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Regulation of the interleukin (IL)-12R beta 2 subunit expression in developing T helper 1 (Th1) and Th2 cells.

Szabo SJ, Dighe AS, Gubler U, Murphy KM - J. Exp. Med. (1997)

Bottom Line: Importantly, IL-4 and IFN-gamma were found to significantly modify IL-12 receptor beta 2 expression after T cell activation.IFN-gamma treatment of early developing Th2 cells maintained IL-12R beta 2 expression and restored the ability of these cells to functionally respond to IL-12, but did not directly inhibit IL-4 or induce IFN-gamma production.Controlling the expression of the IL-12R beta 2 subunit could be an important therapeutic target for the redirection of ongoing Th cell responses.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.

ABSTRACT
The developmental commitment to a T helper 1 (Th1)- or Th2-type response can significantly influence host immunity to pathogens. Extinction of the IL-12 signaling pathway during early Th2 development provides a mechanism that allows stable phenotype commitment. In this report we demonstrate that extinction of IL-12 signaling in early Th2 cells results from a selective loss of IL-12 receptor (IL-12R) beta 2 subunit expression. To determine the basis for this selective loss, we examined IL-12R beta 2 subunit expression during Th cell development in response to T cell treatment with different cytokines. IL-12R beta 2 is not expressed by naive resting CD4+ T cells, but is induced upon antigen activation through the T cell receptor. Importantly, IL-4 and IFN-gamma were found to significantly modify IL-12 receptor beta 2 expression after T cell activation. IL-4 inhibited IL-12R beta 2 expression leading to the loss of IL-12 signaling, providing an important point of regulation to promote commitment to the Th2 pathway. IFN-gamma treatment of early developing Th2 cells maintained IL-12R beta 2 expression and restored the ability of these cells to functionally respond to IL-12, but did not directly inhibit IL-4 or induce IFN-gamma production. Thus, IFN-gamma may prevent early Th cells from premature commitment to the Th2 pathway. Controlling the expression of the IL-12R beta 2 subunit could be an important therapeutic target for the redirection of ongoing Th cell responses.

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Examination of the functional IL-12 responses of developing  Th cells. FACS®-sorted naive CD4+ DO11.10 T cells were cultured with  OVA peptide and irradiated BALB/c splenocytes in the presence of the  primary culture conditions indicated. Cultures were harvested on day 7,  washed, and restimulated at 1.25 × 105 T cells/well with OVA peptide  and BALB/c splenocytes in the presence of anti–IL-4 mAb (10 μg/ml  11B11) and anti IL-10 (20 μg/ml 2A5) and either IL-12 (10 U/ml) or  anti–IL-12 (3 μg/ml TOSH). Supernatants collected after 48 h were analyzed by ELISA for IFN-γ.
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Figure 6: Examination of the functional IL-12 responses of developing Th cells. FACS®-sorted naive CD4+ DO11.10 T cells were cultured with OVA peptide and irradiated BALB/c splenocytes in the presence of the primary culture conditions indicated. Cultures were harvested on day 7, washed, and restimulated at 1.25 × 105 T cells/well with OVA peptide and BALB/c splenocytes in the presence of anti–IL-4 mAb (10 μg/ml 11B11) and anti IL-10 (20 μg/ml 2A5) and either IL-12 (10 U/ml) or anti–IL-12 (3 μg/ml TOSH). Supernatants collected after 48 h were analyzed by ELISA for IFN-γ.

Mentions: To examine whether IFN-γ treatment of developing Th cells during primary culture altered functional responses to IL-12, we measured the IL-12–dependent IFN-γ production in developing Th cells derived under the same conditions used in Fig. 5. Additionally, since production of endogenous IL-4 and IL-10 production by these cells directly inhibits IFN-γ production, we neutralized these cytokines to more clearly assess the true potential of these cells for IL-12 induced IFN-γ production. T cells arising from stimulation in IL-4 plus anti–IL-12 plus IFN-γ responded to IL-12 by producing 550 U/ml of IFN-γ in the secondary stimulation (Fig. 6, top), whereas addition of anti–IFN-γ mAb led to cells producing less than 50 U/ml of IFN-γ upon restimulation (Fig. 6, bottom). For T cells treated with IL-4 and IL-12 during primary activation, IFN-γ in the primary culture was required for IL-12 induced IFN-γ production upon secondary stimulation (Fig. 6, compare column 3 in top and bottom). For Th1 cells, arising from stimulation in the presence of IL-12 and anti–IL-4 mAbs, IFN-γ was not required for subsequent development of IL-12 responsiveness (Fig. 6, compare column 1 in top and bottom). Thus, IFN-γ regulates IL-12 responsiveness with the same pattern as it regulates IL-12R β2 expression in developing Th cells (Fig. 5).


