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High Throughput Sequencing Analysis of the Immunoglobulin Heavy Chain Gene from Flow-Sorted B Cell Sub-Populations Define the Dynamics of Follicular Lymphoma Clonal Evolution.

Carlotti E, Wrench D, Rosignoli G, Marzec J, Sangaralingam A, Hazanov L, Michaeli M, Hallam S, Chaplin T, Iqbal S, Calaminici M, Young B, Mehr R, Campbell P, Fitzgibbon J, Gribben JG - PLoS ONE (2015)

Bottom Line: The analysis of the pattern of somatic hypermutation of the immunoglobulin gene (Ig) is traditionally used for tracking the physiological clonal evolution of B cells within the germinal center and allows to discriminate those cells that have just entered the germinal center and display features of ancestor cells from those B cells that keep re-circulating across different lymphoid organs.By using a lineage trees analysis we observed in all our FL and t-FL cases that the oligoclonal FL population was trapped in a narrow intermediate stage of maturation that maintains the capacity to undergo SHM, but was unable to further differentiate.The presence of such a complex architecture highlights challenges currently encountered in finding a cure for this disease.

View Article: PubMed Central - PubMed

Affiliation: Centre for Haemato-Oncology, Barts Cancer Institute - a CR-UK Centre Of Excellence, Queen Mary University of London, London, United Kingdom.

ABSTRACT
Understanding the dynamics of evolution of Follicular Lymphoma (FL) clones during disease progression is important for monitoring and targeting this tumor effectively. Genetic profiling of serial FL biopsies and examples of FL transmission following bone marrow transplant suggest that this disease may evolve by divergent evolution from a common ancestor cell. However where this ancestor cell resides and how it evolves is still unclear. The analysis of the pattern of somatic hypermutation of the immunoglobulin gene (Ig) is traditionally used for tracking the physiological clonal evolution of B cells within the germinal center and allows to discriminate those cells that have just entered the germinal center and display features of ancestor cells from those B cells that keep re-circulating across different lymphoid organs. Here we investigated the pattern of somatic hypermutation of the heavy chain of the immunoglobulin gene (IgH-VH) in 4 flow-sorted B cells subpopulations belonging to different stages of differentiation, from sequential lymph node biopsies of cases displaying diverse patterns of evolution, using the GS-FLX Titanium sequencing platform. We observed an unexpectedly high level of clonality, with hundreds of distinct tumor subclones in the different subpopulations from the same sample, the majority detected at a frequency <10-2. By using a lineage trees analysis we observed in all our FL and t-FL cases that the oligoclonal FL population was trapped in a narrow intermediate stage of maturation that maintains the capacity to undergo SHM, but was unable to further differentiate. The presence of such a complex architecture highlights challenges currently encountered in finding a cure for this disease.

No MeSH data available.


Related in: MedlinePlus

Merged Lineage Trees showing the dynamics of evolution of the sub-clones.(A) Merged lineage trees generated from the 2 biopsies R1655 FL1 and R3878 FL2 from pt2. G.L. means germline; the dark grey circles represent the CB clones, the medium grey circles the CC, the light grey circles the clones shared (S) among 2 or more populations and the black circles those from the not sorted (NS) whole biopsy. (B) Merged lineage trees obtained from the combination of the CB and CC libraries from the samples R0012 t-FL and R2005 FL2 from pt1. The dark grey circles represent the CB subclones, the medium grey circles the CC and the light grey circles the clones shared (S) by CB and CC. The white circles represent subclones not detected with the 454 sequencing. Squares highlight the MC.
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pone.0134833.g004: Merged Lineage Trees showing the dynamics of evolution of the sub-clones.(A) Merged lineage trees generated from the 2 biopsies R1655 FL1 and R3878 FL2 from pt2. G.L. means germline; the dark grey circles represent the CB clones, the medium grey circles the CC, the light grey circles the clones shared (S) among 2 or more populations and the black circles those from the not sorted (NS) whole biopsy. (B) Merged lineage trees obtained from the combination of the CB and CC libraries from the samples R0012 t-FL and R2005 FL2 from pt1. The dark grey circles represent the CB subclones, the medium grey circles the CC and the light grey circles the clones shared (S) by CB and CC. The white circles represent subclones not detected with the 454 sequencing. Squares highlight the MC.

Mentions: To understand the dynamics associated with the maturation of lymphoma cells in secondary lymphoid organs we reconstructed lineage trees from sequence data obtained from individual and from combined libraries; these latter trees, denoted merged trees, were generated using reads detected in more than one sub-population and in the whole tumor sample (Fig 4A and 4B and S5A–S5D Fig).


