T-cell Receptor Beta-chain Gene Rearrangement Research Articles

High-Throughput T Cell Receptor (TR) Repertoire Analysis of Virus-Specific T Cells: Implications for T Cell Immunotherapy and Viral Infection Risk Stratification

▪Viral infections, mainly by cytomegalovirus (CMV), Epstein Barr virus (EBV) and polyomavirus type I (BKV), are major causes of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). As effective immune responses against human viruses rely on an armamentarium of T-cell receptor (TR) repertoire capable of recognizing a broad range of antigenic peptides of those pathogens, reconstitution of antiviral immunity, either by spontaneous generation of endogenous virus-specific T cells (VSTs) or by adoptive immunotherapy with VSTs, plays a critical role to fight infections.We here evaluated the diversity and clonality of TR repertoire of functional tri-virus-specific T cell products generated from immunocompetent donors (n=10) and compared their TR gene repertoire to that of peripheral blood mononuclear cells (PBMCs) from patients who had undergone allo-HSCT (n=5). To generate tri-VSTs, PBMCs derived from 15-20ml of peripheral blood of normal donors, were exposed to EBV, CMV and BKV overlapping peptides and cultured in the presence of interleukin 4 (IL-4) and IL-7 for 10 days in G-rex bioreactors. Specificity of donor-derived VSTs and patient-derived PBMCs was measured by IFN-γElispot. TR diversity was investigated by next-generation sequencing on a MiSeq Sequencer, after amplification of TR beta chain gene rearrangements by RT-PCR with the BIOMED-2 protocol. Raw NGS reads were filtered based on their length and quality and the filtered-in sequences were submitted to IMGT/HighVQUEST. Metadata analysis and clonotype computation were performed using a validated in-house bioinformatics platform. As clonotype we defined sequences carrying the same TRBV gene and identical CDR3 amino acid sequence.Tri-VSTs provided 947,298 productive TRBV-TRBD-TRBJ rearrangements and a polyclonal and highly diverse TR gene repertoire, consisting of a total of 169,502 unique clonotypes (average: 16,950/sample, range 4,057-45,602), 64,971 (38.3%) of which were expanded (corresponding to more than one sequence). In terms of clonality, the mean relative frequency of the major clonotype in all tri-VSTs was 12.6% (range 3.3-29.2%). Interestingly, among tri-VST cell lines, 637 clonotypes were shared (present in >2/10 samples), 80 were highly shared (present in >3/10 samples) while 7 were present in 6-8 different VST lines and largely expanded, accounting for up to 29.2% of all sequences.Importantly, there were 65 of 96 major VST clonotypes shared, thus suggesting that they were potentially associated with recognition of the targeted viruses. Given that 4/10 VSTs cell lines were not specific for CMV, while being EBV-and BKV-specific, dominant TRs in those 4 cell lines can potentially be associated with EBV- or BKV-activity. By searching a public database of TR clonotypes with known reactivity against EBV and/or CMV (ShugayM, Nucleic Acids Research, 2018), we found 8 shared EBV-specific and 4 shared CMV-specific clonotypes among our VSTs and the 499 public clonotypes. When we compared the produced VSTs with PBMCs from 3 allo-grafted patients with circulating CMV-, BKV- and EBV-specific T cells and previous viral reactivation, we detected 163 shared clonotypes. Likewise, we observed 21 and 23 shared clonotypes in similar frequencies, between VSTs and PBMCs from 2 patients with CMV- or BKV-specific T cell immunity. These data identify clones that potentially expand in vivo and protect patients from viral infections.Overall, our findings reveal high levels of TR clonality in cell lines enriched for T cells reactive against EBV and/or CMV and/or BKV and provide insights into the TR repertoire of ex vivo- or endogenously-generated VSTs. Our approach may help to identify optimal TRs for immunotherapy as well as TRs which can be used as a tool for risk stratification of viral infections. DisclosuresAgathangelidis:Gilead: Research Funding. Gemenetzi:Gilead: Research Funding. Stamatopoulos:Abbvie: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Gilead: Honoraria, Research Funding. Hadzidimitriou:Gilead: Research Funding; Abbvie: Research Funding; Janssen: Honoraria, Research Funding.

