 weeks in 23 antiretroviral-na?ve, HIV-infected patients. Initially, these patients received induction therapy with Trizivir plus lopinavir/ritonavir 400 mg/100mg twice daily. Patients who achieved a viral load 3. Nineteen patients completed induction;of the four who did not, three were lost to follow-up and one withdrew due to gastrointestinal adverse events. In 14 induction completers who had viral load measurements taken at week 48, intent-to-treat: observed analysis showed a week 48 viral load 3 higher than the baseline count. Twelve patients completed the subsequent 48-week Trizivir-alone maintenance phase, of whom 11 (92%) achieved viral loads of both 3 above baseline. Trizivir-only maintenance was associated with fewer adverse events than the Trizivir-lopinavir/ritonavir induction phase and with improvement in total cholesterol, LDL-cholesterol, and triglycerides. Conclusions: Trizivir-alone maintenance after Trizivir-lopinavir/ritonavir induction maintained virologic and CD4+ cell response, and was associated with an improved adverse event and lipid profile.

Cloning and analysis of the envelope protein clone of HIV-1, CHNHLJ03009c34 from an infected individual in Heilongjiang province

To analyze the variability and phenotype of envelope glycoprotein （Env） of human immunodeficiency virus type 1 （HIV-1） prevalent in Heilongjiang province, cloning of the full-length env gene from the peripheral blood mononuclear cells （PBMCs） of an HIV-1 positive individual in Heilongjiang province in China was performed by using conserved region primers. The amplified PCR products were cloned into a plasmid vector and sequenced. Phylogenetic analysis was done upon the full-length Env amino acid sequence. Subsequently, an HIV-1 pseudotyped virus bearing the envelope protein was constructed and the infectivity was examined using U87 cell lines expressing CD4 with either CCR5 or CXCR4. As the result, two functional env clones named as CHNHLJ03009c34 （GenBank Accession No： AY905493 ） and CHNHLJ03009c33 were obtained. It was found that the homology between CHNHLJ03009c34 and an HIV-1 subtype B＇ strain, RIA-2, isolated from Yunnan province, was 91.52% through comparing and analyzing full-length Env amino acid sequence of HIV-1 isolated from either China or abroad. Phylogenetic analysis indicated that CHNHLJ03009c34 has the closest molecular relation with strain RIA2 based on analyzing the full-length of the Env, while it became an independent branch upon analyzing the sequences of C2-V3 region of the Env. The secondary structure analysis of the envelope protein showed that the antigenicity and hydrophobicity of the strain demonstrated have no definite difference from that of RL42. Examination of infectivity showed that pseudovirus CHNHLI03009c34 could only infect U87. CD4. CCR5 cells, indicating that it was a RS-tropic HIV-1. In the conclusion, two HIV-1 env clones from an infected individual in Heilongjiang province have been identified as subtype B＇ and RS-tropic HIV-1. This is the first report on the analysis of primary isolates in Heilongjiang province.

安徽省2011-2012年报告HIV-1新发感染者流行病学特征分析

目的了解安徽省HIV-1新发感染者情况及患者特征。方法对2011年7月至2012年6月安徽省艾滋病确证实验室新确证的748例的HIV-1型感染者通过BED检测,评估新发感染情况并分析其患者特征。结果 2011年7月至2012年6月安徽省报告发现的HIV-1感染者新发感染比例为24.6%,在BED确认的新发感染者中,男性、男男同性性行为者以及医院就诊者比例较高。与既往感染患者相比,新近感染者年龄更轻,且男性所占比例以及男男同性性行为者的比例均较高,并伴有更高的CD4细胞数。结论安徽省HIV-1新发感染者比例较高,男男同性性行为是新发感染的主要危险因素。

