1
|
Ngo VL, Lieber CM, Kang HJ, Sakamoto K, Kuczma M, Plemper RK, Gewirtz AT. Intestinal microbiota programming of alveolar macrophages influences severity of respiratory viral infection. Cell Host Microbe 2024; 32:335-348.e8. [PMID: 38295788 PMCID: PMC10942762 DOI: 10.1016/j.chom.2024.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 12/05/2023] [Accepted: 01/08/2024] [Indexed: 02/12/2024]
Abstract
Susceptibility to respiratory virus infections (RVIs) varies widely across individuals. Because the gut microbiome impacts immune function, we investigated the influence of intestinal microbiota composition on RVI and determined that segmented filamentous bacteria (SFB), naturally acquired or exogenously administered, protected mice against influenza virus (IAV) infection. Such protection, which also applied to respiratory syncytial virus and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was independent of interferon and adaptive immunity but required basally resident alveolar macrophages (AMs). In SFB-negative mice, AMs were quickly depleted as RVI progressed. In contrast, AMs from SFB-colonized mice were intrinsically altered to resist IAV-induced depletion and inflammatory signaling. Yet, AMs from SFB-colonized mice were not quiescent. Rather, they directly disabled IAV via enhanced complement production and phagocytosis. Accordingly, transfer of SFB-transformed AMs into SFB-free hosts recapitulated SFB-mediated protection against IAV. These findings uncover complex interactions that mechanistically link the intestinal microbiota with AM functionality and RVI severity.
Collapse
Affiliation(s)
- Vu L Ngo
- Center for Translational Antiviral Research, Georgia State University Institute for Biomedical Sciences, Atlanta, GA 30303, USA
| | - Carolin M Lieber
- Center for Translational Antiviral Research, Georgia State University Institute for Biomedical Sciences, Atlanta, GA 30303, USA
| | - Hae-Ji Kang
- Center for Translational Antiviral Research, Georgia State University Institute for Biomedical Sciences, Atlanta, GA 30303, USA
| | - Kaori Sakamoto
- Department of Pathology, University of Georgia College of Veterinary Science, Athens, GA 30602, USA
| | - Michal Kuczma
- Center for Translational Antiviral Research, Georgia State University Institute for Biomedical Sciences, Atlanta, GA 30303, USA
| | - Richard K Plemper
- Center for Translational Antiviral Research, Georgia State University Institute for Biomedical Sciences, Atlanta, GA 30303, USA.
| | - Andrew T Gewirtz
- Center for Translational Antiviral Research, Georgia State University Institute for Biomedical Sciences, Atlanta, GA 30303, USA.
| |
Collapse
|
2
|
Ngo VL, Lieber CM, Kang HJ, Sakamoto K, Kuczma M, Plemper RK, Gewirtz AT. Intestinal microbiota programming of alveolar macrophages influences severity of respiratory viral infection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.21.558814. [PMID: 37790571 PMCID: PMC10542499 DOI: 10.1101/2023.09.21.558814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Susceptibility to respiratory virus infections (RVIs) varies widely across individuals. Because the gut microbiome impacts immune function, we investigated the influence of intestinal microbiota composition on RVI and determined that segmented filamentous bacteria (SFB), naturally acquired or exogenously administered, protected mice against influenza virus (IAV) infection. Such protection, which also applied to respiratory syncytial virus and SARS-CoV-2, was independent of interferon and adaptive immunity but required basally resident alveolar macrophages (AM). In SFB-negative mice, AM were quickly depleted as RVI progressed. In contrast, AM from SFB-colonized mice were intrinsically altered to resist IAV-induced depletion and inflammatory signaling. Yet, AM from SFB-colonized mice were not quiescent. Rather, they directly disabled IAV via enhanced complement production and phagocytosis. Accordingly, transfer of SFB-transformed AM into SFB-free hosts recapitulated SFB-mediated protection against IAV. These findings uncover complex interactions that mechanistically link the intestinal microbiota with AM functionality and RVI severity. One sentence summary Intestinal segmented filamentous bacteria reprogram alveolar macrophages promoting nonphlogistic defense against respiratory viruses.
