Background:The Global Programme to Eliminate Lymphatic Filariasis(GPELF)was launched in response to the call proposed at the 50th World Health Assembly.The goal of the GPELF is to ensure that all the countries where t...Background:The Global Programme to Eliminate Lymphatic Filariasis(GPELF)was launched in response to the call proposed at the 50th World Health Assembly.The goal of the GPELF is to ensure that all the countries where the disease is endemic would have been transmission-free or would have entered post-intervention mass drug administration(MDA)surveillance by 2020.However,several countries are still not on track to discontinue MDA as planned.Thus,issues remain regarding the achievement of stated goals and how to effectively monitor the disease in the post-control and post-elimination phases.Main text:China was once a lymphatic filariasis(LF)endemic country with heavy disease burden.There were three milestones in the LF control phase of China,including:the proposal that the major focus of the control strategy should be on infectious sources;the three regimens of diethylcarbamazine(DEC)administration according to LF endemic extent;and the establishment of the threshold for LF transmission interruption.It has been ten years since China entered the post-elimination stage(declaration of LF elimination in China was in 2007).Two schemes and a diagnostic criterion were issued to guide all levels of disease control and prevention workers that conduct LF surveillance,as well as those caring for chronic filariasis patients.Regular training courses are held to maintain LF control skills in grass-root institutions.The Notifiable Diseases Reporting System,which included LF in 2004,plays an important role in LF post-elimination surveillance.Until now,no resurgence of LF cases has been detected,except for LF residue foci being found in Fuchuan County of the Guangxi Zhuang Autonomous Region.To confirm that transmission is no longer achievable after a decade since the declaration of LF elimination in China,it is expected within the next two years a transmission assessment survey,conducted in previous LF-endemic areas.Conclusions:DEC-fortified salt can help accelerate the progress of GPELF before the sprite phase.Sophisticated diagnost展开更多
Objective:To investigate which life stage of the parasite has the ability to stimulate release of pro- or anti-inflammatory mediators from macrophages.Methods:The human macrophage/ monocyte cell line THP-1,the mouse m...Objective:To investigate which life stage of the parasite has the ability to stimulate release of pro- or anti-inflammatory mediators from macrophages.Methods:The human macrophage/ monocyte cell line THP-1,the mouse macrophage cell line RAW 264.7 and naive peritoneal macrophages（PM） from the rodent host Mastomys coucha（M.coucha） were incubated at 37℃in 5%CO<sub>2</sub> atmosphere with extracts of microfilariae（Mf）,third stage infective larvae（L<sub>3</sub>） and adult worms（Ad） of Brugia malayi.After 48 hr post exposure,IL-1β,IL-6,TNF-α,IL-10 and nitric oxide（NO） in cell-free supernatants were estimated.Results:Extracts of all the life stages of the parasite were capable of stimulating pro-（IL-1β,IL-6 and TNF-α） and anti-inflammatory （IL-10） cytokines in both the cell lines and peritoneal macrophages of M.coucha.Mf was the strongest stimulator of pro-inflammatory cytokines followed by L<sub>3</sub> and Ad;however,Ad was a strong stimulator of IL-10 release.Mf was found to have potential to modulate LPS-induced NO release in RAW cells.Ad-induced NO release was concentration dependent with maximum at 20μg/mL in both RAW and PMs.Conclusions:The results show that parasites at all life stages were capable of stimulating pro-（IL-1β,IL-6 and TNF-α） and anti-inflammatory（IL-10） cytokines and NO release from macrophages of susceptible host M.coucha,human and mouse macrophage cell lines.Mf can suppress the LPS-induced NO release in RAW cells.The findings also show that the two cell lines may provide a convenient in vitro system for assaying parasite-induced inflammatory mediator release.展开更多
This paper deals with the studies on the changes of serum specific IgM andIgG,and relationship between the antibody level and infected worm stage of Brugiamalayi.The jirds (Meriones unguiculatus)and BALB/cCR mice were...This paper deals with the studies on the changes of serum specific IgM andIgG,and relationship between the antibody level and infected worm stage of Brugiamalayi.The jirds (Meriones unguiculatus)and BALB/cCR mice were infected with threedifferent stages of Brugia malayi by different routes and serum specific IgM and IgGwere detected by ELISA mcthod.The IgM of infected jirds and mice occurred earlierthan IgG,reached peak at 4～8th weeks,and maintained at a certain level during 30weeks.The responses and toles of IgM and IgG might probably be considered as animmunological characferistic of parasitic helminthic infection.The antibody levels inBALB/cCR mice after infection were higher than those in jirds.展开更多
