Acquisition of potential N-glycosylation sites in the immunoglobulin variable region by somatic mutation is a distinctive feature of follicular lymphoma

Blood ◽  
2002 ◽  
Vol 99 (7) ◽  
pp. 2562-2568 ◽  
Author(s):  
Delin Zhu ◽  
Helen McCarthy ◽  
Christian H. Ottensmeier ◽  
Peter Johnson ◽  
Terry J. Hamblin ◽  
...  

Most patients with follicular lymphoma (FL) have somatically mutated V genes with intraclonal variation, consistent with location in the germinal center site. Using our own and published sequences, we have investigated the frequency of potential N-glycosylation sites introduced into functional VH genes as a consequence of somatic mutation. FL cells were compared with normal memory B cells or plasma cells matched for similar levels of mutation. Strikingly, novel sites were detected in 55 of 70 (79%) patients with FL, compared to 7 of 75 (9%) in the normal B-cell population (P < .001). Diffuse large B-cell lymphoma (DLCL) showed an intermediate frequency (13 of 32 [41%] patients). Myeloma and the mutated subset of chronic lymphocytic leukemia showed frequencies similar to those of normal cells in 5 of 64 (8%) patients and 5 of 40 (13%) patients, respectively. In 3 of 3 random patients with FL, immunoglobulin was expressed as recombinant single-chain Fv inPichia pastoris, and glycosylation was demonstrated. These findings indicate that N-glycosylation of the variable region may be common in FL and in a subset of DLCL. Most novel sites are located in the complementarity-determining regions. VH sequences of nonfunctional VH genes contained few sites, arguing for positive selection in FL. One possibility is that the added carbohydrate in the variable region contributes to interaction with elements in the germinal center environment. This common feature of FL may be critical for tumor behavior.

Blood ◽  
1994 ◽  
Vol 83 (11) ◽  
pp. 3279-3288 ◽  
Author(s):  
RE Hawkins ◽  
D Zhu ◽  
M Ovecka ◽  
G Winter ◽  
TJ Hamblin ◽  
...  

Abstract Idiotypic determinants on neoplastic B cells could provide tumor antigens for vaccination of patients with B-cell tumors. Because this approach requires an individual vaccine for each patient, simple methods for obtaining idiotypic antigen are desirable. Using polymerase chain reaction (PCR) with family-based V-gene and J-region primers, the variable region genes of heavy and light chains (VH and VL) of Ig have been obtained from biopsy material from 13 patients with B-cell tumors. In each case, analysis of random clones derived from the PCR product showed repeated, clonally-related sequences, whereas normal lymphoid tissue generated no repeated sequences. In 3/3 cases, the repeated sequences were found to be the same as those in a tumor-derived hybridoma. Mutational patterns in the V-genes differed among the tumors, with follicular lymphoma tending to be more highly mutated. The individual VH and VL sequences have been assembled with a flexible linker sequence to encode single-chain Fv (scFv). The scFv sequences can be cloned into bacterial expression vectors to produce protein, or into vectors suitable for direct vaccination using naked DNA. In a model system, expressed scFv protein retained all idiotypic determinants defined by a panel of five anti-idiotypic monoclonal antibodies (MoAbs). Similarly, expressed scFv proteins from two patients were shown to react with anti-idiotypic antibodies. This approach allows production of potential vaccines from surgical biopsies within 2 to 3 weeks.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 606-606
Author(s):  
Christian H. Ottensmeier ◽  
Katy J. McCann ◽  
Peter Johnson ◽  
Freda K. Stevenoson

