Abstract
In the present paper we have shown evidence for a significant increase of type II sPLA2 activity in A-LAK cells. The A-LAX-mediated cytotoxicity against YAC-1 target cells was strongly inhibited by two inhibitors of sPLA2, p-BPB and mepacrine, suggesting the involvement of this enzyme in the lytic mechanism of A-LAK. On the other hand, stimuli such as A23187 ionophore and TPA, which were able to induce in control cells an increased AA release, failed to cause this effect in IL-2-treated cells, suggesting that PLA2 was not active in these cells. Thus, we analyzed the levels of calpactin I, which is considered to be involved in the down-regulation of PLA2 activity. HrIL-2 treatment led to an increased expression of calpactin I at both the RNA and the protein level. A substantial portion of calpactin I was associated with the external surface of A-LAK and was able to exert a strong inhibitory effect on a purified porcine pancreatic PLA2 activity in vitro. Our results suggest that the role of calpactin I could be relevant to regulate PLA2 activity, and to protect the effector cells against a possible toxic effect which this enzyme could exert if present at high levels.
| Original language | English |
|---|---|
| Pages (from-to) | 274-282 |
| Number of pages | 9 |
| Journal | Cellular Immunology |
| Volume | 170 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Jun 15 1996 |
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ASJC Scopus subject areas
- Cell Biology
- Immunology
Cite this
Phospholipase A2 activity and calpactin I levels in rat lymphokine-activated killer cells : Correlation with the cytotoxic activity. / Cifone, M. Grazia; Cironi, Luisa; Roncaioli, Paola; Martinotti, Stefano; Toniato, Elena; Cilenti, Lucia; Botti, Dario; Solito, Egle; Parente, Luca; Santoni, Angela.
In: Cellular Immunology, Vol. 170, No. 2, 15.06.1996, p. 274-282.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Phospholipase A2 activity and calpactin I levels in rat lymphokine-activated killer cells
T2 - Correlation with the cytotoxic activity
AU - Cifone, M. Grazia
AU - Cironi, Luisa
AU - Roncaioli, Paola
AU - Martinotti, Stefano
AU - Toniato, Elena
AU - Cilenti, Lucia
AU - Botti, Dario
AU - Solito, Egle
AU - Parente, Luca
AU - Santoni, Angela
PY - 1996/6/15
Y1 - 1996/6/15
N2 - In the present paper we have shown evidence for a significant increase of type II sPLA2 activity in A-LAK cells. The A-LAX-mediated cytotoxicity against YAC-1 target cells was strongly inhibited by two inhibitors of sPLA2, p-BPB and mepacrine, suggesting the involvement of this enzyme in the lytic mechanism of A-LAK. On the other hand, stimuli such as A23187 ionophore and TPA, which were able to induce in control cells an increased AA release, failed to cause this effect in IL-2-treated cells, suggesting that PLA2 was not active in these cells. Thus, we analyzed the levels of calpactin I, which is considered to be involved in the down-regulation of PLA2 activity. HrIL-2 treatment led to an increased expression of calpactin I at both the RNA and the protein level. A substantial portion of calpactin I was associated with the external surface of A-LAK and was able to exert a strong inhibitory effect on a purified porcine pancreatic PLA2 activity in vitro. Our results suggest that the role of calpactin I could be relevant to regulate PLA2 activity, and to protect the effector cells against a possible toxic effect which this enzyme could exert if present at high levels.
AB - In the present paper we have shown evidence for a significant increase of type II sPLA2 activity in A-LAK cells. The A-LAX-mediated cytotoxicity against YAC-1 target cells was strongly inhibited by two inhibitors of sPLA2, p-BPB and mepacrine, suggesting the involvement of this enzyme in the lytic mechanism of A-LAK. On the other hand, stimuli such as A23187 ionophore and TPA, which were able to induce in control cells an increased AA release, failed to cause this effect in IL-2-treated cells, suggesting that PLA2 was not active in these cells. Thus, we analyzed the levels of calpactin I, which is considered to be involved in the down-regulation of PLA2 activity. HrIL-2 treatment led to an increased expression of calpactin I at both the RNA and the protein level. A substantial portion of calpactin I was associated with the external surface of A-LAK and was able to exert a strong inhibitory effect on a purified porcine pancreatic PLA2 activity in vitro. Our results suggest that the role of calpactin I could be relevant to regulate PLA2 activity, and to protect the effector cells against a possible toxic effect which this enzyme could exert if present at high levels.
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UR - http://www.scopus.com/inward/citedby.url?scp=0030585387&partnerID=8YFLogxK
U2 - 10.1006/cimm.1996.0161
DO - 10.1006/cimm.1996.0161
M3 - Article
VL - 170
SP - 274
EP - 282
JO - Cellular Immunology
JF - Cellular Immunology
SN - 0008-8749
IS - 2
ER -