The Journal of Immunology, 2008, 180, 3578-3584
Copyright © 2008 by The American Association of Immunologists, Inc.
Questionable Relevance of 
T Lymphocytes in Renal Cell Carcinoma1
Brant A. Inman*,
Xavier Frigola
,
Kimberley J. Harris,
Susan M. Kuntz,
Christine M. Lohse
,
Bradley C. Leibovich* and
Eugene D. Kwon2,*,
* Department of Urology,
Department of Immunology, and
Department of Health Sciences Research, Mayo Clinic College of Medicine, Rochester, MN 55905
 |
Abstract
|
|---|
Adoptive 
T cell immunotherapy has moved briskly into clinical trials prompted by several small studies suggesting abundant accumulation of T cells within renal cell carcinoma (RCC). In this study, we re-examined levels of T cells within RCC tumors and correlated levels of these cells with pathologic features and outcome associated with this form of cancer. Tissues from 248 consecutive clear cell RCC tumors obtained from 2000 to 2003 were stained and quantified for total CD3+ and T cells per mm2. Wilcoxon rank sum and Kruskal-Wallis tests were used to evaluate associations between T cell amounts and prognostic factors (age, gender, tumor size, stage, grade, tumor necrosis). Cox models were used to assess associations with RCC-specific death. Median numbers of total CD3+ and T cells were 281/mm2 (interquartile range (IQR): 149–536) and 2.6/mm2 (IQR: 1.3–4.6), respectively. The median percentage of CD3+ T cells that were T cells was 1.0% (IQR: 0.4–1.9). This low percentage of intratumoral T cells was diluted even further with rising CD3+ T cell infiltration. Percentages of T cells were not associated with even one single clinicopathologic feature examined. Median follow-up for this study was 3.1 years (48 patients died of RCC) and Cox analysis failed to demonstrate that T cells (hazard ratio = 1.02, p = 0.25) were predictive of RCC-specific death. T cells are rare and not recruited nor expanded within RCC tumors. Percentages of T cells fail to correlate with any prognostic features of RCC nor specific death. As such, the role of T cells in RCC immunobiology remains questionable.
|
Introduction
|
|---|
Immunotherapy has long represented a mainstay treatment for patients with advanced renal cell carcinoma (RCC)3 (1, 2). Despite the clinical investigation of various agents for anticancer treatment, immunotherapy with high-dose IL-2 persists as the only therapeutic modality that can produce durable and even complete responses in minor subsets of patients with metastatic RCC (3). It is therefore understandable that many groups remain actively engaged in seeking out novel approaches to manipulate the patient’s immune system to evoke more efficacious immunotherapeutic responses to manage advanced RCC.
The vast majority of human T cell-mediated immunity is provided by T lymphocytes, of which >95% express the 
β TCR. In contrast, <5% of circulating T cells express the TCR and the role of such T cells remains hotly debated and enigmatic. One recent experimental antitumoral approach that has been proposed as a treatment for advanced RCC is adoptive T cell immunotherapy (4, 5, 6). The rationale for this approach has been primarily predicated on: 1) a reported relative abundance of T cells in the mononuclear cell infiltrates of RCC tumors (7), 2) associations of T cells with some pathologic features of RCC and (8), and 3) demonstrations that T cells stimulated with pyrophosphate derivatives exhibit cytolytic activity against RCC target cells ex vivo (4, 7). Of concern, however, is that much of the impetus for clinical trial testing of T cell adoptive immunotherapy has been provided by way of indirect immunologic studies (5, 6), typically involving very small numbers of patient tumor specimens and often without consideration of RCC tumor subtype (4, 7, 8, 9, 10).
