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Jacqueline Araujo Fiuza - One of the best experts on this subject based on the ideXlab platform.
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vaccination using live attenuated leishmania donovani centrin deleted parasites induces protection in dogs against leishmania infantum
Vaccine, 2015Co-Authors: Jacqueline Araujo Fiuza, Helton C Santiago, Angamuthu Selvapandiyan, Sreenivas Gannavaram, Daniel Menezes Souza, Livia Silva Araujo Passos, Ludmila Zanandreis De Mendonca, Denise Da Silveira LemosgiunchettiAbstract:Live attenuated Leishmania donovani parasites such as LdCen−/− have been shown elicit protective immunity against leishmanial infection in mice and hamster models. Previously, we have reported on the induction of strong immunogenicity in dogs upon vaccination with LdCen−/− including an increase in immunoglobulin isotypes, higher Lymphoproliferative Response, higher frequencies of activated CD4+ and CD8+ T cells, IFN-γ production by CD8+ T cells, increased secretion of TNF-α and IL-12/IL-23p40 and, finally, decreased secretion of IL-4. To further explore the potential of LdCen−/− parasites as vaccine candidates, we performed a 24-month follow up of LdCen−/− immunized dogs after challenge with virulent Leishmania infantum, aiming determination of parasite burden by qPCR, antibody production (ELISA) and cellular Responses (T cell activation and cytokine production) by flow cytometry and sandwich ELISA. Our data demonstrated that vaccination with a single dose of LdCen−/− (without any adjuvant) resulted in the reduction of up to 87.3% of parasite burden after 18 months of virulent challenge. These results are comparable to those obtained with commercially available vaccine in Brazil (Leishmune®). The protection was associated with antibody production and CD4+ and CD8+ proliferative Responses, as well as T cell activation and significantly higher production of IFN-γ, IL-12/IL-23p40 and TNF-α, which was comparable to Responses induced by immunization with Leishmune®, with significant differences when compared to control animals (Placebo). Moreover, only animals immunized with LdCen−/− expressed lower levels of IL-4 when compared to animals vaccinated either with Leishmune® or PBS. Our results support further studies aiming to demonstrate the potential of genetically modified live attenuated L. donovani vaccine to control L. infantum transmission in endemic areas for CVL.
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induction of immunogenicity by live attenuated leishmania donovani centrin deleted parasites in dogs
Vaccine, 2013Co-Authors: Jacqueline Araujo Fiuza, Helton C Santiago, Angamuthu Selvapandiyan, Sreenivas Gannavaram, Natasha Delaqua Ricci, Lilian Lacerda Bueno, Daniella Castanheira Bartholomeu, Rodrigo Correaoliveira, Hira L Nakhasi, Ricardo Toshio FujiwaraAbstract:Zoonotic visceral leishmaniasis, caused by the intracellular protozoan parasite Leishmania infantum, is a neglected tropical disease that is often fatal when untreated. Dogs are considered the main reservoir of L. infantum in zoonotic VL as the presence of infected dogs may increase the risk for human infection. Canine visceral leishmaniasis (CVL) is a major veterinary and public health problem in Southern Europe, Middle East and South America. Control of animal reservoirs relies on elimination of seropositive dogs in endemic areas. However, treatment of infected dogs is not considered a favorable approach as this can lead to emergence of drug resistance since the same drugs are used to treat human infections. Therefore, vaccination against CVL remains the best alternative in control of the animal reservoirs. In this study, we present data on the immunogenicity profile of a live attenuated parasite LdCen(-/-) in a canine infection model and compared it to that of Leishmune(®), a commercially available recombinant vaccine. The immunogenicity of the LdCen(-/-) parasites was evaluated by antibody secretion, production of intracytoplasmic and secreted cytokines, activation and proliferation of T cells. Vaccination with LdCen(-/-) resulted in high immunogenicity as revealed by the higher IgGTotal, IgG1, and IgG2 production and higher Lymphoproliferative Response. Further, LdCen(-/-) vaccinated dogs showed higher frequencies of activated CD4+ and CD8+ T cells, IFN-γ production by CD8+ T cells, increased secretion of TNF-α and IL-12/IL-23p40 and decreased secretion of IL-4. These results contribute to the understanding of immunogenicity elicited by live attenuated L. donovani parasites and, consequently, to the development of effective vaccines against visceral leishmaniasis.