Objective: To detect and identify filarial parasites in dried blood spots(DBS) collected from domestic cats using high resolution melting real-time PCR(HRM RT-PCR). Methods: A total of 208 DBS were collected from dome...Objective: To detect and identify filarial parasites in dried blood spots(DBS) collected from domestic cats using high resolution melting real-time PCR(HRM RT-PCR). Methods: A total of 208 DBS were collected from domestic cats in a brugian filariasis endemic areas in Surat Thani Province, southern Thailand. Microfilariae were found in 9 blood slides using Giemsa-stained thick blood film. The extracted DNA from blood spot volumes of 10 and 20 μL DBS with positive filarial parasites in cats were performed using HRM RT-PCR method. The primers were designed based on the partial mitochondrial 12S rRNA gene for identifying Brugia malayi, Brugia pahangi, Dirofilaria immitis. All purified samples were then detected. Results: Using different volumes of 10 μL and 20 μL DBS could easily distinguish filarial parasites and showed similar results. PCR amplicons of Brugia malayi, Brugia pahangi and Dirofilaria immitis were determined at melting peak(temperature) of 75.70℃, 77.46 ℃, and 73.56 ℃, respectively. All 9 positive DBS samples showed positive Brugia pahangi and similar nucleotide sequences. Conclusions: This HRM RT-PCR method is able to diagnose, identify and discriminate filarial parasites collected from DBS, which is simple and inexpensive compared with other probe-based genotyping methods. Furthermore, this method is useful to survey, prevent and control filariasis.展开更多
Objective:To explore the effect of herbal polyphenolics on filariasis in vitro.Methods:Two herbal extracts,methanolic extracts of roots of Vitex negundo Linn.（Nirgundi） and leaves of Aegle marmelos Juss.（Beal） in ...Objective:To explore the effect of herbal polyphenolics on filariasis in vitro.Methods:Two herbal extracts,methanolic extracts of roots of Vitex negundo Linn.（Nirgundi） and leaves of Aegle marmelos Juss.（Beal） in different concentrations ranging from 40-80 ng/mL were tested for their antifilarial activity either alone or in combination with diethyl carbonate（DEC）（300μg/mL） and/or H<sub>2</sub>O<sub>2</sub>（0.5 mM）.Results:Combination of DEC and each extract had significant anti-filarial effect.And fractions of both extracts were not effective as crude herbal extract.Conclusions: Such unique pharmacodynamics reported in this study might provide new drug development stratagem against filariasis.展开更多
Objective: To evaluate the effect of short-term and long-term immunization of recombinant disorganized muscle protein-1(r DIM-1) in rodents against human filarial parasite Brugia malayi.Methods: Recombinant Brugia mal...Objective: To evaluate the effect of short-term and long-term immunization of recombinant disorganized muscle protein-1(r DIM-1) in rodents against human filarial parasite Brugia malayi.Methods: Recombinant Brugia malayi DIM-1(rDIM-1 bm) protein was cloned, expressed and purified using a Ni-NTA affinity column. Mastomys coucha were immunized with rDIM-1 bm in three immunization schedules: short-term(3-dose of rDIM-1 bm), and long-term(booster doses till 3-and 6-week) and subsequently challenged with infective third-stage larvae of filarial parasite Brugia malayi(L3). Microfilaraemia was monitored in L3 exposed groups on day 90 post larval inoculation(p.l.i.) and continued till day 205 p.l.i. On day 205 p.l.i. all the infected animals were killed and total worm burden was estimated. Cellular proliferative response, macrophage activity, nitric oxide(NO) release, specific IgG and its subtypes, IgE, IgA and Th1(IFN-γ, TNF-ααand IL-2) and Th2(IL-4, IL-5, IL-6, IL-10 and IL-13) cytokine release were determined. Results: Of the 3 different immunization schedules, shortterm immunization(3-dose schedule) showed better reduction in microfilarial burden(36%-63%) in the peripheral circulation, adult worm load(52%), whereas long-term immunization(3-and 6-week schedule) exerted less effect on peripheral microfilariae count(9%-58%), and adult worm burden(9%-12.5%). Short-term immunization resulted in upregulation of cellular proliferation, macrophages activity, NO release, specific IgG, IgG1, IgG2 a, Ig G2 b, IgE and IgA levels and both Th1(IFN-γ, TNF-α and IL-2) and Th2(IL-4, IL-5, IL-6, IL-10 and IL-13) cytokine release whereas long-term immunization(3-and 6-week schedule) exerted less effect on parasite burden and showed mixed immunological responses. None of the rDIM-1 bm administration schedules induced any pathology in lymphoid tissues, or alteration in mast cell number and granularity. Conclusions: The short-term immunization with rDIM-1 bm(3-dose schedule) induces robust immune responses and protects the host from 展开更多
