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T helper subset differentiation in the absence of invariant chain.

Brown DR, Swier K, Moskowitz NH, Naujokas MF, Locksley RM, Reiner SL - J. Exp. Med. (1997)

Bottom Line: We wished to determine whether this unexpected efficiency of T helper subset induction despite inefficient T cell stimulation could be modeled in vitro.In the presence of rIL-12 or rIL-4 naive parasite-specific transgenic T cells could mature into IFN-gamma-or IL-4-secreting T helper cells, respectively, even when antigen presentation was suboptimal or antigen dose was submitogenic.These experiments demonstrate that activation of T helper cells to a threshold required for IL-2 production or proliferation is not required to achieve induction of disease-regulating T helper cell effector functions, and that pathogen-associated secondary activation signals may facilitate the full differentiation of T helper subsets during limiting presentation of antigenic peptides.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, Gwen Knapp Center for Lupus & Immunology Research, University of Chicago, Illinois 60637, USA.

ABSTRACT
The outcome of murine infection with Leishmania major is regulated by major histocompatibility complex class II-restricted T helper cells. Invariant chain-deficient (Ii -/-) mice have impaired ability to present major histocompatibility complex class II-restricted antigens, and reduced numbers of CD4+ T cells. Despite these deficits, C57BL/6 Ii -/- mice controlled L. major infection comparably to wild-type mice. As assessed by mRNA analysis and in vitro antigen restimulation for IFN-gamma, Ii -/- mice had normal induction of Th1 subset differentiation even though antigen-dependent proliferation of their lymph node cells was substantially compromised. In addition, BALB/c Ii -/- mice exhibited a progressive course of infection and Th2 effector cell development that were comparable to that seen in wild-type BALB/c mice. We wished to determine whether this unexpected efficiency of T helper subset induction despite inefficient T cell stimulation could be modeled in vitro. In the presence of rIL-12 or rIL-4 naive parasite-specific transgenic T cells could mature into IFN-gamma-or IL-4-secreting T helper cells, respectively, even when antigen presentation was suboptimal or antigen dose was submitogenic. These experiments demonstrate that activation of T helper cells to a threshold required for IL-2 production or proliferation is not required to achieve induction of disease-regulating T helper cell effector functions, and that pathogen-associated secondary activation signals may facilitate the full differentiation of T helper subsets during limiting presentation of antigenic peptides.

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IL-12 sustains T  cell IFN-γ production at suboptimal levels of stimulation.  Splenocytes from Ii+ mice were  incubated with varying amounts  of the LACK peptide epitope  (Peptide; 5 × 105 APCs/well),  inoculated into wells at varying  numbers (APCs; 2.5 μM peptide), or inoculated into wells using a fixed number of cells and  amount of peptide (α–class II;  5 × 105 APCs/well, 1.25 μM  peptide). After washing, 2 × 105  TCR transgenic lymph node T  cells were added to the wells in  the presence of rIL-12 (2 ng/ml).  In the right panel, anti-class II mAb M5/114 was titrated into the wells using the dilutions shown. Supernatants were collected after 48 h and assayed for  IL-2 and IFN-γ using ELISA. Values represent means and standard deviations of triplicate determinations, and are representative of three separate experiments.
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Figure 7: IL-12 sustains T cell IFN-γ production at suboptimal levels of stimulation. Splenocytes from Ii+ mice were incubated with varying amounts of the LACK peptide epitope (Peptide; 5 × 105 APCs/well), inoculated into wells at varying numbers (APCs; 2.5 μM peptide), or inoculated into wells using a fixed number of cells and amount of peptide (α–class II; 5 × 105 APCs/well, 1.25 μM peptide). After washing, 2 × 105 TCR transgenic lymph node T cells were added to the wells in the presence of rIL-12 (2 ng/ml). In the right panel, anti-class II mAb M5/114 was titrated into the wells using the dilutions shown. Supernatants were collected after 48 h and assayed for IL-2 and IFN-γ using ELISA. Values represent means and standard deviations of triplicate determinations, and are representative of three separate experiments.

Mentions: To confirm that rIL-12 could sustain IFN-γ production under conditions where the numbers of class II/peptide complexes might be limited, experiments were carried out using the same preparations of normal Ii + APCs in which either amounts of peptide, numbers of APCs, or numbers of accessible class II/peptide complexes were titrated. For the latter condition, dilutions of anti–class II monoclonal antibody were included in the cultures during the period of presentation to transgenic T cells. All of the experiments were performed in the presence of rIL-12. Supernatants were collected after 48 h and analyzed for the presence of IL-2 and IFN-γ (Fig. 7). Under each set of conditions, the amount of IL-2 recovered was directly related to the degree of class II–dependent stimulation. In contrast, under these same conditions, the amount of IFN-γ recovered was essentially stable. Thus, as assessed using these transgenic T cells, and as suggested by cells recovered from infected mice (Fig. 4), IL-12 preserves IFN-γ production under conditions suboptimal for inducing IL-2 or lymphoproliferation.


T helper subset differentiation in the absence of invariant chain.

