Pentoxifylline inhibits Ig kappa gene transcription and rearrangements in pre-B cells.

Pentoxifylline (PF) has been used in a wide variety of clinical situations; however, the molecular consequences of this drug are not well characterized. In this paper we assayed the effects of PF in two models of pre-B differentiation. In 70Z pre-B cells, transcriptional induction of rearranged Ig kappa-chain gene in response to LPS was suppressed by PF, without affecting the induction of Rel family proteins. In contrast, kappa induction by IFN-gamma was not suppressed by PF, indicating that the drug inhibited certain activation pathways. We also found that LPS-induced activation of germline kappa transcription and V kappa to J kappa recombination were inhibited by PF in the pre-B cell line 38B9. These observations suggest that PF may adversely affect B lymphopoiesis during chronic administration.