In response to these concerns, we quantified levels of T cells present in 248 consecutive clear cell RCC (ccRCC) tumor specimens and correlated these values with widely accepted clinicopathologic prognostic features of ccRCC aggressiveness as well as cancer-specific outcomes. In this study, we report that percentages of intratumoral T cells are consistently low in nearly all tumor specimens examined and failed to correlate with any prognostic feature of ccRCC or with cancer-specific survival. Percentages of T cells bearing the TCR were no higher in the tumor than in the peripheral blood and, in fact, declined even further with rising CD3+ T cells infiltration of ccRCC tumors. Taken together, these data suggest that T cells do not accumulate within ccRCC tumors and argue strongly against T cell clonal expansion or recruitment into ccRCC tumors. Moreover, we did not observe a single association between the low level of T cells within renal tumors and any of the established prognostic clinicopathologic features described for ccRCC. Thus, a role for T cells in altering the biology of ccRCC tumors, either in the normal in situ setting or in the context of immunotherapy, should be carefully reconsidered.
|
Materials and Methods
|
|---|
RCC patients
After obtaining institutional review board approval, we identified a consecutive series of patients who were treated surgically with partial or radical nephrectomy for ccRCC from 2000 to 2003 and for whom fresh-frozen tissue was available for evaluation. We restricted our analysis to noncystic clear cell cases because this is the predominant histologic variant of RCC (
80% of cases) and carries a prognosis that is different from the papillary and chromophobe variants of RCC (11). A total of 248 patients met these inclusion criteria and all were followed postoperatively for the development of important clinical outcomes such as metastasis and death. Symptomatic patients were defined by their presentation with a palpable renal mass, abdominal discomfort, gross hematuria, acute onset varicocele, or constitutional symptoms including rash, sweats, weight loss, fatigue, early satiety, and anorexia. Death was attributed to RCC if it was listed as the immediate or contributing cause of death on the death certificate. In cases where the cause of death was ambiguous or unknown, the entire medical record was reviewed by a urologist and the death was attributed to RCC if the patient had metastatic RCC within 6 mo of the date of death.
Isolation of PBMCs
PBMCs were isolated from 13 Leukotrap WB leukoreduction filters (Pall) used in the routine processing of normal human donor blood. The filters were backflushed with 50 ml of 5 mM EDTA in PBS and eluted cells were layered onto a Lymphoprep sucrose density gradient (Accurate Chemical & Scientific) that was then centrifuged at 2000 rpm for 30 min. The mononuclear interface layer was collected and washed twice, resuspended in ACK buffer (155 mM NH4Cl, 10 mM KHCO3, and 0.1 mM EDTA, pH 7.2), and then washed twice in 0.9% NaCl. The remaining cell population was counted using trypan blue exclusion and then cryopreserved at –80°C in Recovery cell freezing media (Invitrogen Life Technologies).
Antibodies
The primary Abs used in this study included polyclonal rabbit anti-human CD3 (A0452; DakoCytomation), Immu510 murine anti-human TCR mAb (Beckman Coulter), and TCR--1 clone 11F2 murine anti-human TCR mAb (BD Biosciences). For flow cytometry experiments, PE-labeled TCR--1 (BD Biosciences) and Immu510 labeled with Alexa488 by a Zenon labeling kit (Invitrogen Life Technologies) were used. Isotype control Abs used in various experiments were purchased from BD Biosciences.
Flow cytometry
Before staining, frozen PBMCs were thawed at 37°C for 2 min, washed with FACS buffer (PBS, 3% FBS, and 1 mM EDTA), and counted using trypan blue exclusion. In brief, 106 cells were used for each experimental condition. Fc receptors were blocked with 2% human serum (Sigma-Aldrich) for 20 min and then the appropriate Abs were added for 30 min, both steps occurring in the dark at 4°C. After two washes in FACS buffer, cell surface expression of CD3 and TCR was quantified by flow cytometry using a FACSCalibur FACS (BD Bisociences) and analyzed with FlowJo software (Tree Star). Gating was done on forward vs side scatter plots for live lymphocytes and 2 x 104 cells were counted and included for each analysis. Matched isotype controls for R-PE and Alexa Fluor 488 were used to determine thresholds for positive expression.