Collapse
|
3
|
|
4
|
Sales MM, Bezerra CNA, Hiraki Y, Melo NB, Rebouças NA. Clonally rearranged T-cell receptor beta chain genes in HTLV-I carriers with abnormal, non-flower-like, lymphocytes. Eur J Haematol 2005; 75:280-7. [PMID: 16146533 DOI: 10.1111/j.1600-0609.2005.00506.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND The diagnosis of Adult T-cell leukemia/lymphoma ATLL subtypes in human T-lymphotropic virus type I (HTLV-I) carriers based in morphology and immunophenotype of lymphocytes can be challenger. We propose that polymerase chain reaction (PCR) amplification of the rearranged TCR gene in HTLV-I healthy carriers would be a convenient method for establishing the nature of the circulating T lymphocytes in asymptomatic HTLV-I carriers, presenting only mild and inconclusive signals of deviation from normality. METHODS Using PCR, we analyzed the genetic recombination pattern of the T-cell beta-chain receptor gene (TCR-beta) in order to identify clonal expansion of peripheral blood T lymphocytes in 17 HTLV-I-positive healthy carriers and in nine normal HTLV-I-negative blood donors. To evaluate the performance of PCR in detection of clonality, we also analyzed 18 patients with post-thymic/mature T-cell malignancies presenting circulating abnormal lymphocytes. RESULTS Seven of the 17 HTLV-I positive individuals presented circulating abnormal lymphocytes; monoclonal or oligoclonal expansion of T-cells was detected in five of the 17 HTLV-I-positive individuals, all of them presenting abnormal lymphocytes. Clonal expansion was not detected in any of the negative controls or in any of the 12 remaining healthy carriers. All patients in the positive control group tested positive by PCR and Southern blots. Southern blots were negative for all 17 healthy carriers. CONCLUSIONS PCR amplification of segments of rearranged TCR-beta is reliable for allowing early detection of small populations of clonal T cells in blood samples from asymptomatic HTLV-I carriers, providing an additional alert in the follow-up of carriers with abnormal circulating lymphocytes.
Collapse
Affiliation(s)
- Maria M Sales
- Serviço de Hematologia, Divisão de Laboratório Central, Departamento de Patologia/Hospital das Clínicas, Universidade de São Paulo, Av. Prof. Lineu Prestes 1524, 05508-900-São Paulo, SP, Brazil
| | | | | | | | | |
Collapse
|
5
|
Yang XY, Xu D, Du J, Kamino H, Rakeman J, Ratech H. Rapid detection of clonal T-cell receptor-beta gene rearrangements in T-Cell lymphomas using the LightCycler-polymerase chain reaction with DNA melting curve analysis. J Mol Diagn 2005; 7:81-8. [PMID: 15681478 PMCID: PMC1867496 DOI: 10.1016/s1525-1578(10)60012-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
Various molecular methods have been developed to diagnose clonal T-cell receptor (TCR) gene rearrangements in clinical samples. Most polymerase chain reaction strategies for detecting clonal TCR gene rearrangements rely on either gel or capillary electrophoresis. However, a cumbersome manual transfer step separates amplification from analysis. Recently, we developed a novel polymerase chain reaction assay using the LightCycler system to detect clonal immunoglobulin heavy chain gene rearrangement. In the current study, we extend this work to include the TCR. We report that clonal TCR-beta (TCR-beta) gene rearrangements can be detected in less than 1 hour after preparing the DNA by measuring DNA melting immediately after amplification in a single closed capillary tube. We retrospectively studied 52 fresh-frozen tissue samples from patients clinically suspected of T-cell malignancy. A clonal TCR-beta gene rearrangement was detected in 14 samples by DNA melting curve analysis. When DNA melting was compared to the gold standard methods of Southern blot or denaturing gradient gel electrophoresis, it achieved a sensitivity equal to 71% and a specificity equal to 94%. We also compared melting curve analysis and polyacrylamide gel electrophoresis: melting curve analysis reached a sensitivity equal to 100% and a specificity equal to 97%. We conclude that DNA melting curve analysis in the LightCycler system has potential for clinical use as a new, ultra-fast method for the initial diagnosis of clonal TCR-beta gene rearrangements.
