Co-infection: the outcome of Plasmodium infection differs according to the time of pre-existing helminth infection

Abstract

Although helminth-Plasmodium coinfections are common in tropical regions, the implications of this co-existence for the host immune response are poorly understood. In order to understand the effect of helminth infection at different times of coinfection on the immune response against Plasmodium infection, BALB/c mice were intraperitoneally infected with Taenia crassiceps (Tc). At 2 (Tc2) or 8 (Tc8) weeks post-infection, mice were intravenously infected with 1 × 10 Plasmodium yoelii (Py) 17XL-parasitized red blood cells. Py 17XL-single-infected mice developed cachexia, splenomegaly, and anemia, and died at 11 days post-infection. Importantly, Tc2 + Py-coinfected mice showed increased survival of 58% on day 11, but developed pathology (cachexia and splenomegaly) and succumbed on day 18 post-coinfection, this latter associated with high levels of IL-1β and IL-12, and reduced IFN-γ in serum compared with Py 17XL-single-infected mice. Interestingly, Tc8 + Py-coinfected mice showed increased survival up to 80% on day 11 and succumbed on day 30 post-coinfection. This increased survival rate conferred by chronic helminth infection was associated with a decreased pathology and mixed inflammatory-type 1/anti-inflammatory-type 2 immune profile as evidenced by the production of high levels of IL-12 and IL-10, and reduced TNF-α from macrophages, high levels of IL-4 and IL-10, and low levels of IFN-γ from spleen cells. Also high serum levels of IL-1β, TNF-α, IL-12, IL-4, and IL-10, but a significant reduction of IFN-γ were observed. Together, these data indicate that polarization of the cell-mediated response modulated by a pre-existing helminth infection differentially impacts on the host immune response to Py 17XL in a time-dependent manner.

Asymptomatic Malaria Infection Is Maintained by a Balanced Pro- and Anti-inflammatory Response

“…Also, participants were not followed to determine if any of them progressed to febrile disease and to assess trends in the cytokine profile during asymptomatic infection and disease onset in the same individuals. Also, the presence of other infectious diseases such as helminth co-infections which were unaccounted for may account for some of the differences in the cytokine profile since they are common in children of school-going age (Brooker et al, 2007;Salazar-Castañón et al, 2018). Nevertheless, we have been able to show that asymptomatic malaria infections are characterized by a concomitant upregulation of both proand anti-inflammatory cytokines, specifically TNF-α, IFN-γ, IL-6, IL-17A, and IL-4 as assessed in this study.…”

Trypanosoma brucei infection protects mice against malaria

“…crassiceps and P . yoelli survived longer than mice infected with the malaria parasite only, which the authors correlated with a reduction in IFN-γ levels [65]. These studies point to a crucial role for IFN-γ in modulating a secondary Plasmodium infection.…”

Macrophage migration inhibitory factor of Thelazia callipaeda induces M2‐like macrophage polarization through TLR4‐mediated activation of the PI3K‐Akt pathway

“…Parasite MIF can participate in regulating the host's immune response and is an important medium for the host to resist infection and promote immune cell stress responses 1,21,22 . Several studies have reported that parasite MIF encodes 114–146 amino acids and the relative molecular mass is 11–16.4 kDa 23 . Many studies have shown that the MIF trimer is the biologically active form.…”