Immunohistochemistry
ccRCC cryosections were mounted on Superfrost Plus slides, air dried, and fixed in –20°C acetone. Serial sections were stained on a DakoCytomation Autostainer for CD3 and for the TCR using the Biocare Mach 4 HRP-polymer (Biocare Medical) and DakoCytomation EnVision+ System-HRP (diaminobenzidine) kits, respectively. Slides were blocked with H2O2 for 5 min, followed by incubation with primary Ab for 30 min at room temperature. Labeled polymer was then applied at room temperature for 30 min followed by incubation with chromogen substrate for 10 min. Finally, sections were counterstained with Hematoxylin 7211 (Richard-Allan Scientific). Positive controls for CD3 and TCR staining consisted of human tonsillar tissue resected for chronic tonsillitis (12). Irrelevant isotype-matched Abs were used to control for nonspecific staining.
Pathologic evaluation
Each tumor specimen was centrally reviewed by a urologic pathologist blinded to clinical outcome to obtain a consistent set of histopathologic prognostic features for analysis, including: International Union Against Cancer histologic subtype (13), nuclear grade (14), tumor-node-metastasis (TNM) 2002 tumor stage (15), tumor size, the presence of histologic coagulative tumor necrosis, and sarcomatoid differentiation (11). To quantify T lymphocytes, numbers of CD3+ and T cells in each of five representative high-powered fields were systematically counted using a Leica DMR microscope (Leica Microsystems). Using a 10/25 eyepiece and a x40 objective, the Leica DMR has an object field diameter of 0.625 mm resulting in a high-powered field area of 0.307 mm2. We therefore present all CD3+ T cell data as number of cells per mm2 of tumor tissue. T cell counts are also expressed as the number of cells per mm2 of tumor tissue as well as a percentage of overall CD3+ T cells to indicate the contribution of T cells relative to the intratumoral pool of infiltrating CD3+ T cells.
Statistical methods
The associations of CD3+ and T cells with clinicopathologic features of the ccRCC cohort were evaluated using Wilcoxon rank sum and Kruskal-Wallis tests. Survival outcomes of the study cohort were estimated using the Kaplan-Meier method. Greenwood’s estimate of the SE was used on the complementary log-log scale to construct 95% confidence intervals (CI) for these estimates. Cox proportional hazards models were used to assess the magnitude of associations between CD3+ and T cells with patient outcome, both univariately and after multivariate adjustment for the SSIGN score. The SSIGN score is a validated prognostic tool for surgically treated ccRCC that incorporates tumor stage, tumor size, tumor grade and the presence of histologic coagulative tumor necrosis to predict cancer-specific survival (16). Graphical methods used to evaluate the functional form of the association of CD3+ and T cells with death from ccRCC did not indicate that these features should be transformed or categorized (even after deleting one T cell outlier).
The agreement of the two anti- TCR Abs in detecting T cells by flow cytometry was evaluated using the cell as the unit of measure and each patient as an independent sample. 
statistics were therefore generated for each of the 13 patients whose PBMCs were studied and these 13 values were then tested for pooling using the technique of Donner and Klar for multiple samples (17). Due to the large number of cells counted in FACS experiments and the resulting high level of statistical power, the test for heterogeneity among the 13 independent samples was highly significant (p < 0.001), indicating that pooling of the statistics would not be valid. We therefore report the individual statistics instead of one overall measure of Ab agreement.
|
Results
|
|---|
Characteristics and clinical outcomes of the study cohort
The clinicopathologic characteristics of the study cohort are given in Table I. Median patient age was 64 years (interquartile range (IQR): 56–72) and the median duration of patient follow up was 3.1 years. To date, 68 patients (27%) have died, 48 of whom died of ccRCC at a median of 1.3 years following nephrectomy. The estimated cancer-specific survival rates at 1, 3 and 5 years following surgery were 92% (95% CI, 89–96%; at risk = 222), 81% (95% CI, 76–86%; at risk = 107) and 75% (95% CI, 68–83; at risk = 21), respectively.
