scholarly journals Proper Read Filtering Method to Adequately Analyze Whole-Transcriptome Sequencing and RNA Based Immune Repertoire Sequencing Data for Tumor Milieu Research

Cancers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3693
Author(s):  
Sungyoung Lee ◽  
Seulki Song ◽  
Sung-Soo Yoon ◽  
Youngil Koh ◽  
Hongseok Yun

Analysis of the T-cell receptor (TCR) repertoire is essential to characterize the extensive collections of T-cell populations with recognizing antigens in cancer research, and whole transcriptome sequencing (WTS) and immune repertoire sequencing (IR-seq) are commonly used for this measure. To date, no standard read filtering method for IR measurement has been presented. We assessed the diversity of the TCR repertoire results from the paired WTS and IR-seq data of 31 multiple myeloma (MM) patients. To invent an adequate read filtering strategy for IR analysis, we conducted comparisons with WTS results. First, our analyses for determining an optimal threshold for selecting clonotypes showed that the clonotypes supported by a single read largely affected the shared clonotypes and manifested distinct patterns of mapping qualities, unlike clonotypes with multiple reads. Second, although IR-seq could reflect a wider TCR region with a higher capture rate than WTS, an adequate comparison with the removal of unwanted bias from potential sequencing errors was possible only after applying our read filtering strategy. As a result, we suggest that TCR repertoire analysis be carried out through IR-seq to produce reliable and accurate results, along with the removal of single-read clonotypes, to conduct immune research in cancer using high-throughput sequencing.

2018 ◽  
Author(s):  
Aishwarya Iyer ◽  
Jordan Patterson ◽  
Thomas Salopek ◽  
Gane Ka-Shu Wong ◽  
Robert Gniadecki

AbstractMycosis fungoides (MF), the most common type of cutaneous T-cell lymphoma, is believed to represent a clonal expansion of a transformed skin resident memory T-cell. T-cell receptor (TCR) clonality (i.e. identical sequences of rearranged TCRα, β and γ), the key premise of this hypothesis, has been difficult to document conclusively because malignant cells are not readily distinguishable from the tumor infiltrating, reactive lymphocytes, which contribute to the TCR clonotypic repertoire of MF. Here we have successfully adopted the technique of targeted whole exome and whole transcriptome sequencing (WES/WTS) to identify the repertoire of rearranged TCR genes in tumor enriched samples from patients with MF. Although most of the investigated biopsies of MF had the expected monoclonal rearrangements of TCRγ of the frequency corresponding to the frequency of tumor cells, in half of the samples we detected multiple (up to seven) TCRα and -β clonotypes by WES and WTS. Our findings are compatible with the model in which the initial malignant transformation in MF does not occur in mature, memory T-cells but rather at the level of T-lymphocyte progenitor after TCRγ rearrangement but before TCRβ or TCRα rearrangements. The WES/WTS method is potentially applicable to other types of T-cell lymphomas and enables comprehensive characterization of the TCR repertoire and mutational landscape in these malignancies.


2019 ◽  
Vol 3 (7) ◽  
pp. 1175-1184 ◽  
Author(s):  
Aishwarya Iyer ◽  
Dylan Hennessey ◽  
Sandra O’Keefe ◽  
Jordan Patterson ◽  
Weiwei Wang ◽  
...  

Abstract Mycosis fungoides (MF), the most common type of cutaneous T-cell lymphoma, is believed to represent a clonal expansion of a transformed skin-resident memory T cell. T-cell receptor (TCR) clonality (ie, identical sequences of rearranged TCRα, TCRβ, and TCRγ), the key premise of this hypothesis, has been difficult to document conclusively because malignant cells are not readily distinguishable from the tumor-infiltrating reactive lymphocytes that contribute to the TCR clonotypic repertoire of MF. Here, we have successfully adopted targeted whole-exome sequencing (WES) to identify the repertoire of rearranged TCR genes in tumor-enriched samples from patients with MF. Although some of the investigated MF biopsies had the expected frequency of monoclonal rearrangements of TCRγ corresponding to that of tumor cells, the majority of the samples presented multiple TCRγ, TCRα, and TCRβ clonotypes by WES. Our findings are compatible with the model in which the initial malignant transformation in MF does not occur in mature memory T cells but rather at the level of T-lymphocyte progenitors before TCRβ or TCRα rearrangements. We have also shown that WES can be combined with whole-transcriptome sequencing in the same sample, which enables comprehensive characterization of the TCR repertoire in relation to tumor content. WES/whole-transcriptome sequencing might be applicable to other types of T-cell lymphomas to determine clonal dominance and clonotypic heterogeneity in these malignancies.


2021 ◽  
pp. 106689692110313
Author(s):  
Alexander M. Strait ◽  
Julia A. Bridge ◽  
Anthony J. Iafrate ◽  
Marilyn M. Li ◽  
Feng Xu ◽  
...  

