The longitudinal relationship between the systemic inflammatory response, circulating T-lymphocytes, interleukin-6 and -10 in patients undergoing immunotherapy for metastatic renal cancer

OBJECTIVE

To examine the longitudinal relationship between the systemic inflammatory response, circulating T‐lymphocyte subpopulations, interleukin‐6 and ‐10 in patients undergoing immunotherapy for metastatic renal cancer, as the inflammation‐based Glasgow Prognostic Score (GPS) provides additional prognostic information in patients with advanced renal cancer, but the basis of the relationship between the systemic inflammatory response and poorer survival is not clear, and nor is the effect of immunotherapy on related variables.

PATIENTS AND METHODS

The study included 23 patients with metastatic renal cancer and starting immunotherapy. Samples of blood were drawn for routine laboratory analysis and to quantify cytokines using enzyme‐linked immunosorbent assays before immunotherapy, and repeated after 2 weeks of treatment.

RESULTS

Most patients had a good performance status, favourable or intermediate Memorial Sloane‐Kettering Cancer Center (MSKCC) risk scores, and with elevated C‐reactive protein (>10 mg/L), GPS (1 or 2), interleukin‐6 (>4 pg/mL) and interleukin‐10 (>10 pg/mL). Patients who completed one cycle of immunotherapy were more likely to have a normal MSKCC (P < 0.05) or GPS (P < 0.05) scores, whilst the percentage of lymphocytes was lower (P < 0.05). The MSKCC and the GPS scores did not alter significantly during one cycle of immunotherapy. Similarly, leukocyte counts, CD4+ and CD8+ T‐lymphocytes, interleukin‐6 and ‐10 concentrations did not change significantly.

CONCLUSIONS

The pretreatment systemic inflammatory response and its related lymphopenia are important in determining the tolerance to immunotherapy in patients with metastatic renal cancer. Immunotherapy is not associated with changes in circulating T‐lymphocytes, nor the systemic inflammatory response.     

Interleukin-2 blocks the antitumour activity caused by depletion of CD25 cells in a murine renal adenocarcinoma model

OBJECTIVE: To test the effectiveness of antimouse CD25 monoclonal antibody (mAb) against murine renal adenocarcinoma (RENCA) cells, as immunoregulatory/suppressor cells are known to be involved in tumour development in vivo, but the functions of these cells are not yet clear, and eliminating naive CD25 (interleukin-2 receptor alpha)-positive T cells elicits potent immune responses to syngeneic tumours in vivo. MATERIALS AND METHODS: Aliquots of 1 x 10(4) or 1 x 10(5) RENCA cells were implanted into the subcapsule of the left kidney of syngeneic male Balb/c mice. Mice were injected with 125 micro g of antimouse CD25 mAb to deplete CD25(+) cells before RENCA implantation. Then 10(4) units of recombinant human interleukin-2 (rhIL-2) were subcutaneously injected twice daily for 7 days. Fourteen or 25 days later the tumour size was determined by laparotomy, and cells sorted using two-colour flow cytometry. RESULTS: Depletion of naive CD25(+) cells with anti-CD25 mAb and rhIL-2 administration effectively induced anti-RENCA tumour activity in Balb/c hosts. However, co-administration of anti-CD25 mAb and rhIL-2 abrogated this significant suppression of RENCA tumour growth. RENCA implantation reduced the proportion of CD4(+) cells among splenocytes, whereas anti-CD25 mAb treatment increased it. The proportion of CD25(+)CD8(+) cells among splenocytes and that of CD25(+) cells among CD8(+) cells were markedly reduced by co-administration of anti-CD25 mAb and rhIL-2 with RENCA implantation. Both CD4(+) and CD8(+) cells were stained around the remnant microscopic RENCA tumour after anti-CD25 mAb treatment. CONCLUSION: Either depletion of naive CD25(+) cells or rhIL-2 administration suppressed RENCA tumour growth in murine hosts. However, co-administration of anti-CD25 mAb and rhIL-2 abrogated this significant suppression of RENCA tumour growth.     

The prognostic value of peritumoral regulatory T cells and its correlation with intratumoral cyclooxygenase‐2 expression in clear cell renal cell carcinoma

OBJECTIVE

To investigate the prognostic value of regulatory T cells (Tregs) and its correlation with cyclooxygenase‐2 (COX‐2) expression in clear cell renal cell carcinoma (RCC).

