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Biomedical subjects

D M Knowles

Publications and source records attributed to D M Knowles.

At least 127 records · Page 7Linked to original sources

Hairy cell leukemia-associated antigen LeuM5 (CD11c) is preferentially expressed by benign activated and neoplastic CD8 T cells.

LeuM5 antigen (CD11c, p150.95) expression, widely used as an immunodiagnostic marker for B-cell hairy cell leukemia, was examined on benign, normal peripheral blood T cells before and after stimulation in vitro with phytohemagglutinin and on a large, diverse panel of 73 T-cell neoplasms. Resting T cells lacked LeuM5. Intracytoplasmic LeuM5 was detectable at 3 to 4 days and surface membrane LeuM5 was detectable continuously between 5 and 17 days on greater than or equal to 20% CD3 cells (maximum, 42% CD3 cells at 10 days) after activation. Two-color flow cytometric analysis of the activated T cells demonstrated that a maximum of 60% CD8 but only 25% CD4 cells expressed LeuM5; the mean percentage of LeuM5+ CD8 cells was 44% compared with 12% LeuM5+ CD4 cells. A variable proportion of the neoplastic T cells in 19 of 73 (26%) T-cell neoplasms were LeuM5+. Twelve of 18 CD4-CD8+ (67%) but only 5 of 40 CD4+ CD8- T-cell neoplasms expressed LeuM5. These studies demonstrate that the LeuM5 antigen is 1) expressed in association with T-cell activation, 2) preferentially expressed by activated CD8 cells, and 3) variably expressed by neoplastic T cells, but particularly by those exhibiting the CD4- CD8+ phenotype.

Antigens, Differentiation↗

Flow cytometric and immunohistochemical characterization of the gamma/delta T-lymphocyte population in normal human lymphoid tissue and peripheral blood.

We determined the quantitative and topographic distribution of gamma/delta lymphocytes in normal human lymphoid tissue and peripheral blood using a monoclonal antibody that detects a framework determinant on delta molecules and delineated the immunophenotypic characteristics of the gamma/delta lymphocyte population by one- and/or two-color immunohistochemical and two- and/or three-color flow cytometric analysis. Variable, but generally small, numbers of gamma/delta lymphocytes are present in peripheral blood and in all lymphoid tissues. The vast majority, greater than or equal to 90%, of lymphoid tissue delta lymphocytes reside in interfollicular (T-cell) zones. Approximately 90% of delta thymocytes are present in the thymic medulla. The percentage of CD3-positive T cells that express delta are: spleen 12.5 +/- 8.1%, peripheral blood 4.0 +/- 3.1%, appendix 2.9 +/- 1%, lymph node 2.2 +/- 1%, thymus 1.4 +/- 0.5%, and tonsil 0.7 +/- 0.5%. We further demonstrated that 1) gamma/delta-thymocytes and gamma/delta peripheral lymphocytes express T-cell lineage restricted antigens CD3 and CD2 but only a variable subset, 30% to 90%, express T-cell lineage associated antigens CD5 and/or CD8; (2) approximately 60% of gamma/delta thymocytes express low-density CD4 while all gamma/delta peripheral lymphocytes lack detectable CD4; 3) gamma/delta lymphocytes lack natural killer (NK), macrophage, and B-cell associated antigens CD16, CD14, and CD20, respectively, but greater than or equal to 70% of gamma/delta T lymphocytes express CD11b, Leu7, and NKH-1, antigens, which are also expressed by suppressor/cytotoxic and NK cells; and 4) a large subpopulation, approximately 25%, of gamma/delta thymocytes are in S1-G2 phase, while greater than or equal to 98% of gamma/delta peripheral lymphocytes are small lymphocytes in G0-G1 phase and lack activation/proliferation markers. Together these results indicate that gamma/delta lymphocytes are resting, mature T cells that probably play a primary role in suppressor/cytotoxic phenomena. They also indicate that gamma/delta lymphocytes variably express multiple-cell surface antigens associated with various cell lineages, suggesting that gamma/delta lymphocytes represent a considerably more heterogeneous cell population than previously appreciated and that they may actually subserve multiple functions.