2006-2011年玉溪市≥50岁人群HIV-1新近感染情况及特征分析

目的分析2006-2011年玉溪市≥50岁人群中HIV-1新近感染情况和特征,为完善老年人艾滋病监测体系及进行流行病学调查提供参考依据。方法采用ML-PA法检测2006-2011年新报告的HIV/AIDS中HIV-1新近感染情况,按是否≥50岁进行新近感染比例及人群特征的对比分析。结果 HIV-1新近感染64例(3.17%,95%CI:2.41%～5.58%),其中<50岁新近感染比例为3.28%(95%CI:2.48%～4.08%)、≥50岁为1.54%(95%CI:0.61%～3.51%),差异无统计学意义(P>0.05);但是该两个年龄组的HIV/AIDS年度报告率、感染途径、性别、职业、文化程度、样本来源和地区分布等差异均有统计学意义(P均<0.05)。结论玉溪市老年人HIV/AIDSHIV-1新近感染比例与非老年人群相同,但是人群特征不同,建立监测体系应该成为评估老年人艾滋病流行态势的策略之一。

HIV-1新近感染两种检测方法在临床应用中的对比

目的比较HIV抗体明胶颗粒凝集检测法(Micro Liquid HIV PA,ML-PA)与BED-CEIA法在新近感染HIV患者中的检测结果,为ML-PA法的临床应用提供经验。方法对确认为HIV阳性的300例新报告感染者及132例长期感染样本分别用两种方法进行新近感染检测,获得2009-2011年第二季度常规检测新报告感染者及吸毒人群、男男同性恋人群新近感染比例。结果 300例新报告感染者样本中259例样本被两种方法同时判定为HIV长期感染,有4例样本被同时判定为HIV新近感染,两种方法对HIV-1是否为新近感染和长期感染结果判定不同(P=0.012<0.05)且一致性较差(Kappa值=0.127);对132例长期感染的样本检测结果显示,BED-CEIA法中128例判为长期感染,而ML-PA法中131例判定为长期感染。对2009-2011年第二季度常规检测新报告感染者及吸毒人群、男男性行为人群用两种方法进行检测得出结果显示流行趋势相同。结论两种方法检测新近感染结果显示一致性较差,但是可以用两种方法共同分析新近感染比例,ML-PA法可以进行更多、更大范围的应用。

Viral infections and cell cycle G2/M regulation

Progression of cells from G2 phase of the cell cycle to mitosis is a tightly regulated cellular process that requires activation of the Cdc2 kinase, which determines onset of mitosis in all eukaryotic cells. In both human and fission yeast (Schizosaccharomyces pombe) cells, the activity of Cdc2 is regulated in part by the phosphorylation status of tyrosine 15 (Tyr15) on Cdc2, which is phosphorylated by Wee1 kinase during late G2 and is rapidly dephosphorylated by the Cdc25 tyrosine phosphatase to trigger entry into mitosis. These Cdc2 regulators are the downstream targets of two well- characterized G2/M checkpoint pathways which prevent cells from entering mitosis when cellular DNA is damaged or when DNA replication is inhibited. Increasing evidence suggests that Cdc2 is also commonly targeted by viral proteins, which modulate host cell cycle machinery to benefit viral survival or replication. In this review, we describe the effect of viral protein R (Vpr) encoded by human immunodeficiency virus type 1 (HIV-1) on cell cycle G2/M regulation. Based on our current knowledge about this viral effect, we hypothesize that Vpr induces cell cycle G2 arrest through a mechanism that is to some extent different from the classic G2/M checkpoints. One the unique features distinguishing Vpr-induced G2 arrest from the classic checkpoints is the role of phosphatase 2A (PP2A) in Vpr-induced G2 arrest. Interestingly, PP2A is targeted by a number of other viral proteins including SV40 small T antigen, polyomavirus T antigen, HTLV Tax and adenovirus E4orf4. Thus an in-depth understanding of the molecular mechanisms underlying Vpr-induced G2 arrest will provide additional insights into the basic biology of cell cycle G2/M regulation and into the biological significance of this effect during host-pathogen interactions.

