Prostaglandin E2 inhibits IL-10 production by bovine CD4plus T cells

Although prostaglandin E₂ (PGE₂) is a pro-inflammatory mediator, it also produces some effect which is anti-inflammatory in character. It is suggested that one of the mechanisms responsible for the latter effect is the increased synthesis of IL-10. The aim of this study has been to determine the influence of PGE₂ on IL-10 production by bovine CD⁴⁺ and CD⁸⁺ T cells and NK cells. With this aim, peripheral blood mononuclear cells collected from 12-month-old heifers (n = 10) were treated without or with PGE₂ (10⁻⁶ M). Flow cytometric analysis showed that PGE₂ caused a reduction in the percentage of IL-10 producing CD⁴⁺ T cells (P < 0.001), while leaving the secretion of this cytokine by CD⁸⁺ T cells and NK cells unaffected. This seems to indicate that PGE₂ in cattle does not produce an anti-inflammatory effect by increasing the synthesis of IL-10; contrary to this, it may aggravate an inflammatory response by inhibiting the secretion of this cytokine by CD⁴⁺ T cells.