Angamuthu Selvapandiyan - One of the best experts on this subject based on the ideXlab platform.
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live attenuated leishmania donovani centrin knock out parasites generate non inferior protective immune Response in aged mice against visceral leishmaniasis
PLOS Neglected Tropical Diseases, 2016Co-Authors: Parna Bhattacharya, Sreenivas Gannavaram, Ranadhir Dey, Pradeep K Dagur, Amritanshu B Joshi, Nevien Ismail, Alain Debrabant, Adovi Akue, Mark A Kukuruga, Angamuthu SelvapandiyanAbstract:Background Visceral leishmaniasis (VL) caused by the protozoan parasite Leishmania donovani causes severe disease. Age appears to be critical in determining the clinical outcome of VL and at present there is no effective vaccine available against VL for any age group. Previously, we showed that genetically modified live attenuated L. donovani parasites (LdCen-/-) induced a strong protective innate and adaptive immune Response in young mice. In this study we analyzed LdCen-/- parasite mediated modulation of innate and adaptive immune Response in aged mice (18 months) and compared to young (2 months) mice. Methodology Analysis of innate immune Response in bone marrow derived dendritic cells (BMDCs) from both young and aged mice upon infection with LdCen-/- parasites, showed significant enhancement of innate effector Responses, which consequently augmented CD4+ Th1 cell effector function compared to LdWT infected BMDCs in vitro. Similarly, parasitized splenic dendritic cells from LdCen-/- infected young and aged mice also revealed induction of proinflammatory cytokines (IL-12, IL-6, IFN-γ and TNF) and subsequent down regulation of anti-inflammatory cytokine (IL-10) genes compared to LdWT infected mice. We also evaluated in vivo protection of the LdCen-/- immunized young and aged mice against virulent L. donovani challenge. Immunization with LdCen-/- induced higher IgG2a antibodies, Lymphoproliferative Response, pro- and anti-inflammatory cytokine Responses and stimulated splenocytes for heightened leishmanicidal activity associated with nitric oxide production in young and aged mice. Furthermore, upon virulent L. donovani challenge, LdCen-/- immunized mice from both age groups displayed multifunctional Th1-type CD4 and cytotoxic CD8 T cells correlating to a significantly reduced parasite burden in the spleen and liver compared to naive mice. It is interesting to note that even though there was no difference in the LdCen-/- induced innate Response in dendritic cells between aged and young mice; the adaptive Response specifically in terms of T cell and B cell activation in aged animals was reduced compared to young mice which correlated with less protection in old mice compared to young mice. Conclusions Taken together, LdCen-/- immunization induced a significant but diminished host protective Response in aged mice after challenge with virulent L. donovani parasites compared to young mice.
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vaccination using live attenuated leishmania donovani centrin deleted parasites induces protection in dogs against leishmania infantum
Vaccine, 2015Co-Authors: Jacqueline Araujo Fiuza, Helton C Santiago, Angamuthu Selvapandiyan, Sreenivas Gannavaram, Daniel Menezes Souza, Livia Silva Araujo Passos, Ludmila Zanandreis De Mendonca, Denise Da Silveira LemosgiunchettiAbstract:Live attenuated Leishmania donovani parasites such as LdCen−/− have been shown elicit protective immunity against leishmanial infection in mice and hamster models. Previously, we have reported on the induction of strong immunogenicity in dogs upon vaccination with LdCen−/− including an increase in immunoglobulin isotypes, higher Lymphoproliferative Response, higher frequencies of activated CD4+ and CD8+ T cells, IFN-γ production by CD8+ T cells, increased secretion of TNF-α and IL-12/IL-23p40 and, finally, decreased secretion of IL-4. To further explore the potential of LdCen−/− parasites as vaccine candidates, we performed a 24-month follow up of LdCen−/− immunized dogs after challenge with virulent Leishmania infantum, aiming determination of parasite burden by qPCR, antibody production (ELISA) and cellular Responses (T cell activation and cytokine production) by flow cytometry and sandwich ELISA. Our data demonstrated that vaccination with a single dose of LdCen−/− (without any adjuvant) resulted in the reduction of up to 87.3% of parasite burden after 18 months of virulent challenge. These results are comparable to those obtained with commercially available vaccine in Brazil (Leishmune®). The protection was associated with antibody production and CD4+ and CD8+ proliferative Responses, as well as T cell activation and significantly higher production of IFN-γ, IL-12/IL-23p40 and TNF-α, which was comparable to Responses induced by immunization with Leishmune®, with significant differences when compared to control animals (Placebo). Moreover, only animals immunized with LdCen−/− expressed lower levels of IL-4 when compared to animals vaccinated either with Leishmune® or PBS. Our results support further studies aiming to demonstrate the potential of genetically modified live attenuated L. donovani vaccine to control L. infantum transmission in endemic areas for CVL.