PATIENTS AND METHODS

CD4+, Foxp3+ tumour‐infiltrating lymphocytes and tumour COX‐2 expression were assessed by immunohistochemistry in tissue microarrays containing RCC from 125 patients. Prognostic effects of low and high expression were evaluated by Cox regression and Kaplan–Meier analysis using the median values as thresholds. The expression of Tregs and COX‐2 were compared with the clinicopathological variables. In addition, Tregs and its correlation with COX‐2 expression was also analysed.

RESULTS

Peritumoral Tregs were positively correlated with intratumoral COX‐2 expression (Spearman rank correlation 0.336, P < 0.001). Peritumoral Tregs were associated with TNM stage (P = 0.001) and tumour size (P = 0.002), while intratumoral COX‐2 expression was associated with TNM stage (P = 0.018) and grade (P = 0.013). Using multivariate analysis, increased peritumoral Tregs, higher TNM stage (III + IV), larger tumour size (≥7 cm) and higher nuclear grade (III + IV) were independent predictors for significantly shorter overall survival and disease‐free survival.

CONCLUSIONS

Increased peritumoral Tregs are associated with worse prognosis in clear cell RCC. The high intratumoral COX‐2 expression may be the underlying reason for the aberrant gathering of Tregs. These results suggest that clinical application of COX‐2 inhibitors may benefit those patients with higher intratumoral COX‐2 immunostaining by reducing the transformation of Tregs in RCC.     

The immunologic function of 1B2+ double negative (CD4-CD8-) T cells in the 2C transgenic mouse

BACKGROUND: 2C mice bearing the cytotoxic TCR for class I L(d) on a C57BL/6 (B6) background have a preponderance of 1B2+CD8+ T cells directed against L(d). These naive CD8+ T cells are not directly cytotoxic without prior in vivo or in vitro activation. However, after in vitro sensitization, they become highly cytotoxic and will acutely and specifically reject a tolerant L(d+) BALB/c heart graft. Anti-lymphocyte serum (ALS) treatment eliminates CD4+ and CD8+ cells and a large double negative (CD4-CD8-) 1B2+ non-cytotoxic transgenic cell population remains. The immunological function of this unique peripheral population of T cells is investigated in the 2C transgenic mouse. MATERIALS AND METHODS: To determine the activation characteristics of the 2C CD4-CD8- T cells, 2C peripheral T cells were analyzed for 1B2+, CD8+, and CD4+ marker by FACS before and 48-h after 0.5 cc ALS i.p. Similarly, in vitro, the response of these 2C CD4-CD8- T cells remaining after deletion of mature CD4+ and CD8+ T cells with ALS plus complement were evaluated by mixed lymphocyte culture and cytotoxic T lymphocyte after 7 days culture with BALB/c, IL-2, or BALB/c + IL-2. Parallel experiments were performed with control non-transgenic B6 mice. Following in vitro culture with BALB/c + IL-2, 2C CD4-CD8- T cells were injected into B6 mice with a tolerant BALB/c heart (tolerization via anti-CD4 mAb and intrathymic BALB/c) to determine their immunogenicity. RESULTS: While peripheral T cells in control B6 mice have <5% CD4-CD8- cells, transgenic 2C mice have a significantly increased percentage at 29 to 35% (P < 0.01). After the deletion of CD4+ and CD8+ T cells with either in vivo or in vitro ALS, 2C CD4-CD8- T cells increased to 96 to 99%. After 7-day culture, the 2C CD4-CD8- T cells decreased again to 33 to 38%. Simultaneously, 2C CD8+ T cells decreased from 56 to 62% to 0.1 to 3% after ALS treatment, but again increased to 61 to 70% after in vitro culture. Untreated 2C cells responded to IL-2 or BALB/c antigen equally well. However, after ALS treatment, CD4-CD8- T cells responded to IL-2 and IL-2 plus antigen, but not BALB/c antigen alone. Finally, CD4-CD8- T cells cultured for 7 days with BALB/c + IL-2 rejected the tolerant BALB/c heart in 5.3 +/- 0.3 days. CONCLUSION: In the periphery of transgenic 2C mice is a unique CD4-CD8- population of T cells bearing the transgenic specific marker 1B2. These non-cytotoxic cells can be optimally stimulated to develop marked specific L(d) cytotoxicity in parallel with the expression of the CD8+ epitope.     

