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Inhibition of Granulomatous Inflammation and Prophylactic Treatment of Schistosomiasis with a Combination of Edelfosine and Praziquantel.

Yepes E, Varela-M RE, López-Abán J, Rojas-Caraballo J, Muro A, Mollinedo F - PLoS Negl Trop Dis (2015)

Bottom Line: Using in vitro and in vivo approaches, we have found that the alkylphospholipid analog edelfosine kills schistosomula, and displays anti-inflammatory activity.The combined treatment of PZQ and edelfosine during a few days before and after cercariae infection in a schistosomiasis mouse model, simulating a prophylactic treatment, led to seven major effects: a) killing of Schistosoma parasites at early and late development stages; b) reduction of hepatomegaly; c) granuloma size reduction; d) down-regulation of Th1, Th2 and Th17 responses at late post-infection times, thus inhibiting granuloma formation; e) upregulation of IL-10 at early post-infection times, thus potentiating anti-inflammatory actions; f) down-regulation of IL-10 at late post-infection times, thus favoring resistance to re-infection; g) reduction in the number of blood granulocytes in late post-infection times as compared to infected untreated animals.Taken together, these data suggest that the combined treatment of PZQ and edelfosine promotes a high decrease in granuloma formation, as well as in the cellular immune response that underlies granuloma development, with changes in the cytokine patterns, and may provide a promising and effective strategy for a prophylactic treatment of schistosomiasis.

View Article: PubMed Central - PubMed

Affiliation: IBSAL-CIETUS (Instituto de Investigación Biomédica de Salamanca-Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca), Facultad de Farmacia, Universidad de Salamanca, Salamanca, Spain; Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, CSIC-Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain.

ABSTRACT

Background: Schistosomiasis is the third most devastating tropical disease worldwide caused by blood flukes of the genus Schistosoma. This parasitic disease is due to immunologic reactions to Schistosoma eggs trapped in tissues. Egg-released antigens stimulate tissue-destructive inflammatory and granulomatous reactions, involving different immune cell populations, including T cells and granulocytes. Granulomas lead to collagen fibers deposition and fibrosis, resulting in organ damage. Praziquantel (PZQ) is the drug of choice for treating all species of schistosomes. However, PZQ kills only adult Schistosoma worms, not immature stages. The inability of PZQ to abort early infection or prevent re-infection, and the lack of prophylactic effect prompt the need for novel drugs and strategies for the prevention of schistosomiasis.

Methodology/principal findings: Using in vitro and in vivo approaches, we have found that the alkylphospholipid analog edelfosine kills schistosomula, and displays anti-inflammatory activity. The combined treatment of PZQ and edelfosine during a few days before and after cercariae infection in a schistosomiasis mouse model, simulating a prophylactic treatment, led to seven major effects: a) killing of Schistosoma parasites at early and late development stages; b) reduction of hepatomegaly; c) granuloma size reduction; d) down-regulation of Th1, Th2 and Th17 responses at late post-infection times, thus inhibiting granuloma formation; e) upregulation of IL-10 at early post-infection times, thus potentiating anti-inflammatory actions; f) down-regulation of IL-10 at late post-infection times, thus favoring resistance to re-infection; g) reduction in the number of blood granulocytes in late post-infection times as compared to infected untreated animals.

Conclusions/significance: Taken together, these data suggest that the combined treatment of PZQ and edelfosine promotes a high decrease in granuloma formation, as well as in the cellular immune response that underlies granuloma development, with changes in the cytokine patterns, and may provide a promising and effective strategy for a prophylactic treatment of schistosomiasis.

No MeSH data available.


Related in: MedlinePlus

IL-2 and IL-4 plasma levels in drug treated- and untreated-mice.The plasma levels of the indicated cytokines were determined in uninfected-untreated naive mice and the distinct untreated and treated infected mice, namely infected untreated (untreated), PZQ, EDLF and PZQ+EDLF as shown in Materials and Methods. Samples were taken at week 3 p.i. Data are shown as means ± SEM of eight mice. Asterisks represent statistical significance with respect to the infected untreated group. (***) p<0.001.
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pntd.0003893.g005: IL-2 and IL-4 plasma levels in drug treated- and untreated-mice.The plasma levels of the indicated cytokines were determined in uninfected-untreated naive mice and the distinct untreated and treated infected mice, namely infected untreated (untreated), PZQ, EDLF and PZQ+EDLF as shown in Materials and Methods. Samples were taken at week 3 p.i. Data are shown as means ± SEM of eight mice. Asterisks represent statistical significance with respect to the infected untreated group. (***) p<0.001.