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induction of immunogenicity by live attenuated leishmania donovani centrin deleted parasites in dogs
Vaccine, 2013Co-Authors: Jacqueline Araujo Fiuza, Helton C Santiago, Angamuthu Selvapandiyan, Sreenivas Gannavaram, Natasha Delaqua Ricci, Lilian Lacerda Bueno, Daniella Castanheira Bartholomeu, Rodrigo Correaoliveira, Hira L Nakhasi, Ricardo Toshio FujiwaraAbstract:Zoonotic visceral leishmaniasis, caused by the intracellular protozoan parasite Leishmania infantum, is a neglected tropical disease that is often fatal when untreated. Dogs are considered the main reservoir of L. infantum in zoonotic VL as the presence of infected dogs may increase the risk for human infection. Canine visceral leishmaniasis (CVL) is a major veterinary and public health problem in Southern Europe, Middle East and South America. Control of animal reservoirs relies on elimination of seropositive dogs in endemic areas. However, treatment of infected dogs is not considered a favorable approach as this can lead to emergence of drug resistance since the same drugs are used to treat human infections. Therefore, vaccination against CVL remains the best alternative in control of the animal reservoirs. In this study, we present data on the immunogenicity profile of a live attenuated parasite LdCen(-/-) in a canine infection model and compared it to that of Leishmune(®), a commercially available recombinant vaccine. The immunogenicity of the LdCen(-/-) parasites was evaluated by antibody secretion, production of intracytoplasmic and secreted cytokines, activation and proliferation of T cells. Vaccination with LdCen(-/-) resulted in high immunogenicity as revealed by the higher IgGTotal, IgG1, and IgG2 production and higher Lymphoproliferative Response. Further, LdCen(-/-) vaccinated dogs showed higher frequencies of activated CD4+ and CD8+ T cells, IFN-γ production by CD8+ T cells, increased secretion of TNF-α and IL-12/IL-23p40 and decreased secretion of IL-4. These results contribute to the understanding of immunogenicity elicited by live attenuated L. donovani parasites and, consequently, to the development of effective vaccines against visceral leishmaniasis.
Giuseppe Gerna - One of the best experts on this subject based on the ideXlab platform.
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maternal immune correlates of protection from human cytomegalovirus transmission to the fetus after primary infection in pregnancy
Reviews in Medical Virology, 2017Co-Authors: Daniele Lilleri, Giuseppe GernaAbstract:Summary Immune control of primary human cytomegalovirus (HCMV) infection appears to depend on the interaction of humoral and T-cell Responses. In this review, we have separately explored the 2 arms of the immune Response to primary HCMV infection in HCMV-seronegative pregnant women transmitting (T) or not transmitting (NT) the infection to the fetus, with the objective of correlating the immune risk factors associated with vertical HCMV transmission. As for the humoral Response, the following findings were documented: (i) in competitive binding assays, antibody titers to different antigenic sites of the gH pentamer complex were significantly lower in T compared with NT women; (ii) in addition, the number of neutralization sites recognized by T was significantly lower compared with NT women; (iii) the plaque formation inhibition assay showed a faster kinetics and a higher titer in NT women. As for T-cell immunity, the delayed expression of 3 immunological parameters (Lymphoproliferative Response, CD45RA reexpression in both CD4+ and CD8+ HCMV-specific T cells, and interleukin-2 production by HCMV-specific CD4+ T cells) were significantly associated with vertical transmission. This overview provides important information at the population level, which may help to inform the evaluation of interventions such as vaccination or treatments designed to interrupt intrauterine transmission of HCMV during primary infection. However, although we are waiting for an HCMV vaccination to become available, we emphasize that none of these parameters can be prognostically used on an individual basis because of the great variation in values among women.