Abstract Immunogenetic analysis of B-cell malignancies can provide important information that relates to the cellular origin and clonal history of these lymphomas and give clues as to possible pathogenic mechanisms. In follicular lymphoma (FL), immunoglobulin variable region (V) genes are commonly somatically mutated and display intraclonal heterogeneity consistent with location in the germinal centre (GC). In this analysis of 44 cases of FL we find that, with minor exceptions, both the VH and VL gene usage reflects that of the normal B cell repertoire, indicative of a common antigenic drive and in support of a final transforming event in the GC. We have previously reported a high incidence of potential N-glycosylation sites in the VH genes of FL, which have been introduced by the process of somatic mutation. Here we have assessed both the VH and VL genes and find that sites are universally present and further demonstrate that they are available for functional glycosylation. The majority of sites are found in VH (81%) and are located predominantly within CDR2 and CDR3, with few sites present in the FRs. Sites are also evident in VL (45%) where they are focused mainly in CDR3 and CDR1. A minor subset (10%) has sites in VL only. In total, 26 different N-glycosylation motifs were observed, with NIS being the most commonly used. The natural motif in the V4–34 germline gene appears unimportant, and can be lost. Scrutiny of the somatic mutations giving rise to these motifs reveals that the acquisition of sites was predominantly (73%) achieved by a single amino acid (aa) replacement to Asn at position 1 of the motif, either with or without an additional, non-essential aa replacement at another position. Common ‘hotspots’ were observed within the CDR2 for the VH gene segments V3–23, V3–48, V3–07 and V3–15. It appears likely that the acquisition of N-glycosylation sites in the antigen-binding site during somatic mutation in the GC and the subsequent addition of oligosaccharides is important to the lifestyle of FL and may provide a critical second tumorigenic event. In turn, it may be possible to exploit this seemingly essential feature to develop novel therapeutic approaches.


Blood ◽  
2002 ◽  
Vol 100 (7) ◽  
pp. 2659-2661 ◽  
Author(s):  
Delin Zhu ◽  
Jennifer Orchard ◽  
David G. Oscier ◽  
Dennis H. Wright ◽  
Freda K. Stevenson

Tumors of the splenic marginal zone can present in spleen or blood. The maturational status of the neoplastic B cells from each site appears heterogeneous, with either unmutated or mutated variable-region heavy chain (VH) genes. To determine an influence of tissue location, we assessed matched blood and splenic tumor cells from 4 patients and found them identical. However, one patient with unmutated VH genes in blood and spleen developed a clonally related diffuse large B-cell lymphoma in the chest wall. Strikingly, this subclone had undergone significant somatic mutation, with clear intraclonal heterogeneity. To our knowledge, this is the first case of a B-cell tumor showing initiation of somatic mutation in vivo. The finding emphasizes that the tissue microenvironment can influence tumor cell behavior and possibly affect disease progression. Importantly, because several replacement mutations were located within or close to the complementarity-determining regions (CDRs), it raises the question of a role for antigen in driving tumor growth.


Blood ◽  
1994 ◽  
Vol 83 (11) ◽  
pp. 3279-3288 ◽  
Author(s):  
RE Hawkins ◽  
D Zhu ◽  
M Ovecka ◽  
G Winter ◽  
TJ Hamblin ◽  
...  

Idiotypic determinants on neoplastic B cells could provide tumor antigens for vaccination of patients with B-cell tumors. Because this approach requires an individual vaccine for each patient, simple methods for obtaining idiotypic antigen are desirable. Using polymerase chain reaction (PCR) with family-based V-gene and J-region primers, the variable region genes of heavy and light chains (VH and VL) of Ig have been obtained from biopsy material from 13 patients with B-cell tumors. In each case, analysis of random clones derived from the PCR product showed repeated, clonally-related sequences, whereas normal lymphoid tissue generated no repeated sequences. In 3/3 cases, the repeated sequences were found to be the same as those in a tumor-derived hybridoma. Mutational patterns in the V-genes differed among the tumors, with follicular lymphoma tending to be more highly mutated. The individual VH and VL sequences have been assembled with a flexible linker sequence to encode single-chain Fv (scFv). The scFv sequences can be cloned into bacterial expression vectors to produce protein, or into vectors suitable for direct vaccination using naked DNA. In a model system, expressed scFv protein retained all idiotypic determinants defined by a panel of five anti-idiotypic monoclonal antibodies (MoAbs). Similarly, expressed scFv proteins from two patients were shown to react with anti-idiotypic antibodies. This approach allows production of potential vaccines from surgical biopsies within 2 to 3 weeks.


Blood ◽  
1998 ◽  
Vol 91 (4) ◽  
pp. 1145-1151 ◽  
Author(s):  
Masanori Taniguchi ◽  
Kouji Oka ◽  
Atsunori Hiasa ◽  
Motoko Yamaguchi ◽  
Toshiyuki Ohno ◽  
...  