Animals↗

Western thymomas lack Epstein-Barr virus by Southern blotting analysis and by polymerase chain reaction.

The authors investigated 16 western thymomas, 9 from the United States and 7 from Europe, for the presence of Epstein-Barr virus (EBV) DNA sequences by both Southern blot hybridization analysis and polymerase chain reaction using EBV-specific DNA probes that detect the long internal repeat and terminal repeat regions and the EBNA-1 gene. None of the 16 thymomas contained evidence of the EBV genome, even though we could detect EBV by Southern blotting when EBV DNA represents less than or equal to 1% of the total DNA and by polymerase chain reaction when a single EBV-positive cell is present among 10(5) EBV-negative cells. These results fail to demonstrate EBV genome in western thymomas and stand in contrast to those of McGuire et al (Am J Pathol 1988, 131:385) who previously reported that the EBV genome is present in thymomas occurring in southern Chinese patients. Therefore EBV does not appear to be implicated in the pathogenesis of all thymomas. The presence of EBV in eastern thymomas, regions where EBV is endemic may be due to epidemiologic factors and/or genetic predispositions.

Adult↗

Acquired immunodeficiency syndrome-associated non-Hodgkin's lymphoma.

The clinical picture is of aggressive high and intermediate grade lymphoma with extranodal presentation either as the first manifestation or during the course of HIV infection. The dramatic growth of tumors, leukopenia, opportunistic infections, and pre-existing AIDS-related problems of KS and chronic infections have made treatment extremely difficult. New regimens using short courses of chemotherapy, GM-CSF, and antiviral therapy have raised hopes that these measures will lead to improved survival.

Acquired Immunodeficiency Syndrome↗

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.

Antigens, Differentiation↗

Molecular genetic analysis of three AIDS-associated neoplasms of uncertain lineage demonstrates their B-cell derivation and the possible pathogenetic role of the Epstein-Barr virus.

Each of three individuals with acquired immunodeficiency syndrome (AIDS) developed a pleomorphic malignant neoplasm in which a precise histopathologic diagnosis could not be rendered. In each case, the tumor cells expressed leukocyte common antigen and a variable constellation of antigens associated with B- and T-cell activation (HLA-DR, T9, T10, BL2, BL3, Ki-24, BLAST-2). They lacked all B cell, T cell, myeloid, and monocyte lineage-restricted antigens, resulting in their classification as hematopoietic neoplasms of uncertain lineage. However, antigen receptor gene rearrangement analysis demonstrated that each of these three neoplasms exhibited clonal immunoglobulin heavy chain and kappa light chain gene rearrangements and lacked T-cell receptor beta chain gene rearrangements and therefore were B cell-derived non-Hodgkin's lymphomas (NHL) representative of an equivalent, relatively mature stage of B-cell differentiation. In contrast with most AIDS-associated NHLs, each of these three neoplasms lacked c-myc gene rearrangements and contained Epstein-Barr virus (EBV) proteins and/or sequences. These studies demonstrate that these three AIDS-associated neoplasms of uncertain lineage exhibit a strikingly similar constellation of distinctly uncommon morphologic, immunophenotypic, and molecular genetic characteristics that distinguishes them substantially from the vast majority of NHLs that have been reported to occur in association with AIDS. The consistent presence of EBV proteins and/or DNA sequences suggests that the Epstein-Barr virus played a pathogenetic role in the development of these three AIDS-associated neoplasms. Finally, these studies further illustrate the utility of antigen receptor gene rearrangement analysis in the diagnosis and classification of hematopoietic neoplasms of uncertain lineage.

Acquired Immunodeficiency Syndrome↗

Transformation and plasmacytoid differentiation of EBV-infected human B lymphoblasts by ras oncogenes.

