Toxocara canis induces inflammatory infiltrates in lung. The aim of this work was to analyze the number and distribution of T (CD3, CD4 and CD8) and B (IgA) cells in lungs of Toxocara canis experimentally infected BALB/c mice.
Six groups (ten animals each) were used. Three of them were orally infected with 1500 T. canis eggs and the other three received just saline. One of each group was killed at days 5, 30 and 60 after infection (PI). Histological samples from these lungs were stained by immunohistochemistry using monoclonal antibodies. The density (cells/mm2) of positive cells at the interstitial, perivascular and peribronchial regions were recorded using a computer assisted image analyzer.
Density of CD3 cells increased at the interstitial (5d and 30d PI), perivascular and peribronchial (30d PI) regions (P<0.05) in infected animals. CD4 cells increased in these animals in all regions (60d PI, P<0.05). CD8 cells increased in infected animals in all regions at day 5 PI (P<0.05) and at the peribronchial region in day 30 PI (P<0.05). Finally, IgA cells increased (P<0.05) in infected animals at the perivascular (5d PI) and peribronchial (30 and 60d PI) regions.
Increases in cytotoxic CD8 cells in the acute phase and helper CD4 cells in late phase infection suggest a mixed immune response elicited by T. canis. In both cases the cells localized at the tissue parenchyma, possibly due to the release of secretory/excretory antigens in the tissue by the migratory route followed by the parasite. Perivascular and peribronchial infiltration may occur as a result of cell signalling. This type of changes in lymphocyte cells in the lung may predispose to allergic reactions as suggested in asthmatic human beings.
Proyecto PAPIIT IN-212501