外源性IL-2对小鼠CD4^＋CD25^＋调节性T细胞影响的实验研究

目的：探讨IL-2对CD4＋CD25＋调节性T细胞（Tregs）的增殖及功能的影响。方法：提取B6小鼠脾脏细胞,流式细胞仪分离CD4＋CD25＋Tregs,将新鲜分离的CD4＋CD25＋Tregs与抗CD3单克隆抗体、同种同系抗原递呈细胞（APCs）及外源性IL-2共同培养,测定其增殖活性;并检测体外扩增后的CD4＋CD25＋Tregs的免疫抑制活性及其Foxp3的表达。结果：与外源性IL-2共同培养的CD4＋CD25＋Tregs增殖程度强烈,与对照组比较,差异有统计学意义（P〈0.05）;体外扩增的CD4＋CD25＋Tregs抑制CD4＋CD25-T细胞增殖活性的能力与新鲜分离的CD4＋CD25＋Tregs相似（P〉0.05）。体外扩增的CD4＋CD25＋Tregs的Foxp3表达与新鲜分离的CD4＋CD25＋Tregs亦相似（P〉0.05）。结论：外源性IL-2能够消除CD4＋CD25＋Tregs的无反应状态,且体外扩增的CD4＋CD25＋Tregs保持了其抑制活性。     

Characterization of bone metastases in patients with renal cell cancer

OBJECTIVE: To characterize the clinical features of bone metastases in patients with renal cell carcinoma (RCC) treated with interleukin-2 therapy. Bone lesions contribute to significant morbidity and mortality, and although present in up to half of patients with RCC, their behaviour and response to therapy have not been well characterized. PATIENTS AND METHODS: We evaluated skeletal metastases in 19 patients with bone lesions who received either moderate- or high-dose interleukin-2 therapy. Data on bone disease, including location and number of bone lesions, need for bone-specific therapies and use of pain medications, were noted. The response of bone lesions to interleukin-2 was compared with the response of other systemic metastatic sites. RESULTS: Skeletal metastases resulted in significant morbidity by causing pain (75%) and other complications requiring surgical and/or radiotherapeutic intervention (94%) before beginning interleukin-2 therapy. In most patients the response of bone lesions to interleukin-2 was similar to that in their other systemic sites. Treatment with interleukin-2 had no significant effect on the requirement for pain medication for bone pain. However, it may have prevented skeletal complications requiring surgery or radiotherapy. None of the patients had hypercalcaemia; there was no significant association between bone metastases and elevated alkaline phosphatase levels. CONCLUSIONS: Skeletal metastases are a significant contributor to morbidity among patients with RCC. Bone lesions respond similarly to interleukin-2 therapy as other systemic sites. Bisphosphonates appear promising for these predominantly osteolytic lesions.     

Frequency of regulatory T cells in peripheral blood and in tumour‐infiltrating lymphocytes correlates with poor prognosis in renal cell carcinoma

What’s known on the subject? and What does the study add? Treg overexpression has been demonstrated in several neoplasms, including liver, breast, pancreas and melanoma, while it has not been well evaluated in renal cancer. In renal cancer patients versus controls we found an increased expression of these cells, especially in tumour‐infiltrating lymphocytes. Moreover, Treg frequency significantly correlated with pathological stage, nuclear grade and prognostic models.

OBJECTIVE

• ? To compare the frequency of T regulatory cells (Tregs) in peripheral blood of patients (pPB) affected by renal cell carcinoma (RCC) both with the frequency of Tregs found in PB of healthy donors (hPB) and that of Tregs present in tumour infiltrating lymphocytes (TILs). To verify in vitro the inhibitory activity of tumour isolated Tregs on the effector T cells and, finally, to assess the prognostic role of Treg frequency determination.

PATIENTS AND METHODS

• ? Treg frequency in hPB, pPB and TILs was evaluated in 30 patients and 20 healthy controls by measuring both membrane‐CD25 and intracytoplasmic‐Foxp3 expression by flow cytometry.
• ? Treg inhibitory activity was evaluated by an in vitro proliferation assay performed on total, CD25‐depleted mononuclear cells (MNC) and CD25‐depleted MNC cultured in the presence of purified CD25⁺ Tregs.
• ? Finally, Treg frequency in pPB and TIL were correlated with conventional prognostic factors and scores of University of California Los Angeles and Kattan predictive models.