Myofibroblastoma is a rare, benign stromal tumor with a diverse morphologic spectrum. Mammary-type myofibroblastoma (MTMF) is the extra-mammary counterpart of this neoplasm and its occurrence throughout the body has become increasingly recognized. Similar morphologic variations of MTMF have now been described which mirror those seen in the breast. We describe a case of intra-abdominal MTMF composed of short fascicles of eosinophilic spindle cells admixed with mature adipose tissue. The spindle cells stained diffusely positive for CD34, desmin, smooth muscle actin, and h-caldesmon by immunohistochemistry. Concurrent loss of RB1 (13q14) and 13q34 loci were confirmed by fluorescence in situ hybridization whereas anchored multiplex PCR and whole transcriptome sequencing did not reveal any pathognomonic fusions suggesting an alternative diagnosis. To the best of our knowledge this is the first documented case of leiomyomatous variant of MTMF.


2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Gary Kwok Cheong Lee ◽  
Dorothee Bienzle ◽  
Stefan Matthias Keller ◽  
Mei-Hua Hwang ◽  
Nikos Darzentas ◽  
...  

Abstract Background Lymphocytic neoplasms with frequent reactive lymphocytes are uncommonly reported in dogs, and can pose a diagnostic challenge. Different diagnostic modalities such as cytology, flow cytometry, histopathology, immunohistochemistry, and clonality testing, are sometimes required for a diagnosis. This report illustrates the value of using a multi-modal diagnostic approach to decipher a complex lymphocytic tumor, and introduces immune repertoire sequencing as a diagnostic adjunct. Case presentation A 10-month-old Great Dane was referred for marked ascites. Cytologic analysis of abdominal fluid and hepatic aspirates revealed a mixed lymphocyte population including numerous large lymphocytes, yielding a diagnosis of lymphoma. Flow cytometrically, abdominal fluid lymphocytes were highly positive for CD4, CD5, CD18, CD45, and MHC II, consistent with T cell lymphoma. Due to a rapidly deteriorating clinical condition, the dog was euthanized. Post mortem histologic evaluation showed effacement of the liver by aggregates of B cells surrounded by T cells, suggestive of hepatic T cell-rich large B cell lymphoma. Immune repertoire sequencing confirmed the presence of clonal B cells in the liver but not the abdominal fluid, whereas reactive T cells with shared, polyclonal immune repertoires were found in both locations. Conclusions T cell-rich large B cell lymphoma is a rare neoplasm in dogs that may be challenging to diagnose and classify due to mixed lymphocyte populations. In this case, the results of histopathology, immunohistochemistry and immune repertoire sequencing were most consistent with a hepatic B cell neoplasm and reactive T cells exfoliating into the abdominal fluid. Immune repertoire sequencing was helpful in delineating neoplastic from reactive lymphocytes and characterizing repertoire overlap in both compartments. The potential pitfalls of equating atypical cytomorphology and monotypic marker expression in neoplasia are highlighted.


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 4035-4035
Author(s):  
Deqiang Wang ◽  
Xiaofeng Chen ◽  
Yaping Xu ◽  
Yuange He ◽  
Lifeng Li ◽  
...  

4035 Background: Gastric adenocarcinoma (GAC) is with a complex microenvironment of tumor cells. A better understanding of the immune landscape of GACs may lead to the improved treatment strategies with ICIs. Methods: To determine whether the molecular characteristics can serve in prognostic stratification of GACs, tumor tissue and blood samples were collected from 231 GAC patients. The median follow-up time was 34 months. The TCR profile was determined by TCR-β CDR3 sequencing while mutation and gene expression profiles were determined by whole exon and whole transcriptome sequencing, respectively. Tumour-infiltrating immune cells were characterized using immunofluorescence (IF) staining. Results: The results showed the OS of patients with high levels of TCR clonality (TCR clonal expansion) was significantly improved compared with patients with low levels (HR = 1.80 and 2.22, p = 0.022 and 0.008, respectively) in the whole group and in the subgroup of patients with stages IB to III disease. Furthermore, low local clonality was an independent risk factor for OS (adjusted-HR = 1.68 and 1.95, p = 0.049 and 0.029, respectively). Thus, TCR clonal expansion in tumour tissue had a strong prognostic value for GAC patients, independent of clinicopathological factors. Based on whole exon and whole transcriptome sequencing, RNF43/FBXW7/ARID2 mutations and local TCR clonality jointly impacted prognosis (p < 0.001), and functional changes in corresponding Wnt pathway/Notch pathway/SWI/SNF complex characterized a GAC subset with enhanced tumour immunogenicity and TCR clonal expansion. TCR CDR3 sequence similarity comparisons yielded clusters of TCR clones of likely similar functions. The most expansive TCR clusters negatively correlated with the percentage of subclonal mutations (Pearson r = -0.8183, p < 0.001), indicating that tumors with less genomic heterogeneity might induce a greater immune response. By IF staining and mutual correlation analysis, only M1 macrophages showed a significant positive correlation with local TCR clonality for epithelia, stroma, and total cell counts. Tumors were categorized according to the density of M1 macrophages, M1 macrophage infiltrated subtype was associated with favorable OS (p = 0.040 and 0.043) and its combination with the local TCR clonality improved prognosis stratification (p < 0.001). Finally, the scoring by local TCR clonality, RNF43/FBXW7/ARID2 mutations and M1 infiltration determined the best prognosis (p < 0.001). Conclusions: TCR profiles were associated with genomic alterations and may serve as a prognostic biomarker for GACs. A multi-omic model including TCR profiles might produce an improved stratification for treatments and outcomes.


Sign in / Sign up

Export Citation Format

Share Document