Expression of neurotrophin receptors in normal and malignant B lymphocytes.
In order to define a cellular model suitable for studying, in vitro, the molecular properties and functions of neurotrophin receptors in human lymphocytes, TrkA, TrkB, TrkC and p75(NTR) expression was investigated in a panel of EBV immortalized lymphoblastoid (LCL) and Burkitt lymphoma-derived cell lines (BLs) compared to primary B lymphocytes by RT-PCR and flow cytometric analysis. Our data show that trkA and trkB are transcribed in most B cell lines of normal and malignant origin. For several of them, we also gained first evidence of trkC expression in B cells. All cell lines and primary B cells lack p75(NTR) expression. These data suggest that neurotrophin receptors expression in the B cell lines correlates to some extent with the phenotypic maturation stage and endogenous viral activity levels. Our data suggest that TrkA and TrkB, once activated, provide a partial rescue from apoptosis, whereas TrkC stimulates the progression through the cell cycle without affecting cell survival. Finally, the identification of a number of cell lines showing single expression of one of the Trk receptors has disclosed the availability of a cellular tool for further studies on their function, and mechanisms of signal transduction in the B cell moiety in the absence of p75(NTR).
D'Onofrio
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M
Department of Molecular Pathology, Istituto Neurologico Mediterraneo IRCCS Neuromed, Parco Tecnologico, Località Camerelle, 86077 Pozzilli, Isernia, Italy. nicoletti@neuromed.it
de Grazia
U
U
Morrone
S
S
Cuomo
L
L
Spinsanti
P
P
Frati
L
L
Gulino
A
A
Ragona
G
G
D000818:Animals; D017209:Apoptosis; D001402:B-Lymphocytes / Q000378:metabolism*; D001483:Base Sequence; D002051:Burkitt Lymphoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D002460:Cell Line; D017931:DNA Primers / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D066298:In Vitro Techniques; D051381:Rats; D020917:Receptor, trkA / Q000235:genetics; D020813:Receptor, trkB / Q000235:genetics; D020812:Receptor, trkC / Q000235:genetics; D017475:Receptors, Nerve Growth Factor / Q000235:genetics*; D015398:Signal Transduction; D014407:Tumor Cells, Cultured
D017931:DNA Primers; D017475:Receptors, Nerve Growth Factor; D020917:Receptor, trkA; D020813:Receptor, trkB; D020812:Receptor, trkC