Immu510 and TCR--1 Abs identify similar populations of T cells
We initially optimized our immunohistochemistry (IHC) protocol using the Immu510 Ab because this Ab is a published pan- TCR-recognizing Ab that can be used for IHC study of fresh-frozen human tissues (12, 18). To confirm that Immu510 was capable of accurately identifying T cells, we compared it to a second mAb, TCR--1 (19), in flow cytometry experiments. Thirteen independent peripheral blood samples were tested for Ab concordance by three double-staining sequences: Immu510 followed 30 min later by TCR--1, TCR--1 followed 30 min later by Immu510, and both Abs given concurrently. These experiments revealed that the sequence of Ab staining had no impact on T cell detection by either Ab and that the two Abs recognized similar cells bearing the TCR (Fig. 1). Specifically, the statistics for agreement between the two Abs in the 13 patient PBMC samples studied were 0.643, 0.734, 0.790, 0.794, 0.828, 0.861, 0.864, 0.870, 0.904, 0.909, 0.929, 0.939, and 0.973, respectively.
Intratumoral T cells are not prognostic indicators of ccRCC outcome
Several small reports have suggested that T cells might be important in the pathogenesis of RCC (Table II and Refs. 4 and 7, 8, 9, 10), and clinical trials testing T cell immunotherapy in RCC patients are already underway (5, 6). We performed IHC for CD3 and the TCR on fresh-frozen tumor specimens obtained from a consecutive series of 248 ccRCC cases. Due to its known enrichment for T cells, human palatine tonsillar tissue, surgically removed for chronic tonsillitis, was used as a positive control (Fig. 2, A and B, and Ref. 12). We observed that the median number of CD3+ T cells in the ccRCC specimens was 281/mm2 (IQR: 149–536) while the median number of T cells was 2.6/mm2 (IQR: 1.3–4.6). When T cells were expressed as a percentage of CD3+ T cells, the median percentage of CD3+ T cells bearing TCR was 1.0% (IQR: 0.4–1.9). However, 3 of 248 tumors contained CD3+ T cell infiltrates comprised of 
20% T cells (Fig. 2F). We also observed that the median percentage of T cells decreased (even below peripheral blood values) as intratumoral CD3+ T cell counts increased, suggesting that intratumoral T cells are diluted by increasing T cell infiltration (Fig. 3A). This observation does not support that T cells accumulate within ccRCC tumors, whether through active recruitment or intratumoral clonal expansion.
Associations of intratumoral CD3+ and T cell counts with conventional ccRCC prognostic features were also explored and we observed no associations between the percentage of intratumoral T cells that expressed the TCR and any of the well-established prognostic factors for ccRCC (Table III). We also found no association between absolute T cell counts and the SSIGN score (Fig. 3B), indicating that T cell counts remained low as the severity of disease increased, bolstering the argument that clonal expansion and specific recruitment of T cells does not occur in ccRCC. Univariate Cox models showed that percentages of T cells (hazard ratio = 1.02; 95% CI, 0.99–1.06; p = 0.250) failed to be predictive of cancer-specific survival (Fig. 4). Likewise, after adjusting in multivariate Cox models for the SSIGN score, we still found that percentages of ccRCC-infiltrating T cells (hazard ratio = 0.98; 95% CI. 0.94–1.02; p = 0.392) did not predict cancer-specific survival.
|
Discussion
|
|---|
In our present study, we failed to confirm the previous literature suggesting that T cells accumulate to abundant levels within ccRCCs of the kidney. As such, our study raises a fundamental question as to whether or not T cells play a significant role in the biology of ccRCC (4, 7, 8, 9, 10). Limitations of our study include its relatively short 3-year median follow up which is accompanied by a mortality rate of 27%. However, given that the estimated 10-year ccRCC-specific death rate is roughly 35% (11), it is clear that our current study encompasses more than half of all anticipated events and, thus, portrays a representative experience of expected outcomes for patients with ccRCC. In addition, it is unlikely that other patient selection factors significantly influenced the key findings of our study given that the clinicopathologic features of our study cohort (detailed in Table I) closely parallel features of ccRCC patients encountered in most western medical centers.