RESULTS

• ? Treg frequency was higher in TILs than in pPB (P= 0.002), whereas there were no important differences between hPB and pPB. CD25⁺ cells isolated either from PB and tumours showed the ability to significantly suppress in vitro both proliferation and interferon‐γ production by CD25‐depleted MNC, thus demonstrating that they are active Tregs.
• ? Treg frequency was found to significantly correlate both with pathological stage (pPB, P= 0.03; TIL, P= 0.04) and nuclear grade (TIL, P= 0.005), both for UCLA and Kattan models (all: P < 0.05 for both pPB and TIL).

CONCLUSION

• ? Treg frequency is significantly higher in TIL than in pPB of patients with RCC. Tregs showed in vitro an inhibitory activity on effector T cells isolated from kidney tumours. The increase in both peripheral and intratumoral Tregs in subjects affected with RCC were associated with worse prognosis.

     

CD4+CD25+调节性T细胞对小鼠肝脏移植自发性免疫耐受的影响

目的 研究CD4+CD25+调节性T细胞在诱导自发性肝脏免疫耐受中的作用.方法 向受体和供体注射抗CD25抗体(PC61)后进行小鼠原位肝脏移植,观测其生存时间.术后20～30 d切取移植肝脏行HE染色,同时观察CD4+CD25+T细胞对CD4+T细胞和CD8+T细胞功能的影响.结果 去除受体而不是供体小鼠的CD4+CD25+T细胞可以导致肝移植排斥反应.而且,去除CD4+CD25+T细胞使移植物的白细胞浸润明显增多,组织损伤加重.同时,去除CD4+CD25+T细胞导致CD4+T细胞的增殖活性和CD8+T细胞的细胞毒活性明显增强.结论 受体来源的CD4+CD25+调节性T细胞在小鼠肝脏移植免疫耐受诱导中起重要作用.

Abstract：

Objective To examine the contribution of CD4+ CD25+ regulatory T cells to liver transplant tolerance. Methods After injection of anti-CD25 monoclonal antibody (mAb, PC61), mouse orthotopic liver transplantation was performed and survivals were determined. The paraffin-embedded sections of hepatic allografts were cut and stained with hematoxylin and eosin (HE). Furthermore, the effect of CD4+ CD25+ regulatory T cells on proliferative response of CD4+ T cells and cytotoxicity of CD8+ T cells was examined by depleting these regulatory T cells. Results Depletion of these cells in the recipients but not in the donors before liver transplantation caused rejection. Histological analyses of hepatic allografts with PC61 treatment showed extensive leukocyte infiltration and tissue destruction, whereas those in the control group showed minimal changes. Moreover, elimination of CD4+CD25+ T cells resulted in the enhancement of both proliferative response of CD4+ T cells and cytotoxicity of CD8+ T cells against donor-type alloantigen. Conclusions These results suggest that CD4+CD25+ regulatory T cells were important for tolerance induction to hepatic allografts.     

An investigation to assess the potential of CD25highCD4+ T cells to regulate responses to donor alloantigens in clinically stable renal transplant recipients.

Regulatory T cells are enriched within CD25(high)CD4(+) leukocytes, however their role in renal transplant recipients with stable function vs. recipients with biopsy-proven chronic allograft dysfunction remains unclear. We therefore studied the number, phenotype, and function of CD25(high)CD4(+) cells in the peripheral blood of 30 renal transplant recipients of living-related grafts, comprising 15 rejection-free recipients with stable graft function (Group A) and 15 with biopsy-proven chronic graft dysfunction (Group B). A higher absolute number of CD25(high)CD4(+) cells were present in the peripheral blood of rejection-free recipients (Group A) vs. those recipients with chronic graft dysfunction (Group B) (P = 0.019); but there was no significant difference with healthy volunteers (P = 0.084). In carboxyfluorescein diacetate succinimidyl ester-mixed leukocyte culture assays, depletion of CD25(high)CD4(+) revealed active regulation in 11 (74%) of 15 rejection-free recipient samples (Group A) in response to donor- but not third party-leukocytes, whereas no regulatory activity was observed in any samples from recipients with chronic graft dysfunction (Group B). In conclusion, these data provide evidence for the presence of an increased number of CD25(high)CD4(+) T cells with donor-specific regulatory activity in the peripheral blood of renal transplant recipients with stable graft function compared with recipients with chronic graft dysfunction.     

