Co-infection restrainsLitomosoides sigmodontisfilarial load and plasmodialP. yoeliibut notP. chabaudiparasitaemia in mice

Abstract

Infection with multiple parasite species is clearly the norm rather than the exception, in animals as well as in humans. Filarial nematodes and Plasmodium spp. are important parasites in human public health and they are often co-endemic. Interactions between these parasites are complex. The mechanisms underlying the modulation of both the course of malaria and the outcome of filarial infection are poorly understood. Despite increasing activity in recent years, studies comparing co- and mono-infections are very much in their infancy and results are contradictory at first sight. In this study we performed controlled and simultaneous co-infections of BALB/c mice with Litomosoides sigmodontis filaria and with Plasmodium spp. (Plasmodium yoelii 17 XNL or Plasmodium chabaudi 864VD). An analysis of pathological lesions in the kidneys and lungs and a parasitological study were conducted at different times of infection. Whatever the plasmodial species, the filarial recovery rate was strongly decreased. The peak of parasitaemia in the plasmodial infection was decreased in the course of P. yoelii infection but not in that of P. chabaudi. Regarding pathological lesions, L. sigmodontis can reverse lesions in the kidneys due to the presence of both Plasmodium species but does not modify the course of pulmonary lesions. The filarial infection induces granulomas in the lungs.

Co‐infection with Chikungunya virus alters trafficking of pathogenic CD 8 + T cells into the brain and prevents Plasmodium ‐induced neuropathology

“…Worms [Schistosoma sp (Hartgers & Yazdanbakhsh, 2006;Waknine-Grinberg et al, 2010;Bucher et al, 2011;Wang et al, 2013Wang et al, , 2014, Litomosoides sigmodontis (Karadjian et al, 2014), and Heligmosomoides polygyrus (Su et al, 2005)] and bacteria [Mycobacterium tuberculosis (Li & Zhou, 2013), Listeria monocytogenes (Qi et al, 2013), and Salmonella (Cunnington et al, 2012)] have been shown to alter the pathological outcome of malaria infection through bystander regulation of the host immunity. Specific to the PbA-ECM model, the mechanisms leading to ECM protection during co-infection were mostly due to the suppression of the pro-inflammatory response induced by the heterologous pathogen, which occurs from 4 days post-Plasmodium infection onwards.…”

Migratory phase of Litomosoides sigmodontis filarial infective larvae is associated with pathology and transient increase of S100A9 expressing neutrophils in the lung

“…Furthermore, the recent observation of granulomas, mainly constituted of T cells and macrophages, in the lung of L . sigmodontis infected mice at day 8 post inoculation also reinforce this hypothesis [13]. However, the presence of an inflammatory reaction in the pulmonary tissue has not yet been addressed.…”

Chronic Filarial Infection Provides Protection against Bacterial Sepsis by Functionally Reprogramming Macrophages

“…These forms of immunomodulation by helminths effect bystander immune responses and can improve autoimmune diseases [ 5 – 8 ] or allergy [ 9 – 12 ] while efficacy of vaccinations is reduced [ 13 , 14 ]. Furthermore, several epidemiological reports and animal studies have demonstrated that helminth infections alter immune responses to unrelated pathogens [ 15 – 18 ].…”