A non-human primate derived anti-P-selectin glycoprotein ligand-1 antibody curtails acute pancreatitis by alleviating the inflammatory responses

Acute pancreatitis (AP) is a devastating disease characterized by an inflammatory disorder of the pancreas. P-selectin glycoprotein ligand-1 (PSGL-1) plays a crucial role in the initial steps of the adhesive at process to inflammatory sites, blockade of PSGL-1 might confer potent anti-inflammatory effects. In this study, we generated two non-human primate derived monoclonal antibodies capable of efficiently targeting human PSGL-1, RH001-6 and RH001-22, which were screened from immunized rhesus macaques. We found that RH001-6, can effectively block the binding of P-selectin to PSGL-1, and abolish the adhesion of leukocytes to endothelial cells in vitro. In vivo, we verified that RH001-6 relieved inflammatory responses and pancreatic injury in both caerulein and l-arginine induced AP models. We also evaluated the safety profile after RH001-6 treatment in mice, and verified that RH001-6 did not cause any significant pathological damages in vivo. Taken together, we developed a novel non-human primate derived PSGL-1 blocking antibody with high-specificity, named RH001-6, which can interrupt the binding of PSGL-1 and P-selectin and attenuate inflammatory responses during AP. Therefore, RH001-6 is highly potential to be further developed into therapeutics against acute inflammatory diseases, such as AP.

A trimeric RBD protein as a booster vaccine enhanced the humoral response and broad neutralization against SARS-CoV-2 in mice / 中华微生物学和免疫学杂志

Objective:To investigate the efficacy of a SARS-CoV-2 recombinant protein vaccine as a booster dose.Methods:A new immunogen, namely RBD-sc-trimer, was designed by tandem repeating of single receptor binding domain (RBD) of SARS-CoV-2 spike (S) protein to mimic the trimeric form of RBD presented by the virus. The RBD-sc-trimer protein was expressed as a His-tagged fusion protein using a baculovirus expression system and purified by nickel affinity column. The purified protein was identified by Western blot. Its in vitro binding activity to human angiotensin converting enzyme 2 (hACE2) was analyzed by ELISA. The immunogenicity of RBD-sc-trimer as well as RBD proteins of other forms including RBD dimer (RBD-Fc), RBD monomer (RBD) and S protein trimer (S trimer) as a booster dose was evaluated in BALB/c mice. Results:In terms of both binding and neutralizing antibodies against SARS-CoV-2, RBD-sc-trimer showed an immunogenicity that was superior to that of RBD-Fc and RBD and close to the level of S trimer. The antibody response induced by RBD-sc-trimer was characterized as Th1-biased. Moreover, it displayed a stronger cross-neutralization activity against SARS-CoV-2 Beta, Delta and Omicron variants. The titer of neutralizing antibody against Omicron induced by RBD-sc-trimer only decreased by 9.1 folds relative to the prototype strain, while the antibody response induced by RBD-Fc and S trimer decreased by 68.4 and 70.8 folds, respectively.Conclusions:The recombinant protein, RBD-sc-trimer, which was capable of eliciting stronger humoral response in mice as a booster dose and showed the superiority in raising cross-reactive antibodies against SARS-CoV-2 variants over non-trimeric RBD forms, should be considered as an optimal immunogen for the development of more effective SARS-CoV-2 vaccines.

Expert recommendations on booster immunization strategies of 2019-nCoV vaccines / 中华临床感染病杂志

Since the end of 2019, the COVID-19 caused by 2019-nCoV has emerged and the pandemic ravaged the world, which seriously threatens global public health security and economic development. 2019-nCoV vaccine is an effective weapon to combat the viral infection, however, studies have shown that vaccine-induced immune protection decreases over time, coupled with some novel and immune escape variants continual emerging. Therefore, it is urgent to complete booster immunization to improve protection. At present, 2019-nCoV vaccines based on a variety of technical platforms have been approved and available in China. Therefore, we developed this sequential vaccination strategy guide to provide documentation guidance for the prevention and control of the epidemic caused by 2019-nCoV and its variant strains.

