Immune killing of migratory stage of Trichinella spiralis by lung cells

GENTILINI, M.V, FALDUTO G.H., SARACINO P., CALCAGNO M., VENTURIELLO, S.M.

Newport, Rhode Island

Conferencia; Biology of Host-Parasite Interactions conference; 2012

Gordon Conferences

We have recently demonstrated the development of an inflammatory lung immune response and the capacity of the lung to retain the migratory stage (MS) of T. spiralis during its way to striated muscles (days 6-13 p.i.).Considering that the effector immune mechanism to kill the MS is dependent of the presence of antibodies (Abs) against the MS surface antigens (anti-MS Abs) and leukocytes functioning as effector cells through an antibody-dependent cellular cytotoxic (ADCC) mechanism; our aim was to determine the capacity of the lung cells to act as effectors in the MS death.We developed an in vitro ADCC assay where MS were put in contact with lung cells obtained from infected (days 6 and 13 pi) or non-infected Wistar rats, in the presence or absence of anti-MS Abs present in lung tissue extracts and sera at the same days p.i.Results showed that: 1) lung cells were able to kill the MS by an ADCC mechanism; 2) lung cells from infected rats showed higher cytotoxic activity against MS than control rat cells; 3) lung cells from day 13 p.i. were able to kill the MS in the presence and absence of anti-MS Abs. The latter phenomenon can be possible due to a) the presence of IgE on the surface of leukocytes, suggesting an increase in the expression of Fcå receptors expression (flow cytometry); and b) an increase of number of eosinophil in comparison with the number of cells present on day 6 pi and control rats (cytological studies). The results demonstrate the capacity of the lung cells to kill the MS and that the heminthocytotoxic activity increases throughout the infection.This work is the first report demonstrating the importance of the lung in the host?s immune defense during the primary infection with T. spiralis.