Mentions: In order to explore the effect of EDLF-containing treatments on cellular immune response, we used a flow cytometry-based methodology to measure the levels of several cytokines in the sera of mice at 3 and 8 weeks p.i. At early stages of infection (3rd week p.i.), the distinct PZQ, EDLF or PZQ+EDLF treatments drastically inhibited the infection-induced increase in IL-2 production, as a typical Th1 cytokine, whereas the Th2 cytokine IL-4 level was not affected (Fig 5). Interestingly, the above three treatments induced an increase in the level of IL-10 at week 3 p.i. (Fig 6), thus suggesting the triggering of an anti-inflammatory action as IL-10 inhibits production of pro-inflammatory cytokines [61, 62]. Because at this early stage of infection (week 3 p.i.) the IL-4 and IL-10 levels were not affected by the infection (Figs 5 and 6), these data indicated that the Th2 and Treg responses were not elicited by the parasite at this infection period, and thereby the actions detected on the IL-10 level following the above three treatments suggested a direct interaction of PZQ and EDLF with the corresponding T cell subsets. Then, after eight weeks p.i. the data on IL-10 levels differed greatly from those obtained at early stages of infection (Fig 6). As infection progresses to late stages (week 8 p.i.), infected untreated mice showed elevated levels of IL-10 in plasma (Fig 6), indicative of Treg and Th2 responses. However, treatments with PZQ and above all PZQ+EDLF led to a drastic reduction in the level of IL-10, reaching a level that was even lower than that detected in naive mice (Fig 6). Because mice were not treated any longer since the day 9 of infection, it is expected that they were free of PZQ and EDLF by the eighth week p.i., and therefore the changes in cytokine production could be due to an immunological reaction to either the surviving or dead parasites at their different developmental stages. Because IL-10 blocks the development of resistance to re-infection with S. mansoni [63], the inhibition of IL-10 production in the combined PZQ+EDLF treatment at late stages of infection, together with its drastic inhibitory action on granuloma formation and egg count, suggests that this combination treatment could be of particular interest for a prophylactic use against schistosomiasis.


Inhibition of Granulomatous Inflammation and Prophylactic Treatment of Schistosomiasis with a Combination of Edelfosine and Praziquantel.

Yepes E, Varela-M RE, López-Abán J, Rojas-Caraballo J, Muro A, Mollinedo F - PLoS Negl Trop Dis (2015)

IL-2 and IL-4 plasma levels in drug treated- and untreated-mice.The plasma levels of the indicated cytokines were determined in uninfected-untreated naive mice and the distinct untreated and treated infected mice, namely infected untreated (untreated), PZQ, EDLF and PZQ+EDLF as shown in Materials and Methods. Samples were taken at week 3 p.i. Data are shown as means ± SEM of eight mice. Asterisks represent statistical significance with respect to the infected untreated group. (***) p<0.001.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4507859&req=5

pntd.0003893.g005: IL-2 and IL-4 plasma levels in drug treated- and untreated-mice.The plasma levels of the indicated cytokines were determined in uninfected-untreated naive mice and the distinct untreated and treated infected mice, namely infected untreated (untreated), PZQ, EDLF and PZQ+EDLF as shown in Materials and Methods. Samples were taken at week 3 p.i. Data are shown as means ± SEM of eight mice. Asterisks represent statistical significance with respect to the infected untreated group. (***) p<0.001.
Mentions: In order to explore the effect of EDLF-containing treatments on cellular immune response, we used a flow cytometry-based methodology to measure the levels of several cytokines in the sera of mice at 3 and 8 weeks p.i. At early stages of infection (3rd week p.i.), the distinct PZQ, EDLF or PZQ+EDLF treatments drastically inhibited the infection-induced increase in IL-2 production, as a typical Th1 cytokine, whereas the Th2 cytokine IL-4 level was not affected (Fig 5). Interestingly, the above three treatments induced an increase in the level of IL-10 at week 3 p.i. (Fig 6), thus suggesting the triggering of an anti-inflammatory action as IL-10 inhibits production of pro-inflammatory cytokines [61, 62]. Because at this early stage of infection (week 3 p.i.) the IL-4 and IL-10 levels were not affected by the infection (Figs 5 and 6), these data indicated that the Th2 and Treg responses were not elicited by the parasite at this infection period, and thereby the actions detected on the IL-10 level following the above three treatments suggested a direct interaction of PZQ and EDLF with the corresponding T cell subsets. Then, after eight weeks p.i. the data on IL-10 levels differed greatly from those obtained at early stages of infection (Fig 6). As infection progresses to late stages (week 8 p.i.), infected untreated mice showed elevated levels of IL-10 in plasma (Fig 6), indicative of Treg and Th2 responses. However, treatments with PZQ and above all PZQ+EDLF led to a drastic reduction in the level of IL-10, reaching a level that was even lower than that detected in naive mice (Fig 6). Because mice were not treated any longer since the day 9 of infection, it is expected that they were free of PZQ and EDLF by the eighth week p.i., and therefore the changes in cytokine production could be due to an immunological reaction to either the surviving or dead parasites at their different developmental stages. Because IL-10 blocks the development of resistance to re-infection with S. mansoni [63], the inhibition of IL-10 production in the combined PZQ+EDLF treatment at late stages of infection, together with its drastic inhibitory action on granuloma formation and egg count, suggests that this combination treatment could be of particular interest for a prophylactic use against schistosomiasis.