Collapse
Affiliation(s)
- Xiao Yan Yang
- Department of Pathology, Montefiore Medical Center, Albert Einstein College of Medicine, North 4, 111 East 210th St., Bronx, NY 10467, USA
| | | | | | | | | | | |
Collapse
|
6
|
Sales MM, Bezerra CNA, Hiraki Y, Melo NB, Rebouças NA. Identification of clonally rearranged T-cell receptor beta chain genes in HTLV-I carriers as a potential instrument for early detection of neoplasia. Braz J Med Biol Res 2005; 38:695-704. [PMID: 15917950 DOI: 10.1590/s0100-879x2005000500006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We analyzed the genetic recombination pattern of the T-cell receptor beta-chain gene (TCR-beta) in order to identify clonal expansion of T-lymphocytes in 17 human T-lymphotropic virus type I (HTLV-I)-positive healthy carriers, 7 of them with abnormal features in the peripheral blood lymphocytes. Monoclonal or oligoclonal expansion of T-cells was detected in 5 of 7 HTLV-I-positive patients with abnormal lymphocytes and unconfirmed diagnosis by using PCR amplification of segments of TCR-beta gene, in a set of reactions that target 102 different variable (V) segments, covering all members of the 24 V families available in the gene bank, including the more recently identified segments of the Vbeta-5 and Vbeta-8 family and the two diversity beta segments. Southern blots, the gold standard method to detect T-lymphocyte clonality, were negative for all of these 7 patients, what highlights the low sensitivity of this method that requires a large amount of very high quality DNA. To evaluate the performance of PCR in the detection of clonality we also analyzed 18 leukemia patients, all of whom tested positive. Clonal expansion was not detected in any of the negative controls or healthy carriers without abnormal lymphocytes. In conclusion, PCR amplification of segments of rearranged TCR-beta is reliable and highly suitable for the detection of small populations of clonal T-cells in asymptomatic HTLV-I carriers who present abnormal peripheral blood lymphocytes providing an additional instrument for following up these patients with potentially higher risk of leukemia.
Collapse
Affiliation(s)
- M M Sales
- Serviço de Hematologia, Divisão de Laboratório Central, Departamento de Patologia, Hospital das Clínicas, São Paulo, SP, Brasil
| | | | | | | | | |
Collapse
|
7
|
Assaf C, Hummel M, Zemlin M, Steinhoff M, Geilen CC, Stein H, Orfanos CE. Transition of Sézary syndrome into mycosis fungoides after complete clinical and molecular remission under extracorporeal photophoresis. J Clin Pathol 2005; 57:1325-8. [PMID: 15563677 PMCID: PMC1770516 DOI: 10.1136/jcp.2004.017160] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Mycosis fungoides (MF) and Sezary syndrome (SS) are the most common clinical variants of cutaneous T cell lymphoma. Although thought to be closely related to mature T helper cells, the relation between the neoplastic cells in MF and SS is still not fully clarified. This report describes a patient with complete remission of SS under treatment with extracorporeal photophoresis (ECP), who subsequently developed typical plaques of MF and large cell lymphoma (LCL). Serial polymerase chain reaction analyses confirmed identical T cell receptor beta and gamma gene rearrangements in SS, MF, and LCL, and complete disappearance of the circulating malignant T cell clone from the peripheral blood after ECP. These findings indicate that the neoplastic cells in SS, MF, and LCL are derived from a common precursor T cell, despite the change in clinical phenotype.
Collapse
Affiliation(s)
- C Assaf
- Department of Dermatology, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Fabeckstrasse 60-62, 14195 Berlin, Germany.
| | | | | | | | | | | | | |
Collapse
|
8
|
Spagnolo DV, Ellis DW, Juneja S, Leong ASY, Miliauskas J, Norris DL, Turner J. The role of molecular studies in lymphoma diagnosis: a review. Pathology 2004; 36:19-44. [PMID: 14757555 DOI: 10.1080/00313020310001648404] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Lymphoma classification is based on a multiparametric approach to diagnosis, in which clinical features, morphology, immunophenotype, karyotype and molecular characteristics are important to varying degrees. While in most cases, a diagnosis can be confidently established on the basis of morphology and immunophenotype alone, a small proportion of diagnostically difficult cases will rely on molecular studies to enable a definitive diagnosis. This review discusses the various molecular techniques available including Southern blotting (SB), polymerase chain reaction (PCR), fluorescence in situ hybridisation (FISH)--including multicolour-FISH/spectral karyotyping and comparative genomic hybridisation--and also gene expression profiling using cDNA microarray technology. Emphasis is given to the analysis of antigen receptor gene rearrangements and chromosomal translocations as they relate to lymphoma diagnosis and also in the setting of minimal residual disease (MRD) detection and monitoring. Laboratories performing these tests need to have expertise in these areas of testing, and there is a need for greater standardisation of molecular tests. It is important to know the sensitivity and specificity of each test as well as its limitations and the pitfalls in the interpretation of results. Above all, results of molecular testing should never be considered in isolation, and must always be interpreted in the context of clinical and other laboratory data.