前列腺癌患者外周血中CD4^＋CD25^high调节性T细胞及调节因子TGF-β1和COX-2的表达

目的：通过检测前列腺癌患者以及健康志愿者外周血中CD4＋CD25high调节性T细胞、TGF-β1及COX-2的表达,初步探讨CD4＋CD25high调节性T细胞在前列腺癌发病机制中的作用及其与TGF-β1和COX-2的相关性。方法：应用流式细胞术检测30例前列腺癌患者治疗前后（其中前列腺癌局限组11例,非局限组19例）及20例健康志愿者外周血单个核细胞（PBMC）中CD4＋CD25high调节性T细胞占CD4＋T细胞的比例;应用酶联免疫吸附试验（ELISA）检测其外周血清中TGF-β1和COX-2的表达。对前列腺癌患者上述指标进行术前术后对比分析,另对CD4＋CD25high调节性T细胞与TGF-β1及COX-2的相关性进行分析;并探讨上述指标在前列腺癌患者局限组和非局限组间是否存在差异性。结果：流式细胞术检测显示,前列腺癌患者治疗前PBMC中CD4＋CD25high调节性T细胞占CD4＋T细胞的比例为（18.32±7.49）%,高于健康志愿者对照组（7.77±1.86）%（P〈0.05）。前列腺癌患者治疗后其比值为（17.34±5.87）%,较治疗前稍减低,但两者相比无显著差异（P〉0.05）。ELISA检测外周血清中TGF-β1和COX-2显示,前列腺癌组分别为（215.97±55.16）ng/ml和（6.88±5.14）ng/ml,对照组分别为（149.75±47.11）ng/ml和（5.65±2.69）ng/ml;前列腺癌患者外周血清中TGF-β1的表达水平高于健康志愿者对照组（P〈0.05）,COX-2的表达水平与对照组无显著差异（P〉0.05）。通过多重线性回归分析表明,前列腺癌患者PBMC中CD4＋CD25high调节性T细胞的表达与血清中TGF-β1和COX-2的表达无显著相关。前列腺癌局限组和非局限组外周血中CD4＋CD25high调节性T细胞、TGF-β1及COX-2的表达均无显著性差异（P〉0.05）。结论：前列腺癌患者PBMC中CD4＋CD25high调节性T细胞可能参与前列腺癌的发生,其增殖机制与血清中TGF-β1和COX-2的表达无关,可能与肿瘤本身及肿瘤局部微环境相关。     

Low‐Dose IL‐2 for In Vivo Expansion of CD4+ and CD8+ Regulatory T Cells in Nonhuman Primates

IL‐2 is a known potent T cell growth factor that amplifies lymphocyte responses in vivo. This capacity has led to the use of high‐dose IL‐2 to enhance T cell immunity in patients with AIDS or cancer. However, more recent studies have indicated that IL‐2 is also critical for the development and peripheral expansion of regulatory T cells (Tregs). In the current study, low‐dose IL‐2 (1 million IU/m² BSA/day) was administered to expand Tregs in vivo in naïve nonhuman primates. Our study demonstrated that low‐dose IL‐2 therapy significantly expanded peripheral blood CD4⁺ and CD8⁺ Tregs in vivo with limited expansion of non‐Treg cells. These expanded Tregs are mainly CD45RA^? Foxp3 ^high activated Tregs and demonstrated potent immunosuppressive function in vitro. The results of this preclinical study can serve as a basis to develop Treg immunotherapy, which has significant therapeutic potential in organ/cellular transplantation.     