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development of human cytomegalovirus specific t cell immunity during primary infection of pregnant women and its correlation with virus transmission to the fetus
The Journal of Infectious Diseases, 2007Co-Authors: Daniele Lilleri, Maria Grazia Revello, Maurizio Zavattoni, Milena Furione, Chiara Fornara, Giuseppe GernaAbstract:Objective. We sought to study the development of human cytomegalovirus (HCMV)–specific T cell–mediated immune Responses during primary HCMV infection in pregnancy. Methods. The HCMV-specific Lymphoproliferative Response (LPR) and intracellular cytokine (interferon [IFN]– g and interleukin [IL]–2) production were investigated during the first year after primary infection in 49 pregnant women and 9 nonpregnant control subjects. An HCMV-specific CD4 + and CD8 + T cell LPR was detected by the 5,6-carboxyfluorescein diacetate succinimidyl ester dilution method, and a cell-division index was calculated. Results. The CD4 + T cell LPR developed slightly earlier than the CD8 + T cell LPR. However, CDI values for both T cell subpopulations were lower than those of seropositive control subjects in both pregnant and nonpregnant individuals. During the first month after infection, IFN-g–producing CD4 + and CD8 + T cells were consistently observed, whereas IL-2–producing T cells were very rarely detected in blood. A correlation between the development of HCMV-specific LPR and virus clearance from blood was observed. A significantly delayed development of the CD4 + T cell LPR was observed in infected mothers who transmitted virus to the fetus, compared with those who did not. Conclusions. The development of adaptive T cell immunity after primary HCMV infection appears to be a complex and slow process until a memory T cell Response develops. The T cell immune Response appears to influence vertical HCMV transmission.
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prospective simultaneous quantification of human cytomegalovirus specific cd4 and cd8 t cell reconstitution in young recipients of allogeneic hematopoietic stem cell transplants
Blood, 2006Co-Authors: Daniele Lilleri, Giuseppe Gerna, Chiara Fornara, Laura Lozza, Rita Maccario, Franco LocatelliAbstract:We investigated immune reconstitution against human cytomegalovirus (HCMV) in 57 hematopoietic stem cell transplant (HSCT) recipients, aged 1 to 24 years, through a novel method combining T-cell stimulation by HCMV-infected autologous dendritic cells with simultaneous cytometric quantification of HCMV-specific, IFNγ-producing CD4+ and CD8+ T cells. Lymphoproliferative Response (LPR) to HCMV antigens was also determined. Patients were stratified into 2 groups according to HCMV serostatus, comprising 39 HCMV-seropositive (R+) and 18 HCMV-seronegative (R–) patients who received a transplant from a sero-positive donor. Recovery of both HCMV-specific CD4+ and CD8+ T-cell immunity occurred in all 39 R+ patients within 6 months and in 6 (33%) of 18 R– patients within 12 months. In R+ patients, the median numbers of HCMV-specific CD8+ and CD4+T cells were significantly higher than those of healthy controls, starting from days +60 and +180, respectively. In R– patients, the median numbers of HCMV-specific T cells were consistently lower than in R+ patients. LPR was delayed compared with reconstitution of IFNγ-producing T cells. Patients with delayed specific immune reconstitution experienced recurrent episodes of HCMV infection. HCMV seropositivity of young HSCT recipients is the major factor responsible for HCMV-specific immune reconstitution, irrespective of donor serostatus, and measurement of HCMV-specific T cells appears useful for correct management of HCMV infection.
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Lymphoproliferative Response in primary human cytomegalovirus hcmv infection is delayed in hcmv transmitter mothers
The Journal of Infectious Diseases, 2006Co-Authors: Maria Grazia Revello, Daniele Lilleri, Maurizio Zavattoni, Milena Furione, Emilia Genini, Giuditta Comolli, Giuseppe GernaAbstract:Background. The T cell-mediated immune Response to human cytomegalovirus (HCMV) after primary infection, as well as the determinants of intrauterine transmission, are poorly understood. Methods. Sequential peripheral blood leukocyte samples from 74 pregnant women and 29 nonpregnant individuals with primary infection were examined for HCMV-specific CD4 + T cells by cytokine flow cytometry (CFC) and Lymphoproliferative Response (LPR) analysis. Immunological results for 19 transmitter and 21 nontransmitter mothers were compared. Results. Comparison of CFC and LPR analysis results showed that (1) there was no difference between pregnant and nonpregnant individuals; (2) HCMV-specific CD4 + T cells were detected by CFC, in the absence of an LPR to HCMV, in the great majority or the totality (according to different intervals) of samples collected from both pregnant and nonpregnant individuals during follow-up; and (3) LPR to HCMV was significantly (P<.001) lowered or delayed in transmitter mothers, compared with that in nontransmitter mothers. Conclusions. Pregnancy does not influence the HCMV-specific immune Response. A dissociation between CFC Response and LPR is commonly observed in patients with primary infections, and ad hoc studies aimed at understanding the mechanism(s) of the reduced LPR in transmitter mothers are warranted.
