On the possible relationship between staphylococcal superantigens and increased Vbeta5.1 usage in cutaneous T-cell lymphoma.
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Publications and source records attributed to R D Bigler.
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CD7, a molecule normally expressed on 90% of normal CD4+ T cells, is often deficient on the malignant T cells of cutaneous T cell lymphoma. To investigate the clinical and biologic implications of CD7 expression, blood lymphocytes from 42 patients with the leukemic phase of cutaneous T cell lymphoma (CD4/CD8 ratio of 10 or more with evidence of a T cell clone in the blood) were analyzed for level of expression of CD7 by flow cytometry. CD7 expression by cells did not clearly segregate into two distinct subgroups that are either CD7 positive or CD7 negative as generally thought; however, nine of 17 patients with a predominantly CD4+CD7+ tumor population on early studies became CD4+CD7- over time whereas the converse situation was not observed. In addition, of three patients with evidence of large tumor cells in the blood coexisting with smaller cells, discordant CD7 expression was observed in one instance. In lymph node specimens, the percentage of cells expressing CD7 and other T cell markers did not correlate with histologic evidence of involvement. CD7 expression on blood lymphocytes also did not correlate with patients' survival nor to serum IgE levels or blood eosinophil counts, a finding suggesting that this marker does not identify functional cell subsets that produce serum interleukin-4 or -5, respectively. We speculate that the level of CD7 expression on malignant T cells may be the effect of sustained antigen stimulation in vivo analogous to what has been proposed to occur with normal T cells during aging.
We studied the role of fine-needle aspiration (FNA) in the evaluation of lymphadenopathy associated with cutaneous T-cell lymphoma (CTCL) in 11 patients with lymphadenopathy and compared findings with corresponding histologic material. Molecular genetic analysis for T-cell clonality by polymerase chain reaction (PCR) was performed on all aspirates. Immunophenotyping was successful in 4 of 7 cases in which flow cytometry was attempted from the aspirated material. Cytologic evaluation of FNA samples correlated strongly with histologic rating of involvement based on numbers of atypical cerebriform lymphocytes in the nodal specimen. Of 7 nodal specimens with scattered or small groups of atypical cells in the background of dermatopathic lymphadenopathy (LN1-2), the cytologic diagnosis was interpreted as reactive in all instances. Of 4 specimens with highly suspect (LN3) or definite histologic involvement (LN4), the cytologic diagnosis was likewise suspect or malignant. The correlation between molecular genetic studies on FNA samples and studies on tissue was not significant; in 2 cases, a T-cell clone was detected in the nodal tissue sample but not in the FNA sample, suggesting undersampling. A T-cell clone was detected by PCR in 5 of 7 nodal specimens judged reactive by FNA biopsy or histologic assessment. FNA for cytologic and molecular genetic analysis is a useful method to evaluate lymphadenopathy associated with CTCL and may obviate the need for surgical biopsy.
BACKGROUND: The serum concentration of soluble alpha chain of the interleukin-2 receptor (sIL-2R) correlates with tumor burden in cutaneous T-cell lymphoma (CTCL). Therefore the sIL-2R level may be useful to monitor the condition of patients treated with extracorporeal photopheresis or other treatments. OBJECTIVE: Our goal was to determine the utility of serum sIL-2R as a test in monitoring of patients with advanced CTCL. METHODS: Serum sIL-2R was measured serially in 36 patients with advanced CTCL treated with extracorporeal photopheresis and other modalities (interferon alfa, methotrexate, topical nitrogen mustard, electron beam). RESULTS: Serum concentrations of sIL-2R as well as lactate dehydrogenase (LDH) correlated strongly with lymph node size, but only sIL-2R correlated significantly with the severity of skin manifestations in erythrodermic patients. In addition, serum sIL-2R, but not LDH, was significantly higher in patients with nodal involvement. The level of sIL-2R also was significantly higher in patients with large-cell transformation in the skin or lymph nodes compared with patients without transformed disease. During treatment, serum concentrations of both serum sIL-2R and LDH correlated with changes in clinical status, but only sIL-2R showed statistically significant differences in mean levels for different relative global response scores. Pretreatment levels of both sIL-2R and LDH correlated significantly with survival, but only sIL-2R retained significance when both were entered into the Cox proportionate hazards model. CONCLUSION: The concentration of serum sIL-2R correlates well with disease status and is more useful than LDH or Sézary cell counts to monitor clinical change in patients with advanced CTCL. Moreover, our data suggest that sIL-2R is produced at a relatively low rate by tissue-based lymphoma cells, and that large-cell transformation in CTCL results in marked increase in sIL-2R production in some patients.