Objective:To evaluate the immunostimulatory potential of crossreactive molecule heat shock protein 60(HSP60)of filarial parasite Brugia malayi and Leishmania donovani.Methods:HSP60 of Brugia malayi(BmHSP60)was amplifi...Objective:To evaluate the immunostimulatory potential of crossreactive molecule heat shock protein 60(HSP60)of filarial parasite Brugia malayi and Leishmania donovani.Methods:HSP60 of Brugia malayi(BmHSP60)was amplified using gene-specific primer,cloned in p Tri Ex4 vector,expressed in BL21-DE3 cells,and recombinant HSP60(rHSP60)of~65 k Da was purified by affinity chromatography using Ni-NTA column.The recombinant protein was desalted by the dialysis membrane,and the presence of endotoxin level was determined by Limulus amebocyte lysate assay.The recombinant protein was tested for cell proliferation,nitric oxide release,expression of Th1 and Th2 cytokines,and transcription factors(STATs)in vitro using murine macrophage cell line(J774 A.1).Results:Higher cell proliferation indicated that BmHSP60 had immunostimulatory potential.rBmHSP60 exposure upregulated the expression of iNOS,STAT1,STAT4,Th1 cytokines(IFN-γ,TNF-α,IL-12),and nitric oxide release.In addition,no remarkable change was observed in the expression of IL-6,IL-10,and STAT3 in macrophage cell line J774 A.1.The ELISA analysis showed the levels of IFN-γ,TNF-α,and IL-12 were upregulated while IL-10 level was downregulated,revealing that BmHSP60 triggered a Th1 immune response.Conclusions:Our study demonstrates that rBmHSP60 has immunogenic properties which effectively enhances the Th1 type immune responses,and can be used as an immunoprophylactic agent against leishmaniasis.Furthermore,in vivo studies are in progress to determine the protective role of rBmHSP60 against Leishmania donovani infection in a mouse model.展开更多
基金the National Key Research and Development Program of China(No.2016YFC1202000,2016YFC1202002,2016YFC1202003).
文摘Background:The Global Programme to Eliminate Lymphatic Filariasis(GPELF)was launched in response to the call proposed at the 50th World Health Assembly.The goal of the GPELF is to ensure that all the countries where the disease is endemic would have been transmission-free or would have entered post-intervention mass drug administration(MDA)surveillance by 2020.However,several countries are still not on track to discontinue MDA as planned.Thus,issues remain regarding the achievement of stated goals and how to effectively monitor the disease in the post-control and post-elimination phases.Main text:China was once a lymphatic filariasis(LF)endemic country with heavy disease burden.There were three milestones in the LF control phase of China,including:the proposal that the major focus of the control strategy should be on infectious sources;the three regimens of diethylcarbamazine(DEC)administration according to LF endemic extent;and the establishment of the threshold for LF transmission interruption.It has been ten years since China entered the post-elimination stage(declaration of LF elimination in China was in 2007).Two schemes and a diagnostic criterion were issued to guide all levels of disease control and prevention workers that conduct LF surveillance,as well as those caring for chronic filariasis patients.Regular training courses are held to maintain LF control skills in grass-root institutions.The Notifiable Diseases Reporting System,which included LF in 2004,plays an important role in LF post-elimination surveillance.Until now,no resurgence of LF cases has been detected,except for LF residue foci being found in Fuchuan County of the Guangxi Zhuang Autonomous Region.To confirm that transmission is no longer achievable after a decade since the declaration of LF elimination in China,it is expected within the next two years a transmission assessment survey,conducted in previous LF-endemic areas.Conclusions:DEC-fortified salt can help accelerate the progress of GPELF before the sprite phase.Sophisticated diagnost
基金supported by a grant Indian Council of Medical Research, New Delhi and SP/SO/B-46/2000 from the Department of Science and Technology,New DelhiUGC Senior Research Fellowship support to SKV
