Biomedical subjects

G E Peoples

Publications and source records attributed to G E Peoples.

At least 19 recordsLinked to original sources

PubMed2004

The utility of a rapid parathyroid assay for uniglandular, multiglandular, and recurrent parathyroid disease.

The rapid parathyroid hormone assay (rPTH) is an effective tool in minimally invasive resections of parathyroid adenomas. However, there are relatively few reports examining its utility in the full spectrum of parathyroid disease. The purpose of this study was to examine the utility of the rapid parathyroid hormone assay in uniglandular, multiglandular, and recurrent hyperparathyroidism. A retrospective analysis of all patients undergoing parathyroid resection from June 2001 to March 2003 was undertaken. All patients underwent preoperative localization studies. Rapid parathyroid hormone (PTH) levels were drawn immediately prior to and 10 minutes following parathyroid resection. A decline of > or = 50 per cent rPTH qualified as a successful/complete resection. Additional intraoperative samples were drawn as needed for patients with multiglandular disease. Of 46 treated patients who were examined (average age, 54 years), 30 had single, 12 patients had multigland disease, and 4 had recurrent/persistent hyperparathyroidism. Thirty-seven patients had primary hyperparathyroidism (32 with single and 3 with double adenomas; 2 with hyperplasia), 4 patients had secondary hyperparathyroidism, and 5 tertiary hyperparathyroidism. All procedures were considered successful, as every patient exhibited a postresection decrement in rPTH exceeding 50 per cent (average decrement, 91%). Although 2 patients exhibited a postoperative PTH increase exceeding 50 per cent of the preoperative value, all remained asymptomatic and eucalcemic (median follow-up, 21.5 months). The rPTH assay is an effective tool in determining success of parathyroidectomy in patients with primary uni- and multiglandular as well as recurrent hyperparathyroidism. It can be used to achieve minimally invasive neck dissections or guide surgical decision-making in more complex cases.

Calcium↗

PubMed2000

Quality of life and cost effectiveness analysis of therapy for locally recurrent rectal cancer.

PURPOSE: This study was performed to determine the quality of life and cost-effectiveness of therapeutic options for patients with locally recurrent rectal carcinoma, determined from the perspectives of patients and health care providers. METHODS: We reviewed the records of patients (N = 68) with locally recurrent rectal carcinoma evaluated from 1992 through 1995. We constructed a decision-analytic model incorporating outcomes, survival, and costs. Utilities were elicited from convenience samples of health care providers and patients using the standard gamble technique. RESULTS: The median survival for patients undergoing surgical resection (n = 40) was 42 months, compared with 16.8 months for patients undergoing diagnostic or palliative surgery (n = 16) and 18.3 months for patients treated nonoperatively (n = 12; P < 0.005). The mean cost of treatment per patient was $19,283 for the nonoperative group, $45,647 for the diagnostic or palliative surgery group, and $70,878 for the surgical resection group. The diagnostic or palliative surgical strategy was dominated by the nonoperative strategy because the former had greater costs with fewer health benefits. The incremental cost-utility ratio of surgical resection compared with nonoperative management using health care provider utilities was $109,777 per quality-adjusted life year gained; it was reduced to $56,698 using per quality-adjusted life year using mean patient utilities. CONCLUSIONS: Patients with recurrent rectal carcinoma view surgery and morbidity to be less severe than health care providers. Diagnostic or palliative surgery is expensive and affects quality-adjusted survival adversely compared with nonoperative therapy. Surgical resection may be a cost-effective use of resources, particularly when cost-effectiveness is calculated using patient preferences.

Aged↗

PubMed2000

Secretion of CXC chemokine IP-10 by peripheral blood mononuclear cells from healthy donors and breast cancer patients stimulated with HER-2 peptides.