Adenovirus-mediated CD40 ligand therapy induces tumor cell apoptosis and systemic immunity in the TRAMP-C2 mouse prostate cancer model

BACKGROUND: The interaction between CD40 ligand (CD40L) and CD40 on antigen presenting cells is essential for the initiation of antigen-specific T-cell responses, whereas CD40L stimulation of CD40+ tumor cells can induce cellular apoptosis. We investigated the anti-tumor effects induced by CD40L gene transfer into the mouse prostate adenocarcinoma cell line TRAMP-C2, both in vitro and in vivo. METHODS: TRAMP-C2 cells were transduced with an adenoviral vector encoding CD40L (AdCD40L). The induced expression of co-stimulatory molecules and cell viability was analyzed. AdCD40L-transduced TRAMP-C2 cells were used in prophylactic vaccination studies, while therapeutic studies were performed using peritumoral injections of AdCD40L. RESULTS: AdCD40L yielded reduced TRAMP-C2 cell viability and induced apoptosis in vitro. Vaccination with CD40L-expressing TRAMP-C2 cells induced anti-tumor immunity and peritumoral AdCD40L injections induced tumor growth suppression. CONCLUSIONS: Our observations highlight the therapeutic potential of using AdCD40L as a monotherapy or in combination with conventional chemotherapy or novel therapies (e.g., oncolytic viruses). The use of AdCD40L offers an attractive option for future clinical trials.     

Differential expression of interleukin-15, a pro-inflammatory cytokine and T-cell growth factor, and its receptor in human prostate.

BACKGROUND: Pro-inflammatory interleukin (IL)-15 plays a major role in host defense and chronic inflammation by stimulating T-lymphocyte recruitment and growth. Expression of IL-15 and IL-15 receptor (IL-15R) in human prostate was examined. METHODS: Normal and benign hyperplastic (BPH) prostate specimens (n = 23) were analyzed for IL-15 and IL-15Ralpha-chain expression by immunohistochemistry and Real-Time-PCR/RT-PCR. Regulation of prostatic stromal cell (PSC) IL-15 mRNA and effect of IL-15 on prostatic cell growth were analysed in vitro. RESULTS: In normal prostate, anti-IL-15 and anti-IL-15Ralpha-chain reactivity were restricted to smooth muscle and stromal cells. However, in BPH, in addition epithelial cells frequently exhibited discrete anti-IL-15R and often intense, membranous anti-IL-15 reactivity. IL-15/IL-15R mRNA were detected in all prostatic cells types. In BPH tissues, IL-15 mRNA content was variable (15-fold). IL-15 mRNA synthesis of PSC was significantly up-regulated by IFN-gamma. Furthermore IL-15 strongly stimulated the growth of BPH-T-lymphocytes and weakly that of carcinoma cell lines, but not of stromal cells. CONCLUSIONS: Overexpression of IL-15 and IL-15Ralpha-chain in BPH and massive proliferation of BPH-T-lymphocytes induced by IL-15 suggest a role for IL-15 in prostatic inflammation. Since IFN-gamma, a T-lymphocyte product, stimulates prostatic IL-15 production; chronic inflammation might be triggered by this paracrine loop.     

Analysis of renal cell carcinoma with subdiaphragmatic macroscopic venous invasion (T3b)

OBJECTIVE

To review our institutional experience of surgery for renal cell carcinoma (RCC) with subdiaphragmatic macroscopic venous invasion (T3b) and to assess variables associated with cancer‐specific survival (CSS), as the stratification of RCC with venous involvement (T3b and T3c) is subject to debate.

PATIENTS AND METHODS

We retrospectively reviewed the hospital records of patients who underwent a radical nephrectomy with resection of subdiaphragmatic tumour thrombus (T T) between October 1990 and May 2006. The log‐rank and Cox uni‐ and multivariate regression analysis were used to evaluate predictive factors for CSS.

RESULTS

In all, 101 cases were identified. In the N0M0 group, univariate Cox regression analysis confirmed that ipsilateral adrenal gland invasion, Mayo Clinic level of T T, histological subtype and fat invasion were significantly associated with worse CSS. In multivariate Cox regression analysis, only Mayo Clinic level of T T was an independent predictor for CSS. In the subgroup with renal vein involvement only, the median CSS was not reached. In the subgroups with level I, II and III T T involvement, the median CSS was 69, 26 and 21 months, respectively. In the N+ and/or M+ group, only tumour size and type were independent predictors of CSS, while the level of T T was not. Radical nephrectomy yielded poor results with a median CSS of 13 months.

CONCLUSION

The Mayo Clinic level of T T is an independent prognostic predictor for CSS in non‐metastatic T3b RCC. We strongly support the need for re‐classification of the currently applied 2002 Tumour‐Node‐Metastasis staging system, which in its present form does not discriminate between levels of subdiaphragmatic venous invasion.     

HLA‐G on peripheral blood CD4+ T lymphocytes: a potential predictor for acute renal rejection

HLA‐G Expression in grafts and serum has been shown to improve graft acceptance. However, its expression on peripheral blood lymphocytes (PBLs) during acute rejection (AR) remains unknown. In this study, we serially monitored HLA‐G expression on CD4⁺ and CD8⁺ PBLs of 66 recipients undergoing renal transplantation using flow cytometry at different time points before and after transplantation, as well as during AR episode. In stable recipients, HLA‐G expression on CD4⁺ PBLs declined during the first week after transplantation and increased continuously with immunosuppressive therapy. Then, expression declined gradually after 1 month and remained at a higher level compared with pretransplantation. When AR occurred, HLA‐G expression decreased significantly compared with the stable level. In three recipients suffering from recurrent rejection, it remained at a low level despite impact immunosuppressive treatment. With mix lymphocyte assay, HLA‐G⁺ CD4⁺ T cells showed inhibitory role on proliferation of peripheral blood mononuclear cell. HLA‐G expression on CD8⁺ PBLs was almost undetectable at different time points in the recipients and healthy controls. Our results suggest that HLA‐G on CD4⁺ PBLs might provide a potential marker for the early diagnosis of renal AR and for the immunosuppressive status of recipients.     

CTLA4‐Ig Restores Rejection of MHC Class‐II Mismatched Allografts by Disabling IL‐2‐Expanded Regulatory T Cells

Allograft acceptance and tolerance can be achieved by different approaches including inhibition of effector T cell responses through CD28‐dependent costimulatory blockade and induction of peripheral regulatory T cells (Tregs). The observation that Tregs rely upon CD28‐dependent signals for development and peripheral expansion, raises the intriguing possibility of a counterproductive consequence of CTLA4‐Ig administration on tolerance induction. We have investigated the possible negative effect of CTLA4‐Ig on Treg‐mediated tolerance induction using a mouse model of single MHC class II‐mismatched skin grafts in which long‐term acceptance was achieved by short‐term administration of IL‐2/anti‐IL‐2 complex. CTLA4‐Ig treatment was found to abolish Treg‐dependent acceptance in this model, restoring skin allograft rejection and Th1 alloreactivity. CTLA4‐Ig inhibited IL‐2‐driven Treg expansion, and prevented in particular the occurrence of ICOS⁺ Tregs endowed with potent suppressive capacities. Restoring CD28 signaling was sufficient to counteract the deleterious effect of CTLA4‐Ig on Treg expansion and functionality, in keeping with the hypothesis that costimulatory blockade inhibits Treg expansion and function by limiting the delivery of essential CD28‐dependent signals. Inhibition of regulatory T cell function should therefore be taken into account when designing tolerance protocols based on costimulatory blockade.     

Metastatic type-2 papillary renal cell carcinoma responded to interleukin-2 therapy: case report

This report documents a case of metastatic papillary renal cell carcinoma (PRCC) which successfully responded to interleukin-2 (IL-2) therapy. A 59-year-old male presented with a left renal mass measuring 3.0 cm in diameter and a right adrenal mass measuring 5.0 cm in diameter. He underwent a left partial nephrectomy and a right adrenalectomy. The histological findings revealed pT1bN1M1 type-2 PRCC and metastatic renal cell carcinoma in the right adrenal gland. The patient was given interferon-α (IFN-α) after the operation for 3 months. A CT scan revealed a metastatic nodule measuring 6.0 cm in diameter near the surface of the liver at 4 months after the opereation. The patient was given interleukin-2 (IL-2), 7 × 10⁵ units/day intravenously, for 3 days per week. A CT scan revealed this hepatic nodule to have decreased in size from 6.0 to 4.0 cm after 4 months of IL-2 therapy. However, a new metastatic nodule measuring 6.0 cm in diameter was found which came in contact with the spleen. Next, the patient was given an increased dose of IL-2 from 7 × 10⁵ to 1.4 × 10⁶ units/day intravenously, for 3 days per week. At 9 months of follow-up after the dose escalation, a CT scan revealed a dramatic decrease in the size of these two metastatic nodules to 1.5 and 0.5 cm, respectively. This is a very rare case in that it represents a type-2 PRCC which dramatically responded to low-dose IL-2 therapy.