Borrelia burgdorferiStimulates In Vitro a Selective Expansion of CD3−CD4−CD8−(Triple Negative) Autoreactive Cells in Naive Rhesus Monkey Lymphocytes

Autoreactive cell lines were generated from cell suspensions of freshly isolated naive monkey lymph node (LN) cells and peripheral blood mononuclear cells by cocultivation with freeze-thawed Borrelia burgdorferi spirochetes (Bb/FT). These cells produced interleukin (IL)-6 when cocultured with autologous antigen-presenting cells (APCs) alone without Bb/FT. IL-6 production was not observed when control cell lines were stimulated in the same fashion. CD4+-enriched T cell populations obtained from the LN autoreactive cell line also produced IL-6 when cultivated with APCs alone. When these cells were cultivated further in the presence of APCs, a population of cells whose phenotype was CD56+/-CD4-CD8-CD3- was predominantly selected. These cells both proliferated and produced IL-6 when cocultured with APCs alone. The possible relevance of these cells to Lyme disease pathogenesis remains to be determined.