Collapse
Affiliation(s)
- Dominic V Spagnolo
- Division of Tissue Pathology, The Western Australian Centre for Pathology and Medical Research (PathCentre), Nedlands, WA, Australia.
| | | | | | | | | | | | | |
Collapse
|
9
|
Lin CW, Chang CL, Li CC, Chen YH, Lee WH, Hsu SM. Spontaneous regression of Kikuchi lymphadenopathy with oligoclonal T-cell populations favors a benign immune reaction over a T-cell lymphoma. Am J Clin Pathol 2002; 117:627-35. [PMID: 11939739 DOI: 10.1309/d4bh-g1wu-0ub0-u9jd] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
To aid in the initial diagnosis of Kikuchi lymphadenitis and to assess whether the composition of the T cells might shed light on the pathogenesis, we used nested polymerase chain reaction tests followed by high-resolution gel electrophoresis to determine the pattern of T-cell antigen receptor rearrangement in 56 consecutive cases. Except for 1 unusual case with recurrent lymphadenopathy, none had a monoclonal beta or gamma rearrangement. Eight cases had a polyclonal pattern at both beta and gamma loci, 20 cases had a mixed polyclonal beta and oligoclonal gamma pattern, and 27 cases had an oligoclonal pattern at both loci. The high frequency of oligoclonality did not indicate an early-stage T-cell lymphoma in evolution, as confirmed by spontaneous resolution of the lymphadenopathy in all cases within 6 months. Rather, it is consistent with reports of oligoclonal T cells in a variety of immune reactions. We conclude that, in the vast majority of cases, absence of a monoclonal T-cell receptor rearrangement excludes the possibility of T-cell lymphoma, and the presence of an oligoclonal pattern implies a benign immune reaction.
Collapse
Affiliation(s)
- Chung-Wu Lin
- Department of Pathology, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei
| | | | | | | | | | | |
Collapse
|
10
|
Tarusawa M, Yashima A, Endo M, Maesawa C. Quantitative assessment of minimal residual disease in childhood lymphoid malignancies using an allele-specific oligonucleotide real-time quantitative polymerase chain reaction. Int J Hematol 2002; 75:166-73. [PMID: 11939263 DOI: 10.1007/bf02982022] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
We developed an assay using a real-time quantitative polymerase chain reaction (RQ-PCR) for the quantitative assessment of minimal residual disease (MRD) in childhood lymphoid malignancies by using a consensus V-region probe combining a allele-specific oligonucleotide (ASO) reverse primer. Our strategy employs a set consisting of a consensus V-region probe, an ASO reverse primer, and a patient-specific forward primer for clonal antigen-receptor (IgH, immunoglobulin heavy chain; TCR, T-cell receptor) gene rearrangements (IgH-ASO and TCR-ASO RQ-PCR assays). The limit of detection in both assays was 5 copies of the target/10(5) cell equivalents. We tested the assays in 17 childhood malignancies (14 cases of acute lymphoblastic leukemia and 3 of non-Hodgkin's lymphoma). High correlation coefficients of the standard curves (>0.980) and PCR efficiency (>0.95) were achieved with all primer/probe sets. In 2 (12%) of the 17 patients, ASO primers could not be designed because there was no junctional N-sequence. The quantitative data suggest that the copy number of clonal antigen receptors markedly decreased after induction therapy in 15 of 17 patients and that 1 patient relapsed and died of the disease. Consensus probes make it possible to examine a large number of patients with only a limited number of probes. The strategy used for IgH-ASO and TCR-ASO RQ-PCR assays is accurate and reliable in the clinical prospective study of MRD in childhood lymphoid malignancies.
Collapse
Affiliation(s)
- Mitsu Tarusawa
- Department of Pathology, Iwate Medical University School of Medicine, Morioka, Japan
| | | | | | | |
Collapse
|
11
|
Alkan S, Cosar E, Ergin M, Hsi E. Detection of T-cell receptor-gamma gene rearrangement in lymphoproliferative disorders by temperature gradient gel electrophoresis. Arch Pathol Lab Med 2001; 125:202-7. [PMID: 11175635 DOI: 10.5858/2001-125-0202-dotcrg] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Polymerase chain reaction amplification of DNA for T-cell receptor (TCR) gene rearrangement analysis is helpful in the evaluation of T-cell lymphoproliferative disorders. Detection of polymerase chain reaction products is limited by the poor resolution of bands analyzed by agarose or polyacrylamide gel electrophoresis. To improve the detection of a clonal T-cell population, we used temperature gradient gel electrophoresis (TGGE) as an alternative method for analysis of TCR gene rearrangement. DESIGN One hundred eighteen archival DNA samples were randomly selected based on previous Southern blot analysis results. Samples included 58 T-cell neoplasms with positivity for TCR beta gene rearrangement, 22 cases of reactive hyperplasia with germline pattern for both TCR beta and J(H), and 38 patients with B-cell lymphoma. MOLT-16, a T-cell lymphoblastic cell line, was used for the sensitivity assay. Polymerase chain reaction was performed using GC-clamped multiplex primers to amplify the TCR gamma locus and was analyzed by TGGE. The range of temperature gradients was empirically determined for optimal resolution of bands. RESULTS The sensitivity of TGGE was 0.1% when DNA from the MOLT-16 cell line was serially diluted with DNA from reactive lymphoid tissue. Fifty-four (93%) of 58 T-cell neoplasms with TCR beta gene rearrangements showed rearrangement patterns by TCR gamma TGGE, and only 1 of 60 samples (reactive or B-cell lymphomas) showed evidence of gene rearrangement by TGGE. Patients with T-cell neoplasm and involvement of multiple sites showed an identical migration pattern by TGGE analysis. CONCLUSION We demonstrate that TGGE is an effective method for analysis of TCR gene rearrangement in the evaluation of nodal and extranodal lymphoid lesions.