文摘Objective:To investigate which life stage of the parasite has the ability to stimulate release of pro- or anti-inflammatory mediators from macrophages.Methods:The human macrophage/ monocyte cell line THP-1,the mouse macrophage cell line RAW 264.7 and naive peritoneal macrophages（PM） from the rodent host Mastomys coucha（M.coucha） were incubated at 37℃in 5%CO<sub>2</sub> atmosphere with extracts of microfilariae（Mf）,third stage infective larvae（L<sub>3</sub>） and adult worms（Ad） of Brugia malayi.After 48 hr post exposure,IL-1β,IL-6,TNF-α,IL-10 and nitric oxide（NO） in cell-free supernatants were estimated.Results:Extracts of all the life stages of the parasite were capable of stimulating pro-（IL-1β,IL-6 and TNF-α） and anti-inflammatory （IL-10） cytokines in both the cell lines and peritoneal macrophages of M.coucha.Mf was the strongest stimulator of pro-inflammatory cytokines followed by L<sub>3</sub> and Ad;however,Ad was a strong stimulator of IL-10 release.Mf was found to have potential to modulate LPS-induced NO release in RAW cells.Ad-induced NO release was concentration dependent with maximum at 20μg/mL in both RAW and PMs.Conclusions:The results show that parasites at all life stages were capable of stimulating pro-（IL-1β,IL-6 and TNF-α） and anti-inflammatory（IL-10） cytokines and NO release from macrophages of susceptible host M.coucha,human and mouse macrophage cell lines.Mf can suppress the LPS-induced NO release in RAW cells.The findings also show that the two cell lines may provide a convenient in vitro system for assaying parasite-induced inflammatory mediator release.
文摘This paper deals with the studies on the changes of serum specific IgM andIgG,and relationship between the antibody level and infected worm stage of Brugiamalayi.The jirds (Meriones unguiculatus)and BALB/cCR mice were infected with threedifferent stages of Brugia malayi by different routes and serum specific IgM and IgGwere detected by ELISA mcthod.The IgM of infected jirds and mice occurred earlierthan IgG,reached peak at 4～8th weeks,and maintained at a certain level during 30weeks.The responses and toles of IgM and IgG might probably be considered as animmunological characferistic of parasitic helminthic infection.The antibody levels inBALB/cCR mice after infection were higher than those in jirds.
文摘Objective: To detect and identify filarial parasites in dried blood spots(DBS) collected from domestic cats using high resolution melting real-time PCR(HRM RT-PCR). Methods: A total of 208 DBS were collected from domestic cats in a brugian filariasis endemic areas in Surat Thani Province, southern Thailand. Microfilariae were found in 9 blood slides using Giemsa-stained thick blood film. The extracted DNA from blood spot volumes of 10 and 20 μL DBS with positive filarial parasites in cats were performed using HRM RT-PCR method. The primers were designed based on the partial mitochondrial 12S rRNA gene for identifying Brugia malayi, Brugia pahangi, Dirofilaria immitis. All purified samples were then detected. Results: Using different volumes of 10 μL and 20 μL DBS could easily distinguish filarial parasites and showed similar results. PCR amplicons of Brugia malayi, Brugia pahangi and Dirofilaria immitis were determined at melting peak(temperature) of 75.70℃, 77.46 ℃, and 73.56 ℃, respectively. All 9 positive DBS samples showed positive Brugia pahangi and similar nucleotide sequences. Conclusions: This HRM RT-PCR method is able to diagnose, identify and discriminate filarial parasites collected from DBS, which is simple and inexpensive compared with other probe-based genotyping methods. Furthermore, this method is useful to survey, prevent and control filariasis.
基金supported by the Grants under the Department of Biotechnology,India(DBT) Funded Project "Repository for the Filarial Parasites and Reagents"(NO. BT/INF/22/1/2007)
文摘Objective:To explore the effect of herbal polyphenolics on filariasis in vitro.Methods:Two herbal extracts,methanolic extracts of roots of Vitex negundo Linn.（Nirgundi） and leaves of Aegle marmelos Juss.（Beal） in different concentrations ranging from 40-80 ng/mL were tested for their antifilarial activity either alone or in combination with diethyl carbonate（DEC）（300μg/mL） and/or H<sub>2</sub>O<sub>2</sub>（0.5 mM）.Results:Combination of DEC and each extract had significant anti-filarial effect.And fractions of both extracts were not effective as crude herbal extract.Conclusions: Such unique pharmacodynamics reported in this study might provide new drug development stratagem against filariasis.