Sreenivas Gannavaram - One of the best experts on this subject based on the ideXlab platform.
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live attenuated leishmania donovani centrin knock out parasites generate non inferior protective immune Response in aged mice against visceral leishmaniasis
PLOS Neglected Tropical Diseases, 2016Co-Authors: Parna Bhattacharya, Sreenivas Gannavaram, Ranadhir Dey, Pradeep K Dagur, Amritanshu B Joshi, Nevien Ismail, Alain Debrabant, Adovi Akue, Mark A Kukuruga, Angamuthu SelvapandiyanAbstract:Background Visceral leishmaniasis (VL) caused by the protozoan parasite Leishmania donovani causes severe disease. Age appears to be critical in determining the clinical outcome of VL and at present there is no effective vaccine available against VL for any age group. Previously, we showed that genetically modified live attenuated L. donovani parasites (LdCen-/-) induced a strong protective innate and adaptive immune Response in young mice. In this study we analyzed LdCen-/- parasite mediated modulation of innate and adaptive immune Response in aged mice (18 months) and compared to young (2 months) mice. Methodology Analysis of innate immune Response in bone marrow derived dendritic cells (BMDCs) from both young and aged mice upon infection with LdCen-/- parasites, showed significant enhancement of innate effector Responses, which consequently augmented CD4+ Th1 cell effector function compared to LdWT infected BMDCs in vitro. Similarly, parasitized splenic dendritic cells from LdCen-/- infected young and aged mice also revealed induction of proinflammatory cytokines (IL-12, IL-6, IFN-γ and TNF) and subsequent down regulation of anti-inflammatory cytokine (IL-10) genes compared to LdWT infected mice. We also evaluated in vivo protection of the LdCen-/- immunized young and aged mice against virulent L. donovani challenge. Immunization with LdCen-/- induced higher IgG2a antibodies, Lymphoproliferative Response, pro- and anti-inflammatory cytokine Responses and stimulated splenocytes for heightened leishmanicidal activity associated with nitric oxide production in young and aged mice. Furthermore, upon virulent L. donovani challenge, LdCen-/- immunized mice from both age groups displayed multifunctional Th1-type CD4 and cytotoxic CD8 T cells correlating to a significantly reduced parasite burden in the spleen and liver compared to naive mice. It is interesting to note that even though there was no difference in the LdCen-/- induced innate Response in dendritic cells between aged and young mice; the adaptive Response specifically in terms of T cell and B cell activation in aged animals was reduced compared to young mice which correlated with less protection in old mice compared to young mice. Conclusions Taken together, LdCen-/- immunization induced a significant but diminished host protective Response in aged mice after challenge with virulent L. donovani parasites compared to young mice.
