Activation of a murine T-cell hybridoma by cationized bacteria.

Cationic particles interact by electrostatic forces with membrane components of diverse cell types, including lymphocytes. Contact with cationized streptococci was shown to induce a murine T-cell hybridoma to transcribe lymphokine mRNA as well as secrete interleukin-2. This activation was accompanied by a rise in intracellular calcium. Cationized streptococci-induced activation of this T-cell hybridoma could be specifically inhibited by either chelating extracellular calcium or by treating with CD4 monoclonal antibody. These data indicate that the in vitro behaviour of T cells can be modulated by charged microbial particles; such interactions may have relevance for chronic inflammation associated with some bacterial infections.