The biological effects of ras oncogene activation in B cells were studied by using amphotropic retroviral vectors to introduce H- or N-ras oncogenes into human B lymphoblasts immortalized by Epstein-Barr virus. Expression of both H- and N-ras oncogenes led to malignant transformation of these cells, as shown by clonogenicity in semisolid media and tumorigenicity in immunodeficient mice. In addition, terminal differentiation into plasma cells was detectable as specific changes in morphology, immunoglobulin secretion, and cell surface antigen expression. This combined effect, promoting growth and differentiation in human lymphoblasts, represents a novel biological action of ras oncogenes and has implications for the pathogenesis of terminally differentiated B-lymphoid malignancies such as multiple myeloma.

Animals↗

Angiotropic large cell lymphoma (intravascular malignant lymphomatosis) of the kidney: presentation as minimal change disease.

We report the first case of angiotropic large-cell lymphoma (intravascular malignant lymphomatosis) presenting as minimal change disease (MCD) and diagnosed by renal biopsy. Neoplastic lymphoid cells were disseminated throughout the glomerular capillary bed and were associated with diffuse foot process effacement. The tumor had the immunophenotype of a B cell lymphoma (reactive with LCA and L-26 and unreactive with FVIII-R-Ag, Leu-M-1, alpha-1-antichymotrypsin, lysozyme, UCHL-1, Leu-22, kappa, and lambda). The temporal association between the onset of lymphoma and MCD, and the failure of the nephrotic syndrome to respond to immunosuppressive therapy support a role for lymphoma in the pathogenesis of MCD in this patient.

Biopsy↗

Immunophenotypic analysis of the inflammatory infiltrate in ocular cicatricial pemphigoid. Further evidence for a T cell-mediated disease.

Ocular cicatricial pemphigoid (OCP) is characterized by the deposition of immunoglobulin and complement along the conjunctival epithelial basement membrane zone (BMZ). In order to further elucidate the cellular populations of the local inflammatory infiltrates, the authors used a panel of monoclonal antibodies in cryostat tissue sections to delineate T cell subsets, B lymphocytes, dendritic cells, and macrophages in six patients with OCP. In comparison with matched controls of the epibulbar conjunctiva, the authors discovered a threefold increase in T lymphocytes within the epithelium and a 20-fold increase within the substantia propria. In contrast with the normal-standing population of conjunctival T lymphocytes, there were activated interleukin 2 receptor (IL-2R)-positive lymphocytes in both the epithelium and the substantia propria. Macrophages were the second most common cells in the substantia propria, accounting for 12.7% of the mononuclear population--a threefold increase over the normal percentage. B cells and plasma cells, normally absent from epibulbar conjunctiva, were the next most prominent populations, constituting 6.9 and 4.6%, respectively, of all mononuclear cells. Dendritic cells which process antigen locally constituted only 1.2% of the mononuclear cell population, but were increased 25-fold over normal controls. By elaborating cytokines that promote fibroplasia, the T cells in OCP may be effector cells along with macrophages and other inflammatory cells in bringing about scarification of the substantia propria, and may furthermore be responsible for an immunoregulatory defect that allows local B lymphocytes to produce autoantibodies to the BMZ.

Aged↗

Immunoglobulin VH gene expression in human B cell lines and tumors: biased VH gene expression in chronic lymphocytic leukemia.

We have studied frequencies of VH gene utilization in a panel of monoclonal Epstein-Barr virus (EBV)-transformed B cell lines derived from human adult and fetal tissues as well as in monoclonal B cells obtained from fresh chronic lymphocytic leukemia (CLL) samples. The results show that IgM-secreting EBV cell lines from both fetal and adult tissues utilize VH genes from particular families roughly in proportion to estimated family size, suggesting that the repertoire of sigM-positive B cells in both fetal and adult organs is 'normalized' with respect to the V(H) gene family. In contrast, we find a highly biased pattern of VH gene expression in CLLs. The significance of these findings is discussed in the context of mechanisms that could be involved in normal B cell repertoire development and in the process of malignant transformation of precursors of CLL.