Analysis of T-Cell Receptor Gene Rearrangement for Predicting Clinical Outcome in Patients With Cutaneous T-Cell Lymphoma

To extend previous observations regarding the prognostic value of analyzing lymph node DNA from patients with cutaneous T-cell lymphoma for the presence of a monoclonal T-cell population by Southern blot vs polymerase chain reaction (PCR) methods. Inception cohort study from 1982 to 1998. Recruitment of new patients ended in 1994. A tertiary care referral center in Seattle, Wash. Patients Fifty-five uniformly staged patients with the diagnosis of cutaneous T-cell lymphoma who underwent a lymph node biopsy, 21 with clinically abnormal nodes and 34 with normal nodes. Interventions Lymph nodes were evaluated for T-cell receptor (TCR) gamma-chain gene rearrangement by 2 PCR methods: capillary electrophoresis and denaturing gradient gel electrophoresis. The same lymph nodes were evaluated by Southern blot analysis for TCR beta-chain gene rearrangement and examined histopathologically on the basis of the National Cancer Institute lymph node classification system. Patients were observed clinically for a mean of 9.5 years. Skin stage, clinical lymph node examination, lymph node histologic examination, Southern blot analysis, and PCR analyses were evaluated as potential prognostic predictors by univariate and multivariate analyses. The statistical association of TCR analysis and clinical outcome was determined among all patients. Hazard ratios (HRs) by Cox proportional hazards regression analysis were used to estimate the risk of a poor clinical outcome. Cumulative survival rates were analyzed by the Kaplan-Meier method. A skin stage of T3 (tumors) or T4 (erythroderma) was the most powerful predictor of a poor clinical outcome (HR, 31.3 vs T1; P<.001). Patients with detectable TCR gamma-chain gene rearrangement in lymph node DNA by PCR also were more likely to have a poor outcome (HR, 5.1; P<.001), but it was a less powerful predictor than skin stage. Even when the skin stage, presence or absence of lymphadenopathy, and histologic lymph node score were known for the patient, Southern blot analysis still added to prediction of a poor outcome (HR, 9.3; P = .007), whereas PCR provided no statistically significant additional information on outcome. Detection of a monoclonal T-cell population by PCR in lymph nodes of patients with cutaneous T-cell lymphoma does not enhance prediction of clinical outcome and probability of survival beyond what can be determined from clinical examination and histologic lymph node scores. Skin stage and the presence or absence of lymphadenopathy remain the most important determinants of clinical outcome.

Analysis of T-cell receptor gene rearrangement in lymph nodes of patients with mycosis fungoides. Prognostic implications.

To determine the prognostic value of analyzing lymph node (LN) DNA from patients with mycosis fungoides for the presence of a monoclonal T-cell population. Inception cohort study. A tertiary care referral center in Seattle, Wash. Fifty-five uniformly staged patients with the diagnosis of mycosis fungoides and who had a lymph node biopsy, 21 with clinically abnormal nodes and 34 with normal nodes. Lymph nodes were evaluated by Southern blot analysis for T-cell receptor beta-chain (TCRB) gene rearrangement and by histopathologic examination for the LN classification using the National Cancer Institute system. Patients were observed clinically for a mean (+/- SD) of 4.7 +/- 3.4 years. Patients with detectable TCRB gene rearrangement in lymph node DNA had an increased likelihood of a poor clinical outcome and a decreased probability of survival (P < .001 for both) compared with patients with the TCRB germline. Although patients with clinically enlarged nodes were more likely to have the TCRB gene rearranged, those with normal nodes and the TCRB gene rearranged also had a poor clinical outcome and a decreased probability of survival. Similar to those with the TCRB gene rearranged, most patients with advanced histopathologic changes (LN3 and LN4) had a poor prognosis. The presence of a rearranged TCRB gene, however, correctly predicted some patients with intermediate LN scores (LN2) who had a poor clinical outcome. Detection of a monoclonal T-cell population, as demonstrated by a rearranged TCRB gene on Southern blot analysis, in LNs of patients with mycosis fungoides is predictive of a poor clinical outcome and a reduced probability of survival. Lymph node TCRB gene analysis provides additional prognostic information for patients with mycosis fungoides with intermediate LN histopathology.

Productive T-cell receptor beta-chain gene rearrangement: coincident regulation of cell cycle and clonality during development in vivo.