Abstract To clarify the cellular origin of de novo CD5+ diffuse large B-cell lymphoma (CD5+ DLBL), particularly in comparison with other CD5+ B-cell neoplasms such as chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL), we analyzed the nucleotide sequence of the Ig heavy chain variable region (IgVH) genes of de novo CD5+ DLBL cases. All 4 cases examined had extensive somatic mutations in contrast with CLL or MCL. The VH gene sequences of de novo CD5+ DLBL displayed 86.9% to 95.2% homology with the corresponding germlines, whereas those of simultaneously analyzed CLL and MCL displayed 97.6% to 100% homology. The VH family used was VH3 in 1 case, VH4 in 2 cases, and VH5 in 1 case. In 2 of 4 examined cases, the distribution of replacement and silent mutations over the complementarity determining region and framework region in the VH genes was compatible with the pattern resulting from the antigen selection. Clinically, CD5+DLBL frequently involved a variety of extranodal sites (12/13) and lymph node (11/13). Immunophenotypically, CD5+ DLBL scarcely expressed CD21 and CD23 (3/13 and 2/13, respectively). These findings indicate that de novo CD5+ DLBL cells are derived from a B-1 subset distinct from those of CLL or MCL.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4630-4630
Author(s):  
Marion Travert ◽  
Patricia Ame-Thomas ◽  
Thierry Fest ◽  
Céline Pangault ◽  
Gilbert Semana ◽  
...  

Abstract Follicular lymphoma are characterized by the rearrangement of the bcl-2 gene, present in more than 90% of patients. Over-expression of the bcl-2 protein resulting from this translocation is associated with the inability to eradicate the lymphoma, by inhibiting apoptosis. Despite the median survival ranges from 8 to 15 years, leading to the designation of indolent lymphoma, patients with advanced-stage follicular lymphoma are not cured with current therapeutic options. Numerous reports have shown that Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) can induce apoptosis in a wide variety of transformed cell lines of diverse lineage, but does not appear to kill normal cells, even though TRAIL mRNA is expressed at significant levels in most normal tissues. As cell death induced by TRAIL occurs almost exclusively in tumor cells, it suggests that this drug is safe to use as an antitumor therapy. We therefore investigated the efficiency of this cytokine to induce apoptosis in germinal center derived B cell lymphoma, despite bcl-2 over-expression. Our study was also designed to evaluate the role of CD40L, one of the main differentiation signal involved in B cell maturation during the germinal center reaction, on the regulation of TRAIL-induced apoptosis. This study was performed on three germinal center derived tumor cell lines (BL2, VAL and RL), and on normal and tumor primary cells obtained from human tonsils and lymph nodes. Our data show that normal B lymphocytes obtained from tonsil biopsies are resistant to TRAIL-mediated apoptosis, when B lymphoma cells issued from lymph node of numerous patients are significantly sensitive to the cytokine. When we treat these lymphoma cells with trimeric huCD40L, we partly rescue these cells from spontaneous apoptosis which naturally occurs after few days of culture, and reverse by 50% TRAIL-mediated apoptosis when cells were co-treated with huCD40L for 16 hours. Similar results were reproduced on some germinal center derived cell lines. BL2 was indeed found highly sensitive to TRAIL-induced apoptosis following a 24 hour exposure. On the opposite, VAL and RL were almost insensitive. We have demonstrate that apoptosis is exclusively mediated by TRAIL-R1 in BL2. Analysis of signalling pathways revealed that the protection to TRAIL-induced apoptosis by CD40L is due to some specific anti-apoptotic molecules that will be described. Genes encoding these molecules are targets of the NFκB signalling pathway activated by CD40L. Our results suggest that activation of NFκB and induction of anti-apoptotic molecules by CD40L play an important role in the protection of germinal center derived B cell lymphomas against apoptosis. Then, NFκB inhibitors may be wise to use in clinical trials in conjunction with TRAIL against follicular lymphomas.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1589-1589 ◽  
Author(s):  
Miguel Alcoceba ◽  
Elena Sebastián ◽  
Ana Balanzategui ◽  
Luis Marín ◽  
Santiago Montes-Moreno ◽  
...  