Regulation of the interleukin (IL)-12R beta 2 subunit expression in developing T helper 1 (Th1) and Th2 cells.

Szabo SJ, Dighe AS, Gubler U, Murphy KM - J. Exp. Med. (1997)

Examination of the functional IL-12 responses of developing  Th cells. FACS®-sorted naive CD4+ DO11.10 T cells were cultured with  OVA peptide and irradiated BALB/c splenocytes in the presence of the  primary culture conditions indicated. Cultures were harvested on day 7,  washed, and restimulated at 1.25 × 105 T cells/well with OVA peptide  and BALB/c splenocytes in the presence of anti–IL-4 mAb (10 μg/ml  11B11) and anti IL-10 (20 μg/ml 2A5) and either IL-12 (10 U/ml) or  anti–IL-12 (3 μg/ml TOSH). Supernatants collected after 48 h were analyzed by ELISA for IFN-γ.
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Related In: Results  -  Collection

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Figure 6: Examination of the functional IL-12 responses of developing Th cells. FACS®-sorted naive CD4+ DO11.10 T cells were cultured with OVA peptide and irradiated BALB/c splenocytes in the presence of the primary culture conditions indicated. Cultures were harvested on day 7, washed, and restimulated at 1.25 × 105 T cells/well with OVA peptide and BALB/c splenocytes in the presence of anti–IL-4 mAb (10 μg/ml 11B11) and anti IL-10 (20 μg/ml 2A5) and either IL-12 (10 U/ml) or anti–IL-12 (3 μg/ml TOSH). Supernatants collected after 48 h were analyzed by ELISA for IFN-γ.
Mentions: To examine whether IFN-γ treatment of developing Th cells during primary culture altered functional responses to IL-12, we measured the IL-12–dependent IFN-γ production in developing Th cells derived under the same conditions used in Fig. 5. Additionally, since production of endogenous IL-4 and IL-10 production by these cells directly inhibits IFN-γ production, we neutralized these cytokines to more clearly assess the true potential of these cells for IL-12 induced IFN-γ production. T cells arising from stimulation in IL-4 plus anti–IL-12 plus IFN-γ responded to IL-12 by producing 550 U/ml of IFN-γ in the secondary stimulation (Fig. 6, top), whereas addition of anti–IFN-γ mAb led to cells producing less than 50 U/ml of IFN-γ upon restimulation (Fig. 6, bottom). For T cells treated with IL-4 and IL-12 during primary activation, IFN-γ in the primary culture was required for IL-12 induced IFN-γ production upon secondary stimulation (Fig. 6, compare column 3 in top and bottom). For Th1 cells, arising from stimulation in the presence of IL-12 and anti–IL-4 mAbs, IFN-γ was not required for subsequent development of IL-12 responsiveness (Fig. 6, compare column 1 in top and bottom). Thus, IFN-γ regulates IL-12 responsiveness with the same pattern as it regulates IL-12R β2 expression in developing Th cells (Fig. 5).

Bottom Line: Importantly, IL-4 and IFN-gamma were found to significantly modify IL-12 receptor beta 2 expression after T cell activation.IFN-gamma treatment of early developing Th2 cells maintained IL-12R beta 2 expression and restored the ability of these cells to functionally respond to IL-12, but did not directly inhibit IL-4 or induce IFN-gamma production.Controlling the expression of the IL-12R beta 2 subunit could be an important therapeutic target for the redirection of ongoing Th cell responses.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.

ABSTRACT
The developmental commitment to a T helper 1 (Th1)- or Th2-type response can significantly influence host immunity to pathogens. Extinction of the IL-12 signaling pathway during early Th2 development provides a mechanism that allows stable phenotype commitment. In this report we demonstrate that extinction of IL-12 signaling in early Th2 cells results from a selective loss of IL-12 receptor (IL-12R) beta 2 subunit expression. To determine the basis for this selective loss, we examined IL-12R beta 2 subunit expression during Th cell development in response to T cell treatment with different cytokines. IL-12R beta 2 is not expressed by naive resting CD4+ T cells, but is induced upon antigen activation through the T cell receptor. Importantly, IL-4 and IFN-gamma were found to significantly modify IL-12 receptor beta 2 expression after T cell activation. IL-4 inhibited IL-12R beta 2 expression leading to the loss of IL-12 signaling, providing an important point of regulation to promote commitment to the Th2 pathway. IFN-gamma treatment of early developing Th2 cells maintained IL-12R beta 2 expression and restored the ability of these cells to functionally respond to IL-12, but did not directly inhibit IL-4 or induce IFN-gamma production. Thus, IFN-gamma may prevent early Th cells from premature commitment to the Th2 pathway. Controlling the expression of the IL-12R beta 2 subunit could be an important therapeutic target for the redirection of ongoing Th cell responses.

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