Th-1/Th-2 type cytokine profiles of pig T-cells cultured with antigen-treated monocyte-derived dendritic cells.

To examine the effects of cytokine environment at the time of antigenic exposure on T-cell cytokine profiles following T-cell-antigen presenting cell (APC) interaction, pig monocyte-derived dendritic cells (mDCs) were treated with hen egg white lysozyme (HEWL) or killed Mycobacterium tuberculosis (Mtb) alone or with a recombinant pig cytokine (TNF-alpha, interleukin (IL)-12, IL-10, interferon (IFN)-gamma or IL-6) and then incubated with autologous T-cell-enriched lymphocytes. Messenger RNA was isolated from the T-cells and used to evaluate the effects of treatment on IL-12p35, IFN-gamma, IL-4, IL-10 and IL-13 expression using RT-PCR. T-cells exposed to HEWL-treated mDCs expressed high IL-13 and moderate IL-10 and IFN-gamma, suggesting T-helper 2 (Th-2) bias. Addition of any cytokine during HEWL treatment of mDCs reduced subsequent expression of IL-10 and IL-13 by T-cells. Added IL-12 increased IFN-gamma mRNA. T-cells exposed to Mtb-treated mDCs expressed increased IFN-gamma and decreased IL-10 suggesting Th-1 bias. Addition of cytokines to mDCs treated with Mtb altered T-cell cytokine mRNA expression such that TNF-alpha, IFN-gamma or IL-12 increased IFN-gamma; IL-12 and IFN-gamma suppressed IL-10, while IL-10 and IL-12 enhanced IL-13. Messenger RNA for IL-4 and IL-12p35 was not detected in the T-cells. Results suggest Th-1/Th-2 type response bias in pigs T-cells as a function of antigen type and that cytokine environment at the time of antigen-mDC interaction alters cytokine profiles of T-cells responding to antigen-pulsed mDCs. Hence, cytokines may allow designed steering of porcine immune response.