基金supported by Indian council of Medical Research,New Delhi,India(ICMR approval no.F/802/2010-ECD-11)CSIR,New Delhi,India,for award of Emeritus Scientist(scheme No.21(0963)/13/EMRII grant,29-10-2014)to P.K.M.
文摘Objective: To evaluate the effect of short-term and long-term immunization of recombinant disorganized muscle protein-1(r DIM-1) in rodents against human filarial parasite Brugia malayi.Methods: Recombinant Brugia malayi DIM-1(rDIM-1 bm) protein was cloned, expressed and purified using a Ni-NTA affinity column. Mastomys coucha were immunized with rDIM-1 bm in three immunization schedules: short-term(3-dose of rDIM-1 bm), and long-term(booster doses till 3-and 6-week) and subsequently challenged with infective third-stage larvae of filarial parasite Brugia malayi(L3). Microfilaraemia was monitored in L3 exposed groups on day 90 post larval inoculation(p.l.i.) and continued till day 205 p.l.i. On day 205 p.l.i. all the infected animals were killed and total worm burden was estimated. Cellular proliferative response, macrophage activity, nitric oxide(NO) release, specific IgG and its subtypes, IgE, IgA and Th1(IFN-γ, TNF-ααand IL-2) and Th2(IL-4, IL-5, IL-6, IL-10 and IL-13) cytokine release were determined. Results: Of the 3 different immunization schedules, shortterm immunization(3-dose schedule) showed better reduction in microfilarial burden(36%-63%) in the peripheral circulation, adult worm load(52%), whereas long-term immunization(3-and 6-week schedule) exerted less effect on peripheral microfilariae count(9%-58%), and adult worm burden(9%-12.5%). Short-term immunization resulted in upregulation of cellular proliferation, macrophages activity, NO release, specific IgG, IgG1, IgG2 a, Ig G2 b, IgE and IgA levels and both Th1(IFN-γ, TNF-α and IL-2) and Th2(IL-4, IL-5, IL-6, IL-10 and IL-13) cytokine release whereas long-term immunization(3-and 6-week schedule) exerted less effect on parasite burden and showed mixed immunological responses. None of the rDIM-1 bm administration schedules induced any pathology in lymphoid tissues, or alteration in mast cell number and granularity. Conclusions: The short-term immunization with rDIM-1 bm(3-dose schedule) induces robust immune responses and protects the host from
基金supported by Department of Science and Technology,Science and Engineering Research Board,New Delhi,India(N-PDF Project No PDF/2016/001487)
文摘Objective:To evaluate the immunostimulatory potential of crossreactive molecule heat shock protein 60(HSP60)of filarial parasite Brugia malayi and Leishmania donovani.Methods:HSP60 of Brugia malayi(BmHSP60)was amplified using gene-specific primer,cloned in p Tri Ex4 vector,expressed in BL21-DE3 cells,and recombinant HSP60(rHSP60)of~65 k Da was purified by affinity chromatography using Ni-NTA column.The recombinant protein was desalted by the dialysis membrane,and the presence of endotoxin level was determined by Limulus amebocyte lysate assay.The recombinant protein was tested for cell proliferation,nitric oxide release,expression of Th1 and Th2 cytokines,and transcription factors(STATs)in vitro using murine macrophage cell line(J774 A.1).Results:Higher cell proliferation indicated that BmHSP60 had immunostimulatory potential.rBmHSP60 exposure upregulated the expression of iNOS,STAT1,STAT4,Th1 cytokines(IFN-γ,TNF-α,IL-12),and nitric oxide release.In addition,no remarkable change was observed in the expression of IL-6,IL-10,and STAT3 in macrophage cell line J774 A.1.The ELISA analysis showed the levels of IFN-γ,TNF-α,and IL-12 were upregulated while IL-10 level was downregulated,revealing that BmHSP60 triggered a Th1 immune response.Conclusions:Our study demonstrates that rBmHSP60 has immunogenic properties which effectively enhances the Th1 type immune responses,and can be used as an immunoprophylactic agent against leishmaniasis.Furthermore,in vivo studies are in progress to determine the protective role of rBmHSP60 against Leishmania donovani infection in a mouse model.
