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Objective@#To understand the situation of ticks carrying pathogens in border areas of Heilongjiang province.@*Methods@#From 2009 to 2018, tick specimens were collected in Yichun, Daxing′anling area and Jiamusi in Heilongjiang province. A total of 2 530 ticks were studied, including 800 Ixodes persulcatus and 1 730 Dermacentor silvarum. Tick-borne encephalitis virus (TBEV), severe fever with thrombocytopenia syndrome virus (SFTSV), omsk hemorrhagic fever virus (OHFV), langat virus (LGTV), powassan virus (POWV) were detected by real-time RT-PCR. Spotted fever group rickettsia (SFGR) and Borrelia burgdorferi sensulato (B.b.s.l) were detected by PCR in ticks collected from Jiamusi area.@*Results@#All tick speciments collected were negative for TBEV, SFTSV, OHFV, LGTV and POWV. Tick specimens from Jiamusi carried SFGR and B. b.s.l.with positive rates of 59.5% and 8.9%.@*Conclusions@#The ticks in border areas of Heilongjiang province carry spotted fever group rickettsia and Borrelia burgdorferi, and the carrying rate of spotted fever group rickettsia is high. The monitoring and control of ticks and tick-borne diseases should be strengthened.
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OBJECTIVE: One approach to identifying HIV-1 vaccine candidates is to dissect the natural antiviral immune response in treatment-naïve individuals infected for over ten years, considered slow progressor patients (SPs). It is suspected that SP plasma has strongly neutralizing antibodies (NAb) targeting specific HIV viral epitopes. METHODS: NAbs levels of 11 HIV-1-infected SPs were detected by PBMC-based neutralization assays. To investigate SP NAb epitope, this study used a biopanning approach to obtain mimotopes of HIV-1 that were recognized by SP plasma NAbs. IgG was purified from hightiter NAb SP plasma, and used as the ligand for three rounds of biopanning to select HIV-specific mimotopes from a phage-displayed random peptide library. Double-antibody sandwich ELISA, competitive inhibition assays, and peptide sequence analysis were used to evaluate the characteristics of phage-borne mimotopes. RESULTS: SPs had significantly more plasma neutralizing activity than typical progressors (TPs) (p = 0.04). P2 and P9 plasma, which have highest-titer HIV-NAb, were selected as ligands for biopanning. After three rounds of biopanning, 48 phage clones were obtained, of which 22 clones were consistent with requirement, binding with HIV-1 positive plasma and unbinding with HIV-1 negative plasma. Compared with linear HIV-1 protein sequence and HIV-1 protein structure files, only 12 clones were possible linear mimotopes of NAbs. In addition, the C40 clone located in gp41 CHR was found to be a neutralizing epitope, which could inhibit pooled HIV-1 positive plasma reaction. CONCLUSION: Biopanning of serum IgG can yield mimotopes of HIV-1-related antigen epitopes. This methodology provides a basis for exploration into HIV-1-related antigen-antibody interactions and furthers NAb immunotherapy and vaccine design.
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Humans , Antibodies, Neutralizing/immunology , Epitopes/immunology , HIV Antibodies/immunology , HIV Infections/immunology , HIV-1 , China , Cross Reactions , Enzyme-Linked Immunosorbent Assay , /immunology , /immunology , Peptide LibraryABSTRACT
ObjectiveTo screen mimetic HIV-1 neutralizing epitopes from plasma with high level neutralizing antibody,and to provide useful information for further study of the interaction between antigen and antibody.MethodsIn order to gain neutralizing antibody recognized mimotopes, we detected neutralizing antibodieslevelsof 11HIV-1infectedslowprogressorsbyPBMC-basedneutralization assays.High-titer HIV-neutralizing antibodies from plasma of SPs was used as the ligand for biopanning by phage-displayed random peptide library.Positive phage clones was evaluated by ELISA,sequenced,and analyzed for homology to HIV-1 env by local BLAST to deduce the neutralizing peptide.ResultsTwenty-two clones were obtained consistent with requirement through three rounds biopanning.After comparison analysis,twelve clones include C8 were obtained as mimotopes of neutralizing antibody,C40 located in gp41Ⅱ cluster with the highest titer by inhibition ratio may be as neutralizing epitope.Conclusion By the use of IgG antibodies from SPs to screen the phage random polypeptide library,one can acquire multiple phage mimetic peptides of HIV related antigen epitope.(Chin J Lab Med,2012,35:838-842 )
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Objective To study the relationships between neutralizing antibody response against heterologous virus and disease progression in Chinese HIV-1 B'/C infected individuals. Methods Plasmas from HIV-1-infected individuals, grouped as HIV chronically infected or AIDS according to CD4+ count and clinical symptom, were tested for neutralizing activity against the three HIV-1 isolates with very low homology in vitro. Six two-fold dilutions of each plasma sample (from 1/10 to 1/320) were tested against each virus from the panel. Giving a 50% reduction in p24Ag compared with normal human plasma control wells was defined as positive. The breadth of the cross-neutralizing response was defined based on the number of viruses that were effectively neutralized by any given patient-derived plasma sample. The magnitude of the crossneutralizing response was defined based on the average neutralizing titer against all heterologous viruses. Resuits We found that there revealed a significant difference between HIV chronically infected and AIDS group in the breaths and magnitudes of neutralizing heterologous virus. There was higher prevalence for the frequency of neutralizing heterologous virus in HIV chronically infected than AIDS. The results showed that there was positive correlation between the breadths and magnitudes of neutralizing response against heterologous virus and the plasma HIV RNA level in HIV chronically infected group, while not in AIDS group. There was no association between the breadth of the neutralizing responses against heterologous virus and CD4 T cell counts. Conclusion The capacity of neutralizing antibodies against heterologous virus varied among different disease stage. There were higher titers of neutralizing antibodies in HIV chronically infected than AIDS group. The loss of neutralizing antibodies in plasma from AIDS group appears to be associated with a narrowing of the antibody response during disease progression. These suggest that the presence of neutralizing antibodies against hetreologous virus was associated with disease progression.
