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Conditions that induce tolerance in mature CD4+ T cells.

Lanoue A, Bona C, von Boehmer H, Sarukhan A - J. Exp. Med. (1997)

Bottom Line: Mature CD4+6.5+ cells that were transferred into antigen-containing recipients went through an initial phase of expansion after which most cells were deleted and those remaining became unresponsive, as previously described for CD8+ cells.It was only after decreasing cell numbers by CD4 antibody treatment and by repeatedly reintroducing antigen thereafter that unresponsiveness of 6.5+ cells was achieved and maintained.In no case could we observe the appearance of antigen-specific T cells with a Th2 cytokine profile among the remaining cells and therefore conclude that deletion and anergy represent the major mechanisms of tolerance in our studies.

View Article: PubMed Central - PubMed

Affiliation: Unité Institut National de la Santé et de la Recherche Médicale 373, Institut Necker, Paris.

ABSTRACT
Establishment of antigen-specific tolerance among mature T cells has been a long debated, yet poorly understood issue. In this study we have used transgenic mice bearing a class II--restricted TCR specific for the hemmagglutinin of the influenza virus in order to test the behavior of CD4+ T cells upon exposure to antigen in different forms and doses. We first studied the fate of T cells expressing the transgenic TCR (6.5) in double transgenic mice where HA was expressed as a self antigen by hemapoietic cells. In these mice, we found some mature T cells in periphery that had escaped thymic deletion and that showed signs of activation but which were anergic. Mature CD4+6.5+ cells that were transferred into antigen-containing recipients went through an initial phase of expansion after which most cells were deleted and those remaining became unresponsive, as previously described for CD8+ cells. Inducing tolerance in CD4+6.5+ cells in situ in single transgenic mice proved a difficult task: classical protocols using single doses of soluble or deaggregated antigen as well as feeding antigen all failed to induce antigen-specific unresponsiveness. It was only after decreasing cell numbers by CD4 antibody treatment and by repeatedly reintroducing antigen thereafter that unresponsiveness of 6.5+ cells was achieved and maintained. In no case could we observe the appearance of antigen-specific T cells with a Th2 cytokine profile among the remaining cells and therefore conclude that deletion and anergy represent the major mechanisms of tolerance in our studies.

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Effect of repeated  doses of antigen on the number  and function of 6.5+ cells. 6.5+mice were injected i.v. with  PBS, 0.1 mg of peptide or 0.1  mg of HA-Ig five times every  other day and were killed 6 d after the last injection. The absolute numbers of 6.5+ cells in the  thymus (A) and lymph nodes (B)  are shown as well as the proliferation values of lymph node cells  upon antigenic stimulation in  vitro with different peptide doses  (C). Percentages of 6.5+ cells  among total T cells are also  shown (D).
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Figure 4: Effect of repeated doses of antigen on the number and function of 6.5+ cells. 6.5+mice were injected i.v. with PBS, 0.1 mg of peptide or 0.1 mg of HA-Ig five times every other day and were killed 6 d after the last injection. The absolute numbers of 6.5+ cells in the thymus (A) and lymph nodes (B) are shown as well as the proliferation values of lymph node cells upon antigenic stimulation in vitro with different peptide doses (C). Percentages of 6.5+ cells among total T cells are also shown (D).

Mentions: Because it had been demonstrated that tolerance induction in CD8+ cells is dependent on antigen persistence (24, 25), we injected 6.5+ mice i.v. with 0.1 mg of HA-Ig or peptide five times every other day and analyzed them 6 days after the last injection. The numbers of 6.5+ cells in the thymus and periphery are shown in Fig. 4 and were markedly decreased in the thymus and in the lymph nodes of treated animals. The decrease in lymph nodes was antigen-specific because the proportion of 6.5+ cells among CD4+ and CD8+ cells was likewise decreased. Despite the fact that, in terms of molarity, 0.1 mg of the peptide represents at least 2 × 104 more peptide molecules than 0.1 mg of the HA-Ig, no difference was observed in their capacity to induce partial deletion or to decrease the proliferative response of antigen-specific cells. This could mean that peptide may be very rapidly cleared upon injection when compared with proteins. Furthermore, the fact that the proteic antigen that contains the peptide sequence has an Ig-Fc part may facilitate its uptake and presentation by Fc receptor–bearing APCs. For these reasons, in all protocols tested hereafter we used the HA-Ig and not the peptide as source of soluble antigen.