CXC chemokines play an important role in recruitment of T cells to the site of activation and regulation of angiogenesis. CXC chemokines are secreted by T cells stimulated with cytokines or by established cytotoxic T lymphocyte (CTL) lines at recognition of conventional antigen (Ag), but the activation requirements and the relationship of interferon-gamma (IFN-gamma) inducible protein (IP-10) secretion with IFN-gamma induction in lymphocytes are still unclear. We studied the induction of IP-10 from nonadherent peripheral blood mononuclear cells (PBMC) by IFN-gamma, interleukin-12 (IL-12), and the HER-2 peptide E75, which forms a CTL-defined antigen. We found that IFN-gamma alone was a weak inducer of IP-10 in these cells, whereas IL-12 was a significantly stronger inducer of IP-10. In the presence of IL-12, the tumor peptide E75 (HER-2, 369-377) was a stronger inducer of IP-10 than was IL-12 alone. E75 and its variants mutated at position 5 could also induce IP-10 in the absence of exogenous IL-12 or IFN-gamma. IP-10 induction by E75 required HLA-A2 presentation and B7-CD28 interactions and was partially inhibited by blocking of CD40-CD40L interactions. These results indicate that presentation of tumor peptides to peripheral T cells can induce a fast chemokine response, which in its early phase may be higher than the IFN-gamma response. This shows that the IP-10 response was independent of any early-phase IFN-gamma response in peripheral T cells. This may be important for understanding the regulation of the balance between chemoattractant chemokines (CC) and CXC chemokines by tumor Ag and may have implications for understanding the mechanisms of polarization of T cells and conditioning of antigen-presenting cells (APC) by tumor antigens.

Breast Neoplasms↗

PubMed2000

Peptide priming of cytolytic activity to HER-2 epitope 369-377 in healthy individuals.

The presence of tumor-reactive CTLs in tumor infiltrates and in the peripheral blood of cancer patients demonstrates an immune response against tumors that apparently cannot control disease spread. This raises concerns as to whether amplification of this response may be useful during disease progression. Induction of tumor-reactive CTLs in healthy donors at risk, as well as in patients free of disease, may be therapeutically important, based on the hypothesis that CTLs that recognize tumors early may be more effective in containing their progression than CTLs that expand only when the disease progresses. To address the feasibility of priming cytolytic activity in healthy donors, we used the HER-2 peptide E75 (369-377) as an immunogen and autologous peripheral blood mononuclear cell-derived dendritic cells as antigen-presenting cells. We found that of 10 healthy donors tested, two responded at priming with E75 presented on autologous dendritic cells by induction of E75-specific CTL activity. Three other responders were identified after two additional restimulations. Of these five responders, three recognized E75 presented on the ovarian tumor line SKOV3.A2, as demonstrated by cold-target inhibition experiments. Induction of cytolytic activity at priming was enhanced in responders by tumor necrosis factor-alpha and interleukin 12 but not in the nonresponders. AlphaB7.1 monoclonal antibody added at priming enhanced induction of lytic activity in only one of the four nonresponding donors tested, suggesting that in the majority of donors, E75-precursor CTLs were not tolerized. Because of the possibility that disease may develop in nonresponders, strategies to improve the immunogenicity of tumor antigens for healthy donors may be required for development of cancer vaccines.

B7-1 Antigen↗

PubMed1999

Vaccine implications of folate binding protein, a novel cytotoxic T lymphocyte-recognized antigen system in epithelial cancers.

The immune system can be efficiently stimulated and targeted to specific antigens expressed exclusively or preferentially by experimental cancers. The foremost limitations to extending this vaccine technology to the prevalent epithelial-derived cancers are the lack of: (a) identified tumor-associated antigens recognized by cellular immunity; (b) antigens expressed on the majority of tumor cells during disease progression; and (c) immunogenic CTL epitopes. To date, only HER-2/neu has been shown to be the source of naturally occurring, MHC-restricted, CTL-recognized peptides in epithelial tumors. In this study, we demonstrate that the human high-affinity folate binding protein (FBP), which is a source of antigenic peptides recognized in ovarian cancer, is also recognized in breast cancer. Both immunodominant E39 (FBP, 191-199) and subdominant E41 (FBP, 245-253) epitopes are presented by HLA-A2 in these cancers. These peptides are efficient at amplifying the response of tumor-associated lymphocyte populations in terms of lytic function, enhanced proliferation, and specific IFN-gamma release. On a per cell basis, tumor-associated lymphocytes stimulated with the FBP peptides exhibit enhanced cytotoxicity not only against peptide-loaded targets but also against FBP-expressing epithelial tumors of different histologies. Furthermore, FBP peptides induced E39-specific CTLs and E39- and E41-specific IFN-gamma and IP-10 secretion in certain healthy donors. The broad distribution of FBP among >90% of ovarian and endometrial carcinomas, as well as 20-50% of breast, lung, colorectal, and renal cell carcinomas, along with pronounced differential overexpression in malignant tissues compared with the extremely limited expression in normal epithelium, suggests the exciting potential of a widely applicable FBP-based vaccine in epithelial cancers.