Human Identical Sequences of SARS-CoV-2 Promote Clinical Progression of COVID-19 by Upregulating Hyaluronan via NamiRNA-Enhancer Network

The COVID-19 pandemic is a widespread and deadly public health crisis. The pathogen SARS-CoV-2 replicates in the lower respiratory tract and causes fatal pneumonia. Although tremendous efforts have been put into investigating the pathogeny of SARS-CoV-2, the underlying mechanism of how SARS-CoV-2 interacts with its host is largely unexplored. Here, by comparing the genomic sequences of SARS-CoV-2 and human, we identified five fully conserved elements in SARS-CoV-2 genome, which were termed as "human identical sequences (HIS)". HIS are also recognized in both SARS-CoV and MERS-CoV genome. Meanwhile, HIS-SARS-CoV-2 are highly conserved in the primate. Mechanically, HIS-SARS-CoV-2, behaving as virus-derived miRNAs, directly target to the human genomic loci and further interact with host enhancers to activate the expression of adjacent and distant genes, including cytokines gene and angiotensin converting enzyme II (ACE2), a well-known cell entry receptor of SARS-CoV-2, and hyaluronan synthase 2 (HAS2), which further increases hyaluronan formation. Noteworthily, hyaluronan level in plasma of COVID-19 patients is tightly correlated with severity and high risk for acute respiratory distress syndrome (ARDS) and may act as a predictor for the progression of COVID-19. HIS antagomirs, which downregulate hyaluronan level effectively, and 4-Methylumbelliferone (MU), an inhibitor of hyaluronan synthesis, are potential drugs to relieve the ARDS related ground-glass pattern in lung for COVID-19 treatment. Our results revealed that unprecedented HIS elements of SARS-CoV-2 contribute to the cytokine storm and ARDS in COVID-19 patients. Thus, blocking HIS-involved activating processes or hyaluronan synthesis directly by 4-MU may be effective strategies to alleviate COVID-19 progression.

Interaction network of SARS-CoV-2 with host receptome through spike protein

Host cellular receptors are key determinants of virus tropism and pathogenesis. Virus utilizes multiple receptors for attachment, entry, or specific host responses. However, other than ACE2, little is known about SARS-CoV-2 receptors. Furthermore, ACE2 cannot easily interpret the multi-organ tropisms of SARS-CoV-2 nor the clinical differences between SARS-CoV-2 and SARS-CoV. To identify host cell receptors involved in SARS-CoV-2 interactions, we performed genomic receptor profiling to screen almost all human membrane proteins, with SARS-CoV-2 capsid spike (S) protein as the target. Twelve receptors were identified, including ACE2. Most receptors bind at least two domains on S protein, the receptor-binding-domain (RBD) and the N-terminal-domain (NTD), suggesting both are critical for virus-host interaction. Ectopic expression of ASGR1 or KREMEN1 is sufficient to enable entry of SARS-CoV-2, but not SARS-CoV and MERS-CoV. Analyzing single-cell transcriptome profiles from COVID-19 patients revealed that virus susceptibility in airway epithelial ciliated and secretory cells and immune macrophages highly correlates with expression of ACE2, KREMEN1 and ASGR1 respectively, and ACE2/ASGR1/KREMEN1 (ASK) together displayed a much better correlation than any individual receptor. Based on modeling of systemic SARS-CoV-2 host interactions through S receptors, we revealed ASK correlation with SARS-CoV-2 multi-organ tropism and provided potential explanations for various COVID-19 symptoms. Our study identified a panel of SARS-CoV-2 receptors with diverse binding properties, biological functions, and clinical correlations or implications, including ASGR1 and KREMEN1 as the alternative entry receptors, providing insights into critical interactions of SARS-CoV-2 with host, as well as a useful resource and potential drug targets for COVID-19 investigation.

One-Step Rapid Quantification of SARS-CoV-2 Virus Particles via Low-Cost Nanoplasmonic Sensors in Generic Microplate Reader and Point-of-Care Device

The spread of SARS-CoV-2 virus in the ongoing global pandemics has led to infections of millions of people and losses of many lives. The rapid, accurate and convenient SARS-CoV-2 virus detection is crucial for controlling and stopping the pandemics. Diagnosis of patients in the early stage infection are so far limited to viral nucleic acid or antigen detection in human nasopharyngeal swab or saliva samples. Here we developed a method for rapid and direct optical measurement of SARS-CoV-2 virus particles in one step nearly without any sample preparation using a spike protein specific nanoplasmonic resonance sensor. We demonstrate that we can detect as few as 30 virus particles in one step within 15 minutes and can quantify the virus concentration linearly in the range of 103 vp/ml to 106 vp/ml. Measurements shown on both generic microplate reader and a handheld smartphone connected device suggest that our low-cost and rapid detection method may be adopted quickly under both regular clinical environment and resource-limited settings.