Alleles↗

Hemangioma with Kaposi's sarcoma-like features: report of two cases.

We describe two children with vascular neoplasms that resembled Kaposi's sarcoma in places. Both presented with intraabdominal masses and severe thrombocytopenia. At autopsy the tumors extensively infiltrated the peritoneum and retroperitoneum and surrounded or invaded numerous organs including the kidneys, pancreas, adrenal glands, gastrointestinal tract, mesentery, and lymph nodes in both cases, and spleen or bone marrow in one case each. The neoplasms were histologically identical and displayed two patterns: dilated vascular spaces (angiomatous areas) lined by flat endothelial-like cells and areas of spindle cells forming slitlike vascular spaces similar to those described in Kaposi's sarcoma. Tumor cells in both cases expressed markers for endothelial cells. The clinical and histologic character of these neoplasms differentiates them from Kaposi's sarcoma, hemangioendothelioma, and from conventional juvenile hemangioma.

Child, Preschool↗

Immunophenotypic and antigen receptor gene rearrangement analysis in T cell neoplasia.

The author reviews the immunophenotypic profiles displayed by the major clinicopathologic categories of T cell neoplasia, the immunophenotypic criteria useful in the immunodiagnosis of T cell neoplasia, and the contributions made by antigen receptor gene rearrangement analysis to the understanding of T cell neoplasia. Neoplasms belonging to distinct clinicopathologic categories of T cell neoplasia often exhibit characteristic immunophenotypic profiles. Approximately 80% of lymphoblastic lymphomas and 20% of acute lymphoblastic leukemias express phenotypes consistent with prethymic and intrathymic stages of T cell differentiation, including intranuclear terminal deoxynucleotidyl transferase. Cutaneous T cell lymphomas of mycosis fungoides type usually express pan-T cell antigens CD2, CD5, and CD3, often lack the pan-T cell antigen CD7, and usually express the mature, peripheral helper subset phenotype, CD4+ CD8-. Cutaneous T cell lymphomas of nonmycosis fungoides type and peripheral T cell lymphomas often lack one or more pan-T cell antigens and, in addition, occasionally express the anomalous CD4+ CD8+ or CD4- CD8- phenotypes. T gamma-lymphoproliferative disease is divisable into two broad categories: those cases that are CD3 antigen positive and exhibit clonal T cell receptor beta chain (TCR-beta) gene rearrangements and those cases that are CD3 antigen negative and exhibit the TCR-beta gene germline configuration. Human T cell lymphotropic virus-I (HTLV-I) associated Japanese, Carribean, and sporadic adult T cell leukemia/lymphomas usually express pan-T cell antigens, the CD4+ CD8- phenotype, and various T cell-associated activation antigens, including the interleukin-2 receptor (CD25). Immunophenotypic criteria useful in the immunodiagnosis of T cell neoplasia include, in increasing order of utility, T cell predominance, T cell subset antigen restriction, anomalous T cell subset antigen expression, and deletion of one or more pan-T cell antigens. Only in exceptional circumstances do normal, non-neoplastic T cell populations express the CD4- CD8- or the CD4+ CD8+ phenotype and/or lack one or more pan-T cell antigens. T cell receptor beta chain gene rearrangement analysis represents an accurate, objective, and sensitive molecular genetic marker of T cell lineage and clonality that allows discrimination among non-T cell, polyclonal T cell and monoclonal T cell populations. Non-T cells exhibit the TCR-beta gene germline configuration.(ABSTRACT TRUNCATED AT 400 WORDS)

Cell Differentiation↗

Serological analysis and biochemical characterization of monoclonal antibodies defining antigens of human hepatocellular carcinoma.

