TY - JOUR
T1 - Neurotensin - macrophage interaction
T2 - Specific binding and augmentation of phagocytosis
AU - Bar-Shavit, Z.
AU - Terry, S.
AU - Blumberg, S.
AU - Goldman, R.
PY - 1982/7
Y1 - 1982/7
N2 - Neurotensin (NT) was found to bind to thioglycollate-elicited mouse peritoneal macrophages and to modulate their phagocytic capability. A Scatchard analysis of the binding curve of [3H]NT suggests the presence of two subclasses of binding sites having a.-a KD of 0.9 nM (4800 sites per cell) and b.-a KD of 28 nM (33500 sites per cell). NT as well as two of its partial sequences, NT(8-13) and NT(6-13) competed with [3H]NT for its binding whereas NT(1-10) was rather ineffective. [3H]NT was also competitively displaced by tuftsin, substance P (SP) and by SP (1-4). The KI values estimated for all the above competitive inhibitors of [3H]NT binding (except for NT) suggest interaction with the relatively low affinity sites. NT exerts a biphasic effect on the phagocytic response of macrophages. At a concentration range of 10-14-10-9 M NT had a dose dependent augmenting effect on the phagocytic response (up to 2 fold), further increase in concentration (>10-9M) of NT resulted in a gradual decrease of the augmented response which disappears at 10-7 M NT. NT(8-13), NT(6-13) as well as NT(1-10) augment the phagocytic response of macrophages. However the maximal effect with these peptides was attained at about 10-7 M and stayed at the same level at concentrations up to 10-5 M. The phagocytosis augmenting dose-response curves of these peptides resembled that of tuftsin and SP, two unrelated peptides. It is suggested that NT-phagocyte interaction may be of relevance in the regulation of the functions of phagocytic cells.
AB - Neurotensin (NT) was found to bind to thioglycollate-elicited mouse peritoneal macrophages and to modulate their phagocytic capability. A Scatchard analysis of the binding curve of [3H]NT suggests the presence of two subclasses of binding sites having a.-a KD of 0.9 nM (4800 sites per cell) and b.-a KD of 28 nM (33500 sites per cell). NT as well as two of its partial sequences, NT(8-13) and NT(6-13) competed with [3H]NT for its binding whereas NT(1-10) was rather ineffective. [3H]NT was also competitively displaced by tuftsin, substance P (SP) and by SP (1-4). The KI values estimated for all the above competitive inhibitors of [3H]NT binding (except for NT) suggest interaction with the relatively low affinity sites. NT exerts a biphasic effect on the phagocytic response of macrophages. At a concentration range of 10-14-10-9 M NT had a dose dependent augmenting effect on the phagocytic response (up to 2 fold), further increase in concentration (>10-9M) of NT resulted in a gradual decrease of the augmented response which disappears at 10-7 M NT. NT(8-13), NT(6-13) as well as NT(1-10) augment the phagocytic response of macrophages. However the maximal effect with these peptides was attained at about 10-7 M and stayed at the same level at concentrations up to 10-5 M. The phagocytosis augmenting dose-response curves of these peptides resembled that of tuftsin and SP, two unrelated peptides. It is suggested that NT-phagocyte interaction may be of relevance in the regulation of the functions of phagocytic cells.
UR - http://www.scopus.com/inward/record.url?scp=0020324255&partnerID=8YFLogxK
U2 - 10.1016/0143-4179(82)90070-1
DO - 10.1016/0143-4179(82)90070-1
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AN - SCOPUS:0020324255
SN - 0143-4179
VL - 2
SP - 325
EP - 335
JO - Neuropeptides
JF - Neuropeptides
IS - 6
ER -