Antigen Presentation↗

PubMed1998

Ovarian cancer-associated lymphocyte recognition of folate binding protein peptides.

BACKGROUND: Tumor-associated lymphocytes (TAL) isolated from ovarian cancer patients contain cytotoxic T lymphocytes (CTL) capable of recognizing specific HLA/peptide complexes on tumor cells leading to tumor cell lysis. Currently, HER2/neu, overexpressed in only 30% of breast and ovarian cancers, is the only known source of CTL-recognized peptides in epithelial cancers. Therefore, we have investigated peptides derived from folate binding protein (FBP), which is over-expressed in more than 90% of ovarian cancers and in the majority of other epithelial tumors. METHODS: TAL were isolated from the malignant ascites of four consecutive HLA-A2+ ovarian cancer patients and incubated in IL-2. Initial chromium-release assays were performed within 1 week. T2 cells, incubated with peptide, were used to reconstitute T cell epitopes. The FBP sequence was interrogated for HLA-A2 binding peptides, and five were synthesized (E37-41). RESULTS: Freshly cultured, unstimulated ovarian TAL recognize peptides derived from FBP. These peptides are presented in the context of HLA-A2, and are specifically recognized in a HLA class I-restricted fashion. TAL recognition of these reconstituted T cell epitopes is concentration dependent. Furthermore, the FBP peptides are shown by cold target inhibition studies to be naturally processed and presented antigens. CONCLUSIONS: FBP peptides are recognized by freshly isolated TAL from ovarian cancer patients, suggesting in vivo expression and sensitization. Because FBP is over-expressed 20-fold in most adenocarcinomas, these peptides may be used in a widely applicable peptide-based vaccine for epithelial tumors.

Cancer Vaccines↗

PubMed1995

Tumor-specific and HLA-A2-restricted cytolysis by tumor-associated lymphocytes in human metastatic breast cancer.

A tumor-specific cytotoxic T lymphocyte (CTL) immune response has been well documented in melanoma, renal cell carcinoma, and ovarian cancer. Conflicting evidence exists regarding the existence of tumor-specific CTL populations in breast cancer. Tumor cells and tumor-associated lymphocytes (TAL) were isolated from the pleural effusions of six consecutive patients with metastatic breast cancer. After solid-phase anti-CD3 stimulation, TAL cultures were expanded with weekly autologous tumor stimulation and low-dose IL-2 for 3 wk. T cell populations were characterized using flow cytometric analysis and ranged from 49 to 91% CD8+, > 98% CD3+, and < 3% CD16+. Functionally, tumor-stimulated TAL showed tumor-specific recognition of autologous tumor cells (241 +/- 142 LU20/10(7)) and no detectable lysis of autologous fibroblasts, Daudi or K562. Cytotoxicity of TAL against HLA-A2+ allogeneic targets was significantly higher when compared with HLA-A2- tumor cell lines (127 +/- 76 vs 6 +/- 18 LU, p = 0.0001). This cytotoxicity against autologous and allogeneic tumor cells was blocked by anti-HLA-A2 mAb and cold HLA-A2+ targets in cold-target inhibition assays. TAL from all HLA-A2+ patients recognized GP2, a known, HER2/neu-derived tumor-associated peptide Ag that is HLA-A2 restricted. We have shown that TAL obtained from metastatic effusions of breast cancer patients contain lymphocytes that can recognize and lyse autologous and allogeneic tumor cells in a tumor-specific, HLA-A2-restricted fashion. In addition, tumor-specific TAL derived from breast cancer patients can selectively lyse HLA-A2+ pancreatic and ovarian tumor cell targets, suggesting a common HLA-A2-restricted tumor-associated Ag between these distinct epithelial cancers. Further elucidation of the cell-mediated immune response to breast cancer and the identification of shared TAA could result in the development of broadly applicable vaccine therapies for many cancers.

Adenocarcinoma↗

PubMed1995

Peripheral blood T lymphocytes and lymphocytes infiltrating human cancers express vascular endothelial growth factor: a potential role for T cells in angiogenesis.