Laboratory Profile of HIV-2 and Dual HIV-1/HIV-2 Associated Acquired Immunodeficiency Syndrome in Nigeria

Background: HIV-2 is comparatively less pathogenic with slow progression of infection to clinical disease and consequently there is less of information on the occurrence of HIV-2 associated disease than HIV-1. We hereby describe some laboratory profiles of individuals presenting with HIV-2 and dual HIV-1/2 related AIDS at the University College hospital in Ibadan over a period of seven years. Methodology: Blood samples from patients presenting with the AIDS defining illness at the University College Hospital, Ibadan, Nigeria were tested for antibodies to HIV-1/2 using rapid test devices or ELISA. Initially reactive samples were further tested by immunoblotting for differentiation into HIV-1 or HIV-2 or HIV-1/2 dual infection. Blood samples from individuals with confirmed infections were further analyzed for CD4 cell lymphocyte number, plasma HIV-1 RNA concentration, hematological and blood chemistry parameters. The data analysis was done using descriptive statistics and Levene-S test for equality of variance. Results: Thirty five patients, 18 and 17 with HIV-2 and dual HIV-1/2 infections respectively were identified during the period covered by this study (2005-2012). The median age of the patients was 48 years old (Range: 42 - 70 years old) and mean CD4 cell count of HIV-2 patients at enrollment was 324 (Range: 16 - 696) and 350 (Range 54 - 863) per microlitre of blood for patients with dual HIV-1/2 infection. HIV-1 RNA was not detected in the plasma of the 18 patients with serological HIV-2 infection but 2 (11.8%) of the 17 patients with dual HIV-1/2 serological profile had detectable HIV-1 RNA (1,287,275 copies/ml and 1,816,491 copies/ml). Conclusion: The results emphasize the need to consider HIV-2 infection in the investigation of patients presenting with the AIDS related illness but with negative HIV-1serology. The study also shows the importance of inclusion of multispot HIV-1 and 2 rapid tests for differentiating HIV-1 from HIV-2 infections in regions where both types of HIV circulate or epidemiologically indicated.

Prokaryotic Expression and Purification of HIV-1 Vif and hAPOBEC3G, Preparation of Polyclonal Antibodies

To prepare HIV-1 Vif and hAPOBEC3G and to produce their antibodies, the full length gene fragment of HIV-1 vif was amplified by PCR from a plasmid of HIV-1 NL4.3 cDNA, and the APOBEC3G gene was obtained by RT-PCR from the total RNA of H9 cells. The resulting DNA construct was cloned into a prokaryotic expression vector (pET-32a). Recombinant pET-vif and pET-APOBEC3G were expressed respectively in Eserichia coli BL21 (DE3) as an insoluble protein. The vector also contained a six-histidine tag at the C-terminus for convenient purification and detection. To express and purify the HIV-1 Vif and hAPOBEC3G in E.coli cells, the accuracy of inserted gene and specificity of proteins were detected by the two enzyme digestion method, SDS-PAGE, and Western blotting. Rabbits were then immunized by Vif or APOBEC3G protein and serum samples were tested by indirect ELISA to determine the level of antibodies. Immunoenzyme and immunofluorescence assays were performed to identify the specificity of polyclonal antibodies. The titer of the anti-Vif antibodies was 1:204800, and that of the anti-APOBEC3G antibodies was 1:102400. Thus the antibodies could detect the antigen expression in the cells, demonstrating that fusion proteins with high purity and their corresponding polyclonal antibodies with high titer and specificity were achieved.

HIV-1 Primarily Targets the Innate Immune System and Only Secondarily Modulates Adaptive Immune Cell Depletion

Persistence of HIV-1 infection allows for permissive microenvironmental conditioning in terms of contextual innate immune participation. The progression of host cell injury constitutes an additional parametric formulation in self-amplifying modulation of the adaptive immune response in a manner that inclusively promotes the emergence of a final stage of AIDS that is both depletive and permissive for opportunistic infections and various forms of neoplasia. It is within contextual indices of promotion of depleted T-helper lymphocytes and of augmented viremic loads that manifestations of classic lesions emerge as the AIDS phenomenon. It is further to be realized that an apoptotic response of multiple cell subtypes including T-lymphocytes includes host-cell participation within formulated settings of further persistence of the retroviral infection. An all-inclusive phenomenon of dendritic cell-lymphocyte synapse formulation corresponds to the establishment of HIV-1 infection that specifically conditions all subsequent stages in depletion of the injured host cells regardless of the dynamics or kinetics of the retroviral replicative infectious process itself.