Brown DR, Swier K, Moskowitz NH, Naujokas MF, Locksley RM, Reiner SL - J. Exp. Med. (1997)

IL-12 sustains T  cell IFN-γ production at suboptimal levels of stimulation.  Splenocytes from Ii+ mice were  incubated with varying amounts  of the LACK peptide epitope  (Peptide; 5 × 105 APCs/well),  inoculated into wells at varying  numbers (APCs; 2.5 μM peptide), or inoculated into wells using a fixed number of cells and  amount of peptide (α–class II;  5 × 105 APCs/well, 1.25 μM  peptide). After washing, 2 × 105  TCR transgenic lymph node T  cells were added to the wells in  the presence of rIL-12 (2 ng/ml).  In the right panel, anti-class II mAb M5/114 was titrated into the wells using the dilutions shown. Supernatants were collected after 48 h and assayed for  IL-2 and IFN-γ using ELISA. Values represent means and standard deviations of triplicate determinations, and are representative of three separate experiments.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2196096&req=5

Figure 7: IL-12 sustains T cell IFN-γ production at suboptimal levels of stimulation. Splenocytes from Ii+ mice were incubated with varying amounts of the LACK peptide epitope (Peptide; 5 × 105 APCs/well), inoculated into wells at varying numbers (APCs; 2.5 μM peptide), or inoculated into wells using a fixed number of cells and amount of peptide (α–class II; 5 × 105 APCs/well, 1.25 μM peptide). After washing, 2 × 105 TCR transgenic lymph node T cells were added to the wells in the presence of rIL-12 (2 ng/ml). In the right panel, anti-class II mAb M5/114 was titrated into the wells using the dilutions shown. Supernatants were collected after 48 h and assayed for IL-2 and IFN-γ using ELISA. Values represent means and standard deviations of triplicate determinations, and are representative of three separate experiments.
Mentions: To confirm that rIL-12 could sustain IFN-γ production under conditions where the numbers of class II/peptide complexes might be limited, experiments were carried out using the same preparations of normal Ii + APCs in which either amounts of peptide, numbers of APCs, or numbers of accessible class II/peptide complexes were titrated. For the latter condition, dilutions of anti–class II monoclonal antibody were included in the cultures during the period of presentation to transgenic T cells. All of the experiments were performed in the presence of rIL-12. Supernatants were collected after 48 h and analyzed for the presence of IL-2 and IFN-γ (Fig. 7). Under each set of conditions, the amount of IL-2 recovered was directly related to the degree of class II–dependent stimulation. In contrast, under these same conditions, the amount of IFN-γ recovered was essentially stable. Thus, as assessed using these transgenic T cells, and as suggested by cells recovered from infected mice (Fig. 4), IL-12 preserves IFN-γ production under conditions suboptimal for inducing IL-2 or lymphoproliferation.

Bottom Line: We wished to determine whether this unexpected efficiency of T helper subset induction despite inefficient T cell stimulation could be modeled in vitro.In the presence of rIL-12 or rIL-4 naive parasite-specific transgenic T cells could mature into IFN-gamma-or IL-4-secreting T helper cells, respectively, even when antigen presentation was suboptimal or antigen dose was submitogenic.These experiments demonstrate that activation of T helper cells to a threshold required for IL-2 production or proliferation is not required to achieve induction of disease-regulating T helper cell effector functions, and that pathogen-associated secondary activation signals may facilitate the full differentiation of T helper subsets during limiting presentation of antigenic peptides.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, Gwen Knapp Center for Lupus & Immunology Research, University of Chicago, Illinois 60637, USA.

ABSTRACT
The outcome of murine infection with Leishmania major is regulated by major histocompatibility complex class II-restricted T helper cells. Invariant chain-deficient (Ii -/-) mice have impaired ability to present major histocompatibility complex class II-restricted antigens, and reduced numbers of CD4+ T cells. Despite these deficits, C57BL/6 Ii -/- mice controlled L. major infection comparably to wild-type mice. As assessed by mRNA analysis and in vitro antigen restimulation for IFN-gamma, Ii -/- mice had normal induction of Th1 subset differentiation even though antigen-dependent proliferation of their lymph node cells was substantially compromised. In addition, BALB/c Ii -/- mice exhibited a progressive course of infection and Th2 effector cell development that were comparable to that seen in wild-type BALB/c mice. We wished to determine whether this unexpected efficiency of T helper subset induction despite inefficient T cell stimulation could be modeled in vitro. In the presence of rIL-12 or rIL-4 naive parasite-specific transgenic T cells could mature into IFN-gamma-or IL-4-secreting T helper cells, respectively, even when antigen presentation was suboptimal or antigen dose was submitogenic. These experiments demonstrate that activation of T helper cells to a threshold required for IL-2 production or proliferation is not required to achieve induction of disease-regulating T helper cell effector functions, and that pathogen-associated secondary activation signals may facilitate the full differentiation of T helper subsets during limiting presentation of antigenic peptides.

Show MeSH
Related in: MedlinePlus