Collapse
Affiliation(s)
- S Alkan
- Department of Pathology, Loyola University Medical Center, Maywood, IL 60153, USA
| | | | | | | |
Collapse
|
12
|
Affiliation(s)
- D A Arber
- Division of Pathology, City of Hope National Medical Center, Duarte, California, USA.
| |
Collapse
|
13
|
High detection rate of T-cell receptor beta chain rearrangements in T-cell lymphoproliferations by family specific polymerase chain reaction in combination with the GeneScan technique and DNA sequencing. Blood 2000. [DOI: 10.1182/blood.v96.2.640] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
The distinction between benign polyclonal and malignant monoclonal lymphoid disorders by morphology or immunophenotyping is frequently difficult. Therefore, the demonstration of clonal B-cell or T-cell populations by detecting identically rearranged immunoglobulin (Ig) or T-cell receptor (TCR) genes is often used to solve this diagnostic problem. Whereas the detection of rearranged Ig genes is well established, TCR gamma (γ) and beta (β) gene rearrangements often escape detection with the currently available polymerase chain reaction (PCR) assays. To establish a sensitive, specific, and rapid method for the detection of rearranged TCR-β genes, we developed a new PCR approach with family-specific Jβ primers and analyzed the resulting PCR products by high-resolution GeneScan technique. The superior efficiency of this new method was demonstrated by investigating 132 DNA samples extracted from lymph node and skin biopsy specimens (mostly formalin fixed) and blood samples of 62 patients who had a variety of T-cell lymphomas and leukemias. In all but 1 of the tumor samples (98.4%) a clonal amplificate was detectable after TCR-β PCR and the same clonal T-cell population was also found in 15 of 18 (83%) of the regional lymph nodes and in 7 of 11 (64%) of the peripheral blood samples. Direct comparison of these results with those obtained currently by the most widely applied TCR-γ PCR revealed an approximate 20% lower detection rate in the same set of samples than with the TCR-β PCR method. These results indicate that the new TCR-β PCR is most suitable for a rapid and reliable detection of clonal T-cell populations.
Collapse
|
14
|
High detection rate of T-cell receptor beta chain rearrangements in T-cell lymphoproliferations by family specific polymerase chain reaction in combination with the GeneScan technique and DNA sequencing. Blood 2000. [DOI: 10.1182/blood.v96.2.640.014k31_640_646] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The distinction between benign polyclonal and malignant monoclonal lymphoid disorders by morphology or immunophenotyping is frequently difficult. Therefore, the demonstration of clonal B-cell or T-cell populations by detecting identically rearranged immunoglobulin (Ig) or T-cell receptor (TCR) genes is often used to solve this diagnostic problem. Whereas the detection of rearranged Ig genes is well established, TCR gamma (γ) and beta (β) gene rearrangements often escape detection with the currently available polymerase chain reaction (PCR) assays. To establish a sensitive, specific, and rapid method for the detection of rearranged TCR-β genes, we developed a new PCR approach with family-specific Jβ primers and analyzed the resulting PCR products by high-resolution GeneScan technique. The superior efficiency of this new method was demonstrated by investigating 132 DNA samples extracted from lymph node and skin biopsy specimens (mostly formalin fixed) and blood samples of 62 patients who had a variety of T-cell lymphomas and leukemias. In all but 1 of the tumor samples (98.4%) a clonal amplificate was detectable after TCR-β PCR and the same clonal T-cell population was also found in 15 of 18 (83%) of the regional lymph nodes and in 7 of 11 (64%) of the peripheral blood samples. Direct comparison of these results with those obtained currently by the most widely applied TCR-γ PCR revealed an approximate 20% lower detection rate in the same set of samples than with the TCR-β PCR method. These results indicate that the new TCR-β PCR is most suitable for a rapid and reliable detection of clonal T-cell populations.
Collapse
|