CD3+ peripheral blood T lymphocytes were evaluated for expression of vascular endothelial growth factor (VEGF), an endothelial cell mitogen and potent angiogenic factor. VEGF mRNA expression was confirmed in CD3+ cells and Jurkat cells, a human T-cell line, by reverse transcription-PCR and in CD4+ and CD8+ T cell subtypes by Northern blot hybridization. Steady-state levels of VEGF mRNA were inducible in CD3+ T cells by hypoxia, a known inducer of VEGF mRNA accumulation. Secreted VEGF was detected in CD4+ and CD8+ T cell- and Jurkat cell-conditioned medium, indicating that T lymphocytes are capable of exporting bioactive concentrations of VEGF into the extracellular space. Human prostate and bladder cancers (prostatic adenocarcinoma and transitional cell carcinomas) were evaluated for VEGF mRNA expression by in situ hybridization. Tumor-infiltrating lymphocytes (TIL), identifiable immunocytochemically as T cells, along with tumor cells in these cancers, expressed VEGF mRNA. TIL in bladder cancers could be labeled with a specific anti-VEGF mAb, indicating that TIL are likely to be able to secrete VEGF protein in situ at bioactive concentrations. The finding that peripheral T cells and TIL in human tumors synthesize a factor known to be a specific mediator of neovascularization suggests a role for T lymphocytes as cellular effectors of angiogenesis.

Base Sequence↗

PubMed1995

T lymphocytes that infiltrate tumors and atherosclerotic plaques produce heparin-binding epidermal growth factor-like growth factor and basic fibroblast growth factor: a potential pathologic role.

Despite significant infiltration into tumors and atherosclerotic plaques, the role of T lymphocytes in these pathological conditions is still unclear. We have demonstrated that tumor-infiltrating lymphocytes (TILs) and plaque-infiltrating lymphocytes (PILs) produce heparin-binding epidermal growth factor-like growth factor (HB-EGF) and basic fibroblast growth factor (bFGF) in vitro under nonspecific conditions and in vivo in tumors by immunohistochemical staining. HB-EGF and bFGF derived from TILs and PILs directly stimulated tumor cells and vascular smooth muscle cells (SMCs) in vitro, respectively, while bFGF displayed angiogenic properties. Therefore, T cells may play a critical role in the SMC hyperplasia of atherosclerosis and support tumor progression by direct stimulation and angiogenesis.

3T3 Cells↗

PubMed1995

Breast and ovarian cancer-specific cytotoxic T lymphocytes recognize the same HER2/neu-derived peptide.

The identification of antigenic peptides presented on the tumor cell surface by HLA class I molecules and recognized by tumor-specific cytotoxic T lymphocytes may lead to a peptide vaccine capable of inducing protective cellular immunity. We demonstrate that both HLA-A2-restricted breast and ovarian tumor-specific cytotoxic T lymphocytes recognize shared antigenic peptides. At least one of these peptides is derived from the oncogene product of HER2/neu, which is overexpressed in 30-40% of all breast and ovarian cancers. T cells sensitized against this nine-amino acid sequence demonstrate significant recognition of HLA-A2+, HER2/neu+ tumors. Since 50% of the tumor-cell population is HLA-A2+ and many different tumors express HER2/neu, this peptide may be widely recognized and have many clinical applications.

Antigens, Neoplasm↗

PubMed1995

Shared T cell epitopes in epithelial tumors.

We have previously shown the importance of human leukocyte antigen (HLA)-A2 and the proto-oncogene HER2/neu in the T cell recognition of ovarian cancer. Since these proteins are ubiquitously expressed in epithelial-derived tumors, we have acid-eluted HLA-bound peptides from ovarian cancers, fractionated the peptides, and reconstituted T cell epitopes on the HLA-A2+ T2 cell line to determine if common tumor-associated antigens exist among HLA-A2+, HER2/neu+ epithelial cancers. We demonstrate that tumor-specific cytotoxic T lymphocytes (CTL) generated from tumor-infiltrating lymphocytes isolated from three ovarian, two breast, and two non-small-cell lung cancers recognize at least three of the same peptide fractions from multiple elutions. One of these peptide fractions coelutes with a HER2/neu-derived peptide which has been shown recently to be recognized by these same CTL. These findings demonstrate that a common peptide-based tumor vaccine is theoretically possible for many different epithelial-derived cancers.

