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T cell receptor engagement can influence T cell motility
T Cell Receptor Engagement Can Influence T Cell Motility F.M. Marelli-Berg, M. Alvarez-Iglesias, K. Prodromidou, G. Lombardi, L. Frasca, L.-P. Berg, and R.I. Lechler
T
HE FUNCTIONAL outcome of the interactions between host T cells and graft endothelial cells (EC) is of crucial importance in organ transplantation because EC are the first allogeneic target encountered by the recipient’s immune system. As a result of these interactions, host T cells migrate through the endothelium of the transplanted organ, a crucial early step in the initiation of graft rejection. The influence of cognate receptor engagement on the recruitment of antigen-specific T cells is poorly understood. As EC express MHC class II molecules during inflammation, CD4⫹ T-cell transmigration from the vascular lumen into the tissue will inevitably be accompanied by cognate recognition of peptide:MHC complexes displayed by the EC. We have reported that alloantigen presentation by costimulation-deficient human EC, while not inducing either proliferative responses or hyporesponsiveness in B7dependent CD4⫹ T cells, enhances transendothelial migration, thus contributing to the recruitment of alloreactive T cells into tissues.1–3 In contrast, antigen (Ag) presentation by EC to B7-independent T cells leads to T cell division but prevents T-cell motility.3 The present study analyzes the relationship between T-cell functional state and migratory ability and how the latter can be influenced by T-cell receptor (TCR)-mediated signals.
described.3 T cells (3 ⫻ 105) were placed into each insert and left to migrate through the Ag-pulsed or unpulsed EC monolayer. The number of migrated T cells was determined by counting the lymphocytes present in the lower well media over the next 48 hours.
MATERIALS AND METHODS Cells
Anergic T Cells are Immobile
In vitro established CD4⫹ T cell clones, specific for influenza haemagglutinin (HA) peptide 307–319 and restricted by DR7, which do not require B7-mediated costimulation to proliferate in response to antigen, were used. EC were isolated from umbilical veins and maintained in culture as previously described.1
T Cell Proliferation Assays T cells (104 cells/well) were cultured in the presence of irradiated ␥-IFN-treated EC or B-LCL (2 ⫻ 104 cells/well) prepulsed with HA peptide. Proliferation was measured as 3H-TdR incorporation as previously described.2
Lymphocyte Transmigration Assays EC were seeded onto tissue culture well inserts (Costar Ltd, High Wycombe, UK) overnight to form a monolayer as previously 0041-1345/01/$–see front matter PII S0041-1345(00)02265-X
RESULTS AND DISCUSSION TCR Ligation Leading to Cell Division Prevents Motility
B7-independent T-cell clones were induced to proliferate by antigen presentation by EC as well as other nonconventional antigen presenting cells. However, transendothelial migration of B7-independent T cells was completely abrogated by recognition of Ag on the EC monolayer. This occurred immediately after cognate recognition as virtually no T cells migrated through the antigen-expressing monolayer and significant differences could be detected as early as two hours after loading the T cells (eg, no T cells versus 20% transmigrated T cells in the presence or absence of Ag, respectively). Abrogation of T-cell motility was also observed when T cells were stimulated either by MHC: peptide bearing transfectants or by coligation of TCR and CD28. In addition, antibody blockade of the IL-2 receptor did not restore migration in any circumstances.
T cells were rendered anergic either by cognate recognition of epithelial cells2 or by T:T Ag presentation.4 Anergic T cells seeded onto EC monolayers were unable to migrate, independently of the occurrence of cognate recognition of the EC, suggesting that these T cells cannot activate signalling pathways necessary for motility. The present report suggests that TCR-mediated signals leading to T-cell division can profoundly inhibit T-cell migration, thus possibly playing a role in the retention of alloreactive T cells in the graft. We have further shown that T-cell migration represents a unique T-cell functional state
From the Department of Immunology and Histopathology, Imperial College School of Medicine, London, UK. Address reprint requests to Dr F. Marelli-Berg, ICSM-Hammersmith Hospital, Du Cane Rd, London W12 ONN, UK. © 2001 by Elsevier Science Inc. 655 Avenue of the Americas, New York, NY 10010
312
Transplantation Proceedings, 33, 312–313 (2001)
T-CELL RECEPTOR EFFECT ON MOTILITY
that is distinct from and incompatible with alternative states, namely T-cell proliferation and anergy. REFERENCES 1. Marelli-Berg FM, Hargreaves REG, Carmichael P, et al: J Exp Med 183:1603, 1996
313 2. Marelli-Berg FM, Frasca L, Imami N, et al: Transplantation 68:280, 1999 3. Marelli-Berg FM, Frasca L, Weng L, et al: J Immunol 162:696, 1999 4. Sidhu S, Deacock S, Bal V, et al: J Exp Med 176:875, 1992
T
HE FUNCTIONAL outcome of the interactions between host T cells and graft endothelial cells (EC) is of crucial importance in organ transplantation because EC are the first allogeneic target encountered by the recipient’s immune system. As a result of these interactions, host T cells migrate through the endothelium of the transplanted organ, a crucial early step in the initiation of graft rejection. The influence of cognate receptor engagement on the recruitment of antigen-specific T cells is poorly understood. As EC express MHC class II molecules during inflammation, CD4⫹ T-cell transmigration from the vascular lumen into the tissue will inevitably be accompanied by cognate recognition of peptide:MHC complexes displayed by the EC. We have reported that alloantigen presentation by costimulation-deficient human EC, while not inducing either proliferative responses or hyporesponsiveness in B7dependent CD4⫹ T cells, enhances transendothelial migration, thus contributing to the recruitment of alloreactive T cells into tissues.1–3 In contrast, antigen (Ag) presentation by EC to B7-independent T cells leads to T cell division but prevents T-cell motility.3 The present study analyzes the relationship between T-cell functional state and migratory ability and how the latter can be influenced by T-cell receptor (TCR)-mediated signals.
