Transferência adotiva dos efeitos indiretos da exposição parenteral a antígenos tolerados

Abstract

Parenteral exposure to antigens to which oral tolerance had been previously induced affects (inhibits) immunological activities connected to unrelated antigens, a phenomenon we have called indirect effects of oral tolerance (Carvalho, et al., 1994). Herein, we investigated the possibility of adoptively transferring oral tolerance and its indirect effects to normal or previously irradiated syngeneic recipients, by spleen cells. Both oral tolerance and its indirect effects were transferred only to irradiated recipients and a larger number of cells was necessary for the transfer of the indirect effects, which suggests the participation of more complex cellular interactions in these effects. In nonirradiated recipients, there is a barrier (syngeneic barrier) that impairs the functional implantation of transferred cells, interfering with their specific immunological activities. We also studied the distribution patterns of transferred cells in different lymphoid organs from recipient mice, by CFSE labeling. In irradiated recipients, independently of the origin of transferred cells, the percentage of labeled cells was higher, in every studied organ. However, the absolute number was a little higher in nonirradiated recipients. Recipients of cells from nontolerant donors displayed a decrease, both in the percentage and in the absolute number of CFSE labeled cells on the third day after cell transference, as compared to recipients of cells from tolerant donors. This suggests different dynamics of decay of adoptively transferred cells from tolerant or non-tolerant donors. Phenomena such as the syngeneic barrier and the indirect effects of oral tolerance will be better understood in models that describe the interdependence among the components of the immune system.