Antigens, Neoplasm↗

PubMed1995

In vitro stimulation of ovarian tumour-associated lymphocytes with a peptide derived from HER2/neu induces cytotoxicity against autologous tumour.

The proto-oncogene HER2/neu encodes for a 185 kDa transmembrane protein with extensive homology to the epidermal growth factor (EGF) receptor. We have previously shown a correlation between HER2/neu expression and the level of in vitro cytotoxicity of tumour-associated lymphocytes (TAL) versus autologous tumour. In addition, we have recently demonstrated that tumour-associated cytotoxic T-lymphocytes (CTL) from ovarian and breast cancer patients can recognize a HER2/neu derived peptide epitope when presented in the context of HLA-A2. Since repeated tumour stimulation of CTL enhances both proliferation and cytotoxicity against autologous tumour, we hypothesized that repeated peptide antigen stimulation would have a similar effect. To be therapeutically useful, the peptide antigen must meet the following conditions: (1) the peptide must be immunogenic and cause a proliferation of CTL to adequate therapeutic numbers, and (2) the peptide-specific CTL which are generated must be cytotoxic against autologous tumour. To test our hypothesis, T-lymphocytes isolated from the ascites of four consecutive HER2/neu+ ovarian cancer patients were initially stimulated with solid phase anti-CD3 antibody and divided into three groups: (1) treatment with recombinant interleukin-2 (IL-2) alone, (2) IL-2 plus weekly stimulation with irradiated autologous tumour cells, and (3) IL-2 plus weekly stimulation with a HER2/neu derived peptide. Peptide-stimulated and tumour-stimulated CTL showed similar increases in proliferation with both groups consistently reaching therapeutic numbers. Peptide-stimulated CTL demonstrated significantly enhanced cytotoxicity against autologous tumour in 4-h chromium release assays as compared to the IL-2 alone group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗

PubMed1994

Human tumor-infiltrating CD4+ T cells react to B cell lines expressing heat shock protein 70.

Human tumor-infiltrating lymphocytes (TIL) include a minor population of tumor-specific T cells, but the nature of the majority of TIL remains unknown. Recently, it has been suggested that T cells that recognize stressed cells may play an important role in immune surveillance. We have examined the proliferative response of anti-CD3-activated TIL cultures from human tumors against heat-stressed (hs) (42.8 degrees C, 25 min) B cell lines (TK6 (HLA-DR7+, -DRw13+, -DRw52+, and -DRw53+) and JY (HLA-DR4+ and -DRw52+)) and the mutant cell line (T2 (no HLA-DR)) by measuring [3H]thymidine incorporation. TIL lines from three of four ovarian cancers, two of four lung cancers, one of two renal cell cancers, one of two melanomas, and one of one breast cancer showed a positive proliferative response against hs-TK6 and/or hs-JY, but not against hs-T2. These TIL did not respond to autologous tumor cells. The response to hs-B cells was mediated by CD4+ TIL and inhibited by anti-HLA-DR Ab, but not by anti-HLA class I. Protein analysis revealed a significant increase of heat shock protein 70 (hsp70) expression in hs-TK6 and hs-JY. In addition, the CD4+ TIL responded to TK6 that had been pulsed with hsp70. This response could be blocked by anti-HLA-DR Ab. The CD4+ TIL produced IFN-gamma, but not IL-4, in response to hs-TK6. From these results, we conclude that hsp70-reactive CD4+ T cells exist in tumor tissues. Furthermore, these TIL recognize stressed cells and seem to play a Th1-like role that may support antitumor T cell responses at local tumor sites.

Antibodies, Monoclonal↗

PubMed1994

HER2/neu-derived peptides are shared antigens among human non-small cell lung cancer and ovarian cancer.

Previously, we have reported a correlation between the expression of HER2/neu and sensitivity to HLA-A2-restricted cytotoxic T-cells (CTL) in ovarian cancer. To investigate the role of HER2/neu in human non-small cell lung cancer (NSCLC), we established autologous tumor-specific CTL from tumor-infiltrating lymphocytes of HLA-A2+ HER2/neu+ NSCLC patients. These CTL lines specifically recognized HLA-A2+ HER2/neu+ autologous and allogeneic NSCLC cell lines as well as HLA-A2+ HER2/neu+ heterologous ovarian cancer cell lines. Furthermore, these CTL recognized an overexpressed, HER2/neu-derived peptide. From these results, we conclude that HLA-A2 serves as a restriction element in NSCLC. More importantly, at least one HER2/neu-derived peptide is a tumor-associated antigen in NSCLC and ovarian cancer.

