Fc receptor-like 1-5 molecules are similarly expressed in progressive and indolent clinical subtypes of B-cell chronic lymphocytic leukemia.
Fc receptor-like (FCRL) 1-5 molecules are exclusively expressed in B-cells and have recently been considered as potential targets for immunotherapy of B-cell malignancies. In this study, the expression pattern of FCRL1-5 molecules was investigated in Iranian patients with B-cell chronic lymphocytic leukemia (B-CLL). Our RT-PCR results have demonstrated that all FCRL molecules, except FCRL4, were expressed in the vast majority of the patients with B-CLL. However, comparison of the relative mRNA expression levels of FCRL between B-CLL (n = 86) and elderly normal subjects (n = 10) revealed significantly lower expression levels of FCRL1 (p < 0.0001), FCRL3 (p = 0.01) and FCRL4 (p = 0.002), but not FCRL2 or FCRL5, in cases with B-CLL. No significant differences were observed between the indolent and progressive subtypes of patients with B-CLL. Comparison between the mutated and unmutated subtypes revealed a significantly higher expression level of FCRL3 (p = 0.017) in patients with mutated CLL. Surface and intracytoplasmic expression of FCRL1, 2, 4 and 5 in leukemic cells of 12 patients by flow cytometry revealed similar results to those obtained by RT-PCR with a few exceptions. Thus, while FCRL4 was expressed in only 2 samples at intracytoplasmic level, FCRL1 and 2 were expressed in the majority of samples, both at surface and intracytoplasm. FCRL5 protein was also detected in 10 samples, but surface expression was confirmed in only 2. Analysis of B-cells from 5 normal subjects by flow cytometry revealed higher expression levels of FCRL molecules compared to CLL. Our results indicate differential expression of FCRL molecules in B-CLL and suggest the potential implication of FCRL1 and 2 for immunotherapeutic interventions.
Kazemi
Tohid
T
Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
Asgarian-Omran
Hossein
H
Hojjat-Farsangi
Mohammad
M
Shabani
Mahdi
M
Memarian
Ali
A
Sharifian
Ramazan Ali
RA
Razavi
Seyed Mohsen
SM
Jeddi-Tehrani
Mahmood
M
Rabbani
Hodjatallah
H
Shokri
Fazel
F
D003593:Cytoplasm / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000145:classification / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D011956:Receptors, Cell Surface / Q000235:genetics*; D011961:Receptors, Fc / Q000235:genetics*; D011971:Receptors, Immunologic / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction
C422179:FCRL2 protein, human; C457775:FCRL3 protein, human; C423544:FCRL4 protein, human; C432367:FCRL5 protein, human; C452186:FCRLA protein, human; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D011961:Receptors, Fc; D011971:Receptors, Immunologic