title: TLR-9 and IL-15 Synergy Promotes the In Vitro Clonal Expansion of Chronic Lymphocytic Leukemia B Cells.
abstract: Clinical progression of B cell chronic lymphocytic leukemia (B-CLL) reflects the clone's Ag receptor (BCR) and involves stroma-dependent B-CLL growth within lymphoid tissue. Uniformly elevated expression of TLR-9, occasional MYD88 mutations, and BCR specificity for DNA or Ags physically linked to DNA together suggest that TLR-9 signaling is important in driving B-CLL growth in patients. Nevertheless, reports of apoptosis after B-CLL exposure to CpG oligodeoxynucleotide (ODN) raised questions about a central role for TLR-9. Because normal memory B cells proliferate vigorously to ODN+IL-15, a cytokine found in stromal cells of bone marrow, lymph nodes, and spleen, we examined whether this was true for B-CLL cells. Through a CFSE-based assay for quantitatively monitoring in vitro clonal proliferation/survival, we show that IL-15 precludes TLR-9-induced apoptosis and permits significant B-CLL clonal expansion regardless of the clone's BCR mutation status. A robust response to ODN+IL-15 was positively linked to presence of chromosomal anomalies (trisomy-12 or ataxia telangiectasia mutated anomaly + del13q14) and negatively linked to a very high proportion of CD38(+) cells within the blood-derived B-CLL population. Furthermore, a clone's intrinsic potential for in vitro growth correlated directly with doubling time in blood, in the case of B-CLL with Ig H chain V region-unmutated BCR and <30% CD38(+) cells in blood. Finally, in vitro high-proliferator status was statistically linked to diminished patient survival. These findings, together with immunohistochemical evidence of apoptotic cells and IL-15-producing cells proximal to B-CLL pseudofollicles in patient spleens, suggest that collaborative ODN and IL-15 signaling may promote in vivo B-CLL growth.
authors.affiliation: The Feinstein Institute for Medical Research, North Shore-Long Island Jewish Health System, Manhasset, NY 11030; Department of Molecular Medicine, Hofstra North Shore-LIJ School of Medicine, Hempstead, NY 11549; pmongini@nshs.edu.
authors.forename: Patricia K A
authors.initials: PK
authors.lastname: Mongini
authors.affiliation: The Feinstein Institute for Medical Research, North Shore-Long Island Jewish Health System, Manhasset, NY 11030;
authors.forename: Rashmi
authors.initials: R
authors.lastname: Gupta
authors.affiliation: The Feinstein Institute for Medical Research, North Shore-Long Island Jewish Health System, Manhasset, NY 11030;
authors.forename: Erin
authors.initials: E
authors.lastname: Boyle
authors.affiliation: The Feinstein Institute for Medical Research, North Shore-Long Island Jewish Health System, Manhasset, NY 11030;
authors.forename: Jennifer
authors.initials: J
authors.lastname: Nieto
authors.affiliation: The Feinstein Institute for Medical Research, North Shore-Long Island Jewish Health System, Manhasset, NY 11030;
authors.forename: Hyunjoo
authors.initials: H
authors.lastname: Lee
authors.affiliation: The Feinstein Institute for Medical Research, North Shore-Long Island Jewish Health System, Manhasset, NY 11030;
authors.forename: Joanna
authors.initials: J
authors.lastname: Stein
authors.affiliation: Department of Pathology, North Shore University Hospital-Long Island Jewish Medical Center, Manhasset, NY 11030;
authors.forename: Jela
authors.initials: J
authors.lastname: Bandovic
authors.affiliation: School of Cancer Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom;
authors.forename: Tatjana
authors.initials: T
authors.lastname: Stankovic
authors.affiliation: Department of Medicine, North Shore University Hospital-Long Island Jewish Medical Center, Manhasset, NY; and.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Barrientos
authors.affiliation: The Feinstein Institute for Medical Research, North Shore-Long Island Jewish Health System, Manhasset, NY 11030; Department of Medicine, North Shore University Hospital-Long Island Jewish Medical Center, Manhasset, NY; and Department of Medicine, Hofstra North Shore-LIJ School of Medicine, Hempstead, NY.
authors.forename: Jonathan E
authors.initials: JE
authors.lastname: Kolitz
authors.affiliation: The Feinstein Institute for Medical Research, North Shore-Long Island Jewish Health System, Manhasset, NY 11030; Department of Medicine, North Shore University Hospital-Long Island Jewish Medical Center, Manhasset, NY; and Department of Medicine, Hofstra North Shore-LIJ School of Medicine, Hempstead, NY.
authors.forename: Steven L
authors.initials: SL
authors.lastname: Allen
authors.affiliation: The Feinstein Institute for Medical Research, North Shore-Long Island Jewish Health System, Manhasset, NY 11030; Department of Medicine, North Shore University Hospital-Long Island Jewish Medical Center, Manhasset, NY; and Department of Medicine, Hofstra North Shore-LIJ School of Medicine, Hempstead, NY.
authors.forename: Kanti
authors.initials: K
authors.lastname: Rai
authors.affiliation: The Feinstein Institute for Medical Research, North Shore-Long Island Jewish Health System, Manhasset, NY 11030; Department of Molecular Medicine, Hofstra North Shore-LIJ School of Medicine, Hempstead, NY 11549;
authors.forename: Charles C
authors.initials: CC
authors.lastname: Chu
authors.affiliation: The Feinstein Institute for Medical Research, North Shore-Long Island Jewish Health System, Manhasset, NY 11030; Department of Molecular Medicine, Hofstra North Shore-LIJ School of Medicine, Hempstead, NY 11549; Department of Medicine, North Shore University Hospital-Long Island Jewish Medical Center, Manhasset, NY; and Department of Medicine, Hofstra North Shore-LIJ School of Medicine, Hempstead, NY.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Chiorazzi
mesh_terms: D051997:ADP-ribosyl Cyclase 1 / Q000378:metabolism; D000368:Aged; D000369:Aged, 80 and over; D017209:Apoptosis / Q000276:immunology; D064007:Ataxia Telangiectasia Mutated Proteins / Q000235:genetics; D001402:B-Lymphocytes / Q000276:immunology; D049109:Cell Proliferation / Q000235:genetics; D002478:Cells, Cultured; D002869:Chromosome Aberrations; D005260:Female; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D019409:Interleukin-15 / Q000276:immunology* / Q000494:pharmacology; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000235:genetics / Q000276:immunology* / Q000401:mortality; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism; D008875:Middle Aged; D053594:Myeloid Differentiation Factor 88 / Q000235:genetics; D009838:Oligodeoxyribonucleotides / Q000494:pharmacology*; D011947:Receptors, Antigen, B-Cell / Q000276:immunology; D015398:Signal Transduction / Q000276:immunology; D051217:Toll-Like Receptor 9 / Q000276:immunology*
chemical_list: C408982:CPG-oligonucleotide; C569274:IL15 protein, human; D007143:Immunoglobulin Heavy Chains; D019409:Interleukin-15; C507779:MYD88 protein, human; D008562:Membrane Glycoproteins; D053594:Myeloid Differentiation Factor 88; D009838:Oligodeoxyribonucleotides; D011947:Receptors, Antigen, B-Cell; C495371:TLR9 protein, human; D051217:Toll-Like Receptor 9; D064007:Ataxia Telangiectasia Mutated Proteins; C498154:CD38 protein, human; D051997:ADP-ribosyl Cyclase 1