Productive gene rearrangement at the T-cell receptor (TCR) beta-chain locus facilitates formation of the "pre-TCR," a molecular complex that is important for the subsequent development of alpha beta T cells. The transition of thymocytes from a population of cells undergoing TCRbeta chain genes to a population enriched in cells with productively rearranged TCRbeta chain genes is known as "beta selection." This is the first point in alpha beta T-cell development at which the products of an activated TCR locus define cell phenotype. Toward an understanding of these events, this study has focused on a set of thymocytes defined by cell surface phenotype as HSA+ CD44low CD25+, in which the bulk of TCRbeta gene rearrangement occurs. The analysis of this set, presented here, allows its novel subdivision into two subsets that are respectively strong candidates for cells immediately prior to and immediately following TCRbeta selection. Cells that have passed beta selection differ from the preceding cells by several criteria, including hyperphosphorylation of Rb, increased expression of cyclins A and B, down-regulation of p27, increased CDK2 activity, an induction of cdc2 activity, and progression through DNA synthesis. Consistent with these changes being attributable to productive TCRbeta chain gene rearrangement, the identified "beta-selected" subset is not detected in mutant mice that cannot assemble a pre-TCR. Interestingly, there is a coincident selective and transient down-regulation of the protein RAG2, on which TCR gene rearrangement obligatorily depends. Together, these findings demonstrate that productive TCR gene rearrangement is associated with events that can ensure thymocyte expansion and monoclonality.

Characterization of T Cells Immortalized by Tax1 of Human T-Cell Leukemia Virus Type 1

Peripheral blood T cells were immortalized in vitro by introduction of the Tax1 gene of human T-cell leukemia virus type 1 (HTLV-1) with a retroviral vector and were characterized for transformation-associated markers. Long-term observation showed that these Tax1-immortalized T cells eventually exhibited very similar features that were characteristic of HTLV-1-immortalized T cells, ie, increased expression of egr-1, c-fos, IL-2R alpha, and Lyn and decreased expression of Lck and cell-surface CD3 antigen. Among these changes, an increase in the expression of Lyn and a decrease in the expression of Lck and cell-surface CD3 antigen were observed only in Tax1-immortalized T cells after long-term culture. The expression level of Tax1 protein did not differ significantly between early and late passage of cells, and the cellular clonality was found to be the same by the analysis of the retroviral vector integration site and the T-cell receptor beta-chain gene rearrangement pattern. These changes in the expression of Lyn, Lck, and cell-surface CD3 antigen probably resulted from indirect effects of Tax1 that appeared after extended culture.

Rearrangements of immunoglobulin and T-cell receptor genes in canine lymphoma/leukemia cells.

Tumor cells from 15 canine lymphoma/leukemia cases were examined for genetic rearrangements of immunoglobulin and T-cell receptor (TCR) genes in parallel with cell surface antigens. Ten of these 15 cases showed rearrangements of the immunoglobulin heavy chain (IgH) gene, while 4 cases displayed TCR beta-chain gene rearrangements on Southern blot analysis. All the cases with IgH gene rearrangements had multicentric form lymphoma, and 6 of the 10 cases were cell surface immunoglobulin-positive. On the other hand, the cases with TCR gene rearrangements included atypical lymphoma/leukemia cases, and 3 of the 4 cases were Thy-1 antigen-positive. Although the tumor cell lineage of a considerable number of lymphoma/leukemia cases could not be determined by phenotypic analysis, examination of the IgH and TCR gene rearrangements disclosed the lineages of 14 of 15 cases. Genetic analysis demonstrated that the tumor cells in most canine multicentric lymphomas were formed by clonal expansion of B-lymphocyte. These findings show that studies on the rearrangements of immunoglobulin and TCR genes are very useful for understanding the cellular origin, clonality and hierarchy of canine lymphoma/leukemia cells.

Inhibition of T-cell receptor beta-chain gene rearrangement by overexpression of the non-receptor protein tyrosine kinase p56lck.