Sézary syndrome is a leukaemic form of cutaneous T-cell lymphoma which presents with multiple cytogenetic abnormalities and responds poorly to chemotherapy. Because of the importance of the p53 tumour suppressor in maintaining genomic stability and in sensitizing transformed cells to DNA damaging agents, we looked for alternations which may affect p53 functions in 18 patients with Sézary syndrome. Cytogenetic analysis suggested frequent p53 gene inactivation since 6/18 patients had loss of one copy of 17p. However, single-strand conformational polymorphism (SSCP) revealed that p53 gene mutations are relatively rare, occurring in only two of 18 Sézary patients. Neither of these two patients was missing a copy of 17p. Possible abnormalities of p53 pathway function through mdm-2 over-expression were also investigated. Although all 18 patients had normal levels of mdm-2 RNA 4/18 over-expressed mdm-2 protein. One patient with advanced disease and the highest percentage of malignant cells overexpressed mdm-2 protein and possessed a nonsense p53 gene mutation. The five patients with abnormalities of p53 or mdm-2 were found to have significantly highest absolute lymphocyte counts and higher absolute numbers of Sézary cells (P=0-021 and 0.027 respectively). In summary, molecular alternations of 17p and potential p53 pathway abnormalities are a common event in Sézary syndrome and appear to be associated with more advanced disease.
BACKGROUND AND DESIGN: The serum concentration of soluble alpha-chain receptor for interleukin-2 (sIL-2R) was determined in 101 patients with cutaneous T-cell lymphoma (CTCL). RESULTS: The serum concentration of sIL-2R correlates positively with CTCL tumor burden as determined by several clinical parameters (ie, clinical subtype of disease, extent of skin involvement, T rating, and stage), by serum lactate dehydrogenase concentration, and by Sézary cell counts in erythrodermic disease. The median value of sIL-2R in erythrodermic CTCL was more than threefold higher than that of classic mycosis fungoides (MF). The proportion of patients with elevated sIL-2R concentration (> 1000 U/mL) also increased in CTCL in a similar fashion according to the clinical type of disease (MF patch phase, 15%; MF plaque phase, 33%; MF tumor phase, 47%; and erythrodermic variants, 90%). However, no correlation was found between sIL-2R serum concentration and expression of membrane-bound IL-2R alpha chain (CD25) on lymphoid cells in skin lesions and peripheral blood. Significantly, multivariate analysis of various prognostic factors demonstrated that in erythrodermic CTCL, sIL-2R serum concentration correlated best with survival and was a better predictor of prognosis than stage, Sézary cell counts, or lactate dehydrogenase values. CONCLUSIONS: These findings document the usefulness of the measurement of the sIL-2R serum concentration to determine tumor burden and prognosis in patients with CTCL.
Monoclonal antibodies (MAbs) reacting with the human T cell receptor (TCR) V beta or V alpha region have been shown to be almost as specific as a private idiotypic MAb in identifying T cell clones. When available, V beta-specific MAbs offer the ease of immunofluorescence analysis to identify and quantitate expanded malignant or nonmalignant T cell populations without requiring polymerase chain reaction (PCR) technology to evaluate expression of V beta gene families. The V beta expression of peripheral blood lymphocytes from twenty-three consecutive patients with Sézary syndrome has been analyzed by reverse transcriptase (RT)-PCR. Ten patients had malignant T cell clones that expressed a TCR V beta corresponding to a commercially available anti-V beta antibody. Immunofluorescence staining with anti-V beta MAbs showed a direct correlation with RT-PCR results in seven of ten patients. No false positive reactivity was noted on immunofluorescence staining with any MAb. Cells from three patients, however, did not react with the corresponding anti-V beta MAb. These three cases expressed a TCR V beta from gene families containing a single member, ie, V beta 14, V beta 18, and V beta 20, yet MAbs reported to be specific for these regions failed to react with the T cell clone from these patients. Sequencing of the PCR product in these cases confirmed the RT-PCR results. Cells from two patients expressed a TCR using V beta 5.1-D beta 1.1 genes with different J-C segments. One patient's cells reacted with an anti-V beta 5.1 MAb (LC4) whereas the other patient's cells bound one-tenth the amount of this same MAb. These results indicate that currently available anti-TCR V region MAbs may not react consistently with T cell clones expressing the corresponding V region or may react with a low affinity making detection difficult. Differences in the J-C junction or in CDR3 may influence the binding of these MAbs. Until the false negative rate is reduced and the fine specificity and affinity of these MAbs is better characterized, both PCR and MAb studies will be required to reliably identify and quantitate clonal T cell populations.