Antigens, Neoplasm↗

PubMed1994

TCR V beta 3+ and V beta 6+ CTL recognize tumor-associated antigens related to HER2/neu expression in HLA-A2+ ovarian cancers.

We have recently shown that HLA-A2-restricted, tumor-specific CTL can be isolated from tumor-infiltrating lymphocytes (TIL) in ovarian cancer, and that the sensitivity of ovarian tumors to these CTL is correlated with HER2/neu expression. Furthermore, utilizing PCR, we have documented previously that V beta 2, V beta 3, V beta 6, and V beta 7 are represented in increased proportions in ovarian tumor-specific CTL lines. Therefore, to correlate the interaction of these specific TCR V beta segments with the HLA-A2 molecule and potential tumor-associated Ags (TAA) related to HER2/neu expression, we have utilized available mAbs to V beta 2, V beta 3, and V beta 6. We found that V beta 2+, V beta 3+, and V beta 6+ CTL mediate antitumor activity, and a combination of these mAbs resulted in 83 to 95% inhibition of the cytotoxicity against autologous tumor from three separate patients. These mAbs also were capable of blocking HLA-A2-matched allogeneic cytotoxicity, suggesting that all three V beta families recognize TAA in the context of HLA-A2. An HLA-A2+ melanoma was transfected with the HER2/neu gene and became sensitive to HLA-A2+ ovarian cancer-specific CTL lysis. This cytotoxicity was mediated by V beta 3+ and V beta 6+ CTL, as demonstrated by mAb-blocking studies. FACS-depletion studies confirmed that CTL populations depleted of V beta 3 or V beta 6 no longer could recognize the HER2/neu transfectant. We conclude that V beta 3 and V beta 6 recognize some TAA that are either derived from the HER2/neu protein or induced by the expression of the HER2/neu gene and presented in the context of HLA-A2. Furthermore, V beta 2 seems to recognize an HER2/neu-unrelated Ag system also presented by HLA-A2.

Antigens, Neoplasm↗

PubMed1994

T lymphocytes synthesize and export heparin-binding epidermal growth factor-like growth factor and basic fibroblast growth factor, mitogens for vascular cells and fibroblasts: differential production and release by CD4+ and CD8+ T cells.

T lymphocytes infiltrate wounds, tumors, and atherosclerotic plaques, pathophysiological processes characterized by the migration and proliferation of vascular cells and fibroblasts. Although T lymphocytes are known to produce cytokines for inflammatory cells, it has not been demonstrated that they synthesize growth factors that are mitogenic for vascular cells and fibroblasts. We demonstrate that cultured T lymphocytes isolated from normal human peripheral blood synthesize and export two well-characterized growth factors, heparin-binding epidermal growth factor-like growth factor (HB-EGF) and basic fibroblast growth factor (bFGF). This conclusion is based on mRNA expression analysis, heparin-affinity chromatography profiles, target-cell specificity, and functional inhibition by specific neutralizing antibodies. Atypically, a substantial amount of T-cell-derived bFGF-like activity appears to be constitutively released into conditioned medium, almost as much as is associated with T-cell lysates. bFGF is synthesized and exported by purified CD4+ and CD8+ T cells, whereas HB-EGF is synthesized and exported primarily by CD4+ T cells. The T-cell-derived HB-EGF and bFGF activities are potent mitogens for fibroblasts and smooth muscle cells, and the bFGF-like activity is also mitogenic for endothelial cells. These results suggest that T lymphocytes may play key roles in mediating smooth muscle hyperplasia associated with atherosclerosis and in angiogenesis associated with wound healing and tumor growth by acting locally to deliver vascular-cell growth factors to tissues.

CD4-Positive T-Lymphocytes↗

PubMed1994

Association of HER2/neu expression with sensitivity to tumor-specific CTL in human ovarian cancer.