Bottom Line: Using in vitro and in vivo approaches, we have found that the alkylphospholipid analog edelfosine kills schistosomula, and displays anti-inflammatory activity.The combined treatment of PZQ and edelfosine during a few days before and after cercariae infection in a schistosomiasis mouse model, simulating a prophylactic treatment, led to seven major effects: a) killing of Schistosoma parasites at early and late development stages; b) reduction of hepatomegaly; c) granuloma size reduction; d) down-regulation of Th1, Th2 and Th17 responses at late post-infection times, thus inhibiting granuloma formation; e) upregulation of IL-10 at early post-infection times, thus potentiating anti-inflammatory actions; f) down-regulation of IL-10 at late post-infection times, thus favoring resistance to re-infection; g) reduction in the number of blood granulocytes in late post-infection times as compared to infected untreated animals.Taken together, these data suggest that the combined treatment of PZQ and edelfosine promotes a high decrease in granuloma formation, as well as in the cellular immune response that underlies granuloma development, with changes in the cytokine patterns, and may provide a promising and effective strategy for a prophylactic treatment of schistosomiasis.

View Article: PubMed Central - PubMed

Affiliation: IBSAL-CIETUS (Instituto de Investigación Biomédica de Salamanca-Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca), Facultad de Farmacia, Universidad de Salamanca, Salamanca, Spain; Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, CSIC-Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain.

ABSTRACT

Background: Schistosomiasis is the third most devastating tropical disease worldwide caused by blood flukes of the genus Schistosoma. This parasitic disease is due to immunologic reactions to Schistosoma eggs trapped in tissues. Egg-released antigens stimulate tissue-destructive inflammatory and granulomatous reactions, involving different immune cell populations, including T cells and granulocytes. Granulomas lead to collagen fibers deposition and fibrosis, resulting in organ damage. Praziquantel (PZQ) is the drug of choice for treating all species of schistosomes. However, PZQ kills only adult Schistosoma worms, not immature stages. The inability of PZQ to abort early infection or prevent re-infection, and the lack of prophylactic effect prompt the need for novel drugs and strategies for the prevention of schistosomiasis.

Methodology/principal findings: Using in vitro and in vivo approaches, we have found that the alkylphospholipid analog edelfosine kills schistosomula, and displays anti-inflammatory activity. The combined treatment of PZQ and edelfosine during a few days before and after cercariae infection in a schistosomiasis mouse model, simulating a prophylactic treatment, led to seven major effects: a) killing of Schistosoma parasites at early and late development stages; b) reduction of hepatomegaly; c) granuloma size reduction; d) down-regulation of Th1, Th2 and Th17 responses at late post-infection times, thus inhibiting granuloma formation; e) upregulation of IL-10 at early post-infection times, thus potentiating anti-inflammatory actions; f) down-regulation of IL-10 at late post-infection times, thus favoring resistance to re-infection; g) reduction in the number of blood granulocytes in late post-infection times as compared to infected untreated animals.

Conclusions/significance: Taken together, these data suggest that the combined treatment of PZQ and edelfosine promotes a high decrease in granuloma formation, as well as in the cellular immune response that underlies granuloma development, with changes in the cytokine patterns, and may provide a promising and effective strategy for a prophylactic treatment of schistosomiasis.

No MeSH data available.


Related in: MedlinePlus