The variable region genes of the T cell receptor (TCR) alpha and beta chains are assembled by somatic recombination of separate germline elements. During thymocyte development, gene rearrangements display both an ordered progression, with beta chain formation preceding alpha chain, and allelic exclusion, with each cell containing a single functional beta chain rearrangement. Although considerable evidence supports the view that the individual loci are regulated independently, signaling molecules that may participate in controlling TCR gene recombination remain unidentified. Here we report that the lymphocyte-specific protein tyrosine kinase p56lck, when overexpressed in developing thymocytes, provokes a reduction in V beta--D beta rearrangement while permitting normal juxtaposition of other TCR gene segments. Our data support a model in which p56lck activity impinges upon a signaling process that ordinarily permits allelic exclusion at the beta-chain locus.

Dominant rearrangements among human tumor-infiltrating lymphocytes. Analysis of T-cells derived from 32 patients with melanoma, lung, and renal cell carcinoma.

Dominant rearrangements of T-cell receptor (TCR) beta-chain genes are reported among tumor-infiltrating lymphocytes (TIL). After interleukin-2 expansion of TIL from renal and lung carcinoma and melanoma biopsy tissues, rearrangements of TCR beta-chain genes were analyzed by Southern blotting. Nongermline restriction fragments, indicating dominant rearrangements, were detected among the TIL from all 6 patients with renal cell carcinoma, 17 of 20 patients with melanoma, and 3 of 6 patients with lung tumors. The restriction-fragment sizes of these dominant rearrangements were heterogeneous among the various patients. Rearrangements into C beta 1 were more common than C beta 2 rearrangements. Phenotypic analyses indicated that dominant rearrangements occurred in both CD4 and CD8 predominant TIL populations. The TIL populations that were extracted were expanded to derive large cell numbers suitable for in vivo transfer in an interleukin-2 and TIL immunotherapy program. The data indicated that the cells delivered to these patients usually were characterized by dominant populations of T-cells with selective TCR gene rearrangements. The significance of selective TCR use requires evaluation of the function and specificity of the TIL comprising these dominant populations both in their native in vivo setting and in the context of therapeutic transfer.

T-cell receptor beta-chain gene rearrangement and expression during human thymic ontogenesis

T-cell receptor (TCR) beta-chain proteins appear early (approximately 15th week of gestation) during human thymic ontogenesis. These beta- chain proteins, which appear before terminal deoxynucleotidyl transferase (TdT), could be an expression of a fully rearranged (V-D- J), incompletely rearranged (D-J), or germline TCR beta-chain gene. The aims of this study, performed from the 15th week onward, were the following: (1) to investigate whether or not TCR beta gene rearranges at an early stage during human thymic ontogenesis; (2) to investigate whether complete presumptive functional (1.3 kb) TCR beta gene transcript is present at these early stages of development, or if incomplete (1 kb) or germ-line (1.1 kb) transcripts are expressed; (3) to examine the phenotype of TCR beta-chain+ cells with two-color fluorescence using monoclonal antibody (MoAb) beta F1 and MoAbs that recognize CD1, CD2, CD3, CD4, CD8, CD5, and CD7 antigens (rabbit anti- calf TdT antiserum was used to detect TdT); and (4) to demonstrate whether or not beta gene N-diversity regions are detectable as early as the 15th week and whether or not N-nucleotide insertions correlate to TdT expression. Fifteen- to 22-week fetal thymuses and pediatric thymuses were investigated. We demonstrated that TCR beta-chain gene rearranged as early as the 15th week in human thymus and that a complete functional TCR beta gene transcript was expressed at these early stages of human development. No other analyses to date have investigated TCR beta gene expression in early human thymus using molecular biology techniques. No significant differences were detectable between phenotypic analysis of fetal and pediatric samples, except for TdT expression, which appeared after the 20th week. Essentially all mCD3+ (OKT3+) cells were beta-chain+ at the different weeks investigated. A significant percentage of CD1+ cells were beta- chain+, and the percentage increased along with the age of development. After the 20th week, we identified three main populations: TdT+, cCD3+, beta F-(early thymic precursors); TdT+, CD1+, beta F1+ (intermediate maturity cortical thymocytes); and TdT-, mCD3+, beta F1++ (mature medullary thymocytes). Given these values, we may consider beta-chain expression an ordered process. beta gene N-nucleotide insertions were correlated to TdT expression, since N-regions increased considerably after the 20th week. A further increase of N-nucleotide insertions was detected from the 22nd week to the 32nd week.

T-cell receptor beta-chain gene rearrangements of T-cell populations expanded from multiple sites of synovial tissue obtained from a patient with rheumatoid arthritis.