In several small studies in which histologic subtype of RCC tumors has been largely ignored, it has been reported that levels of T cells within RCC tumors exceed levels of T cells observed in the periphery. In addition, levels of tumor-infiltrating T cells have been reported to correlate with a few prognostic features of RCC (summarized in Table II). It has further been suggested that T cells, including TCR V9V2 T cells, constitute the predominant lymphocyte population infiltrating RCC tumors and that bromohydrin pyrophosphate-stimulated TCR V9V2 T cells exhibit an ability to lyse RCC target cells in vitro (7). Lastly, a considerable body of literature has reported that T cells play a specialized role in mediating inflammatory responses within normal epithelia injured by trauma, infection, or encroaching malignant processes (20). Emboldened by these collective observations, clinical trials have been pursued with the expectation that adoptive T cell therapy may prove useful as an antitumoral immunotherapeutic approach to treat patients with advanced RCC as well as other forms of malignancy (5, 6).
Our present data fail to support the publication of Viey et al. (7), in which it was reported that T cells (as well as V2 TCR-bearing T cells) comprise "the major component" of infiltrating T cells within renal tumors, observations that were based on detailed investigations of only three patient RCC tumor specimens. Specifically, our examination of 248 consecutive specimens clearly demonstrates that only 1% of all CD3+ T cells within ccRCC specimens are of the T cell subtype. Thus, on average, percentages of T cells within ccRCC tumors remain comparable to values observed in normal peripheral blood, a finding that is consistent with two other studies: one conducted using IHC (8) and the other using flow cytometry (10), both demonstrating very low levels of intratumoral T cells within RCC tumors. This observation alone raises concerns regarding the relevance of T cells in altering the biology of RCC tumors. It is possible that T cells die soon after interacting with tumor cells, thus making their detection by IHC impossible. However, such an occurrence would support our argument that T cells are not effective tumoricidal cells. If T cells die each time they try to infiltrate and attack a tumor, a phenomenon similar to peripheral clonal deletion would be occurring, which would imply that the tumor has gained the capacity of targeted immunosuppression. Why would we want to treat a tumor with a therapy that it so easily bypasses?
The assertion that adoptive transfer of T cells (stimulated and expanded ex vivo) might produce favorable responses in patients with advanced ccRCC is impossible to rule out with the current study data. It is possible that manipulated T cells might acquire functional capacities that they did not possess naturally and therefore become more tumoricidal. However, our study raises substantive concerns about the likelihood of eliciting such favorable responses using T cell therapy. Specifically, we failed to observe a single correlation between percentages of intratumoral T cells and any of the conventional predictors of ccRCC outcome. This lack of association between percentages of intratumoral T cells and conventional predictors of ccRCC outcome argues against a significant role for T cells in regulating ccRCC biology. This particular conclusion is supported by consensus observations by others that robust predictive markers for cancer typically exhibit significant associations with other established features of disease, often because such markers contribute (either directly or indirectly) to key mechanisms involved with malignant inception or progression (21). Thus, if T cells were indeed mediating antitumoral responses against ccRCC tumors, we would have expected to observe at least some correlation between percentages of T cells within ccRCC tumors and other established clinicopathologic predictors of ccRCC behavior. No such relationships were observed in our present study. Adding to our concerns, we further demonstrate that as levels of infiltrating CD3+ T cells rise within ccRCC tumors, percentages of T cells actually decline, implying a dilution effect that argues against either active recruitment or clonal expansion of T cells within ccRCC tumors. Given that our study of 248 consecutive patient specimens is several times larger than the aggregate of all previous studies published pertaining to T cells within ccRCC, it is highly unlikely that the values we report are artifactual (due to insufficient sampling of tumors). Also, determinations of T cell levels within renal tumors without regard to histologic subtype (i.e., by including papillary or chromophobe RCC tumors) could lead to estimations of T cell levels that are not at all relevant to most patients with RCC. This is important because RCC tumors of the clear cell subtype represent the most common (80%) of all renal malignancies and, in contrast to papillary and chromophobe RCC tumors, ccRCC is notably more aggressive and is more amenable to immunotherapeutic intervention. It is for these critical reasons that we restricted our present study to an examination of ccRCC tumors.
