Genetic Background Affects the Mucosal Secretory IgA Levels, Parasite Burden, Lung Inflammation, and Mouse Susceptibility toAscaris suumInfection

Abstract

Ascariasis is a neglected tropical disease, widespread in the world and causing important socioeconomic impacts. The presence of various stages of worm development in the pulmonary and intestinal mucosa induces a humoral and cellular immune response. However, although there is much evidence of the protective role of mucosal immunity against various pathogens, including helminthes, there is still a gap in the knowledge about the immune response and the mechanisms of action that are involved in protection against diseases, especially in the initial phase of ascariasis. Then, the aim of this study was to evaluate the kinetic aspects of the immune parasitological parameters in intestinal and pulmonary mucosa in male mice with early ascariasis. Therefore, two mice strains showed a different susceptibility to ascariasis (BALB/c and C57BL6/j), when experimentally infected with 2,500 infective eggs of Ascaris suum from time-point 0 and the immune parasitological parameters evaluated each two days after infection, during the period of 12 days. The results were suggestive of a synergetic action of intestinal and pulmonary SIgA contributing for the protection against early ascariasis by reducing the amount of migrating larval as well as the influx of leukocytes in the lung and the consequent impair of the pulmonary capacity.

Th2-biased immune responses to body migrating Ascaris larvae in primary infection are associated with pathology but not protection

“…The differences in hepatic and pulmonary larval load were therefore apparently not due to unequal efficiency in the invasion of the intestinal barrier by Ascaris L3, but likely due to differences in migration behavior, whereby substrain-specific differences (CBA/Ca in previous studies vs. CBA/JR in our study) could be relevant here. A recent comparative study in Ascaris -infected BALB/c and C57BL/6J mice showed a correlation between higher concentrations of total sIgA in the intestinal fluid and a lower parasite load in the more resistant BALB/c mice 48 . Thus, a comparison of the sIgA levels also for CBA and C57BL/6 mice might represent a valuable addition for future studies examining the intrinsic resistance mechanisms to larval ascariasis.…”