Abstract
Two murine, keyhole limpet hemocyanin-specific Th cell clones were studied for their ability to respond to antibody-mediated stimulation of the TCR complex or to Ag-pulsed accessory cells by hydrolyzing inositol phospholipids. Both clones were positive for the determinant expressed on the ε chain of CD3 that is recognized by the mAb, 145-2C11 (2C11 mAb); one clone also expressed the V(β)8 epitope of the α/β chains of the TCR recognized by the F23.1 mAb. Treatment of these cells with 2C11 or F23.1 mAb adsorbed onto polystyrene beads induced a time-dependent accumulation of inositol phosphates (IP). Keyhole limpet hemocyanin-pulsed accessory cells which expressed the appropriate MHC phenotype also induced IP accumulation, whereas no response was induced by medium-treated or MHC congenic accessory cells. The hydrolysis of inositol phospholipids induced by TCR perturbation depended upon the presence of exogenous Ca2+; Mg2+ did not substitute for Ca2+. Treatment of cells with ionomycin at concentrations up to 30 μM was unable to induce hydrolysis of inositol phospholipids, indicating that entrance of Ca2+ was itself insufficient to generate IP. Stimulated IP generation was rapidly blocked upon addition of EGTA to the incubation medium. Reducing the level of exogenous Ca2+ decreased the production of inositol mono-, bis-, and trisphosphate isomers similarly, suggesting that extracellular Ca2+ was required for the initiation of the hydrolysis rather than affecting phospholipase C affinity for its substrates. We concluded that activation of inositol phospholipid hydrolysis by perturbation of the TCR complex in the Th cell clones under investigation displays a Ca2+-dependent component which is likely to be proximal to IP generation.
| Original language | English |
|---|---|
| Pages (from-to) | 587-595 |
| Number of pages | 9 |
| Journal | Journal of Immunology |
| Volume | 143 |
| Issue number | 2 |
| State | Published - Jan 1 1989 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Immunology
Cite this
Hydrolysis of inositol phospholipids induced by stimulation of the T cell antigen receptor complex in antigen-specific, murine helper T cell clones. Requirement for exogenous calcium. / Bonvini, E.; DeBell, K. E.; Kolber, Michael A; Hoffman, T.; Hodes, R. J.; Taplits, M. S.
In: Journal of Immunology, Vol. 143, No. 2, 01.01.1989, p. 587-595.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Hydrolysis of inositol phospholipids induced by stimulation of the T cell antigen receptor complex in antigen-specific, murine helper T cell clones. Requirement for exogenous calcium
AU - Bonvini, E.
AU - DeBell, K. E.
AU - Kolber, Michael A
AU - Hoffman, T.
AU - Hodes, R. J.
AU - Taplits, M. S.
PY - 1989/1/1
Y1 - 1989/1/1
N2 - Two murine, keyhole limpet hemocyanin-specific Th cell clones were studied for their ability to respond to antibody-mediated stimulation of the TCR complex or to Ag-pulsed accessory cells by hydrolyzing inositol phospholipids. Both clones were positive for the determinant expressed on the ε chain of CD3 that is recognized by the mAb, 145-2C11 (2C11 mAb); one clone also expressed the V(β)8 epitope of the α/β chains of the TCR recognized by the F23.1 mAb. Treatment of these cells with 2C11 or F23.1 mAb adsorbed onto polystyrene beads induced a time-dependent accumulation of inositol phosphates (IP). Keyhole limpet hemocyanin-pulsed accessory cells which expressed the appropriate MHC phenotype also induced IP accumulation, whereas no response was induced by medium-treated or MHC congenic accessory cells. The hydrolysis of inositol phospholipids induced by TCR perturbation depended upon the presence of exogenous Ca2+; Mg2+ did not substitute for Ca2+. Treatment of cells with ionomycin at concentrations up to 30 μM was unable to induce hydrolysis of inositol phospholipids, indicating that entrance of Ca2+ was itself insufficient to generate IP. Stimulated IP generation was rapidly blocked upon addition of EGTA to the incubation medium. Reducing the level of exogenous Ca2+ decreased the production of inositol mono-, bis-, and trisphosphate isomers similarly, suggesting that extracellular Ca2+ was required for the initiation of the hydrolysis rather than affecting phospholipase C affinity for its substrates. We concluded that activation of inositol phospholipid hydrolysis by perturbation of the TCR complex in the Th cell clones under investigation displays a Ca2+-dependent component which is likely to be proximal to IP generation.
AB - Two murine, keyhole limpet hemocyanin-specific Th cell clones were studied for their ability to respond to antibody-mediated stimulation of the TCR complex or to Ag-pulsed accessory cells by hydrolyzing inositol phospholipids. Both clones were positive for the determinant expressed on the ε chain of CD3 that is recognized by the mAb, 145-2C11 (2C11 mAb); one clone also expressed the V(β)8 epitope of the α/β chains of the TCR recognized by the F23.1 mAb. Treatment of these cells with 2C11 or F23.1 mAb adsorbed onto polystyrene beads induced a time-dependent accumulation of inositol phosphates (IP). Keyhole limpet hemocyanin-pulsed accessory cells which expressed the appropriate MHC phenotype also induced IP accumulation, whereas no response was induced by medium-treated or MHC congenic accessory cells. The hydrolysis of inositol phospholipids induced by TCR perturbation depended upon the presence of exogenous Ca2+; Mg2+ did not substitute for Ca2+. Treatment of cells with ionomycin at concentrations up to 30 μM was unable to induce hydrolysis of inositol phospholipids, indicating that entrance of Ca2+ was itself insufficient to generate IP. Stimulated IP generation was rapidly blocked upon addition of EGTA to the incubation medium. Reducing the level of exogenous Ca2+ decreased the production of inositol mono-, bis-, and trisphosphate isomers similarly, suggesting that extracellular Ca2+ was required for the initiation of the hydrolysis rather than affecting phospholipase C affinity for its substrates. We concluded that activation of inositol phospholipid hydrolysis by perturbation of the TCR complex in the Th cell clones under investigation displays a Ca2+-dependent component which is likely to be proximal to IP generation.
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M3 - Article
C2 - 2472446
AN - SCOPUS:0024323611
VL - 143
SP - 587
EP - 595
JO - Journal of Immunology
JF - Journal of Immunology
SN - 0022-1767
IS - 2
ER -