Nonlinear Uncertain HIV-1 Model Controller by Using Control Lyapunov Function

In this paper, we introduce a new Control Lyapunov Function (CLF) approach for controlling the behavior of nonlinear uncertain HIV-1 models. The uncertainty is in decay parameters and also external control setting. CLF is then applied to different strategies. One such strategy considers input into infected cells population stage and the other considers input into a virus population stage. Furthermore, by adding noise to the HIV-1 model a realistic comparison between control strategies is presented to evaluate the system’s dynamics. It has been demonstrated that nonlinear control has effectiveness and robustness, in reducing virus loading to an undetectable level.

Stochastic HIV Infection Model with CTLs Immune Response Driven by Lévy Jumps

This paper mainly investigates the effect of the lévy jumps on the stochastic HIV infection model with cytotoxic T lymphocytes (CTLs) immune response. First, we prove that there is a unique global positive solution in any population dynamics, then we find sufficient conditions for the extinction of the disease. For proofing the persistence in mean, a special Lyapunov function be established, we obtain that if the infected CD4+ T-cells and virus particles will persistence in mean. Finally, numerical simulations are carried out to illustrate the theoretical results.

Sunlenca■(Lenacapavir):A first-in-class,long-acting HIV-1 capsid inhibitor for treating highly multidrug-resistant HIV-1 infection

Lenacapavir,also known as GS-6207,under the brand name Sunlenca,was developed by Gilead Sciences Inc.It has been approved in the EU,Canada,and US for use alongside other antiretrovirals in adults with multidrug-resistant HIV infection and those who cannot otherwise establish an effective antiviral treat-ment regimen(Fig.1)1,2.The US Food and Drug Administration(FDA)approval is mainly based on the result of the phase II/III CAPELLA trial(NCT04150068)2.In the lenacapavir group,over 80%of patients with multidrug-resistant HIV-1 had fewer than 50 viral RNA copies per milliliter by week 26,and no serious adverse events related to the drug were reported 3,4.

急性脑梗死中医证型与血清IL-1在近期感染中的相关性研究

目的探讨急性脑梗死中医证型在近期感染中与血清IL-1的关系。方法利用双抗体夹心酶联免疫吸附法检测126例急性脑梗塞患者外周血IL-1含量,同时将126例患者分为感染组78例和未感染组48例,按证候评分将感染组患者分为火热证31例、痰证20例、痰热(火)证27例,对比IL-1在不同证候中的水平。结果感染组外周血IL-1含量明显高于未感染组(P<0.05);火热证组外周血IL-1含量明显高于痰证、痰热(火)证组(P<0.05)。结论急性脑梗死伴感染患者外周血IL-1含量变化对探讨急性脑梗死发病机理有意义,同时IL-1水平升高可作为判定火热证与非火热证的指标。

gp120-derived amyloidogenic peptides form amyloid fibrils that increase HIV-1 infectivity

Apart from mediating viral entry,the function of the free HIV-1 envelope protein(gp120)has yet to be elucidated.Our group previously showed that EP2 derived from oneβ-strand in gp120 can form amyloid fibrils that increase HIV-1 infectivity.Importantly,gp120 contains~30β-strands.We examined whether gp120 might serve as a precursor protein for the proteolytic release of amyloidogenic fragments that form amyloid fibrils,thereby promoting viral infection.Peptide array scanning,enzyme degradation assays,and viral infection experiments in vitro confirmed that manyβ-stranded peptides derived from gp120 can indeed form amyloid fibrils that increase HIV-1 infectivity.These gp120-derived amyloidogenic peptides,or GAPs,which were confirmed to form amyloid fibrils,were termed gp120-derived enhancers of viral infection(GEVIs).GEVIs specifically capture HIV-1 virions and promote their attachment to target cells,thereby increasing HIV-1 infectivity.Different GAPs can cross-interact to form heterogeneous fibrils that retain the ability to increase HIV-1 infectivity.GEVIs even suppressed the antiviral activity of a panel of antiretroviral agents.Notably,endogenous GAPs and GEVIs were found in the lymphatic fluid,lymph nodes,and cerebrospinal fluid(CSF)of AIDS patients in vivo.Overall,gp120-derived amyloid fibrils might play a crucial role in the process of HIV-1 infectivity and thus represent novel targets for anti-HIV therapeutics.

