Concomitant experimental co-infection by Plasmodium berghei NK65 and Ascaris suum downregulates immunological responses and impairs lung function

Ascariasis and malaria are highly prevalent parasitic diseases in tropical regions and often overlap in endemic areas, contributing to high morbidity and mortality rates in areas with poor sanitary conditions. Several studies aiming to correlate the effects of Ascaris-Plasmodium coinfections have contradictory and inconclusive results. In this context, we investigated parasitological and immunopathological aspects of the lung in an experimental concomitant coinfection by Plasmodium berghei NK65-NY and Ascaris suum during larval ascariasis. The most important findings of P. berghei NK65-NY and A. suum coinfection results in Plasmodium-driven downregulation of the lung immune response that leads to an increase in larval migration in the lungs, as evidenced by the decrease in larvae recovered in the lung parenchyma and the increase in larvae recovered in the airways. This scenario is implicated in an intense hemorrhage in the airways and, consequently, in the commitment of respiratory function that results in high morbidity and early mortality. Taken together, our results suggest that this coinfection may potentiate Ascaris-associated pathology by the downmodulation of the Ascaris-specific immune response, resulting in the early death of affected animals.