Expression of inhibitory receptor ILT3 on neoplastic B cells is associated with lymphoid tissue involvement in chronic lymphocytic leukemia.
T cell responses against leukemia-associated antigens have been reported in chronic lymphocytic leukemia (CLL). However, the relentless accumulation of CLL B cells in some patients indicates that anti-tumor immune responses are inefficient. Inhibitory receptors from the Ig-like transcript (ILT) family, such as ILT3 and ILT4, are crucial to the tolerogenic activity of antigen presenting cells. In this study, we examined the expression of ILT3 on CD5+ B cells obtained from 47 patients with CLL. Using flow cytometry and RT-PCR, we found that B CLL cells from 23 of 47 patients expressed ILT3 protein and mature ILT3 mRNA. ILT3 protein and mRNA were not found in normal B cells obtained from donors without CLL. Expression of ILT4 in normal and B CLL cells showed a pattern similar to ILT3. The frequency of ILT3 positive CLL B cells was higher in patients with lymphoid tissue involvement, suggesting that ILT3 may have prognostic value in CLL. Our findings indicate that expression of ILT3 and ILT4 on CLL B cells represents a phenotypic abnormality that may play a role in tolerization of tumor-specific T cells.
Colovai
Adriana I
AI
Department of Pathology, Columbia University, New York, NY 10032, USA. aic4@columbia.edu
Tsao
Lawrence
L
Wang
Su
S
Lin
Hana
H
Wang
Chuan
C
Seki
Tetsunori
T
Fisher
Julie G
JG
Menes
Manuel
M
Bhagat
Govind
G
Alobeid
Bachir
B
Suciu-Foca
Nicole
N
D000368:Aged; D001402:B-Lymphocytes / Q000276:immunology* / Q000473:pathology; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000096:biosynthesis*; D018956:CD5 Antigens / Q000276:immunology; D002908:Chronic Disease; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping / Q000379:methods; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000276:immunology* / Q000473:pathology; D008221:Lymphoid Tissue / Q000276:immunology* / Q000473:pathology; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics; D011237:Predictive Value of Tests; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D011971:Receptors, Immunologic / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
D015415:Biomarkers; D014408:Biomarkers, Tumor; D018956:CD5 Antigens; C491341:LILRB2 protein, human; C107907:LILRB4 protein, human; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic