The role of tumor necrosis factor (TNF)-alpha in the antitumor effect of intrapleural injection of Lactobacillus casei strain Shirota in mice

The involvement of several cytokines in the antitumor effect induced by intrapleural (i.pl.) injection of heat-killed cells of Lactobacillus casei strain Shirota (LC 9018) in mice was investigated. Injection of LC 9018 i.pl. into Meth A fibrosarcoma (Meth A)-bearing mice not only significantly prolonged the survival of the mice, but also effectively inhibited the accumulation of malignant pleural fluid in the thoracic cavity. In the thoracic cavity of tumor-bearing mice treated with LC 9018, we observed large amounts of several cytokines including interleukin (IL)-1beta, interferon (IFN)-gamma, IL-12 and tumor necrosis factor (TNF)-alpha. Both anti-IFN-gamma and anti-IL-12 monoclonal antibody (mAb) treatments partially diminished the antitumor activity of LC 9018 in vivo, while the treatment of anti-IL-1beta mAb did not influence the survival of the mice. However, anti-TNF-alpha mAb treatment completely abolished the antitumor effect of LC 9018 in vivo, suggesting that in this model LC 9018 has a survival-prolonging effect involving certain cytokines. Moreover, i.pl. injection of mouse recombinant TNF-alpha into Meth A-bearing mice pretreated with anti-TNF-alpha mAb partially restored the survival-enhancing effect of LC 9018. These results led us to conclude that TNF-alpha induced by i.pl. injection of LC 9018 plays an important role in the antitumor effect of LC 9018 in vivo.

MUC1 isoform specific monoclonal antibody 6E6/2 detects preferential expression of the novel MUC1/Y protein in breast and ovarian cancer

The products of the MUC1 gene are known to be highly expressed in human breast cancer cells. The best characterized MUC1 protein is a polymorphic, type 1 transmembrane molecule containing a large extracellular domain composed primarily of a variable number of 20 amino acid tandem repeats. We have recently identified a novel protein product of the MUC1 gene, the MUC1/Y protein, that is also a transmembrane protein but is devoid of the tandem repeat array and its immediate flanking sequences. To analyze its expression in tumor cells we generated monoclonal antibodies directed against the MUC1/Y extracellular domain (anti-MUC1/Yex MAbs). Epitope mapping identified the MAb, 6E6, which recognized the MUC1/Y isoform with exquisite specificity- the repeat-array-containing MUC1 isoform could not compete out this immunoreactivity. A 30mer peptide which is unique for MUC1/Y and corresponds to the "join" region generated by the MUC1/Y specific splice, abrogated all 6E6 MAb immunoreactivity towards MUC1/Y. Immunoprecipitation of the MUC1/Y protein with 6E6 MAbs revealed that, in contrast with the proteolytic cleavage of the tandem-repeat-array-containing MUC1 isoform, MUC1/Y is not cleaved. Flow cytometry analyses using the 6E6 MAbs demonstrated that the MUC1/Y isoform is expressed on the cell surface of both MCF-7 breast cancer cells and malignant epithelial cells present in effusions obtained from breast and ovarian cancer patients. Our results unequivocally establish that the MUC1/Y protein is expressed on the surface of breast cancer cells and cells of other epithelial malignancies. The anti-MUC1/Y MAbs described here can target MUC1/Y expressing tumor cells in vivo and are likely to be important reagents both for epithelial tumor diagnosis and immunotherapy.

Immunohistochemical detection of cytotoxic lymphocytes in malignant serous effusions

The use of ancillary techniques to aid in the diagnosis of metastatic carcinoma in serous effusions has been the subject of numerous studies. In this article, we study 35 cases of malignant effusions (metastatic adenocarcinoma) and 20 benign effusions using a panel of immunohistochemical markers to determine whether changes in the subpopulations of accompanying lymphoid cells can be detected with this technique and whether such changes are associated with the presence of malignancy. We noted a significant increase in cytotoxic lymphocytes, defined as the percentage of all lymphoid cells staining with an antibody to TIA-1 (an antigen localized to the cytotoxic granule membranes of cytotoxic T cells and natural killer cells) in malignant compared with benign effusions (23% vs. 12%; P < 0.05). In addition, nearly all cases in which cytotoxic lymphocytes composed > 20% of the lymphoid cell population contained metastatic tumor. Thus, immunohistochemical staining for TIA-1 can reliably detect cytotoxic lymphocytes in cell blocks of serous effusions; in addition, a relative increase in their number is associated with the presence of malignancy.