In this study T-cell receptor (TcR) beta-chain gene rearrangements of T-cell lines prepared from multiple sites (n = 92) of synovial tissue derived from both knees of a patient with rheumatoid arthritis were analysed. In the majority of T-cell lines, dominant TcR beta-chain gene rearrangements were detected, involving C beta 1 as well as C beta 2. The dominant rearrangement patterns of T-cell lines from different tissue fragments showed significant variability, but some of the DNA restriction fragments were shared by T-cell lines from multiple sites in both knees. The latter observation suggests that identical T-cell clones may be present at different sites in the synovial tissue and in different joints. However, since many T-cell lines yielded different rearrangement patterns, these data also indicate considerable heterogeneity of T cells in the joints. Apart from theoretical implications, this TcR heterogeneity of T cells within an individual patient also has practical consequences for studies on synovial T cells obtained by biopsy.

Lymphomatoid papulosis followed by large-cell lymphoma: immunophenotypical and genotypical analysis

The immunophenotype and genotype of atypical cells in skin and lymph node infiltrates were investigated in a patient with lymphomatoid papulosis (LyP) complicated by anaplastic large-cell lymphoma of the lymph nodes. The large atypical cells in both skin and lymph nodes displayed an almost identical immunophenotype, i.e. CD30+ and CD25+. Southern blot analysis for T-cell receptor beta-chain gene rearrangement revealed an identical gene configuration in DNA extracted from skin and lymph node. Our results strongly support the hypothesis that clonal populations of T cells arising in cutaneous LyP lesions may undergo malignant transformation, spread into regional lymph nodes, and give rise to secondary malignant lymphomas, such as anaplastic large-cell lymphoma.

Rearrangements of immunoglobulin gene and oncogenes in ocular adnexal pseudolymphoma

The organization of immunoglobulin heavy chain (IgH), light chain (kappa and lambda) and T cell receptor (TCR) beta chain gene loci in 10 patients with ocular adnexal pseudolymphoma was investigated. Eight of them showed IgH gene rearrangement in at least one of the 3 restriction enzymes-digested DNAs extracted from ocular adnexal neoplasms. In contrast, none of them exhibited clonal TCR beta chain gene rearrangement. The configuration of bcl-1, bcl-2 and c-myc oncogenes was also studied by Southern blot technique. Two patients had a rearranged joining region, IgH-containing fragment that comigrated with the rearranged bcl-1 fragment. C-myc gene rearrangement was found in only one patient who also had bcl-1 gene rearrangement. In ocular adnexal pseudolymphoma, none demonstrated bcl-2 gene rearrangement; however, in bone marrow cells, one patient with systemic lymphadenopathy exhibited both IgH and bcl-2 gene rearrangements. Three genotypic subsets of these ocular adnexal pseudolymphoma can be identified by the configuration of IgH gene and related oncogenes: with germline configuration of IgH gene and bcl-1, bcl-2 and c-myc oncogenes; with rearrangement of IgH gene but germline configuration of these oncogenes; and with recombination between rearranged IgH and bcl-1 genes. These results suggest in ocular adnexal pseudolymphoma a spectrum of clonal change evolving from polyclonal to monoclonal B-population, and further to monoclonal B-population with rearranged bcl-1, c-myc and/or bcl-2 oncogenes.

Induction by Interleukin-2 of Oligoclonal Expansion of Cultured Tumor-Infiltrating Lymphocytes

To better understand the modulatory effects of interleukin-2 (IL-2) on lymphocyte proliferation, we examined the clonality of the in vitro T-cell response by Southern blot hybridization. Tumor-infiltrating lymphocytes (TILs) grown in the presence of IL-2 for 15-26 days had detectable T-cell receptor beta-chain gene rearrangements, which indicated oligoclonal enhancement in culture in four of nine TIL samples. In contrast, none of 11 uncultured TIL samples had detectable gene rearrangements. Lack of detection in at least three of the five negative, cultured TIL samples could be explained by increased numbers of natural killer cells. We hypothesize that the oligoclonal expansion noted results from the enhanced response of immune-primed T cells to IL-2.

