The mechanism of SiO2 (Aerosil)-mediated enhancement of the proliferative response of mouse spleen lymphocytes to antigen and mitogens in a serum-free system

Abstract

SiO₂ particles enhanced the in vitro proliferation of splenic B cells obtained from BALB/c mice immunized with sheep erythrocytes. T cells from immunized animals were capable of replacing SiO₂ with regard to the enhancement of both in vitro proliferation and the primary immune response. In addition, the stimulating effect of IgG, phytohemagglutinin (PHA) and concanavalin A (Con A) on spleen lymphocytes was also augmented by SiO₂. The enhancing effect of SiO₂ was higher at suboptimal than at supraoptimal concentrations of Con A. SiO₂ is capable of binding Con A. The SiO₂‐bound lectin retained its mitogenic effect on spleen cells and, under certain conditions, SiO₂‐bound Con A was considerably more active in this respect than the free substance.