Overexpression of sialomucin complex, a rat homologue of MUC4, inhibits tumor killing by lymphokine-activated killer cells

Sialomucin complex (SMC) is a large heterodimeric glycoprotein complex composed of a mucin subunit ascites sialoglycoprotein-1 and a transmembrane subunit ascites sialoglycoprotein-2. It is a rat homologue of human mucin gene MUC4 and is abundantly expressed on the cell surface of highly metastatic ascites 13762 rat mammary adenocarcinoma cells. Because of their extended and rigid structures, mucin-type glycoproteins are suggested to have suppressing effects on cell-cell and cell-matrix interactions. During the metastatic process, these effects presumably cause tumor cell detachment from the primary tumor mass and facilitate escape of the tumor cells from immunosurveillance. Analyses of human breast cancer cells in solid tumors and tumor effusions showed that the more aggressive cells in effusions are stained with polyclonal antibodies against SMC more frequently than cells in solid tumors, suggesting a role for MUC4/SMC in tumor progression and metastasis. Previously, we generated recombinant cDNAs for SMC that vary in the number of mucin repeats to study the putative functions of SMC in tumor metastasis. These cDNAs were transfected into human cancer cell lines and tested for the effect of the expression of this gene. Here, using a tetracycline-responsive inducible expression system, we demonstrate that overexpression of SMC masks the surface antigens on target tumor cells and effectively suppresses tumor cell killing by cytotoxic lymphocytes. This effect results from the ability of SMC to block killer cell binding to the tumor cells and is dependent on both overexpression of the mucin and the number of mucin repeats in the expressed SMC. These results provide an explanation for the proposed role of SMC/MUC4 in tumor progression.

Presence and potent immunosuppressive role of interleukin-10 in malignant pleural effusion due to lung cancer

The presence and possible role of interleukin (IL)-10 were examined in malignant pleural effusion due to lung cancer. In 37 out of 55 cases examined, IL-10 was detectable in pleural effusion and the mean level with standard error was 62.1+/-12.1 pg/ ml. Spontaneous and lipopolysaccharide-induced production of anti-tumor cytokines such as IL-1beta and tumor necrosis factor (TNF)-alpha, by pleural macrophages, obtained from five patients with malignant pleurisy, were suppressed by IL-10. These findings suggest that IL-10 is present in the tumor-growing site and acts as a suppressive factor of local anti-tumor immunity in humans.

Without prior stimulation, tumor-associated lymphocytes from malignant effusions lyse autologous tumor cells in the presence of bispecific antibody HEA125xOKT3

Women suffering from advanced stage ovarian or mammary carcinoma frequently develop malignant ascites or pleural effusions consisting of tumor cells and tumor-associated lymphocytes (TALs). Locoregional immunotherapy with bispecific antibodies (bsAbs), which retarget T cells to tumor cells and induce their lysis, has been applied as an adjuvant treatment in the late stage of the disease. Until now, most of these therapies use peripheral blood mononuclear cells (PBMCs) as effector cells that have been stimulated and expanded ex vivo and loaded with bsAb before reinjection. Here we investigated whether TALs derived from malignant ascites or pleural effusions can be used as bsAb-guided effector cells without prior in vitro stimulation. For this we established a bsAb, HEA125xOKT3, which recognizes the epithelial antigen Egp34 on carcinoma cells and the CD3 molecule on T cells. BsAb HEA125xOKT3 induced lysis of various Egp34-expressing carcinoma lines by stimulated PBMCs. Optimal cytotoxicity was achieved at a bsAb concentration of 1 microg/ml. In three ovarian and two mammary carcinoma patients, we demonstrated efficient lytic activity of lymphocytes, isolated from malignant ascites or pleural effusion. Without prior stimulation, they lysed autologous tumor cells in the presence of bsAb HEA125xOKT3, indicating that they are already activated. Along this line, a subset of CD4+ and CD8+ unstimulated TALs expressed the early activation marker CD69. They are, however, negative for CD95, and only a small subpopulation of CD4+ TALs expresses CD25. OKT3/interleukin 2 stimulation of TALs increased the expression of activation markers on the CD4+ and CD8+ T-cell compartment. The activation markers CD69, CD25, CD95, and DR molecules are up-regulated on both T-cell types. However, lysis of autologous tumor cells by stimulated TALs is not significantly enhanced compared with unstimulated TALs. Our results may offer a novel and promising concept of adjuvant immunotherapy for ovarian and mammary carcinoma patients. Preactivation and expansion of PBMCs can be circumvented by exploring the cytotoxic capacity of unstimulated TALs in the presence of bsAbs in a locoregional therapeutic approach.

Presence of serum anti-p53 antibodies is associated with pleural effusion and poor prognosis in lung cancer patients

This study was designed prospectively to evaluate the development of anti-p53 antibodies (Abs) in lung cancer patients in relation to their clinical outcome. Sera, derived from 125 lung cancer patients, consisting of 14 small cell lung cancers (SCLC) and 111 non-SCLCs (NSCLC), were surveyed. The p53-null human NSCLC cell line, NCI-H1299, transfected with a human mutant p53 gene was prepared as the source of p53 antigen for immunoblotting analyses to detect the presence of serum anti-p53 Abs. The control group included sera from 10 healthy adults and 14 patients with benign pulmonary diseases. Clinical data including staging and survival were recorded for statistical analyses. The anti-p53 Abs were found in 8% (10 of 125) of the lung cancer patients studied (8.1% of NSCLC versus 7.1% of SCLC patients), whereas none of the control sera had detectable anti-p53 Abs. The presence of anti-p53 Abs was closely associated with malignant pleural effusions (P = 0.001). The p53 Ab-positive patients had a worse prognosis than the p53 Ab-negative patients (P < 0.02; median survival, 20 versus 41 weeks). In both univariate and multivariate analyses, the tumor extension and probably the presence of anti-p53 Abs were significant predictors for cancer death. The development of anti-p53 Abs (n = 9) was also a predictor for poor survival in patients with malignant effusions (n = 51). In conclusion, the presence of serum anti-p53 Abs is closely associated with malignant pleural effusions in lung cancer patients. It may serve as a negative prognostic factor for survival independent of malignant pleural effusions and tumor staging.

Sialyl stage-specific embryonic antigen-1: a useful marker for differentiating the etiology of pleural effusion

OBJECTIVES

To assess the usefulness of sialyl stage-specific embryonic antigen-1 (SSEA-1) levels in differentiating the etiology of pleural effusion (PE).

DESIGN

A solid-phase immunoradiometric sandwich assay with an FH6 monoclonal antibody was used to measure sialyl SSEA-1 levels in PEs of 132 patients with various diseases. Paired serum sialyl SSEA-1 levels were measured simultaneously in 47 patients with various subtypes of lung cancer

RESULTS

The pleural sialyl SSEA-1 levels were significantly higher in patients who had adenocarcinoma of the lung with positive cytology than in all the other patients, including those having malignancies other than adenocarcinoma of the lung, adenocarcinoma of the lung with cytology-negative PE, and benign diseases. There were no significant differences among sialyl SSEA-1 levels in the pleural fluid containing no adenocarcinoma cells. Using the cutoff value of 265 U/mL, the sensitivity was 64% (25/39) and the specificity was 95% (88/93) for the pleural sialyl SSEA-1 level to differentiate adenocarcinoma from other effusions.

CONCLUSIONS

With high specificity and modest sensitivity, the pleural sialyl SSEA-1 level is a useful biochemical marker for differentiating the etiology of PEs caused by adenocarcinoma from other diseases.

Immunoglobulin VH gene mutational analysis suggests that primary effusion lymphomas derive from different stages of B cell maturation

Primary effusion lymphoma (PEL) is a recently described distinct subtype of non-Hodgkin's lymphoma associated with infection by the Kaposi's sarcoma-associated herpesvirus, also called human herpesvirus-8. Most cases of PEL are also associated with the Epstein-Barr virus (EBV). In order to better characterize the cellular origin of PEL, we investigated the immunoglobulin (Ig) heavy chain variable region (VH,) genes expressed by tumor cells of the BC-1 and BC-3 cell lines derived from PELs and five original PEL specimens. In the six EBV-positive PELs examined, including the BC-1 cell line, the expressed VH gene sequences showed numerous point mutations relative to the putative germline VH gene sequences. In addition, the VH, segment of one of these cases showed intraclonal sequence heterogeneity, indicating ongoing somatic mutation. In five cases, the distribution and type of mutations indicated that tumor cells had been selected by antigen. Because somatically mutated Ig genes are expressed by B cells that have reached a germinal center/post-germinal center stage of development, these findings suggest that the PEL cell of origin is a germinal center or post-germinal center B cell in most cases. In contrast, the VH gene segment expressed by tumor cells of the BC-3 cell line, which was originated from an EBV-negative PEL obtained from an HIV-negative patient, was unmutated, suggesting a pre-germinal center B cell origin for tumor cells of this particular PEL cell line. Taken together, these findings suggest that development of PELs may not be restricted to one stage of B cell differentiation and may represent transformation of B cells at different stages of ontogeny.

Lymphoma cell lines: in vitro models for the study of HHV-8+ primary effusion lymphomas (body cavity-based lymphomas)

Primary effusion lymphoma (PEL; also known as body cavity-based lymphoma) is recognized as a new and unique lymphoma entity occurring predominantly, but not exclusively in human immunodeficiency virus (HIV)-seropositive patients with acquired immunodeficiency syndrome (AIDS). PEL grows exclusively in body cavities as serous lymphomatous effusion without evidence of mass disease or dissemination. Their most unique feature is infection with the newly discovered human herpesvirus-8 (HHV-8; also known as Kaposi's sarcoma-associated herpesvirus), often accompanied by co-infection with Epstein-Barr virus (EBV). A number of continuous lymphoma cell lines have been established from the malignant pleural effusion, ascitic fluid and peripheral blood of patients with AIDS- and non-AIDS-associated PEL. While all cell lines are HHV-8+, about half of them also contain EBV sequences. Stimulation of the cell lines causes switch from latent to lytic HHV-8 infection. The cells are generally negative for T and B cell immunomarkers (except for CD138 suggesting a pre- or terminal plasma cell stage) and positive for some activation and adhesion markers; they are genotypically B cells with their immunoglobulin genes rearranged. Complex, hyperdiploid karyotypes with multiple structural abnormalities are seen in the cell lines examined. No alterations of known proto-oncogenes are detected in PEL, with the exception of BCL-6 mutations occurring in a large percentage of cases. Heterotransplantation of the cell lines into immunodeficient mice leads to the development of lymphomatous effusion and marked angiogenesis. As HHV-8 contains DNA sequences of several protein homologues, the cell lines express various cytokines, cytokine receptors, chemokines, cell cycle and anti-apoptosis modulators which are upregulated upon stimulation. Indeed, some cell lines produce high levels of (human) interleukin-6 and interleukin-10. Taken together, these cell lines represent very important model systems for the elucidation of the pathobiology of PEL; furthermore, the cell lines are extremely useful scientific tools providing a resource to pursue studies of HHV-8-mediated pathogenic mechanisms.

Complement components and their activation products in pleural fluid

STUDY OBJECTIVES

The aim of this study was to determine the role of complement components in pleural effusion measured with novel markers of complement activation, to assess which pathway of activation is predominant in different diseases, and to find out whether the analysis of complement components and their activation products could help in diagnostic procedure differentiating the etiologies of pleural effusion.

PATIENTS

The study population consisted of 71 patients who had pleural effusion secondary to tuberculosis (n=23), rheumatic disease (n=10), or malignancy (n=38).

MEASUREMENTS

Complement components and their activation products, including the soluble terminal complex SC5b-9, were measured in plasma and pleural fluid.

RESULTS

In all patients with rheumatic pleurisy, pleural fluid SC5b-9 was higher than 2 AU/mL and in all patients with malignant pleural fluid it was lower than 2 AU/mL. The mean level of SC5b-9 in rheumatic pleural effusion was also significantly higher than in tuberculosis. In addition, the concentrations of pleural fluid C3 and C4 were significantly lower and the ratio C4d/C4 was significantly higher in rheumatic compared with tuberculous or malignant pleurisy. In plasma, both SC5b-9 and C1s-C1r-C1INH-complexes were significantly higher in rheumatic subjects than in other patients. In stepwise multinominal logistic regression analyses, the most significant predictors for rheumatic pleural fluid were high pleural fluid SC5b-9 and low C4.

CONCLUSIONS

These observations indicate that the complement cascade is activated through both the classic and the alternative pathways in rheumatic pleurisy. Determinations of SC5b-9 and C4d/C4 in pleural fluid were the best variables differentiating rheumatic, tuberculous, and malignant effusions.

Differential diagnosis of tuberculous pleurisy by measurement of cytokine concentrations in pleural effusion

STUDY OBJECTIVE

Measurement of cytokine concentration in serum and pleural effusion may be useful in the differential diagnosis of tuberculous pleurisy.

PATIENTS AND METHODS

We compared the biochemical properties and concentrations of cytokines in serum and pleural effusion samples of 18 patients with tuberculous pleurisy, 7 patients with parapneumonic pleurisy, and 25 patients with malignant pleurisy.

RESULTS

A high value of adenosine deaminase (ADA) was observed in pleural effusion of patients with tuberculosis. The serum concentrations of interleukin (IL)-1-beta, IL-2, interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha were similar among the three groups. However, the concentration of IFN-gamma in pleural effusion was high in tuberculous patients, and that of TNF-alpha was high in tuberculous and parapneumonic pleural fluid, but both cytokines were low in malignant pleural fluid. The sensitivity, specificity and accuracy of IFN-gamma in the diagnosis of tuberculous pleurisy were 94%, 100% and 98%, respectively. Similarly, those of TNF-alpha for the diagnosis of infectious pleurisy including tuberculous and parapneumonic pleurisy were 88%, 80% and 84%, respectively.

CONCLUSIONS

Our results indicate that simultaneous measurement of IFN-gamma and TNF-alpha in pleural effusion is a useful diagnostic tool for differentiating tuberculous pleurisy from parapneumonic and malignant pleurisy.

Growth and antigen recognition of tumor-infiltrating lymphocytes from human breast cancer

In the present study, we isolated tumor-infiltrating lymphocytes (TIL) from 21 primary solid tumors and tumor-associated lymphocytes (TAL) from 9 malignant effusions, respectively, of breast cancer patients. Significant proliferation and expansion of T cells was observed in 23 of 30 distinct samples. TIL were isolated from primary tumors by either enzymatic digestion or mechanical disruption. The TIL cultures were initiated using OKT3 mAb in the presence of moderate concentrations (25-50 U/ml) of IL-2, followed by 100 U/ml of tumor necrosis factor (TNF)-alpha. TAL were not stimulated with OKT3 mAb, but all were successfully expanded in culture in the presence of IL-2 alone or together with TNF-alpha. Seven of nine distinct TAL grew in culture as predominantly CD4+ lines. In contrast, only 14 of 21 (66%) of primary breast TIL expanded in culture and were predominantly of CD8+ phenotype. Autologous tumor lysis was observed in seven of eight cases tested. Only one of the four TIL tested and one of the four TAL tested preferentially lysed autologous tumor. HER-2 peptide E75 (369-377) was recognized by two TIL lines of the five primary TIL tested and three of the four TAL tested. This suggests that E75 may be recognized by primary breast tumors. This may be of interest in developing vaccine strategies for therapeutic management of breast cancer.

Cytodiagnosis of a primary effusion lymphoma. A case report

BACKGROUND

Primary effusion lymphoma (PEL), commonly described in AIDS patients, is a unique subset of lymphoma in which the neoplastic lymphocytes proliferate exclusively in serous cavities.

CASE

A 27-year-old male, HIV positive for five years and with multiple opportunistic infections in the past, was admitted for sudden-onset shortness of breath caused by a pleural effusion. Cytologic examination of the pleural fluid revealed medium to large atypical lymphocytes with a high mitosis rate, suspicious for lymphoma. Further diagnostic tests, such as immunophenotypic analysis and cytogenetic and molecular studies, confirmed the diagnosis of PEL.

CONCLUSION

Cytopathologists and cytotechnologists should be aware of this new entity since additional studies are required for a definitive diagnosis.

Generation of killer activity by interleukin-12 of mononuclear cells in malignant pleural effusions due to lung cancer

In the present study, we examined the ability of interleukin (IL)-12 to generate an antitumor effect in the tumor-growing site. Mononuclear cells (MNC) were obtained from 12 malignant pleural effusions due to lung cancer in the tumor-growing site. Non-major-histocompatibility-complex-restricted killer activity, examined by 4-h 51Cr release assay against Daudi lymphoma cells as well as various lung cancer cell lines (H69 and PC-9), and in vitro production of interferon gamma (IFNgamma), measured by enzyme immunoassay, were investigated as mediators of antitumor effects of host cells activated by IL-12. IL-12 induced killer activity of MNC in pleural effusions (pleural MNC) dose-dependently. Moreover, pleural MNC produced a signficant amount of IFNgamma in response to IL- 12. The killer activities of IL-12-activated blood MNC were higher than those of pleural MNC. The supernatants of pleural effusions of these untreated patients suppressed killer induction by IL-12 of blood MNC of healthy volunteers. These observations suggest that MNC present at the site of growing tumors may act as effector cells against lung cancer in the presence of IL-12.

AIDS-related primary lymphoma of the pleural cavity. A case report

BACKGROUND

Pleural effusions are common in patients with the acquired immunodeficiency syndrome (AIDS). Their most frequent causes are Kaposi's sarcoma and mycobacterial infections. We report cytologic, immunophenotypic and molecular features of a primary pleural non-Hodgkin's lymphoma (NHL) that represent an uncommon cause of isolated pleural effusion in patients with AIDS.

CASE

A 66-year-old, human immunodeficiency virus-positive male presented with chest pain and dyspnea. He had no history of opportunistic infections or Kaposi's sarcoma. A chest radiography displayed a right-sided pleural effusion. Cytology of pleural fluid revealed lymphomatous cells with markedly irregular nuclei. Their immunophenotype was indeterminate. Computed tomography of the thorax and abdomen did not show any tumor mass. Molecular analysis demonstrated that the lymphomatous cells had a B-cell genotype and contained Kaposi's sarcoma-associated herpesvirus (KSHV) and Epstein-Barr virus (EBV) DNA sequences.

CONCLUSION

This case belongs to a new subgroup of AIDS-related NHL that is characterized by unusual morphology, null immunophenotype, B-cell genotype and association with both KSHV and EBV.

Quantitative RNA slot-blot analysis of CCND1/cyclin D1 expression in suspected mantle cell lymphoma

Abnormal CCND1 expression is found in the majority of mantle cell lymphomas (MCL) and in a minority of other mature B cell malignancies. Its evaluation can therefore aid diagnostic classification, in conjunction with clinical, morphological, immunophenotypic and cytogenetic analysis. We describe a rapid slot-blot hybridization technique allowing quantitative assessment of CCND1 expression relative to beta-actin, with a sensitivity cut-off of approximately 10%. This allowed clear separation (P < 0.01) of CCND1 MCL (0.89 +/- 0.4; range 0.23-1.81; n = 25) from control samples (0.02 +/- 0.04; range 0-0.09; n = 22) on limited quantities of RNA (1-3.5 microg). Of nine samples in which a potential diagnosis of MCL lymphoma was based on morphological analysis of paraffin-embedded material, without adequate immunophenotype analysis, all were CCND1 negative and subsequent immunophenotype demonstrated features compatible with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) (CD5+, CD23+, FMC7-) in all cases tested. This study demonstrates the feasibility of slot-blot CCND1 quantification and the importance of the availability of cryopreserved material.