described.3 T cells (3 ⫻ 105) were placed into each insert and left to migrate through the Ag-pulsed or unpulsed EC monolayer. The number of migrated T cells was determined by counting the lymphocytes present in the lower well media over the next 48 hours.
MATERIALS AND METHODS Cells
Anergic T Cells are Immobile
In vitro established CD4⫹ T cell clones, specific for influenza haemagglutinin (HA) peptide 307–319 and restricted by DR7, which do not require B7-mediated costimulation to proliferate in response to antigen, were used. EC were isolated from umbilical veins and maintained in culture as previously described.1
T Cell Proliferation Assays T cells (104 cells/well) were cultured in the presence of irradiated ␥-IFN-treated EC or B-LCL (2 ⫻ 104 cells/well) prepulsed with HA peptide. Proliferation was measured as 3H-TdR incorporation as previously described.2
Lymphocyte Transmigration Assays EC were seeded onto tissue culture well inserts (Costar Ltd, High Wycombe, UK) overnight to form a monolayer as previously 0041-1345/01/$–see front matter PII S0041-1345(00)02265-X
RESULTS AND DISCUSSION TCR Ligation Leading to Cell Division Prevents Motility
B7-independent T-cell clones were induced to proliferate by antigen presentation by EC as well as other nonconventional antigen presenting cells. However, transendothelial migration of B7-independent T cells was completely abrogated by recognition of Ag on the EC monolayer. This occurred immediately after cognate recognition as virtually no T cells migrated through the antigen-expressing monolayer and significant differences could be detected as early as two hours after loading the T cells (eg, no T cells versus 20% transmigrated T cells in the presence or absence of Ag, respectively). Abrogation of T-cell motility was also observed when T cells were stimulated either by MHC: peptide bearing transfectants or by coligation of TCR and CD28. In addition, antibody blockade of the IL-2 receptor did not restore migration in any circumstances.
T cells were rendered anergic either by cognate recognition of epithelial cells2 or by T:T Ag presentation.4 Anergic T cells seeded onto EC monolayers were unable to migrate, independently of the occurrence of cognate recognition of the EC, suggesting that these T cells cannot activate signalling pathways necessary for motility. The present report suggests that TCR-mediated signals leading to T-cell division can profoundly inhibit T-cell migration, thus possibly playing a role in the retention of alloreactive T cells in the graft. We have further shown that T-cell migration represents a unique T-cell functional state
From the Department of Immunology and Histopathology, Imperial College School of Medicine, London, UK. Address reprint requests to Dr F. Marelli-Berg, ICSM-Hammersmith Hospital, Du Cane Rd, London W12 ONN, UK. © 2001 by Elsevier Science Inc. 655 Avenue of the Americas, New York, NY 10010
312
Transplantation Proceedings, 33, 312–313 (2001)
T-CELL RECEPTOR EFFECT ON MOTILITY
that is distinct from and incompatible with alternative states, namely T-cell proliferation and anergy. REFERENCES 1. Marelli-Berg FM, Hargreaves REG, Carmichael P, et al: J Exp Med 183:1603, 1996
313 2. Marelli-Berg FM, Frasca L, Imami N, et al: Transplantation 68:280, 1999 3. Marelli-Berg FM, Frasca L, Weng L, et al: J Immunol 162:696, 1999 4. Sidhu S, Deacock S, Bal V, et al: J Exp Med 176:875, 1992