Limits...
Sensory adaptation in naive peripheral CD4 T cells.

Smith K, Seddon B, Purbhoo MA, Zamoyska R, Fisher AG, Merkenschlager M - J. Exp. Med. (2001)

Bottom Line: Here we show that pMHC contact modulates the expression of CD5 by naive CD4 T cells in a process that requires the continued expression of p56(lck).Reduced CD5 levels in T cells deprived of pMHC contact are predictive of elevated Ca(2)+ responses to subsequent TCR engagement by anti-CD3 or nominal antigen.Adaptation to peripheral pMHC contact may be important for regulating naive CD4 T cell responsiveness.

View Article: PubMed Central - PubMed

Affiliation: Lymphocyte Development Group, MRC Clinical Sciences Centre, ICSM Hammersmith Hospital, London W12 0NN, UK.

ABSTRACT
T cell receptor interactions with peptide/major histocompatibility complex (pMHC) ligands control the selection of T cells in the thymus as well as their homeostasis in peripheral lymphoid organs. Here we show that pMHC contact modulates the expression of CD5 by naive CD4 T cells in a process that requires the continued expression of p56(lck). Reduced CD5 levels in T cells deprived of pMHC contact are predictive of elevated Ca(2)+ responses to subsequent TCR engagement by anti-CD3 or nominal antigen. Adaptation to peripheral pMHC contact may be important for regulating naive CD4 T cell responsiveness.

Show MeSH

Related in: MedlinePlus

Tuning of naive CD4 T cell responsiveness by MHC contact. APC-depleted Rag1o/o Hk AND TCR transgenic LN cells were maintained in 3-D reaggregate culture as in Fig. 4 either in an MHCo/o (black line) or H2k (B10.BR) environment (dashed line). After 3 d cells were loaded with the Ca2+ indicator Fluo-4 and stimulated with subsaturating concentrations of anti-CD3 followed by the addition of cross-linking antibody at 0 s (top) or BM-derived APCs pulsed with the cognate pigeon cytochrome-C peptide 81–104 or the variant peptides K99R or K99A (bottom, the arrow indicates centrifugation of the sample to provide T cell/APC contact, see Materials and Methods).
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2195983&req=5

fig5: Tuning of naive CD4 T cell responsiveness by MHC contact. APC-depleted Rag1o/o Hk AND TCR transgenic LN cells were maintained in 3-D reaggregate culture as in Fig. 4 either in an MHCo/o (black line) or H2k (B10.BR) environment (dashed line). After 3 d cells were loaded with the Ca2+ indicator Fluo-4 and stimulated with subsaturating concentrations of anti-CD3 followed by the addition of cross-linking antibody at 0 s (top) or BM-derived APCs pulsed with the cognate pigeon cytochrome-C peptide 81–104 or the variant peptides K99R or K99A (bottom, the arrow indicates centrifugation of the sample to provide T cell/APC contact, see Materials and Methods).

Mentions: As CD5 is implicated as a modifier of lymphocyte receptor signaling (see Introduction) we were interested in comparing the functional properties of naive T cells expressing the same TCR but different levels of CD5 as the result of environmental MHC exposure. To this end, Rag1o/o AND LN CD4 T cells were placed in an environment either devoid of MHC expression or expressing H-2k, using the 3-D reaggregate system described in Fig. 4. After 3 d the cells were recovered and loaded with the Ca2+ indicator dye Fluo-4 to compare their responsiveness to TCR mediated stimuli. These were provided either by subsaturating concentrations of anti-CD3 followed by cross-linking (Fig. 5 top, cross-linking antibody added at 0 s) or by contact with peptide-loaded BM-derived APCs (Fig. 5, bottom). CD4 T cells that had been deprived of MHC contact (and as a result displayed reduced CD5 levels, see Fig. 4) responded more vigorously than cells from the same donor that had been maintained in an MHC+ environment.


Sensory adaptation in naive peripheral CD4 T cells.

Smith K, Seddon B, Purbhoo MA, Zamoyska R, Fisher AG, Merkenschlager M - J. Exp. Med. (2001)

Tuning of naive CD4 T cell responsiveness by MHC contact. APC-depleted Rag1o/o Hk AND TCR transgenic LN cells were maintained in 3-D reaggregate culture as in Fig. 4 either in an MHCo/o (black line) or H2k (B10.BR) environment (dashed line). After 3 d cells were loaded with the Ca2+ indicator Fluo-4 and stimulated with subsaturating concentrations of anti-CD3 followed by the addition of cross-linking antibody at 0 s (top) or BM-derived APCs pulsed with the cognate pigeon cytochrome-C peptide 81–104 or the variant peptides K99R or K99A (bottom, the arrow indicates centrifugation of the sample to provide T cell/APC contact, see Materials and Methods).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2195983&req=5

fig5: Tuning of naive CD4 T cell responsiveness by MHC contact. APC-depleted Rag1o/o Hk AND TCR transgenic LN cells were maintained in 3-D reaggregate culture as in Fig. 4 either in an MHCo/o (black line) or H2k (B10.BR) environment (dashed line). After 3 d cells were loaded with the Ca2+ indicator Fluo-4 and stimulated with subsaturating concentrations of anti-CD3 followed by the addition of cross-linking antibody at 0 s (top) or BM-derived APCs pulsed with the cognate pigeon cytochrome-C peptide 81–104 or the variant peptides K99R or K99A (bottom, the arrow indicates centrifugation of the sample to provide T cell/APC contact, see Materials and Methods).
Mentions: As CD5 is implicated as a modifier of lymphocyte receptor signaling (see Introduction) we were interested in comparing the functional properties of naive T cells expressing the same TCR but different levels of CD5 as the result of environmental MHC exposure. To this end, Rag1o/o AND LN CD4 T cells were placed in an environment either devoid of MHC expression or expressing H-2k, using the 3-D reaggregate system described in Fig. 4. After 3 d the cells were recovered and loaded with the Ca2+ indicator dye Fluo-4 to compare their responsiveness to TCR mediated stimuli. These were provided either by subsaturating concentrations of anti-CD3 followed by cross-linking (Fig. 5 top, cross-linking antibody added at 0 s) or by contact with peptide-loaded BM-derived APCs (Fig. 5, bottom). CD4 T cells that had been deprived of MHC contact (and as a result displayed reduced CD5 levels, see Fig. 4) responded more vigorously than cells from the same donor that had been maintained in an MHC+ environment.

Bottom Line: Here we show that pMHC contact modulates the expression of CD5 by naive CD4 T cells in a process that requires the continued expression of p56(lck).Reduced CD5 levels in T cells deprived of pMHC contact are predictive of elevated Ca(2)+ responses to subsequent TCR engagement by anti-CD3 or nominal antigen.Adaptation to peripheral pMHC contact may be important for regulating naive CD4 T cell responsiveness.

View Article: PubMed Central - PubMed

Affiliation: Lymphocyte Development Group, MRC Clinical Sciences Centre, ICSM Hammersmith Hospital, London W12 0NN, UK.

ABSTRACT
T cell receptor interactions with peptide/major histocompatibility complex (pMHC) ligands control the selection of T cells in the thymus as well as their homeostasis in peripheral lymphoid organs. Here we show that pMHC contact modulates the expression of CD5 by naive CD4 T cells in a process that requires the continued expression of p56(lck). Reduced CD5 levels in T cells deprived of pMHC contact are predictive of elevated Ca(2)+ responses to subsequent TCR engagement by anti-CD3 or nominal antigen. Adaptation to peripheral pMHC contact may be important for regulating naive CD4 T cell responsiveness.

Show MeSH
Related in: MedlinePlus