Schistosoma mansoni Infection Impairs Antimalaria Treatment and Immune Responses of Rhesus Macaques Infected with Mosquito-Borne Plasmodium coatneyi

Semenya, Amma A.; Sullivan, JoAnn S.; Barnwell, John W.; Secor, W. Evan

doi:10.1128/iai.00590-12

Cited by 25 publications

(16 citation statements)

References 26 publications

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“…Although some animal studies have shown that chronic schistosomiasis protects against severe malaria (5), others have reported that a concurrent schistosome infection enhances the severity of malaria (6)(7)(8)(9)(10). Many factors may account for these differences, including mouse strain, duration and intensity of the helminth infection, Plasmodium strain or species, inoculum size, or route of malaria infection (skin or blood stage) (11). An important limitation of murine studies is the difficulty of establishing chronic schistosome infections comparable to those observed in humans.…”

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confidence: 99%

Protective Effect of Chronic Schistosomiasis in Baboons Coinfected with Schistosoma mansoni and Plasmodium knowlesi

et al. 2016

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c Malaria and schistosomiasis coinfections are common, and chronic schistosomiasis has been implicated in affecting the severity of acute malaria. However, whether it enhances or attenuates malaria has been controversial due the lack of appropriately controlled human studies and relevant animal models. To examine this interaction, we conducted a randomized controlled study using the baboon (Papio anubis) to analyze the effect of chronic schistosomiasis on severe malaria. Two groups of baboons (n ‫؍‬ 8 each) and a schistosomiasis control group (n ‫؍‬ 3) were infected with 500 Schistosoma mansoni cercariae. At 14 and 15 weeks postinfection, one group was given praziquantel to treat schistosomiasis infection. Four weeks later, the two groups plus a new malaria control group (n ‫؍‬ 8) were intravenously inoculated with 10 5 Plasmodium knowlesi parasites and monitored daily for development of severe malaria. A total of 81% of baboons exposed to chronic S. mansoni infection with or without praziquantel treatment survived malaria, compared to only 25% of animals infected with P. knowlesi only (P ‫؍‬ 0.01). Schistosome-infected animals also had significantly lower parasite burdens (P ‫؍‬ 0.004) than the baboons in the P. knowlesi-only group and were protected from severe anemia. Coinfection was associated with increased spontaneous production of interleukin-6 (IL-6), suggesting an enhanced innate immune response, whereas animals infected with P. knowlesi alone failed to develop mitogen-driven tumor necrosis factor alpha and IL-10, indicating the inability to generate adequate protective and balancing immunoregulatory responses. These results indicate that chronic S. mansoni attenuates the severity of P. knowlesi coinfection in baboons by mechanisms that may enhance innate immunity to malaria. P olyparasitism is common in low-resource countries, especially in sub-Saharan Africa. Coinfections may alter disease outcomes and affect both drug and vaccine efficacies (1, 2). The majority of studies on coinfections have focused on interactions between malaria and chronic helminth infections. Interest in studying malaria and schistosomiasis, in particular, comes from the major overlap of the two diseases in areas where they are endemic and the fact that these infections account for a large proportion of global morbidity and mortality (3, 4). Because of the chronicity of schistosome infection, most studies have focused on its impact on susceptibility to clinical malaria.Studies on malaria and schistosomiasis coinfections in human and animal models have generated contradicting results. Although some animal studies have shown that chronic schistosomiasis protects against severe malaria (5), others have reported that a concurrent schistosome infection enhances the severity of malaria (6-10). Many factors may account for these differences, including mouse strain, duration and intensity of the helminth infection, Plasmodium strain or species, inoculum size, or route of malaria infection (skin or blood stage) (11). An important limitat...

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Protective Effect of Chronic Schistosomiasis in Baboons Coinfected with Schistosoma mansoni and Plasmodium knowlesi

et al. 2016

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“…Studies addressing the effect of coinfection on malarial anemia showed variable results with complex outcomes on anemia [21]. Similar outcomes were seen with studies dealing with the issue of treating coinfection or not [22].…”

Section: Treating Coinfecting Organismsmentioning

confidence: 54%

Malaria, Schistosomiasis, and Related Anemia

Gasim¹,

Adam²

2016

Nutritional Deficiency

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Parasitic infections e.g., malaria and helminthiases have a huge impact on public health in endemic areas. Moreover, parasitic infestations are prominent causes of anemia in the tropics and subtropics, further perpetuated by malnutrition, inflammatory, and genetic diseases. "nemia-associating parasitic infections vary depending on the requirements and pathophysiology of the parasites. There is an interplay between different factors that can be segregated as host and parasite factors, resulting in severe anemia accompanying these parasitic infestations. The pathophysiological mechanisms leading to anemia associated with the different parasites vary greatly, including hemolysis, anemia of inflammation, bone marrow suppression, and micronutrients deficiency. The major means to deal with this anemia include prevention and treatment of such infestations.

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“…Macaques are also used to study a wide range of infections with human pathogens or their simian counterparts, as well as vaccines [60,61]. Thus, it is possible to model co-infections in macaques, such as SIV/Plasmodium [62][63][64][65] and Schistosoma/Plasmodium [66] and to study interference with vaccine-induced immune responses [67].…”

Section: Simian Plasmodium Species In Macaquesmentioning

confidence: 99%

In vivo imaging in NHP models of malaria: Challenges, progress and outlooks

Beignon

Grand

Chapon

2014

Parasitology International

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Animal models of malaria, mainly mice, have made a large contribution to our knowledge of host-pathogen interactions and immune responses, and to drug and vaccine design. Non-human primate (NHP) models for malaria are admittedly under-used, although they are probably closer models than mice for human malaria; in particular, NHP models allow the use of human pathogens (Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae and Plasmodium knowlesi). NHPs, whether natural hosts or experimentally challenged with a simian Plasmodium, can also serve as robust pre-clinical models. Some simian parasites are closely related to a human counterpart, with which they may share a common ancestor, and display similar major features with the human infection and pathology. NHP models allow longitudinal studies, from the early events following sporozoite inoculation to the later events, including analysis of organs and tissues, particularly liver, spleen, brain and bone marrow. NHP models have one other significant advantage over mouse models: NHPs are our closest relatives and thus their biology is very similar to ours. Recently developed in vivo imaging tools have provided insight into malaria parasite infection and disease in mouse models. One advantage of these tools is that they limit the need for invasive procedures, such as tissue biopsies. Many such technologies are now available for NHP studies and provide new opportunities for elucidating host/parasite interactions. The aim of this review is to bring the malaria community up to date on what is currently possible and what soon will be, in terms of in vivo imaging in NHP models of malaria, to consider the pros and the cons of the various techniques, and to identify challenges.

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Schistosoma mansoni Infection Impairs Antimalaria Treatment and Immune Responses of Rhesus Macaques Infected with Mosquito-Borne Plasmodium coatneyi

Cited by 25 publications

References 26 publications

Protective Effect of Chronic Schistosomiasis in Baboons Coinfected with Schistosoma mansoni and Plasmodium knowlesi

Protective Effect of Chronic Schistosomiasis in Baboons Coinfected with Schistosoma mansoni and Plasmodium knowlesi

Malaria, Schistosomiasis, and Related Anemia

In vivo imaging in NHP models of malaria: Challenges, progress and outlooks

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