The purpose of this pilot study was to evaluate the role of recombinant interferon alfa 2b (rIFN-a) as adjunct immunomodulatory therapy in patients with Sezary syndrome who were considered unlikely to respond to ExP alone. Six patients were treated with rIFN-a in doses ranging from 3 to 20 million units three times weekly in addition to two consecutive photopheresis treatments every 4 weeks. In addition, to better measure the effect of treatment on circulating neoplastic T-cells, cryopreserved lymphocytes were studied by two-color immunofluorescence and flow cytometry, using anti-CD4 combined with anti-CD29, anti-CD45RA, or anti-CD7. Minimal clinical improvement was observed in 4 patients treated with low doses of rIFN-a (3 to 5 million units TIW), and the response was sustained in only 1 patient. However, a clinically significant and sustained improvement did occur in 1 patient after the dose of rIFN-a was increased (20 million units TIW). Although the encountered toxicity profile from combined ExP/rIFN-a therapy was similar to that expected for ExP or comparable doses of rIFN-a given separately, treatment was discontinued in 2 patients because of adverse effects. Three antibody pairs, i.e., CD4+CD7-, CD4+CD29+, and CD4+CD45RA- subsets, appeared to be useful to monitor changes in blood Sezary cells during treatment. We conclude that the combination of ExP and low doses of rIFN-a does not appear to be effective for patients with advanced Sezary syndrome in this small patient series. However, escalation of interferon dose may be beneficial as shown in one patient, but it cannot be discerned whether the response was due to a combination of therapies, or whether the same therapeutic response would have been achieved with the higher doses of rIFN-a alone. Moreover, while none of the antibody pairs is unique for Sezary cells, the CD4+CD7- subset in appropriate patients provided a good objective measure of response and correlated well with visual Sezary cell counts.
Lovastatin is a widely used anticholesterolemic drug which exercises its effect by inhibiting hepatic cholesterol synthesis and up-regulating low density lipoprotein (LDL) receptors. In the present study, we determined that the drug has no adverse effects on the expression of three cell surface antigens of human monocytes, i.e. high affinity Fc receptors (Fc gamma RI), low affinity Fc receptors (Fc gamma RII) and CD14 antigen. We have shown previously these antigens are regulated by cholesterol and lipoproteins. At 0.5 micrograms/mL of culture medium, lovastatin did not reduce the percentage of receptor-positive cells or the average number of receptor molecules per cell. These observations add to the attractiveness of the drug as an anticholesterolemic agent and also indicate that endogenous cholesterol biosynthesis by monocytes is not required for expression of Fc gamma RI, Fc gamma RII, or CD14.
The CD14 antigen which is expressed on human monocytes and macrophages is a phosphatidylinositol-linked surface protein. We investigated the effects of cellular cholesterol depletion and repletion on cell surface expression of this glycoprotein. Adherent normal human monocytes were cultured for four days in media containing delipidated fetal calf serum which depleted cellular cholesterol. Immunofluorescence analysis demonstrated a markedly diminished surface expression of CD14 on cells cultured in delipidated serum compared to normal serum. Expression of CD64 (high-affinity Fc receptors, Fc gamma RI) also was reduced under these conditions. This inhibition of CD14 expression was overcome by addition to the culture medium of cholesterol, low density lipoprotein, or very low density lipoprotein. All of these supplements replenished cellular cholesterol. Expression of CD64(Fc gamma RI) was not restored by addition of cholesterol. These observations indicate that cholesterol can regulate the surface expression of some phosphatidylinositol-anchored glycoproteins.
The effect of the HLA complex on the TCR repertoire in human peripheral blood was assessed by using nine V beta- and V alpha-specific mAb and the quantitative polymerase chain reaction specific for 22 V beta segments. Studies in randomly selected and unrelated individuals failed to show any influence of the HLA complex on the TCR repertoire. In contrast, studies in large families with multiple siblings showed a strong influence on the TCR repertoire by the HLA complex. In pairwise comparisons, HLA-identical sibs had more similar patterns of V segment frequencies, as measured with the nine V segment-specific mAb, as well as more similar expression levels of V beta-specific RNA, as measured by quantitative polymerase chain reaction, than totally mismatched or haplo-identical sibs. When the amount of V beta-specific RNA expressed in CD4+ and CD8+ T cells was compared, it was found that V beta 2, 5.1, 9, and 20 were skewed toward CD4+ T cells; on the other hand, V beta 7 and 14 showed a bias in expression for CD8+ T cells, suggesting that the former were positively selected predominantly by HLA class II gene products whereas the latter V beta segments were positively selected predominantly by HLA class I gene products. These studies unequivocally document the effects of HLA genes on TCR V segment frequencies and expression levels in peripheral blood T lymphocytes.
