TY - JOUR
T1 - Signals delivered via the QA-2 molecule can synergize with limiting anti-CD3-induced signals to cause t lymphocyte activation
AU - Hahn, Amy B.
AU - Tian, Huan
AU - Wiegand, Gordon
AU - Soloski, Mark J.
N1 - Funding Information:
ACKNOWLEDGEMENTS The authors would like to thank Ms. Lu Qin for her technical assistance, Mr. Kjell Ramsland for maintaining the mouse colony and Ms. Angela James for her help in manuscript preparation. This work was supported by Research Grant IMS-563 from the American Cancer Society and by Training Grant T32-A107247 from the National Institute of Health, Bethesda, Md.
PY - 1992
Y1 - 1992
N2 - Qa-2 is a glycolipid anchored, MHC encoded class I molecule expressed at high levels on all murine peripheral T lymphocytes. Anti-Qa-2 antibodies have previously been found to stimulate T cells to proliferate in the presence of crosslinking antibody and PMA. We have examined the effect of anti-Qa-2 antibodies on T cells stimulated with a suboptimal concentration of immobilized anti-CD3. When anti-Qa-2 antibodies were co-immobilized with limiting anti-CD3, in the absence of PMA, a clear augmentation of T cell proliferation was seen. Interestingly, the co-stimulatory anti-Qa-2 antibodies could be directed against epitopes mapped to either the α3 or the α1/α2 Qa-2 domains. As was the case with activation induced by soluble/crosslinked anti-Qa-2 antibodies plus PMA, CD8+ T cells were less able to be costimulated with anti-Qa-2 antibodies than CD4+ cells. Surprisingly, Ca2+ mobilization was only seen when two anti-Qa-2 antibodies reactive to separate structural domains were co-crosslinked on the surface of Indo-1 loaded T cells with a suboptimal concentration of anti-CD3. Collectively these results raise questions regarding the mechanism of Qa-2 mediated signaling and its potential role in T cell activation.
AB - Qa-2 is a glycolipid anchored, MHC encoded class I molecule expressed at high levels on all murine peripheral T lymphocytes. Anti-Qa-2 antibodies have previously been found to stimulate T cells to proliferate in the presence of crosslinking antibody and PMA. We have examined the effect of anti-Qa-2 antibodies on T cells stimulated with a suboptimal concentration of immobilized anti-CD3. When anti-Qa-2 antibodies were co-immobilized with limiting anti-CD3, in the absence of PMA, a clear augmentation of T cell proliferation was seen. Interestingly, the co-stimulatory anti-Qa-2 antibodies could be directed against epitopes mapped to either the α3 or the α1/α2 Qa-2 domains. As was the case with activation induced by soluble/crosslinked anti-Qa-2 antibodies plus PMA, CD8+ T cells were less able to be costimulated with anti-Qa-2 antibodies than CD4+ cells. Surprisingly, Ca2+ mobilization was only seen when two anti-Qa-2 antibodies reactive to separate structural domains were co-crosslinked on the surface of Indo-1 loaded T cells with a suboptimal concentration of anti-CD3. Collectively these results raise questions regarding the mechanism of Qa-2 mediated signaling and its potential role in T cell activation.
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U2 - 10.3109/08820139209072259
DO - 10.3109/08820139209072259
M3 - Article
C2 - 1350269
AN - SCOPUS:0026636534
SN - 0882-0139
VL - 21
SP - 203
EP - 217
JO - Immunological Investigations
JF - Immunological Investigations
IS - 3
ER -