Human IgG cell neutralizing monoclonal antibodies block SARS-CoV-2 infection

The coronavirus induced disease 19 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a worldwide threat to human lives, and neutralizing antibodies present a great therapeutic potential in curing affected patients. We purified more than one thousand memory B cells specific to SARS-CoV-2 S1 or RBD (receptor binding domain) antigens from 11 convalescent COVID-19 patients, and a total of 729 naturally paired heavy and light chain fragments were obtained by single B cell cloning technology. Among these, 178 recombinant monoclonal antibodies were tested positive for antigen binding, and the top 13 binders with Kd below 0.5 nM are all RBD binders. Importantly, all these 13 antibodies could block pseudoviral entry into HEK293T cells overexpressing ACE2, with the best ones showing IC50s around 2-3 nM. We further identified 8 neutralizing antibodies against authentic virus with IC50s within 10 nM. Among these, 414-1 blocked authentic viral entry at IC50 of 1.75 nM and in combination with 105-38 could achieve IC50 as low as 0.45 nM. Meanwhile, we also found that 3 antibodies could cross-react with the SARS-CoV spike protein. Altogether, our study provided a panel of potent human neutralizing antibodies for COVID19 as therapeutics candidates for further development.

Progress in the mechanism of glycometabolism in memory CD8+ T cell formation / 中华微生物学和免疫学杂志

CD8+T cells are critical immune cells protecting the body against infection and cancer. Long-lived memory CD8+T cells formed in a prior infection can reproduce to mount a faster and stronger im-mune response at a second encounter with the cognate antigen. The activation, clonal expansion and re-sponse of T cells are energetically demanding processes tightly coupled in cellular metabolism. Meanwhile, changes in cellular metabolism could also affect the development of memory T cells following acute infection. In this review, we discussed the current understanding of the mechanism by which glycometabolic pathways manipulate the differentiation of memory CD8+T cells in order to provide reference for improving vaccine de-velopment and cancer treatment.

Erratum to: Irreversible phenotypic perturbation and functional impairment of B cells during HIV-1 infection / 医学前沿

The original version of this article unfortunately contained a mistake. One of the authors of this article has been misspelled. Xiaoyang Zhang should be Xiaoyan Zhang. The update is also provided here.

Plasma exosomes induced by remote ischaemic preconditioning attenuate myocardial ischaemia/reperfusion injury by transferring miR-24.

Remote ischaemic preconditioning (RIPC) is well known to protect the myocardium against ischaemia/reperfusion injury (IRI). Exosomes are small extracellular vesicles that have become the key mediators of intercellular communication. Various studies have confirmed that circulating exosomes mediate RIPC. However, the underlying mechanisms for RIPC-induced exosome-mediated cardioprotection remain elusive. In our study, we found that the expression level of miR-24 was higher in exosomes derived from the plasma of rats subjected to RIPC than in exosomes derived from the plasma of control rats in vivo. The rat plasma exosomes could be taken up by H9c2 cells. In addition, miR-24 was present in RIPC-induced exosomes and played a role in reducing oxidative stress-mediated injury and decreasing apoptosis by downregulating Bim expression in H2O2-treated H9c2 cells in vitro. In vivo, miR-24 in RIPC-induced exosomes reduced cardiomyocyte apoptosis, attenuated the infarct size and improved heart function. Furthermore, the apoptosis-reducing effect of miR-24 was counteracted by miR-24 antagomirs or inhibitors both in vitro and in vivo. Therefore, we provided evidence that RIPC-induced exosomes could reduce apoptosis by transferring miR-24 in a paracrine manner and that miR-24 in the exosomes plays a central role in mediating the protective effects of RIPC.

Clinical value of the plasma circular RNA hsa_circ_0009024 in the diagnosis and treatment of pulmonary tuberculosis / 中华检验医学杂志