Plasma lipoproteins have been implicated in immunoregulation. Here we report that LDL and VLDL up-regulate high affinity Fc receptors (Fc gamma RI) in normal human monocytes. Adherent monocytes were cultured for 4 days in media containing fetal calf serum or delipidated serum. Immunofluorescence analysis showed a significant decrease in percentage of Fc gamma RI-positive cells from 85 +/- 3 in medium containing normal serum to 54 +/- 9 in medium containing delipidated serum. The decrease in the fraction of cells expressing Fc gamma RI was parallel to a decrease in the average number of receptor molecules per cell as indicated by a decrease in the mean value fluorescence intensity from 234 +/- 20 to 112 +/- 14. The inhibition of Fc gamma RI expression was overcome by addition to the culture medium of LDL or VLDL. Since pure cholesterol is ineffective, it is proposed that these lipoproteins deliver a component(s) such as apolipoprotein B-100 which triggers a signal leading to up-regulation of Fc gamma RI in monocytes and macrophages.
Lymphokine-activated killer (LAK) cell activity was measured in human peripheral blood mononuclear cells (PBMC) treated in vitro for 3 days with recombinant interleukin-2 (rIL-2) and mismatched double-stranded RNA (dsRNA). Lytic activity was measured utilizing K562 (NK-sensitive) and 786-0 (NK-resistant) target cells. PBMC cultured with rIL-2 (10-1000 BRMP U/ml) alone showed concentration-dependent lytic activity against the 786-0 target cells, while cells cultured in unsupplemented medium or medium supplemented with mismatched dsRNA (200 micrograms/ml) alone could not lyse the 786-0 targets. The combination of mismatched dsRNA with suboptimal concentrations of rIL-2 (10-30 U/ml) showed enhancement of both natural killer (NK) and LAK cell activities. The uptake of [3H]thymidine by treated effector cells was dependent on time and rIL-2 concentration and was not increased in the cells treated with low-dose rIL-2/mismatched dsRNA, compared to those treated with low-dose rIL-2 or mismatched dsRNA alone. Similarly, changes in the expression of CD3, CD4, CD8, CD57, CD16 and CD25 cell surface antigens were independent or rIL-2 concentration and not altered by the presence of mismatched dsRNA. These results indicate that mismatched dsRNA can potentiate rIL-2-induced LAK cell activity by increasing the functional activity per cell, rather than by increasing the number of activated cells.
The antitumor effects of recombinant interleukin-2 (rIL-2) and mismatched double-stranded RNA (dsRNA) were assessed in tissue culture and in a nude mouse model. Mismatched dsRNA did not show a direct antiproliferative effect against the human malignant melanoma cell line, BRO, in tissue culture. However, treatment of the BRO cells with up to 1000 units/ml rIL-2 in culture showed a slight increase in growth rate. Combined rIL-2/mismatched dsRNA treatment also demonstrated a similar slight enhancement of growth. Nude mice bearing subcutaneous tumors were treated by intraperitoneal injection of low doses (5000-20,000 units) of rIL-2 and mismatched dsRNA (500 micrograms). The in vivo tumor growth was significantly inhibited by the combined treatments (P less than 0.05) and survival was significantly increased (P less than 0.05). Measurement of cytotoxicity using splenocytes from treated animals showed significant augmentation of lytic activity against natural killer (NK)-sensitive YAC-1 cells in all rIL-2/mismatched dsRNA treatment groups, compared to the individual treatments or controls (P less than 0.05). Cytotoxicity of the splenocytes against the NK-resistant BRO cells was also augmented in animals treated with mismatched dsRNA and the highest rIL-2 dose utilized here (P less than 0.01). Renal, liver, and hematological toxicity was evaluated by measurement of blood urea nitrogen, creatinine, serum asparrtate aminotransferase, and a complete blood count with differential. There were no significant differences in these parameters in any of the treatment groups. Similarly, no differences in weight of the animals was seen in any treatment group. These results indicate that the combination of low-dose rIL-2 and mismatched dsRNA can potentiate host-mediated antitumor effects, yielding increased survival, without significant toxicity.