To study potential sources of tumor-associated Ags in human ovarian cancer, we have established two ovarian tumor cell lines (OvS1 and OvA2) from two ovarian cancer patients, which express the cellular oncogene HER2/neu. Corresponding tumor infiltrating lymphocyte cultures have also been established and display an autologous tumor-specific pattern of cytotoxicity that is HLA-A2 restricted. To determine the potential relationship between HER2/neu expression and CTL-mediated cytolysis, we first established tumor cell clones from OvS1. These were categorized as high or low expressors of HER2/neu (cOvS1+ or cOvS1-, respectively), and cOvS1+ clones displayed a significantly higher sensitivity to CTL killing as compared with cOvS1- clones. To modulate the expression of HER2/neu, ovarian cancer cells were treated with IFN-gamma. After this exposure, HER2/neu expression was significantly decreased, whereas the expression of HLA Class I was significantly increased. Despite the increase in HLA Class I molecules on the cell surface, CTL-mediated cytolysis of both OvS1 and OvA2 was significantly decreased. IFN-gamma treated cOvS1+ clones displayed a similar decrease in sensitivity to CTL killing, whereas IFN-gamma treated cOvS1- clones displayed an increase or no change in sensitivity to CTL. To confirm this apparent association between HER2/neu expression and CTL recognition, melanoma tumor cell lines that were insensitive to ovarian tumor-specific CTL were transfected with the HER2/neu gene. An HLA-A2+ HER2/neu-transfected melanoma cell line was made sensitive to HLA-A2 restricted ovarian tumor-specific CTL but not to HLA-A2 unrestricted CTL, whereas an HLA-A2- HER2/neu-transfected melanoma remained insensitive to HLA-A2 restricted CTL. These results demonstrate that the sensitivity of ovarian epithelial tumor cells to CTL-mediated lysis is associated with the level of expression of HER2/neu, suggesting that this oncogene product may serve as a source of tumor-associated Ags or as an inducer of such peptides. This is the first time in a human tumor system that oncogene expression has been related to the induction of antigenicity. These results prompt us to approach new strategies for immunotherapy of cancer.

Antibodies, Monoclonal↗

PubMed1994

Classification of CD4+ T helper cell clones in human melanoma.

We have previously described the generation of tumor-infiltrating lymphocyte (TIL) clones from renal cell cancer by solid-phase anti-CD3 antibody activation and expansion in 100 IU/ml IL-2 plus irradiated allogeneic B cells. These culture conditions did not select for a particular T cell subset. Using these culture conditions, we report here the generation of 66 CD4+ and 36 CD8+ TIL clones from five patients with melanoma. Eighty-five percent of the CD4+ TIL clones were not cytolytic (< 30% lysis, E:T 20:1) as determined by antibody-redirected lysis (ARL), whereas all CD8+ clones showed strong ARL activity (> 30% lysis). Clones were further tested for production of IL-2, IL-4, and IFN-gamma after activation for 48 hr by solid-phase anti-CD3. CD8+ clones produced significant amounts of IFN-gamma, little IL-2, and no IL-4. CD4+ clones were classified as Th0, Th1, or Th2, analogous to the classification of T helper cells in the mouse. Sixty-six percent existed as Th0, producing IL-2, IL-4, and IFN-gamma. Only 15% existed as Th1, producing IL-2 and IFN-gamma, and 19% as Th2, producing IL-4 but no IL-2 or IFN-gamma. In all cases, unstimulated clones or clones stimulated with the allogeneic B cell line did not produce detectable amounts of cytokines. Solid-phase anti-CD3 activation was compared to activation with autologous melanoma cells. Five of nine CD8+ clones produced low amounts of IL-2 (< 200 pg/ml/10(6) cells) in response to autologous tumor, but none of the CD8 clones produced IFN-gamma or IL-4. Also, 5/7 Th0 clones from one patient produced similar amounts of IL-2 after stimulation with anti-CD3 or autologous tumor. The other two clones produced only 10% or less of the amount produced in response to anti-CD3. No IL-4 or IFN-gamma could be detected in response to autologous tumor. In contrast, none of the 12 T helper clones from two other patients produced any cytokines after stimulation with autologous tumor cells. Together these data suggest that the T cell infiltrate in melanoma consists primarily of IL-2-producing Th0 cells, but few of those are triggered by autologous tumor cells.

CD4-Positive T-Lymphocytes↗