A panel of seven murine monoclonal antibodies reactive with human hepatocellular carcinoma (HCC) cell line, SK- HEP-1, resulted in the definition of four distinct antigen systems, designated HB4, HB5, HB1 and HJ2. HB4 antigen was found to be expressed specifically on HCC cell lines and fresh HCC specimens but not on normal liver. Immunoprecipitation tests suggest that the HB4 epitope may be a heat-stable carbohydrate determinant on a high molecular mass molecule. HB5 antigen was found to have less-restricted expression on a panel of normal adult tissues and on melanoma, astrocytoma, sarcoma, neuroblastoma and epithelial cancer cell lines. In fetal and adult liver, HB5 antigen localized to bile canaliculi and ducts. Under reducing conditions, three mAbs detected a Mr 140,000 glycoprotein using lysates of [125-I], [3-H]-glucosamine and [35-S]-methionine labeled SK-HEP-1 cells. Under non-reducing conditions an additional component of greater than Mr 200,000 was also detected. HB1 antigen was found on almost all monolayer cell lines and not on most cultured suspension cells. This antigen was also detected on cultured HCC cells inoculated into nu/nu mice. Immunoprecipitation experiments revealed that the HB1 antigen is a bimolecular complex with an Mr 170,000 alpha chain and Mr 130,000 beta chain under non-reducing conditions, and three subunits of Mr 140,000, Mr 30,000 and Mr 130,000 under reducing conditions. Two antibodies reacted with epitopes on the alpha chain. HJ2 antigenic determinant is a heat-stable component which could not be immunoprecipitated. This most widely expressed antigen was found in secreted form in many of the cells and tissues examined. These antibodies introduce new antigens which may serve as useful markers for the diagnosis, classification and investigation of HCC and other liver diseases.

Antibodies, Monoclonal↗

An overview of ocular adnexal lymphoid tumors.

In comparison with our earlier colleagues quoted in the introduction, we have made substantial progress in understanding the biology of ocular adnexal lymphoid tumors. While we have refined various categories with prognostic clinical value regarding possible associated systemic disease, none is foolproof and all have varying degrees of unpredictability. Comparatively well-differentiated histologic subtypes predominate among ocular adnexal lymphoid tumors. Polyclonal lesions occur less than half as often as monoclonal B-cell lesions. Molecular genetic studies have revealed small clones of monoclonal populations among the B-cells comprising most of the immunophenotypically polyclonal lesions, but no clonal genetic rearrangements have been uncovered within the preponderant constituent T-cell populations. The overall prognosis for ocular adnexal lymphoid tumors is excellent; when lumped together, 67% are not found to be associated with systemic disease with mean follow-ups of over 4 years. This is similar to experience with extranodal and extralymphatic lesions in other sites of the body, which also frequently have a small lymphocyte composition. The incidence of nonocular disease in all categories of our studies, however, will probably increase with the acquisition of longer follow-ups. Careful histopathologic evaluation is as good as immunophenotypic analysis of these lesions in predicting clinical outcome in terms of associated nonocular disease. Polyclonal and well-differentiated B-cell monoclonal lesions displayed equivalent clinical behavior. Benign polyclonal lesions may be associated with systemic disease but in a minority of cases (27%), as has also been determined in earlier studies. Clinical staging is the single most important predictor of associated monocular disease. In this study, patients with stage I-E disease had an 87% chance of not developing any nonocular lymphomatous lesion. We believe that this figure may also somewhat decrease with the passage of time. Precise anatomic localization of the lesion within the adnexa had considerable predictive value. Lesions of the conjunctiva fared the best; those of the orbit had an intermediate prognosis; while lid lesions had the worst prognosis. The most favorable prognosis would be held by a conjunctival lymphoid lesion in stage I-E composed of small lymphocytes. The fact that there is a fairly close equivalence in outcome between polyclonal and monoclonal well-differentiated lesions indicates that these lesions are in the vast majority of cases primary hyperplasias or primary lymphomas. The discovery by genetic probes of small monoclonal populations in immunophenotypically polyclonal lesions suggests that there is an evolution that goes on in situ.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗

Interstitial nephritis related to nonsteroidal anti-inflammatory agents and beta-lactam antibiotics: a comparative study of the interstitial infiltrates using monoclonal antibodies.