Patients with advanced stage cutaneous T cell lymphoma (CTCL) have a median survival of 2-5 years with no currently available curative therapy. This limited pilot study was performed to determine if CTCL patients could undergo autologous bone marrow transplantation (ABMT) as a curative treatment without developing life-threatening infections. Since selection of a chemotherapeutic regimen is essentially empirical at this time, several drug combinations were screened. Total skin electron beam radiotherapy was used prior to transplantation to control the skin disease of four patients. Six patients have been transplanted and all have engrafted normally. Infections that developed after transplantation responded to conventional therapy and were typical of those observed in other patients undergoing ABMT. Five of the six patients had a complete clinical response to ABMT but three of these responses lasted less than 100 days. Two recent patients who were treated with carmustine, etoposide, and cisplatin are alive more than 1 year after transplantation without evidence of active disease. Thus, although this study does not prove the efficacy of ABMT, it does demonstrate that patients with CTCL can undergo ABMT without developing life-threatening infections and that carmustine-etoposide-cisplatin plus ABMT should be evaluated in subsequent studies to treat patients with poor prognosis CTCL.
Four patients with chronic refractory plaque-type psoriasis without arthropathy were treated with extracorporeal photopheresis every other week for 6 to 13 months. In patients 1 and 2, methotrexate was administered concomitantly during the initial part of the trial; the dose was gradually tapered and the drug was discontinued by 6 months. Both patients improved to 23% and 62% of baseline values for percentage of body surface involvement, but their disease then flared when maintenance extracorporeal photopheresis was used alone. Substantial improvement again occurred when lower doses of methotrexate were administered with extracorporeal photopheresis. Patients 3 and 4 were treated initially with extracorporeal photopheresis alone and both improved to 50% and 52% of baseline body surface involvement, respectively, after 4 months of treatment. However, their disease flared because of factors unrelated to treatment. Extracorporeal photopheresis was well tolerated by all patients without evidence of overt toxicity. However, prolonged treatment with extracorporeal photopheresis/methotrexate was accompanied by a decrease in skin reactivity to recall antigens and by decreased capacity of lymphocytes to produce interleukin 2 in response to polyclonal stimuli in vitro. These findings indicate that alternate-week extracorporeal photopheresis has a definite but incomplete suppressive effect on psoriasis vulgaris that may be mediated through an effect on lymphokine production by photomodified cells and that the therapeutic effect of extracorporeal photopheresis may be enhanced by concomitant administration of low doses of methotrexate.
Optimal expression of the high-affinity Fc receptor for IgG (FcRI) by the human monocyte cell line U-937 requires the presence of low density lipoprotein (LDL), and neither cholesterol nor high density lipoprotein can provide the component necessary for optimal FcRI expression. Here we show that FcR-mediated phagocytosis also requires LDL. U-937 cells were cultured in medium containing interferon gamma and either fetal calf serum (FCS) or delipidated FCS (DLFCS). The phagocytosis of IgG-coated erythrocytes was measured by a colorimetric assay. U-937 cells cultured in DLFCS medium had less than 16% of the phagocytic activity of cells cultured in normal FCS medium. Phagocytosis of IgG-coated erythrocytes could be inhibited 85% by the addition of murine IgG2a myeloma protein (5 micrograms/ml). U-937 cells cultured in DLFCS medium supplemented with pure cholesterol in ethanol (10 micrograms/ml) had only 30% of the phagocytic activity of cells grown in FCS medium. Addition of very low density lipoprotein (0.2 mg of protein per ml) to DLFCS medium also failed to increase phagocytosis. However, the addition of LDL (0.2 mg of protein per ml) to DLFCS medium restored 90% of the phagocytic activity. Since neither pure cholesterol nor very low density lipoprotein restored normal phagocytic function to U-937 cells despite a normalization of cellular cholesterol content, the restoration of phagocytosis observed with LDL replacement cannot be explained by mere delivery of cholesterol by LDL. Thus, LDL is required for the expression of FcRI and FcR-mediated phagocytosis by U-937 cells and may be an important regulator of phagocytic activity of monocytes and macrophages in vivo.
The staphylococcal toxins are responsible for a number of diseases in man and other animals. Many of them have also long been known to be powerful T cell stimulants. They do not, however, stimulate all T cells. On the contrary, each toxin reacts with human T cells bearing particular V beta sequences as part of their receptors for major histocompatibility complex protein-associated antigen. The specificity of these toxins for V beta s puts them in the recently described class of superantigens and may account for the differential sensitivity of different individuals to the toxic effects of these proteins.