Abstract Abstract 1589 Introduction: Acquired potentially N-glycosylation sites are produced by somatic hypermutation (SHM) in the immunoglobulin (Ig) variable region. This phenomenon is produced in ∼9% of normal B-cells and seems to be related to certain B-cell lymphoproliferative disorders (B-LPDs) such as follicular lymphoma (FL, 79%), endemic Burkitt lymphoma (BL, 82%) and diffuse large B-cell lymphoma (DLBCL, 41%). These data suggest that new potential N-glycosylation sites could be related to germinal center B (GCB)-LPDs. By contrast, in other B-LPDs, such as chronic lymphocytic leukemia (CLL), mantle cell lymphoma (MCL), MALT lymphoma, Waldenström macroglobulinemia (WM) or multiple myeloma (MM), these modifications have not been analyzed in deep. Aims: To evaluate the acquisition of potential N-glycosylation sites in B-LPDs, including immunohystochemical DLBCL subtypes (GCB and non-GCB) and specific non-GCB-LPDs, such as hairy cell leukemia (HCL), splenic marginal-zone lymphoma (SMZL), CLL, MCL, ocular extranodal marginal zone lymphoma (OAEMZL), MM and WM. Patients: A total of 953 sequences (203 from our group and 750 previously published sequences) of B-LPDs were included. Diagnosis distribution was as follows: DLBCL (n=235), MCL (n=235), CLL (n=166), MM (n=96), OAEMZL (n=82), SMZL (n=68), WM (n=38) and HCL (n=33). Methods: Acquired N-glycosylation sites were counted according to the sequence Asn-X-Ser/Thr, where X could be any amino acid except Pro. Natural motifs in germline sequences of IGHV1–08, IGHV4–34 e IGHV-5a were not considered. Fisher test was used to perform comparisons between groups. To distinguish DLBCL biological subtypes (GCB and non-GCB DLBCL), Hans' algorithm was used. Results: A total of 83 out of the 235 DLBCL cases acquired at least a new N-glycosylation site, a higher value than in normal B-cells (35% vs. 9%, p<0.0001). Higher incidence of these motifs in the group of GCB as compared to non-GCB DLBCL were observed (52% vs. 20%, p<0.0001). Those cases diagnosed of HCL, CLL, MCL, MM, WM, OAEMZL and SMZL presented a reduced number of new N-glycosylation sites, showing similar values than normal B-cells (range 3–18%, p=ns). Conclusions: We described for the first time the pattern of N-glycosylation in HCL, SMZL, OAEMZL and in the immunohystochemical DLBCL subtypes, where the GCB-DLBCL showed a higher number of new N-glycosylation sites with respect to non-GCB DLBCL and other non-GCB-LPDs. The presence of novel N-glycosylation sites in FL, BL and in GCB-DLBCL strongly suggests that these motifs are characteristic of the germinal center B-LPDs. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2000 ◽  
Vol 96 (7) ◽  
pp. 2550-2556
Author(s):  
Christian H. Ottensmeier ◽  
Freda K. Stevenson

Primary diffuse large B-cell lymphomas (DLBCLs) are aggressive tumors accounting for approximately 40% of B-cell malignancies. The immunoglobulin (Ig) variable region genes have undergone rearrangement and are commonly somatically mutated. The majority show intraclonal variation which indicates that somatic mutation has continued after transformation. Typically, cells of DLBCLs express Ig of a single isotype, but there may be accompanying cells that express alternative isotypes. To probe the status of the isotype switch process in DLBCL, 4 cases of tumor-derived constant region transcripts of all isotypes were investigated. Following the identification of the VDJ sequences, the presence of the major isotype expected from immunohistochemical analysis was confirmed at the RNA level. Another 3-4 alternative isotypes were revealed in all cases, some of which could also be detected by immunohistochemistry. All cases were somatically mutated with an intraclonal variation. In 2 cases there were clearly distinct patterns of somatic mutation between isotypes, which was consistent with independent evolution of the tumor subpopulations. There was apparent clustering of mutational patterns into either an IgMD/IgG3/IgA set or an IgG1/IgA set, indicating that the switch to IgA can occur by different routes. Alternative isotype expression is evident in DLBCL at both the RNA and protein levels. The pattern of mutation indicates that switching is occurring in subpopulations of the tumor after malignant transformation. The findings support the concept that isotype switch events may be a feature of DLBCL.


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