Dominant T‐Cell Receptor β‐Chain Gene Rearrangements Indicate Clonal Expansion in the Rheumatoid Joint

T-cell receptor (TcR) beta and delta gene rearrangements were studied in anti-CD3 expanded T-cell populations cultured from the synovial membrane (SM) (n = 5) or synovial fluid (SF) (n = 2) of rheumatoid arthritis (RA) patients. Dominant TcR beta-chain gene rearrangements to C beta 1 were demonstrated in all the patients tested and 1-3 expanded clones per patient were found. Clonal rearrangements to C beta 2 were detected in one SM sample (two clones) and one SF sample (one clone). The TcR delta gene was deleted in all the samples tested. We conclude that clonal dominance may be found in expanded T-cell populations from SM and SF of RA patients. Multiple clones may be present, either using the C beta 1 or C beta 2 gene segment.

T‐cell non‐hodgkin lymphoma in human immunodeficiency virus‐1‐infected individuals

We present two patients with human immunodeficiency virus-1 (HIV-1) infection in whom T-cell non-Hodgkin lymphoma developed, based on pathologic diagnosis, immunophenotyping, and T-cell receptor gene rearrangement. Both cases were positive for human immunodeficiency virus-1 by enzyme-linked immunosorbent assay and immunoblot methods. Histologic sections from each patient showed a high-grade pleomorphic T-cell non-Hodgkin lymphoma, and immunophenotyping demonstrated a prevalence of reactivity for CD4 (helper) over CD8 (suppressor) antigens. T-cell receptor beta-chain gene rearrangement studies revealed a rearranged pattern with either the HindIII or BamHI enzymes, whereas immunoglobulin heavy chain genes retained a germ-line configuration. Viral sequences specific for human T-cell leukemia virus-I, human T-cell leukemia virus-II, or HIV-1 were not detected. Thus, although rare, T-cell non-Hodgkin lymphoma may be observed in HIV-1-infected individuals.

Extranodal Noncutaneous Lymphoid Hyperplasias Represent a Continuous Spectrum of B-Cell Neoplasia: Demonstration by Molecular Genetic Analysis

We investigated 16 lymphoid proliferations occurring in the ocular adnexa, salivary glands, breast, and thyroid gland and satisfying the histopathologic and immunophenotypic criteria of benign lymphoid hyperplasia for the presence of clonal rearrangements of the antigen receptor, c-myc, bcl-1, and bcl-2 genes and Epstein-Barr virus (EBV) DNA sequences. Each of these 16 extranodal, noncutaneous lymphoid neoplasms exhibited clonal immunoglobulin heavy and/or light chain and lacked T-cell receptor (TCR) beta-chain gene rearrangements. The patterns of immunoglobulin gene rearrangements included solitary and multiple barely perceptible to faint bands, solitary clear and definite bands, and solitary high-intensity bands superimposed on a background of multiple less-intense bands. Three ocular adnexal lymphoid neoplasms exhibited bcl-1 or bcl-2 gene rearrangements. None of the 16 lymphoid neoplasms contained EBV DNA sequences. Two patients developed a histopathologically confirmed malignant lymphoma in an extranodal site. None of the remaining 14 patients developed additional lymphoid neoplasms during a mean follow-up period of 30 months, despite conservative therapy. These results demonstrate that extranodal, noncutaneous lymphoid neoplasms meeting the histopathologic and immunophenotypic criteria for benign lymphoid hyperplasia frequently contain occult monoclonal and oligoclonal B-cell populations representing a continuous and progressive spectrum of B-cell neoplasia up to and including malignant lymphoma.

Extranodal noncutaneous lymphoid hyperplasias represent a continuous spectrum of B-cell neoplasia: demonstration by molecular genetic analysis