Conditions that induce tolerance in mature CD4+ T cells.

Lanoue A, Bona C, von Boehmer H, Sarukhan A - J. Exp. Med. (1997)

Effect of repeated  doses of antigen on the number  and function of 6.5+ cells. 6.5+mice were injected i.v. with  PBS, 0.1 mg of peptide or 0.1  mg of HA-Ig five times every  other day and were killed 6 d after the last injection. The absolute numbers of 6.5+ cells in the  thymus (A) and lymph nodes (B)  are shown as well as the proliferation values of lymph node cells  upon antigenic stimulation in  vitro with different peptide doses  (C). Percentages of 6.5+ cells  among total T cells are also  shown (D).
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2196030&req=5

Figure 4: Effect of repeated doses of antigen on the number and function of 6.5+ cells. 6.5+mice were injected i.v. with PBS, 0.1 mg of peptide or 0.1 mg of HA-Ig five times every other day and were killed 6 d after the last injection. The absolute numbers of 6.5+ cells in the thymus (A) and lymph nodes (B) are shown as well as the proliferation values of lymph node cells upon antigenic stimulation in vitro with different peptide doses (C). Percentages of 6.5+ cells among total T cells are also shown (D).
Mentions: Because it had been demonstrated that tolerance induction in CD8+ cells is dependent on antigen persistence (24, 25), we injected 6.5+ mice i.v. with 0.1 mg of HA-Ig or peptide five times every other day and analyzed them 6 days after the last injection. The numbers of 6.5+ cells in the thymus and periphery are shown in Fig. 4 and were markedly decreased in the thymus and in the lymph nodes of treated animals. The decrease in lymph nodes was antigen-specific because the proportion of 6.5+ cells among CD4+ and CD8+ cells was likewise decreased. Despite the fact that, in terms of molarity, 0.1 mg of the peptide represents at least 2 × 104 more peptide molecules than 0.1 mg of the HA-Ig, no difference was observed in their capacity to induce partial deletion or to decrease the proliferative response of antigen-specific cells. This could mean that peptide may be very rapidly cleared upon injection when compared with proteins. Furthermore, the fact that the proteic antigen that contains the peptide sequence has an Ig-Fc part may facilitate its uptake and presentation by Fc receptor–bearing APCs. For these reasons, in all protocols tested hereafter we used the HA-Ig and not the peptide as source of soluble antigen.

Bottom Line: Mature CD4+6.5+ cells that were transferred into antigen-containing recipients went through an initial phase of expansion after which most cells were deleted and those remaining became unresponsive, as previously described for CD8+ cells.It was only after decreasing cell numbers by CD4 antibody treatment and by repeatedly reintroducing antigen thereafter that unresponsiveness of 6.5+ cells was achieved and maintained.In no case could we observe the appearance of antigen-specific T cells with a Th2 cytokine profile among the remaining cells and therefore conclude that deletion and anergy represent the major mechanisms of tolerance in our studies.

View Article: PubMed Central - PubMed

Affiliation: Unité Institut National de la Santé et de la Recherche Médicale 373, Institut Necker, Paris.

ABSTRACT
Establishment of antigen-specific tolerance among mature T cells has been a long debated, yet poorly understood issue. In this study we have used transgenic mice bearing a class II--restricted TCR specific for the hemmagglutinin of the influenza virus in order to test the behavior of CD4+ T cells upon exposure to antigen in different forms and doses. We first studied the fate of T cells expressing the transgenic TCR (6.5) in double transgenic mice where HA was expressed as a self antigen by hemapoietic cells. In these mice, we found some mature T cells in periphery that had escaped thymic deletion and that showed signs of activation but which were anergic. Mature CD4+6.5+ cells that were transferred into antigen-containing recipients went through an initial phase of expansion after which most cells were deleted and those remaining became unresponsive, as previously described for CD8+ cells. Inducing tolerance in CD4+6.5+ cells in situ in single transgenic mice proved a difficult task: classical protocols using single doses of soluble or deaggregated antigen as well as feeding antigen all failed to induce antigen-specific unresponsiveness. It was only after decreasing cell numbers by CD4 antibody treatment and by repeatedly reintroducing antigen thereafter that unresponsiveness of 6.5+ cells was achieved and maintained. In no case could we observe the appearance of antigen-specific T cells with a Th2 cytokine profile among the remaining cells and therefore conclude that deletion and anergy represent the major mechanisms of tolerance in our studies.

Show MeSH
Related in: MedlinePlus