Objective Detecting plasma level of circular RNA(circRNA)hsa_circ_0009024 in pulmonary tuberculosis(TB)patients,and evaluating its diagnostic value for TB.Methods From January 2016 to December 2016, a hosptial-based, case-control study was performed, which include 90 untreated active pulmonary tuberculosis patients(TB group),75 healthy people(healthy control)and 84 patient with other diseases(other disease group).Plasma level of circRNA hsa_circ_0009024 was detected by real-time quantitative polymerase chain reaction.Furthermore, the 90 patients with TB were divided into different subgroups according to cavity formation and the lung fields involvement: patients without lung cavity(55 cases)vs those with lung cavity(35 cases),patients with involvement of <2 lung fields(49 cases)vs≥2 lung fields(41 cases).Plasma levels of hsa _circ_0009024 of 41 TB patientswere monitored andcomparedbefore and after 3 months anti-TB therapy.The sensitivity and specificity of plasma hsa_circ_0009024 were analyzed by using the receiver operating characteristic(ROC)curve.The comparison between two groups was performed with Mann-Whitney U test and the comparison among multigroupswas conducted with Kruskal-Wallis H test.Results Plasma levels of hsa_circ_0009024 in TB patients[1.98(1.42, 2.71)]were significantly higher than healthy controls[1.03(0.78,1.33)]and other disease groups[1. 13(0.77,1.51)](H=76.58,P<0.0001).Plasma levels of hsa_circ_0009024 in cavity pulmonary TB patients were higher than pulmonary TB patients without cavity(U=392.50,P<0.0001).Plasma levels of hsa_circ_0009024 in TB patients with involvement of ≥2 lung fields were higher than <2 lung fields(U=590.50,P=0.0008).As compared to pre -treatment[2.01(1.41, 2.71)], the plasma hsa_circ_0009024 levels decreased significantly in 3 months[1.22(0.85,1.47)](U=292.50,P<0.0001)after anti-TB therapy.The area under the receiver operating characteristics curve(AUC)of plasma hsa_circ_0009024 in discriminating the patients with TB from normal controls, pneumonia patients and lung cancer patients were 0.841 and 0.811, respectively.Conclusion The hsa_circ_0009024 can be used as a potential biomarker in TB diagnosis and monitoring.

Research progress in broad neutralizing antibodies and universal vaccines against influenza A virus / 中华微生物学和免疫学杂志

Influenza vaccination is the most effective means to prevent and control influenza epi-demics, and the universal influenza vaccine which can induce broad and long-term protective effect is still in its infancy. Up to date, several broad neutralizing antibodies that can antagonize a variety of influenza A vi-ruses have been identified, and the crystal structure of the antibody and HA complex reveals at least three highly conserved epitopes. Deep insights into the molecular mechanism of the interactions between neutrali-zing antibodies and virus antigen can elicit a new strategy not only for rational design of universal influenza vaccines, but also for the development of antibody-based therapeutics against influenza virus. In this paper, advances in research of universal neutralizing antibodies and vaccines for Influenza A virus are reviewed.

Engineering the expression of an anti-interleukin-13 antibody through rational design and mutagenesis.

High levels of protein expression are key to the successful development and manufacture of a therapeutic antibody. Here, we describe two related antibodies, Ab001 and Ab008, where Ab001 shows a markedly lower level of expression relative to Ab008 when stably expressed in Chinese hamster ovary cells. We use single-gene expression vectors and structural analysis to show that the reduced titer is associated with the VL CDR2 of Ab001. We adopted two approaches to improve the expression of Ab001. First, we used mutagenesis to change single amino-acid residues in the Ab001 VL back to the equivalent Ab008 residues but this resulted in limited improvements in expression. In contrast when we used an in silico structure-based design approach to generate a set of five individual single-point variants in a discrete region of the VL, all exhibited significantly improved expression relative to Ab001. The most successful of these, D53N, exhibited a 25-fold increase in stable transfectants relative to Ab001. The functional potency of these VL-modified antibodies was unaffected. We expect that this in silico engineering strategy can be used to improve the expression of other antibodies and proteins.

Differential expression profile of long non-coding RNA in the lipopolysaecharide-induced inflammation of monocyte-derived macrophages / 中华危重病急救医学