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Objective To investigate the association between APOBEC3G mRNA levels in peripheral blood mononuclear cells(PBMCs)of HIV/AIDS patients and disease progression in Henan province.Methods Real-time PCR was used to detect the mRNA levels of APOBEC3G in PBMCs of HIV/AIDS patients at difierent disease progression stage.Flow cytometry and automated viral load analyzer were used to count CD4+ T cells and plasma HIV viral loads.Results The mRNA levels of APOBEC3G in HIV/AIDS patients were lower than in HIV-negative controls(t=4.887,P＜0.01),and APOBEC3G levels were significantly higher in slow development group than those in HIV and AIDS groups(P＜0.05).The levels of APOBEC3G mRNA correlated positively with CD4+ T cell counts(R2=0.190,P=0.002)and negatively with HIV-1 viral loads(R2=0.094.P=0.038).Conclusions The APOBEC3G mRNA levels in PBMC of HIV infected individuals are associated with HIV disease pmgression. Higher mRNA expression levels of APOBEC3G may be one of the protective factors which can play important role in delaying disease progression.
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Objective To investigate the killer cell lg-like receptors (KIR) gene frequency of HIV-1 infected slow progressors(SP) and typical progressors(TP), and to analyze the interaction between KIR alleles and the progression of HIV-1 infection in Chinese population. Methods Eighty-one HIV-1 posi-tive individuals including 43 SPs and 38 TPs were recruited. Carriage of KIR genes was assessed using poly-merase chain reaction sequence-specific primers (PCR-SSP) assays. Results KIR2DS3 gene frequency was significantly lower in SP group (3.6%) than that in TP group (14.2%), P =0. 018 ,OR =0. 210,95% CI =0.053-0.833. The number of activating KIR genes was less in SP group than that in TP group, but was not significant (P = 0. 208). Conclusion Lower KIR2DS3 gene frequency may potentially be associated with slower progression to AIDS in Chinese population.
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Objective To study the amino acid mutations in neutralizing antibody 2F5 and 4E10 conserved epitopes ELDKWA and NWFDIT of HIV-1 membrane proximal external region(MPER)in 92 HIV-infected individuals and AIDS patients in China,and to provide a basis for the neutralizing antobodies immunotherapy and a design of vaccines. Methods Nest-PCR methods were used to amplity genes of the HIV-1 env gp41 region.The amplified fragments were sequenced by double-deoxygen terminal method and translated into amino acids for analysis.The mutations of 2F5 and 4E10 neutralizing epitopes were identified by comparison with the epitopes reference data in HIV-1 Sequence Database.Results There were mutations on both 2F5 and 4E10 neutralizing epitopes.2F5 conserved neutralizing epitopes major mutations tocused on E662A(14.1%),K665S(17.4%),A667K(16.3%),and 4E10 conserved neutralizing epltopes major mutations included N671S(13.0%),D674S(3.3%),T676S(16.3%).The mutation rates of 2F5 and 4E10 epitopes were significanfly different between CRF_B'C-clade and B'-clade(P<0.05).The mutata rates of CRF_B'C-clade were higher than that of CRFOI_AE-clade in 2F5 epitopes(P<0.05).The mutation rates of B'-clade in 4E10 eiptopes showed significant difference in slow progressors,HIV-infected individuals and AIDS patients,respectively(P<0.05).Conclusion The HIV-1 patients in China are demonstrated diversified mutations in 2F5 and 4E10 neutralizing epitopes.The mutation degrees of amlno acids in conserved neutralizing epitopes are different in different subtypes.There may be a correlation between neutralizing epitopes mutations of 4E10 with disease progression.
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Objective:To study the relationships between neutralizing antibody response against autologous virus and disease progression of HIV-1 B'/C infected individuals in China.Methods:Twenty-four primary HIV-1 isolates were incubated with autologous plasma collected either freshly or at approximately six months intervals thereafter.Normal human peripheral blood mononuclear cells were incubated with the virus-serum mixtures for 7 days and then the production of p24 antigen was measured.The neutralizing titer of a particular plasma and virus was defined as the reciprocal of the highest dilution giving a 50% reduction in p24 Ag compared with NHP control wells.More than 1∶8 were considered significant and were scored as positive.Results:In neutralizing antibody(Nabs) response against contemporaneous virus,Nabs were produced in all slow progressors(SP) individuals,while only four in 21 of HIV group had.There was statistically significance of the neutralizing antibody titers between SP and HIV.When plasma samples of six months later were tested for their ability to neutralize autologous virus,all of SPs had higher neutralizing antibody titers and the titers of neutralizing antibody in HIV group had increased in different rate.Among the twenty-one individuals of HIV group,12 of these individuals had neutralizing antibody response against autologous virus and other 9 of these individuals had not.NAb titers of SP in six months later plasma were higher than those of HIV.There was a negative correlation between the generation of the neutralizing titer against autologous virus and the plasma HIV RNA level in HIV-1 B'/C infected individuals(including SP,HIV).Conclusion:Neutralizing antibody against autologous viruses in HIV-1 B'/C infected SP is higher than those of HIV group,suggesting that neutralizing antibodies play a vital role in delaying disease progression in these individuals.