Cross regulation by IL-10 and IL-2/IL-12 of the helper T cells and the cytolytic activity of lymphocytes from malignant effusions of lung cancer patients

STUDY OBJECTIVE

Our previous report demonstrated that there was impairment of local cellular immunity with elevated interleukin-10 (IL-10) and undetectable IL-12 in neoplastic pleural effusion. These findings suggest that the local immune reactions favor the T-helper type 2 (Th2) pathway instead of Th1 pathway. The present study was designed to examine whether local cellular immunity could be manipulated by IL-2 and/or IL-12 treatment, and to determine their effect on the helper T-cell pathways and the cytolytic activity of the effusion-associated lymphocytes (EALs).

DESIGN

Using malignant pleural effusions obtained from four patients suffering from adenocarcinoma of lung, we separated the tumor cells from the EALs with Ficol-Hypaque centrifugation, followed by Percoll density centrifugation. To test whether the cytolytic function of lymphocytes could be enhanced by culturing with IL-2 and/or IL-12, lymphocytes were incubated with recombinant IL-2 with/without IL-12 for 6 days. Following this, the tumoricidal activity was assessed in an overnight 5'chromium-release assay. Autologous tumor cells for measuring specific antitumor activity, Daudi cells susceptible to lymphokine-activated killer cells, and NK-susceptible K562 cells were used as target cells.

MEASUREMENTS AND RESULTS

After treatment in vitro with IL-2, IL-12, or IL-2 plus IL-12, the Th pathway shifted from Th2 to Th1 type (increased gamma-interferon production). To further study the effect of cytokine treatment on the cytolytic activity of EALs, it was found that after 6-day culturing, the EALs failed to kill any of the three tumor targets, whereas the 6-day cultured peripheral blood lymphocytes (PBLs) gave low level of cytotoxicity against all three tumor targets. Stimulation with IL-2 alone partially restored the immunocompetence of EALs to kill the tumor targets. Stimulation with IL-12 alone showed no significant effect on their cytolytic activity. However, IL-12 synergized with IL-2 to increase the cytolytic activity of EALs and PBLs against autologous tumor targets. This synergistic effect was not found for Daudi cells and K562 cells.

CONCLUSIONS

These results suggest that EALs activated with IL-12 in the presence of a low concentration of IL-2, which converted the EALs from Th2 pathway to Th1 pathway, could be an alternative source of antitumor effectors for adoptive immunotherapy of cancer.

L-Myc overexpression and detection of auto-antibodies against L-Myc in both the serum and pleural effusion from a patient with non-small cell lung cancer

Non-small cell lung cancer patient was found to have auto-antibodies against L-Myc in both the serum and pleural effusion. The titer of anti-L-Myc antibodies was higher in the pleural effusion than in the serum. Overexpression of L-Myc without DNA amplification was observed in the tumor cells. L-Myc antigen was not detected in either the serum or the pleural effusion. Anti-nuclear antibodies were also detected in both the serum and pleural effusion, although this patient did not have collagen-vascular disease.

Restoration of the immunocompetence by IL-2 activation and TCR-CD3 engagement of the in vivo anergized tumor-specific CTL from lung cancer patients

The present study investigates the nature of the immunosuppressed state of the lymphocytes obtained from the malignant pleural effusion (effusion associated lymphocytes, EAL) of lung cancer patients. The immunocompetence of EAL from 13 patients was assessed by determining their T-helper cell phenotype, proliferative response to alpha CD3-activation, and their cytolytic activity against three tumor targets: the autologous tumor, Daudi, and K562. Flow cytometry analysis showed that the lymphocytes in EAL were predominantly T cells with < 1% natural killer cells. The T-helper cell phenotype was found to be predominantly of Th2 type, but could be readily converted to Th1 type by culturing the EAL in vitro, and this conversion was augmented by interleukin-2 (IL-2) or IL-2 plus alpha CD3. To test the cytolytic activity of EAL, it was found that after 6-day culturing, the EAL remained in an immunosuppressed state so that they failed to kill any of the three tumor targets. Stimulation with IL-2 partially restored the immunocompetence of EAL. Further engagement of TCR-CD3 by alpha CD3 fully restored the cytolytic activity of the EAL to kill the autologous tumor target but not Daudi or K562 tumor cells, and thus seemed to be tumor specific. The specificity was further confirmed by testing the activated EAL and normal donor peripheral blood lymphocytes against a variety of tumor targets and control targets. Furthermore, the killing by EAL against the autologous tumor target seemed to be major histocompatibility complex-restricted and was inhibited by anti-human leukocyte antigen class I antibody. The EAL from lung cancer patients also showed much reduced responsiveness to the alpha CD3 stimulation to induce proliferation, and addition of IL-2 restored the responsiveness. These results suggest that, through close contact with tumor cells, anergy of cytotoxic T lymphocytes (CTLs) was induced in vivo at a localized site. IL-2 stimulation and TCR-CD3 engagement could reverse the anergic state and restored the full competence of CTLs in EAL to mediate the specific anti-tumor killing against the autologous tumor. Proper manipulation of EAL may prove useful as a source of anti-tumor effectors for cancer adoptive immunotherapy.