We investigated 16 lymphoid proliferations occurring in the ocular adnexa, salivary glands, breast, and thyroid gland and satisfying the histopathologic and immunophenotypic criteria of benign lymphoid hyperplasia for the presence of clonal rearrangements of the antigen receptor, c-myc, bcl-1, and bcl-2 genes and Epstein-Barr virus (EBV) DNA sequences. Each of these 16 extranodal, noncutaneous lymphoid neoplasms exhibited clonal immunoglobulin heavy and/or light chain and lacked T-cell receptor (TCR) beta-chain gene rearrangements. The patterns of immunoglobulin gene rearrangements included solitary and multiple barely perceptible to faint bands, solitary clear and definite bands, and solitary high-intensity bands superimposed on a background of multiple less-intense bands. Three ocular adnexal lymphoid neoplasms exhibited bcl-1 or bcl-2 gene rearrangements. None of the 16 lymphoid neoplasms contained EBV DNA sequences. Two patients developed a histopathologically confirmed malignant lymphoma in an extranodal site. None of the remaining 14 patients developed additional lymphoid neoplasms during a mean follow-up period of 30 months, despite conservative therapy. These results demonstrate that extranodal, noncutaneous lymphoid neoplasms meeting the histopathologic and immunophenotypic criteria for benign lymphoid hyperplasia frequently contain occult monoclonal and oligoclonal B-cell populations representing a continuous and progressive spectrum of B-cell neoplasia up to and including malignant lymphoma.

A Clinicopathologically Distinctive Primary Splenic Histiocytic Neoplasm

We describe a primary splenic neoplasm composed of cytomorphologically malignant-appearing erythrophagocytic histiocytoid cells reminiscent of those seen in malignant histiocytosis. However, this neoplasm displayed certain distinctive clinicopathologic features--including localization to the spleen, where it grew as separate discrete nodules--that distinguish it from all previously reported cases of malignant histiocytosis. The cells expressed a monocyte/histiocyte immunophenotype and lacked clonal immunoglobulin and T-cell receptor beta-chain gene rearrangements. Our results suggest that this neoplasm represents a clinicopathologically distinctive and possibly unique tumor derived from the tissue macrophage lineage.

Correlation of T cell receptor gene rearrangements to T cell surface antigen expression and to serum immunoglobulin level in scid mice.

The severe combined immunodeficient (scid) mouse which has undetectable serum immunoglobulin (Ig) contains a small number of thymic lymphocytes which express Thy-1 and IL2 receptors (IL2R) but not Lyt-2 or L3T4 molecules. These thymocytes did not show any rearrangement of T cell receptor (TCR) beta-chain genes. Such thymocyte characteristics in the scid mouse were similar to the 15-day embryonic thymocytes in ordinary mice, indicating that the scid mouse thymocytes are arrested in the early stage of intrathymic differentiation. However, low or medium level serum Ig was occasionally found in the littermates of the scid mouse. The thymocytes of these mice showed some evidence of TCR beta-chain gene rearrangement and the presence of Lyt-2+/L3T4+ cells in correlation with the serum Ig level. In the mice with some serum Ig the thymocyte cell number was increased and the proportion of IL2R+ cells was decreased. Collectively, these results suggest that the rearrangement of TCR beta-chain genes is associated with the expression of Lyt-2 and L3T4 molecules in intrathymic differentiation and probably with cell proliferation of the migrated lymphoid cells in the scid mouse.

Immunoglobulin and T-cell receptor beta-chain gene rearrangement analysis of Hodgkin's disease: implications for lineage determination and differential diagnosis.

The lineage and clonality of Hodgkin's disease (HD) were investigated by analyzing the organization of the immunoglobulin and T-cell receptor beta-chain (T beta) gene loci in 18 cases of HD, and for comparison, in a panel of 103 cases of B- and T-cell non-Hodgkin's lymphomas (NHLs) and lymphoid leukemias (LLs). Sizable clonal B- or T-cell populations, representing greater than or equal to 10% of the pathologic sample, were readily detectable by immunogenotypic analysis in all 103 NHLs and LLs but not in any of the 18 cases of HD. However, extremely minor clonal populations (less than or equal to 1%) were detectable in 3 of 18 cases of HD. We demonstrated that these minor clonal populations do not correspond to Reed-Sternberg (RS) cells since clonal immunoglobulin or T beta gene rearrangements are not detectable in cases of HD containing greater than 25% RS cells. The number of RS cells present in these samples appeared to correlate directly with the pattern of gene rearrangements characteristic of polyclonal T cells. These studies demonstrate that Southern blot hybridization analysis for clonal immunoglobulin and T beta gene rearrangements represents an accurate, objective tool in the differential diagnosis between HD and NHL; that HD is predominantly composed of polyclonal B and T cells; that minor clonal B- or T-cell populations unrelated to RS cells occasionally can be found in HD; and that RS cells do not represent clonal B- or T-cell expansions. Finally, our data preliminarily suggest that RS cells may represent polyclonal T-cell populations.