Nevertheless, proponents of adoptive T cell immunotherapy for the treatment of RCC could suggest that our findings do not necessarily preclude unforeseen therapeutic benefits arising from a T cell-based treatment approach and would likely cite two further observations reported by Viey et al. (4, 7): enrichment of TCR V9V2 T cells within RCC tumors and apparent specific lysis of RCC tumor cells by bromohydrin pyrophosphate expanded TCR V9V2 T cells. In response to the these observations, the finding of enrichment for specific TCR VV-paired T cell subsets within RCC tissues is not entirely unexpected since it is well established that T cells (bearing paired VV TCR and exhibiting limited VDJ diversity) distribute themselves throughout the host in an organ-specific fashion following thymic emigration, presumably to provide a first line of immunologic defense against pathogenic insults specific to each organ type or to down-regulate organ-specific TCR β T cell-mediated autoimmunity (22, 23). With regard to lysis of RCC tumor cells by T cells, the published literature simply fails to support specific lysis of RCC tumors by Phosphostim-expanded (Innate Pharma) TCR V9V2 T cells. In fact, the study by Viey et al. (7) reported roughly 65% lysis of Daudi (Burkitt’s lymphoma) cells, 40% lysis of autologous RCC cells (as well as allogeneic RCC6 tumor cells), and nearly 20% lysis of normal (uncharacterized) renal parenchymal cells in response to patient-matched, Phosphostim-expanded TCR V9V2 T cells (4-h 51Cr release assay; E:T ratio of 30:1). That Phosphostim-expanded TCR V9V2 T cells exhibit an ability to lyse unpurified normal renal cells in bulk culture (as well as Daudi cells) raises the distinct possibility of autoimmune-type injury to one or more of the 20+ odd cell types that comprise the kidney as well as other tissue types during aggressive antitumoral immunotherapeutic treatment provided by adoptive T cell transfer. Additionally, reports of exaggerated TCR β T cell-mediated inflammation in pathogen-challenged (or untreated) T cell-deficient mice also raises questions. In fact, it has recently been suggested that a primary physiologic role of organ-specific T cells may be to down-regulate TCR β T cell-mediated pathogenic or autoimmune inflammatory responses in a manner similar to that described for T regulatory cells (24). T cells may therefore be immunosuppressive, not immunoprotective.
Regardless, the physiologic and pathophysiologic function of T cells remains highly enigmatic and may prove to be dependent on organ-, host-, and disease-specific factors. Our study demonstrates that T cells constitute an extremely minor population of cells within ccRCC tumors; a population that is further diluted with increasing tumor infiltration by CD3+ T cells. In addition, we show that levels of T cells fail to correlate with even one single established clinicopathologic feature of ccRCC, including patient outcome. Based on these observations and the other studies cited above, we conclude that T cells may prove to be unlikely arbiters of antitumoral immunity for the treatment of ccRCC. Our study further suggests that adoptive T cell immunotherapy as a potential treatment for advanced ccRCC (currently in phase II trials) should be closely scrutinized with guarded expectations.
|
Acknowledgements
|
|---|
We thank Dr. James P. Allison (Howard Hughes Medical Institute, Memorial Sloan-Kettering Cancer Center, New York, NY) for critical review and helpful comments during the preparation of this manuscript.
|
Disclosures
|
|---|
The authors have no financial conflict of interest.
|
Footnotes
|
|---|
The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
1 This work was supported in part by gifts from The Richard M. Schulze Family Foundation and The Commonwealth Foundation for Cancer Research. Donations were also provided by the Helen and Martin Kimmel Foundation. 
2 Address correspondence and reprint requests to Dr. Eugene D. Kwon, Department of Urology, Mayo Clinic, 200 First Street Southwest, Rochester, MN 55905. E-mail address: kwon.eugene{at}mayo.edu
3 Abbreviations used in this paper: RCC, renal cell carcinoma; ccRCC, clear cell RCC; CI, confidence interval; IQR, interquartile range; IHC, immunohistochemistry.
Received for publication September 14, 2007.
Accepted for publication December 13, 2007.
|
References
|
|---|
- Rosenberg, S. A., M. T. Lotze, L. M. Muul, S. Leitman, A. E. Chang, S. E. Ettinghausen, Y. L. Matory, J. M. Skibber, E. Shiloni, J. T. Vetto. 1985. Observations on the systemic administration of autologous lymphokine-activated killer cells and recombinant interleukin-2 to patients with metastatic cancer. N. Engl. J. Med. 313: 1485-1492. [Abstract]
- Kirkwood, J. M., J. E. Harris, R. Vera, S. Sandler, D. S. Fischer, J. Khandekar, M. S. Ernstoff, L. Gordon, R. Lutes, P. Bonomi. 1985. A randomized study of low and high doses of leukocyte -interferon in metastatic renal cell carcinoma: the American Cancer Society collaborative trial. Cancer Res. 45: 863-871. [Abstract/Free Full Text]
- Rosenberg, S. A., J. C. Yang, S. L. Topalian, D. J. Schwartzentruber, J. S. Weber, D. R. Parkinson, C. A. Seipp, J. H. Einhorn, D. E. White. 1994. Treatment of 283 consecutive patients with metastatic melanoma or renal cell cancer using high-dose bolus interleukin 2. J. Am. Med. Assoc. 271: 907-913. [Abstract/Free Full Text]
- Viey, E., C. Laplace, B. Escudier. 2005. Peripheral T-lymphocytes as an innovative tool in immunotherapy for metastatic renal cell carcinoma. Expert Rev. Anticancer Ther. 5: 973-986. [Medline]
- Bennouna, J., J. Medioni, F. Rolland, J. L. Misset, M. Campone, H. Sicard, J. Tiollier, F. Romagne, J. Y. Douillard, F. Calvo. 2005. Phase I clinical trial of bromohydrin pyrophosphate, BrHPP (Phosphatim), a Vy9Vd2 T lymphocyte agonist in combination with low dose interleukin-2 in patients with solid tumors. J. Clin. Oncol. 23: 2536
- Bompas, E., E. M. Neidhardt, F. Rolland, I. Philip, C. Galea, S. Salot, J. Tiollier, S. Saiagh, S. Negrier, J. Bennouna. 2006. An autologous Vy9Vd2 T lymphocyte cell therapy product generated by BrHPP (INNACELL [IGD]) in metastatic renal cell carcinoma patients: phase I clinical trial results. J. Clin. Oncol. 24: 2550
- Viey, E., G. Fromont, B. Escudier, Y. Morel, S. Da Rocha, S. Chouaib, A. Caignard. 2005. Phosphostim-activated T cells kill autologous metastatic renal cell carcinoma. J. Immunol. 174: 1338-1347. [Abstract/Free Full Text]
- Kobayashi, H., Y. Tanaka, J. Yagi, H. Toma, T. Uchiyama. 2001. T cells provide innate immunity against renal cell carcinoma. Cancer Immunol. Immunother. 50: 115-124. [Medline]
- Choudhary, A., F. Davodeau, A. Moreau, M. A. Peyrat, M. Bonneville, F. Jotereau. 1995. Selective lysis of autologous tumor cells by recurrent tumor-infiltrating lymphocytes from renal carcinoma. J. Immunol. 154: 3932-3940. [Abstract]
- Kowalczyk, D., W. Skorupski, Z. Kwias, J. Nowak. 1996. Activated T lymphocytes infiltrating renal cell carcinoma. Immunol. Lett. 53: 15-18. [Medline]