Acute interstitial nephritis (AIN) is a common pattern of renal injury induced by therapeutic agents. In order to characterize the types of mononuclear leukocytes infiltrating the kidney in drug-induced interstitial nephritis, a panel of monoclonal antibodies (Leu1, Leu3a, OKT8, OKM1, Leu14, OKT17, IL-2) was applied to cryostat sections of 13 renal biopsies (five non-steroidal anti-inflammatory agents (NSAID) (Group I); five beta-lactam antibiotics (Group II), 3 miscellaneous (Group III]. The majority of infiltrating mononuclear leukocytes were Leu1-positive T cells (71.7 +/- 18.7%), followed by monocytes (15.2 +/- 7.7%) and B cells (7.4 +/- 9.1%). Leu3a/OKT8 ratio was 0.954 +/- 0.341. Rare cells reacted with antibody to the interleukin-2 receptor (1.4 +/- 1.2%). No statistically significant differences could be found in the percentages of T lymphocytes, B lymphocytes, monocytes, activated (IL-2+) T cells or Leu3a/OKT8 (helper/suppressor) ratios in the three groups. In Group II, the following pathologic correlations were seen: Leu3a/OKT8 versus interstitial inflammation (R = -0.848), percent Leu3a versus interstitial inflammation (R = -0.818), percent OKT17 versus tubulitis (R = 0.785), percent Leu14 versus tubular atrophy (R = -0.891), and interstitial edema (R = 0.965). Our findings support a role for cellular immune mechanisms in the pathogenesis of AIN related to both NSAIDs and beta-lactam antibiotics.

Adult↗

Monoclonal antibody Leu-22 (L60) permits the demonstration of some neoplastic T cells in routinely fixed and paraffin-embedded tissue sections.

Monoclonal antibody Leu-22 (L60) detects a T cell-associated antigen which is stably expressed in routinely fixed and paraffin-embedded tissue sections. We investigated the utility of monoclonal antibody Leu-22 to immunophenotype routinely processed lymphoid neoplasms by determining its reactivity in 105 archival pathologic specimens of lymphoid neoplasia that had been previously immunophenotyped by standard cell suspension and frozen tissue section techniques. Monoclonal antibody Leu-22 reacted with 69% of T cell non-Hodgkin's lymphomas (NHLs), including cases belonging to each of the major clinicopathologic categories, and with 22% of B cell NHLs, but did not react with the Reed-Sternberg (RS) cells of Hodgkin's disease (HD). We concluded that monoclonal antibody Leu-22 reacts preferentially but not exclusively with T cell NHLs. Therefore, we performed parallel analyses of the same 105 cases with monoclonal antibodies leukocyte common antigen (LCA), Leu-M1, LN1, and LN2, which detect various paraffin-resistant antigens, and of 80 of these cases with monoclonal antibody UCHL1, which detects a paraffin-resistant T cell-associated antigen. UCHL1 reacted with 61% of the T cell NHLs studied. Sixty-nine percent of T cell NHLs expressed the LCA+, Leu-22+ or Leu-M1+, LN1- phenotype and 47% of B cell NHLs expressed the LCA+, Leu-22-, Leu-M1-, LN1+ phenotype. These phenotypes had a false-positive rate of only 7%. The substitution of UCHL1 for Leu-22 or the combined use of UCHL1 and Leu-22 in this panel did not improve our ability to correctly predict the T cell phenotype of these lymphoid neoplasms. LN1 and LN2 reacted with 13% and 56% of T cell NHLs, respectively, and LN2 reacted with RS cells in 85% of cases of HD. In summary, our results demonstrate that the judicious use of monoclonal antibody Leu-22 in combination with other selected commercially available monoclonal antibodies permits the determination of the B cell or T cell origin of a high proportion of NHLs, and is helpful in the differential diagnosis between HD and NHL among cases that have been routinely fixed and paraffin-embedded.

Antibodies, Monoclonal↗