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vaccination using live attenuated leishmania donovani centrin deleted parasites induces protection in dogs against leishmania infantum
Vaccine, 2015Co-Authors: Jacqueline Araujo Fiuza, Helton C Santiago, Angamuthu Selvapandiyan, Sreenivas Gannavaram, Daniel Menezes Souza, Livia Silva Araujo Passos, Ludmila Zanandreis De Mendonca, Denise Da Silveira LemosgiunchettiAbstract:Live attenuated Leishmania donovani parasites such as LdCen−/− have been shown elicit protective immunity against leishmanial infection in mice and hamster models. Previously, we have reported on the induction of strong immunogenicity in dogs upon vaccination with LdCen−/− including an increase in immunoglobulin isotypes, higher Lymphoproliferative Response, higher frequencies of activated CD4+ and CD8+ T cells, IFN-γ production by CD8+ T cells, increased secretion of TNF-α and IL-12/IL-23p40 and, finally, decreased secretion of IL-4. To further explore the potential of LdCen−/− parasites as vaccine candidates, we performed a 24-month follow up of LdCen−/− immunized dogs after challenge with virulent Leishmania infantum, aiming determination of parasite burden by qPCR, antibody production (ELISA) and cellular Responses (T cell activation and cytokine production) by flow cytometry and sandwich ELISA. Our data demonstrated that vaccination with a single dose of LdCen−/− (without any adjuvant) resulted in the reduction of up to 87.3% of parasite burden after 18 months of virulent challenge. These results are comparable to those obtained with commercially available vaccine in Brazil (Leishmune®). The protection was associated with antibody production and CD4+ and CD8+ proliferative Responses, as well as T cell activation and significantly higher production of IFN-γ, IL-12/IL-23p40 and TNF-α, which was comparable to Responses induced by immunization with Leishmune®, with significant differences when compared to control animals (Placebo). Moreover, only animals immunized with LdCen−/− expressed lower levels of IL-4 when compared to animals vaccinated either with Leishmune® or PBS. Our results support further studies aiming to demonstrate the potential of genetically modified live attenuated L. donovani vaccine to control L. infantum transmission in endemic areas for CVL.
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induction of immunogenicity by live attenuated leishmania donovani centrin deleted parasites in dogs
Vaccine, 2013Co-Authors: Jacqueline Araujo Fiuza, Helton C Santiago, Angamuthu Selvapandiyan, Sreenivas Gannavaram, Natasha Delaqua Ricci, Lilian Lacerda Bueno, Daniella Castanheira Bartholomeu, Rodrigo Correaoliveira, Hira L Nakhasi, Ricardo Toshio FujiwaraAbstract:Zoonotic visceral leishmaniasis, caused by the intracellular protozoan parasite Leishmania infantum, is a neglected tropical disease that is often fatal when untreated. Dogs are considered the main reservoir of L. infantum in zoonotic VL as the presence of infected dogs may increase the risk for human infection. Canine visceral leishmaniasis (CVL) is a major veterinary and public health problem in Southern Europe, Middle East and South America. Control of animal reservoirs relies on elimination of seropositive dogs in endemic areas. However, treatment of infected dogs is not considered a favorable approach as this can lead to emergence of drug resistance since the same drugs are used to treat human infections. Therefore, vaccination against CVL remains the best alternative in control of the animal reservoirs. In this study, we present data on the immunogenicity profile of a live attenuated parasite LdCen(-/-) in a canine infection model and compared it to that of Leishmune(®), a commercially available recombinant vaccine. The immunogenicity of the LdCen(-/-) parasites was evaluated by antibody secretion, production of intracytoplasmic and secreted cytokines, activation and proliferation of T cells. Vaccination with LdCen(-/-) resulted in high immunogenicity as revealed by the higher IgGTotal, IgG1, and IgG2 production and higher Lymphoproliferative Response. Further, LdCen(-/-) vaccinated dogs showed higher frequencies of activated CD4+ and CD8+ T cells, IFN-γ production by CD8+ T cells, increased secretion of TNF-α and IL-12/IL-23p40 and decreased secretion of IL-4. These results contribute to the understanding of immunogenicity elicited by live attenuated L. donovani parasites and, consequently, to the development of effective vaccines against visceral leishmaniasis.
Ziguo Yuan - One of the best experts on this subject based on the ideXlab platform.
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ascaris suum enolase is a potential vaccine candidate against ascariasis
Vaccine, 2012Co-Authors: Ning Chen, Ziguo Yuan, Minjun Xu, Donghui Zhou, Xiuxiang Zhang, Yanzhong Zhang, Xiaowei WangAbstract:: Ascariasis caused by Ascaris is the most common parasite problem in humans and pigs worldwide. No vaccines are available for the prevention of Ascaris infections. In the present study, the gene encoding Ascaris suum enolase (As-enol-1) was amplified, cloned and sequenced. Amino acid sequence alignment indicated that As-enol-1 was highly conserved between different nematodes and shared the highest identity (87%) with enolase from Anisakis simplex s.l. The recombinant pVAX-Enol was successfully expressed in Marc-145 cells. The ability of the pVAX-Enol for inducing immune protective Responses against challenge infection with A. suum L3 was evaluated in Kunming mice. The immune Response was evaluated by Lymphoproliferative assay, cytokine and antibody measurements, and the reduction rate of recovery larvae. The results showed that the mice immunized with pVAX-Enol developed a high level of specific antibody Responses against A. suum, a strong Lymphoproliferative Response, and significant levels of IFN-γ, IL-2, IL-4 and IL-10 production, compared with the other groups immunized with empty plasmid or blank controls, respectively. There was a 61.13% reduction (P<0.05) in larvae recovery compared with that in the blank control group. Our data indicated that A. suum enolase is a potential vaccine candidate against A. suum infection.