HLA class I-restricted and tumor-specific cytotoxic T lymphocytes from metastatic lymph nodes of esophageal cancers

This paper investigates the presence of HLA class I-restricted and tumor-specific cytotoxic T lymphocytes (CTL) in tumor sites of esophageal cancers. Five CTL lines were established from the metastatic lymph nodes or pleural effusion by incubation with interleukin-2 of tumor-infiltrating lymphocytes: cases 1 and 5, HLA-A26- and HLA-A33-restricted and squamous cell carcinoma (SCC)-specific CTL; case 2, HLA-Cw0102-restricted and esophageal SCC-specific CTL; case 3, HLA-A24- and HLA-A26-restricted CTL recognizing histologically different tumor cells; and case 4, HLA-A26-restricted and esophageal SCC-specific CTL. These results suggest the existence of HLA class I-restricted and tumor-specific CTL in metastatic esophageal SCC.

Stimulation of antitumour immunity by intrapleural instillation of a Viscum album L. extract

Intrapleural administration of mistletoe extracts is reported to result in pleurodesis in cancer patients with malignant pleural effusions. In a recent study, 20 consecutive cancer patients with malignant pleural effusions were treated intrapleurally with the mistletoe extract Helixor. The overall response rate for pleurodesis was 72%, with only 1.2% displaying side effects of the World Health Organization classification I. The decline of tumour cells in the effusion liquid correlated negatively with the number of instillations. However, the elimination of tumour cells was associated with a transient increase in macrophages and eosinophils, and a constant increase in CD8+T cells. Compared to the responder group, the non-responders exhibited high proportions of macrophages, CD8+T cells and T cells with human leukocyte antigens with DR specificity (HLA-DR) in the effusion liquid, compatible with a disturbance of macrophage/T cell co-operation and thus failure to eliminate the malignant cells. The preliminary results suggest that mistletoe-mediated pleurodesis is due to a stimulation of antitumour immunity rather than mechanical sclerosis.

T-cell receptor biases and clonal proliferations in blood and pleural effusions of patients with lung cancer

We sought evidence that pulmonary carcinomas mediate a cellular immunologic response by analyzing T-cell antigen receptor beta-chain variable gene (TCRBV) repertoires of lymphocytes from peripheral blood (PBL) and malignant pleural effusions (PEL) of five lung cancer patients. Expression levels of 27 TCRBV were quantitated by multiprobe RNase protection assay (RPA), and clonal expansions were identified by sequence enrichment nuclease assay (SENA) and junctional region sequencing. Abnormal TCRBV expansions were identified in all subjects by RPA (mean 6.9 +/- 1.7/patient), and their number closely correlated with elapsed time since initial diagnosis (r = 0.97). SENA, performed in specimens from three patients, confirmed the presence of mono or oligoclonality in 48% of abnormal RPA expansions, and further identified T-cell clones among TCRBV with normal expression levels. The majority of clonal expansions were among PEL, and were nearly equally divided between CD4 and CD8. These data show that T-cell repertoires of lung cancer patients are characterized by marked abnormalities and frequent clonal expansions, most likely representing responses to unique, tumor-specific antigens (TSA). Moreover, this process appears exaggerated among PEL, further suggesting that malignant effusions include local proliferations of tumor reactive T cells. These findings imply the presence of lung cancer TSA capable of eliciting cellular immune responses and raise the possibility that selective immunotherapies can ultimately be developed.