- Lohse, C. M., J. C. Cheville. 2005. A review of prognostic pathologic features and algorithms for patients treated surgically for renal cell carcinoma. Clin. Lab. Med. 25: 433-464. [Medline]
- Olofsson, K., S. Hellstrom, M. L. Hammarstrom. 1998. The surface epithelium of recurrent infected palatine tonsils is rich in T cells. Clin. Exp. Immunol. 111: 36-47. [Medline]
- Storkel, S., J. N. Eble, K. Adlakha, M. Amin, M. L. Blute, D. G. Bostwick, M. Darson, B. Delahunt, K. Iczkowski. 1997. Classification of renal cell carcinoma: Workgroup No. 1. Union Internationale Contre le Cancer (UICC) and the American Joint Committee on Cancer (AJCC). Cancer 80: 987-989. [Medline]
- Lohse, C. M., M. L. Blute, H. Zincke, A. L. Weaver, J. C. Cheville. 2002. Comparison of standardized and nonstandardized nuclear grade of renal cell carcinoma to predict outcome among 2,042 patients. Am. J. Clin. Pathol. 118: 877-886. [Abstract/Free Full Text]
- Sobin, S. H., C. Wittekind. 2002. TNM Classification of Malignant Tumours Wiley–Liss, New York.
- Frank, I., M. L. Blute, J. C. Cheville, C. M. Lohse, A. L. Weaver, H. Zincke. 2002. An outcome prediction model for patients with clear cell renal cell carcinoma treated with radical nephrectomy based on tumor stage, size, grade, and necrosis: the SSIGN score. J. Urol. 168: 2395-2400. [Medline]
- Donner, A., N. Klar. 1996. The statistical analysis of statistics in multiple samples. J. Clin. Epidemiol. 49: 1053-1058. [Medline]
- Peyrat, M. A., F. Davodeau, I. Houde, F. Romagne, A. Necker, C. Leget, J. P. Cervoni, N. Cerf-Bensussan, H. Vie, M. Bonneville, et al 1995. Repertoire analysis of human peripheral blood lymphocytes using a human V3 region-specific monoclonal antibody: characterization of dual T cell receptor (TCR) -chain expressors and β T cells expressing V3JC-encoded TCR chains. J. Immunol. 155: 3060-3067. [Abstract]
- Borst, J., J. J. van Dongen, R. L. Bolhuis, P. J. Peters, D. A. Hafler, E. de Vries, R. J. van de Griend. 1988. Distinct molecular forms of human T cell receptor detected on viable T cells by a monoclonal antibody. J. Exp. Med. 167: 1625-1644. [Abstract/Free Full Text]
- Carding, S. R., P. J. Egan. 2002. T cells: functional plasticity and heterogeneity. Nat. Rev. Immunol. 2: 336-345. [Medline]
- McShane, L. M., D. G. Altman, W. Sauerbrei, S. E. Taube, M. Gion, G. M. Clark. 2005. Reporting recommendations for tumor marker prognostic studies (REMARK). J. Natl. Cancer Inst. 97: 1180-1184. [Abstract/Free Full Text]
- Asarnow, D. M., T. Goodman, L. LeFrancois, J. P. Allison. 1989. Distinct antigen receptor repertoires of two classes of murine epithelium-associated T cells. Nature 341: 60-62. [Medline]
- Bluestone, J. A., R. Khattri, R. Sciammas, A. I. Sperling. 1995. TCR cells: a specialized T-cell subset in the immune system. Annu. Rev. Cell. Dev. Biol. 11: 307-353. [Medline]
- Hayday, A., R. Tigelaar. 2003. Immunoregulation in the tissues by T cells. Nat. Rev. Immunol. 3: 233-242. [Medline]
Top
Abstract
Introduction