Objective To analyze the expression profile of long non-coding RNA (lncRNA) in the lipopolysaecharide (LPS)-induced inflammation of monocyte-derived macrophages.Methods Peripheral blood mononuclear cells were derived from healthy donor and induced into macrophages. The macrophages were divided into blank control group and LPS (1 mg/L) stimulated 12 hours group. Culture supernatants and cell pellets were harvested in each group, enzyme linked immunosorbent assay (ELISA) was used to assay the production changes of interleukins (IL-1β and IL-6), and tumor necrosis factor-α (TNF-α) in the supernatant. The technique of lncRNA microarray was used to test the lncRNA expression profile in LPS-induced inflammation of macrophages and control macrophages. The raw data of lncRNA were pretreated for normalization. Five lncRNA expressions were validated by real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Furthermore, qRT-PCR was used to detect the expression of NR_028034 in macrophages after LPS-induced inflammation.Results ① The contents of IL-1β (ng/L:562.93±61.17 vs. 59.74±15.68), IL-6 (ng/L: 702.46±92.31 vs. 71.66±18.25) and TNF-α (ng/L: 794.50±63.89 vs. 85.12±22.07) in the LPS group were significantly higher than those in the blank control group (allP < 0.01). These results indicated that the inflammatory model of human macrophages was constructed successfully. ② Compared with blank control group, and 1479 lncRNA which have more than 2 folds variation and significant difference (P < 0.05) by statistical analysis was defined as lncRNA with differential expression. Among these lncRNA, LPS group showed 953 up- regulated and 526 down- regulated genes by 2 folds and 49 up- regulated and 35 down- regulated genes by 5 folds. ③ qRT-PCR results were generally consistent with the microarray data. ④ The expression of NR_028034 was increased by (4.41±0.65), (11.56±2.04), (18.58±1.36) folds compared with blank control group at 3, 6, 12 hours after LPS stimulation (allP < 0.01).Conclusions These data show a significantly altered lncRNA expression profile in the LPS-induced inflammation of monocyte-derived macrophages, suggesting that lncRNA may be involved in regulation of macrophages inflammatory response.

Diagnosis and Treatment Significance of Invasive and Noninvasive Operation for Ventilator-associated Pneumonia / 沈阳医学院学报

Objective:To investigate the diagnosis and treatment significance of invasive and noninvasive operation for ventilator?as?sociated pneumonia ( VAP ) . Methods:A total of 80 cases of VAP suspected patients who had received mechanical ventilation at least 48 hours in ICU from Jun 2014 to Mar 2015 were enrolled. Patients were randomly divided into four groups including noninvasive operation group ( F) , invasive operation group ( Q) , mix group 1 ( H1) and mix group 2 ( H2) . VAP diagnosis rate between groups as well as living time, antibiotic use time, survival rate, calcitonin levels and APACHE II score, oxygenation index were analyzed. Results:Specimen from invasive operation had higher specimens to cultivate positive rate than that from noninvasive operation ( P<0?05), but there was no statistic significant difference in VAP diagnosis rate between two methods (P>0?05). Conclusion:Noninva?sive operation collecting samples for VAP diagnosis is also accurate as invasive one. Collecting specimens from sputum suction tube in the clinical treatment on airway suction is a low cost and simple noninvasive operation.

Escaping mechanism from innate immunity mediated clearance by high pathogenic influenza virus during infection / 中国免疫学杂志

Severe influenza infection is usually associated with hypercytokinemia ,but the type Ⅰ Interferon remains at low lever or absence.The regulatory mechanism on or the immune escaping mechanism from type I interferon by virus remains to be deter -mined.We briefly summarized the progress in this field and raise several questions to be addressed in the future .

HIV/AIDS related mortality in southern Shanxi province and its risk factors / 中华流行病学杂志

<p><b>OBJECTIVE</b>To explore factors influencing mortality rate of HIV/AIDS and to improve the effectiveness of antiretroviral therapy (ART).</p><p><b>METHODS</b>By means of retrospective cohort study and the AIDS control information system, HIV/AIDS case reports and antiviral treatment information of 4 cities in southern Shanxi province up to end of December 2012 were selected, to calculate the mortality rate and treatment coverage based on further data collected, along with analysis using the Cox proportional hazards survival regression.</p><p><b>RESULTS</b>4 040 cases confirmed of HIV/AIDS were included in this study. The average age was (36.0 ± 12.9) years, with 65.3% being male, 56.5% being married, 73.5% having junior high school education or lower, 58.4% being peasants, 54.3% with sexually transmitted infection (40.1% were heterosexual, 14.2% were homosexual), and 38.9% were infected via blood transmission (20.2% were former plasma donors, 16.2% blood transfusion or products recipients, 2.4% were injection drug users). Overall mortality decreased from 40.2 per 100 person/year in 2004 to 6.3 per 100 person/year in 2012, with treatment coverage concomitantly increasing from almost 14.8% to 63.4%. Cox proportional hazards survival regression was used on 4 040 qualified cases, demonstrating the top mortality risk factor was without antiretroviral therapy (RR = 14.9, 95% CI: 12.7-17.4). Cox proportional hazards survival regression was made on 1 938 cases of antiviral treatment, demonstrating that the mortality risk of underweight or obese before treatment was higher than those of normal and overweight cases (RR = 2.7, 95% CI: 1.6-4.5), and the mortality of those having a CD4(+) T-lymphocyte count ≤ 50 cells per µl before treatment was more than 50 cases (RR = 2.6, 95% CI: 1.5-4.5); Cox proportional hazards survival regression was made on 2 102 cases of untreated cases, demonstrating the mortality risk of those initially diagnosed as AIDS was higher than those initially diagnosed as HIV (RR = 3.4, 95% CI: 2.9-4.0).</p><p><b>CONCLUSION</b>The ART could successfully make lower HIV/AIDS mortality rate, indicating effective ART can further decrease mortality.</p>