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protective immunity induced by toxoplasma gondii rhoptry protein 16 against toxoplasmosis in mice
Clinical and Vaccine Immunology, 2011Co-Authors: Ziguo Yuan, Donghui Zhou, Xiuxiang Zhang, Eskild Petersen, Ruiqing Lin, Xuli Chen, Xiaoru Shi, Xiuling Zhong, Bing ZhangAbstract:Toxoplasma gondii can infect a large variety of domestic and wild animals and human beings, sometimes causing severe pathology. Rhoptries are involved in T. gondii invasion and host cell interaction and have been implicated as important virulence factors. In this study, we constructed a DNA vaccine expressing rhoptry protein 16 (ROP16) of T. gondii and evaluated the immune Responses it induced in Kunming mice. The gene sequence encoding ROP16 was inserted into the eukaryotic expression vector pVAX I. We immunized Kunming mice intramuscularly. After immunization, we evaluated the immune Response using a Lymphoproliferative assay, cytokine and antibody measurements, and the survival times of mice challenged lethally. The results showed that mice immunized with pVAX-ROP16 developed a high level of specific antibody Responses against T. gondii ROP16 expressed in Escherichia coli, a strong Lymphoproliferative Response, and significant levels of gamma interferon (IFN-γ), interleukin-2 (IL-2), IL-4, and IL-10 production compared with results for other mice immunized with either empty plasmid or phosphate-buffered saline, respectively. The results showed that pVAX-ROP16 induces significant humoral and cellular Th1 immune Responses. After lethal challenge, the mice immunized with pVAX-ROP16 showed a significantly (P < 0.05) prolonged survival time (21.6 ± 9.9 days) compared with control mice, which died within 7 days of challenge. Our data demonstrate, for the first time, that ROP16 triggers a strong humoral and cellular Response against T. gondii and that ROP16 is a promising vaccine candidate against toxoplasmosis, worth further development.
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toxoplasma gondii microneme protein 6 mic6 is a potential vaccine candidate against toxoplasmosis in mice
Vaccine, 2009Co-Authors: Gaohui Peng, Ziguo Yuan, Donghui Zhou, Ruiqing Lin, Miaomiao Liu, Chao Yan, C C Yin, Xingquan ZhuAbstract:Infection with the intracellular protozoan parasite Toxoplasma gondii causes serious public health problems and is of great economic importance worldwide. Microneme proteins which are responsible for adhesion and invasion have been implicated as vaccine candidates. In this study, we constructed a DNA vaccine expressing microneme protein 6 (MIC6) of T. gondii, and evaluated the immune Response it induced in Kunming mice. The gene sequence encoding MIC6 was inserted into the eukaryotic expression vector pVAXI. We immunized Kunming mice intramuscularly. After immunization, we evaluated the immune Response using Lymphoproliferative assay, cytokine and antibody measurements, and the survival times of mice challenged lethally. The results showed that the group immunized with pVAX-MIC6 developed a high level of specific antibody Responses against T. gondii lysate antigen (TLA), a strong Lymphoproliferative Response, and significant levels of IFN-gamma, IL-2, IL-4 and IL-10 production, compared with the other groups immunized with empty plasmid or phosphate-buffered saline, respectively. These results demonstrate that pVAX-MIC6 induces significant humoral and cellular Th1 immune Responses. After lethal challenge, the mice immunized with the pVAX-MIC6 showed an increased survival time (13.3+/-1.2 days) compared with control mice died within 7 days of challenge. Our data demonstrate, for the first time, that MIC6 triggered a strong humoral and cellular Response against T. gondii, and that the antigen is a potential vaccine candidate against toxoplasmosis, worth further development.
