Differential effects of interleukin‐12 on the development of naive mouse CD4⁺ T cells

Abstract

The influence of interleukin (IL)-12 and IL-4 on the differentiation of naive CD4+ T cells was studied in an accessory cell-free in vitro system. Dense CD4+ T cells were purified from unimmunized mice and activated using immobilized anti-CD3 monoclonal antibodies (mAb) in the presence of IL-4, IL-12, or a combination of both cytokines, and restimulated after 6 days by re-exposure to anti-CD3-coated culture wells. T cells initially activated in the presence of IL-4 produced substantial amounts of IL-4 and trace amounts of interferon (IFN)-gamma after restimulation at day 6 with plate-bound anti-CD3 mAb. By contrast, T cells primed in the presence of IL-12 produced high levels of IFN-gamma and only minimal amounts of IL-4, thus indicating that IL-12 and IL-4 by acting directly on stimulated naive CD4+ T cells support the development of TH1 and TH2 cells, respectively. When naive CD4+ T cells were stimulated in the presence of IL-12 together with IL-4 in comparable concentrations, the effect of IL-12 on TH1 differentiation was largely inhibited by IL-4. On the other hand, IL-12 exerted no inhibitory effect on IL-4-induced TH2 differentiation but rather enhanced the production of IL-4 after restimulation of the respective T cells. Decreasing amounts of IL-4 in combination with a high level of IL-12 led to an increasing production of IFN-gamma by the emerging T cells and, simultaneously, to a relatively high production of IL-4. These data were confirmed by time-course experiments which revealed that the delayed addition of IL-4 to IL-12-primed T cell cultures resulted in a gradual restoration of IFN-gamma production whereas in parallel the secretion of IL-4 was not reduced over a wide period of delay (6-72 h). These results, therefore, demonstrate that (a) IL-4 dominates the effect of IL-12, (b) IL-12 promotes the development of TH1 cells; however, in the presence of IL-12 and relatively high levels of IL-4 also the development of TH2-like cells is slightly but significantly enhanced by IL-12, and (c) high amounts of IL-12 in combination with relatively low levels of IL-4 give rise to a T cell population that upon rechallenge exhibited a cytokine profile resembling that of TH0 cells.

A Filarial Nematode-Secreted Product Signals Dendritic Cells to Acquire a Phenotype That Drives Development of Th2 Cells

“…6a). Similarly, incorporation of neutralizing anti-IL-12 mAb diminished IFN-␥ production in all the cultures, thereby confirming the key role of this cytokine in promoting IFN-␥ production (8,20). In contrast, although addition of anti-IL-12 was found, as expected, to substantially increase IL-4 in these same culture supernatants, addition of rIL-12 only slightly suppressed IL-4 levels, consistent with our previous findings that DC-ES-62 promoted a Th2 phenotype despite the production of substantial levels of p70 IL-12 (Fig.…”

Antigenic dietary protein guides maturation of the host immune system promoting resistance to Leishmania major infection in C57BL/6 mice

“…IL-12 is a cytokine that is determinant in the CD4 + T-cell differentiation to Th1. 46 Infected macrophages of C57BL/6 mice produce high levels of IL-12 and are able to drive Th1 immunity. However, it has been reported previously that APCs from neonates are deficient in pro-inflammatory cytokine secretion.…”

Regulation of the production of soluble IL-4 receptors in murine cutaneous leishmaniasis. The roles of IL-12 and IL-4

“…The development of Th1 responses and secretion of IFN-␥ are highly dependent on the production of IL-12 by cells of the monocytic/macrophage lineage [45][46][47][48][49], and administration of anti-IL-12 antibodies in vivo has been demonstrated to interfere with the development of Th1 responses and indirectly promote that of Th2 responses [37,50,51]. We thus expected that in vivo treatment with anti-IL-12 antibodies would inhibit the ability of cells from C3H mice to produce Th1 cytokines (i.e., IFN-␥) while at the same time increase their production of both IL-4 and sIL-4R.…”