High Throughput Sequencing Analysis of the Immunoglobulin Heavy Chain Gene from Flow-Sorted B Cell Sub-Populations Define the Dynamics of Follicular Lymphoma Clonal Evolution.

Carlotti E, Wrench D, Rosignoli G, Marzec J, Sangaralingam A, Hazanov L, Michaeli M, Hallam S, Chaplin T, Iqbal S, Calaminici M, Young B, Mehr R, Campbell P, Fitzgibbon J, Gribben JG - PLoS ONE (2015)

Merged Lineage Trees showing the dynamics of evolution of the sub-clones.(A) Merged lineage trees generated from the 2 biopsies R1655 FL1 and R3878 FL2 from pt2. G.L. means germline; the dark grey circles represent the CB clones, the medium grey circles the CC, the light grey circles the clones shared (S) among 2 or more populations and the black circles those from the not sorted (NS) whole biopsy. (B) Merged lineage trees obtained from the combination of the CB and CC libraries from the samples R0012 t-FL and R2005 FL2 from pt1. The dark grey circles represent the CB subclones, the medium grey circles the CC and the light grey circles the clones shared (S) by CB and CC. The white circles represent subclones not detected with the 454 sequencing. Squares highlight the MC.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4556522&req=5

pone.0134833.g004: Merged Lineage Trees showing the dynamics of evolution of the sub-clones.(A) Merged lineage trees generated from the 2 biopsies R1655 FL1 and R3878 FL2 from pt2. G.L. means germline; the dark grey circles represent the CB clones, the medium grey circles the CC, the light grey circles the clones shared (S) among 2 or more populations and the black circles those from the not sorted (NS) whole biopsy. (B) Merged lineage trees obtained from the combination of the CB and CC libraries from the samples R0012 t-FL and R2005 FL2 from pt1. The dark grey circles represent the CB subclones, the medium grey circles the CC and the light grey circles the clones shared (S) by CB and CC. The white circles represent subclones not detected with the 454 sequencing. Squares highlight the MC.
Mentions: To understand the dynamics associated with the maturation of lymphoma cells in secondary lymphoid organs we reconstructed lineage trees from sequence data obtained from individual and from combined libraries; these latter trees, denoted merged trees, were generated using reads detected in more than one sub-population and in the whole tumor sample (Fig 4A and 4B and S5A–S5D Fig).

Bottom Line: The analysis of the pattern of somatic hypermutation of the immunoglobulin gene (Ig) is traditionally used for tracking the physiological clonal evolution of B cells within the germinal center and allows to discriminate those cells that have just entered the germinal center and display features of ancestor cells from those B cells that keep re-circulating across different lymphoid organs.By using a lineage trees analysis we observed in all our FL and t-FL cases that the oligoclonal FL population was trapped in a narrow intermediate stage of maturation that maintains the capacity to undergo SHM, but was unable to further differentiate.The presence of such a complex architecture highlights challenges currently encountered in finding a cure for this disease.

View Article: PubMed Central - PubMed

Affiliation: Centre for Haemato-Oncology, Barts Cancer Institute - a CR-UK Centre Of Excellence, Queen Mary University of London, London, United Kingdom.

ABSTRACT
Understanding the dynamics of evolution of Follicular Lymphoma (FL) clones during disease progression is important for monitoring and targeting this tumor effectively. Genetic profiling of serial FL biopsies and examples of FL transmission following bone marrow transplant suggest that this disease may evolve by divergent evolution from a common ancestor cell. However where this ancestor cell resides and how it evolves is still unclear. The analysis of the pattern of somatic hypermutation of the immunoglobulin gene (Ig) is traditionally used for tracking the physiological clonal evolution of B cells within the germinal center and allows to discriminate those cells that have just entered the germinal center and display features of ancestor cells from those B cells that keep re-circulating across different lymphoid organs. Here we investigated the pattern of somatic hypermutation of the heavy chain of the immunoglobulin gene (IgH-VH) in 4 flow-sorted B cells subpopulations belonging to different stages of differentiation, from sequential lymph node biopsies of cases displaying diverse patterns of evolution, using the GS-FLX Titanium sequencing platform. We observed an unexpectedly high level of clonality, with hundreds of distinct tumor subclones in the different subpopulations from the same sample, the majority detected at a frequency <10-2. By using a lineage trees analysis we observed in all our FL and t-FL cases that the oligoclonal FL population was trapped in a narrow intermediate stage of maturation that maintains the capacity to undergo SHM, but was unable to further differentiate. The presence of such a complex architecture highlights challenges currently encountered in finding a cure for this disease.

No MeSH data available.


Related in: MedlinePlus