Research Progress in Escape Mutations of the Human Immunodeficiency Virus under Pressure of HLA-Restricted Cytotoxic T Lymphocytes / 病毒学报

Human immunodeficiency virus type 1 (HIV-1)-specific cytotoxic T lymphocytes (CTLs) play a critical role in the control of HIV-1 infection and replication. HIV-1 evades CTL mediated pressure through viral escape mutations within targeted CTLs epitopes or flanking regions, but this process is usually associated with a viral fitness cost. The mutated epitopes may weaken the level of the original CTL responses, however, the immune system holds potential to mount denovo responses towards those newly emerged epitopes. This article briefly summarizes recent research progress regarding the competition between HIV-1's escape mutations and host CTL responses.

Epigenetic regulatory effects of the methylation of CpG island shore on the expression of lag3 gene in various human T cell lines / 中华微生物学和免疫学杂志

Objective To investigate the effects of DNA methylation on the expression of lympho-cyte activation gene 3 (lag3) in different human T cell lines.Methods A quantitative PCR and a flow cy-tometry analysis were performed to measure the expression of lag3 gene in various T cell lines at mRNA and protein levels.The distribution of CpG sites within the promoter and body of lag3 gene was detected to locate the potential regulatory region(s) (CpG island and CpG island shore).The levels of DNA methylation in each cell line were analyzed.The T cell lines were demethylated with 5-Aza-2′-deoxycytidine (5-Aza-2′-dc) for further investigation on the changes of lag3 gene expression and DNA methylation.Results Jurkat E6-1 cells showed the highest expression level of lag3 gene as compared with J.CaM1.6 and CEM cells.Hyperm-ethylated CpG islands were detected in cells of each cell line.The methylation levels of CpG island shore in J.CaM1.6 and CEM cells were higher than that in Jurkat E6-1 cells.Treatment of J.CaM1.6 and CEM cells with 5-Aza-2′-dc significantly promoted the expression of lag3 gene at mRNA and protein levels as well as the demethylation of CpG island shore.No significant differences with the expression of lag3 gene and the methylation of CpG island were observed in Jurkat E6-1 cells with or without 5-Aza-2′-dc stimulation.Con-clusion Methylation and demethylation of CpG island shore played important roles in regulating the tran-scription of lag3 gene.

In vitro anti-HIV activity and its possible mechanism of an extract of herb medicines, SanJiangDan / 中华微生物学和免疫学杂志

Objective To study in vitro anti-HIV activity of an extract of herb medicines,SanJiangDan,and the possible mechanism.Methods The main active ingredient of SanJiangDan was extracted by distillation.Three subtypes of HIV pseudovirus (B subtype,C subtype,CRF01_AE subtype) were used to evaluate the anti-HIV activity of SanJiangDan extract in vitro.The possible mechanism was evaluated through analyzing the effects of SanJiangDan extract on the expression of surface receptors and cytokines by T cells.The cytotoxicity of SanJiangDan extract was detected by using four different sources of cell lines including epithelial cells Caco-2 cells,TZM cells,Huh7 cells derived from liver cells and lymphocyte Jurkat-T cells.Results SanJiangDan extract effectively inhibited the infection of HIV pseudoviruses at concentrations of 1.6 mg/ml and 0.16 mg/ml.The inhibition rates were 30.9％,36.6％ and 65.0％ for B subtype,C subtype and CRF01_AE subtype respectively at the concentration of 0.16 mg/ml.As the concentration increased to 1.6 mg/ml,the inhibition rates increased to 96.4％ (B subtype),97.4％ (C subtype) and 99.5％ (CRF01_AE subtypes),but no toxicity to host cells was detected.Moreover,SanJiangDan extract inhibited the expression of HIV surface receptors including CD4,CXCR4 and CCR5 on TZM-bl cells,but enhanced IL-2 production.Conclusion SanJiangDan extract could inhibit HIV pseudovirus infection without causing cytotoxicity to host cells in vitro.The possible mechanism might be associated with the reduced expression of CD4,CXCR4 and CCR5 and enhanced secretion of IL-2 as well.