急性脑梗死中医证型与血清IL-1在近期感染中的相关性研究

目的:探讨急性脑梗死中医证型与血清IL-1在近期感染中的相关性。方法:选取2010年1月-2013年1月笔者所在医院接收的急性脑梗死患者152例,分为观察组和对照组,各76例,测定急性心肌梗死患者外周血IL-1的含量,对比IL-1在不同症候中的水平。结果:(1)观察组患者外周血中IL-1含量明显高于对照组(P<0.05);(2)72 h内火热证组IL-1水平均明显高于非火热证组(P<0.05),第7、14天IL-1水平无显著性差异;(3)观察组火热证中,72 h内与第7、14天IL-1含量比较差异有统计学意义(P<0.05),非火热证中无显著性差异。结论:外周血IL-1升高可能成为脑梗死患者急性期感染程度的指标之一,同时也可能成为判定急性脑梗死火热证与非火证的参考指标之一。

DYNAMICS OF AN HIV-1 INFECTION MODEL WITH CELL-MEDIATED IMMUNE RESPONSE AND STOCHASTIC PERTURBATION

In this paper, we introduce the stochasticity into an HIV-1 infection model with cytotoxic T lymphocytes （CTLs） immune response via the technique of parameter perturbation. We show that there is a positive solution as desired in any population dynamics. Then we analyze the long time behavior of this model. We obtain a sufficient condition for the stochastic asymptotic stability in the large of the infection-free equilibrium and give the conditions for the solution fluctuating around the two infection equilibria （one without CTLs being activated and the other with）. Finally, we make sinmlations to conform to our analytical results.

GLOBAL DYNAMICS OF A DELAYED HIV-1 INFECTION MODEL WITH ABSORPTION AND SATURATION INFECTION

In this paper, an HIV-1 infection model with absorption, saturation infection and an intracellular delay accounting for the time between viral entry into a target cell and the production of new virus particles is investigated. By analyzing the characteristic equations, the local stability of an infection-free equilibrium and a chronic-infection equilibrium of the model is established. By using suitable Lyapunov functionals and LaSalle＇s invariance principle, it is proved that if the basic reproduction ratio is less than unity, the infection-free equilibrium is globally asymptotically stable; and if the basic reproduction ratio is greater than unity, sufficient condition is derived for the global stability of the chronic-infection equilibrium.

DYNAMICS OF A NON-AUTONOMOUS HIV-1 INFECTION MODEL WITH DELAYS

In this paper, following a previous paper （[32] Permanence and extinction of a non- autonomous HIV-I model with two time delays, preprint） on the permanence and extinc- tion of a delayed non-autonomous HIV-1 within-host model, we introduce and investigate a delayed HIV-1 model including maximum homeostatic proliferation rate of CD4＋ T- cells and varying coefficients. By applying the asymptotic analysis theory and oscillation theory, we show： （i） the system will be permanent when the threshold value R. 〉 1, and for this case we also obtain the explicit estimate of the eventual lower bound of the HIV-1 virus load; （ii） the threshold value R＊ 〈 1 implies the extinction of the virus. Furthermore, we obtain that the threshold dynamics is in agreement with that of the corresponding autonomous system, which extends the classic results for the system with constant coefficients. Numerical simulations are also given to illustrate our main results, and in particular, some sensitivity test of R. is established.