The Endothelial Landscape and Its Role in Von Hippel-Lindau Disease.

Von Hippel-Lindau disease (VHL) is a rare hereditary disease characterized by the predisposal to develop different types of highly vascularized tumors. VHL patients carry a VHL mutation that causes partial lack of functional VHL protein (pVHL) in all cells, and a total lack thereof in cells harboring a second hit mutation. Absence of pVHL generates a prolonged state of pseudo-hypoxia in the cell due to accumulation of hypoxia inducible factor, an important transcription factor regulating pro-tumorigenic genes. The work here presented focuses on characterizing the endothelium of VHL patients, by means of blood outgrowth endothelial cells (BOECs). Transcriptome analysis of VHL-derived BOECs, further supported by in vitro assays, shows that these cells are at a disadvantage, as evidenced by loss of cell adhesion capacity, angiogenesis defects, and immune response and oxidative metabolic gene downregulation, which induce oxidative stress. These results suggest that the endothelium of VHL patients is functionally compromised and more susceptible to tumor development. These findings contribute to shedding light on the vascular landscape of VHL patients preceding the second hit mutation in the VHL gene. This knowledge could be useful in searching for new therapies for these patients and other vascular diseases.

Mutated Von Hippel-Lindau-renal cell carcinoma (RCC) promotes patients specific natural killer (NK) cytotoxicity.

BACKGROUND: Previous evidence demonstrated that restoration of wild type VHL in human renal cancer cells decreased in vitro NK susceptibility. To investigate on the role of tumoral VHL status versus NK capability in renal cancer patients, 51 RCC patients were characterized for VHL mutational status and NK function. METHODS: VHL mutational status was determined by direct DNA sequencing on tumor tissue. NK cytotoxicity was measured against specific target cells K562, VHL-wild type (CAKI-1) and VHL-mutated (A498) human renal cancer cells through externalization of CD107a and IFN-γ production. Activating NK receptors, NKp30, NKp44, NKp46, NKG2D, DNAM-1, NCAM-1 and FcγRIIIa were evaluated through quantitative RT-PCR. RCC tumoral Tregs were characterized as CD4+CD25+CD127lowFoxp3+ and Treg function was evaluated as inhibition of T-effector proliferation. RESULTS: VHL mutations were detected in 26/55 (47%) RCC patients. IL-2 activated whole-blood samples (28 VHL-WT-RCC and 23 VHL-MUT-RCC) were evaluated for NK cytotoxicity toward human renal cancer cells A498, VHL-MUT and CAKI-1, VHL-WT. Efficient NK degranulation and increase in IFN-γ production was detected when IL-2 activated whole-blood from VHL-MUT-RCC patients were tested toward A498 as compared to CAKI-1 cells (CD107a+NK: 7 ± 2% vs 1 ± 0.41%, p = 0.015; IFN-γ+NK: 6.26 ± 3.4% vs 1.78 ± 0.9% respectively). In addition, IL-2 activated NKs induced higher CD107a exposure in the presence of RCC autologous tumor cells or A498 as compared to SN12C (average CD107a+NK: 4.7 and 2.7% vs 0.3% respectively at 10E:1 T ratio). VHL-MUT-RCC tumors were NKp46+ cells infiltrated and expressed high NKp30 and NKp46 receptors as compared to VHL-WT-RCC tumors. A significant lower number of Tregs was detected in the tumor microenvironment of 13 VHL-MUT-RCC as compared to 13 VHL-WT-RCC tumors (1.84 ± 0.36% vs 3.79 ± 0.74% respectively, p = 0.04). Tregs isolated from VHL-MUT-RCC patients were less suppressive of patients T effector proliferation compared to Tregs from VHL-WT-RCC patients (Teff proliferation: 6.7 ± 3.9% vs 2.8 ± 1.1%). CONCLUSIONS: VHL tumoral mutations improve NKs effectiveness in RCC patients and need to be considered in the evaluation of immune response. Moreover therapeutic strategies designed to target NK cells could be beneficial in VHL-mutated-RCCs alone or in association with immune checkpoints inhibitors.

VHL promotes immune response against renal cell carcinoma via NF-κB-dependent regulation of VCAM-1.

Vascular cell adhesion molecule 1 (VCAM-1) is an adhesion molecule assigned to the activated endothelium mediating immune cells adhesion and extravasation. However, its expression in renal carcinomas inversely correlates with tumor malignancy. Our experiments in clear cell renal cell carcinoma (ccRCC) cell lines demonstrated that von Hippel Lindau (VHL) loss, hypoxia, or PHD (for prolyl hydroxylase domain-containing proteins) inactivation decreased VCAM-1 levels through a transcriptional mechanism that was independent of the hypoxia-inducible factor and dependent on the nuclear factor κB signaling pathway. Conversely, VHL expression leads to high VCAM-1 levels in ccRCC, which in turn leads to better outcomes, possibly by favoring antitumor immunity through VCAM-1 interaction with the α4ß1 integrin expressed in immune cells. Remarkably, in ccRCC human samples with VHL nonmissense mutations, we observed a negative correlation between VCAM-1 levels and ccRCC stage, microvascular invasion, and symptom presentation, pointing out the clinical value of VCAM-1 levels as a marker of ccRCC progression.

Inflammatory cell infiltrate in a responding metastatic nodule after vaccine-based immunotherapy.

A patient with von Hippel Lindau disease, bilateral symmetric renal cell carcinoma and pulmonary metastases treated with immunotherapy is the subject of this study. A left kidney and tumour mass were removed and the tumour cells used to make an autologous tumour/bacille Calmette-Guérin (BCG) vaccine as part of the treatment protocol. The patient's pulmonary nodules responded, but the remaining renal nodule subsequently grew. Samples of both tumours were obtained allowing for an internally controlled evaluation of the histological and immunohistologic differences between a responding and non-responding tumour nodule after therapy. The immunotherapy protocol is designed to promote a T cell response to autologous tumour. Cellular infiltrates were demonstrated in both responding and non-responding nodules compared with the pretreatment tumour specimen, but the responding nodule contained proportionately more T cells as well as markedly increased numbers of plasma cells and granulocytes. This suggested that several arms of the immune system may have been operative in the responding nodule.

Evidence for oligoclonal T-cell response in a metastasis of renal cell carcinoma responding to vaccination with autologous tumor cells and transfer of in vitro-sensitized vaccine-draining lymph node lymphocytes.

Peripheral blood lymphocytes (PBL) and tumor-infiltrating lymphocytes (TIL) of a patient with von Hippel-Lindau disease and renal cell carcinoma were studied for the T-cell receptor beta chain variable region (TCR-V beta) repertoire. The patient was vaccinated with irradiated autologous tumor cells from a renal tumor mass, a vaccine-draining lymph node was removed, and lymphocytes were cultured in the presence of autologous tumor cells and low-dose interleukin 2 (IL2). These lymphocytes were adoptively transferred to the patient together with systemic IL2 (30,000 IU/kg every 8 h). Analysis of TCR-V beta expression was performed by polymerase chain reaction in PBL before, during, and after therapy, in vaccine-draining lymph node lymphocytes, and in TIL obtained from moderately infiltrated, nonresponding renal tumor mass and from a more intensely infiltrated lung metastasis, which was responding to treatment. Significant differences in the expression of TCR-V beta 13.1 by T-cells recovered from these various sites were observed. Also, TIL recovered from the responding lung metastasis and cultured in the presence of IL2 gave rise to autologous tumor-reactive CD4+ T-cells, whereas the nonresponsive renal tumor yielded a mixture of T- and natural killer cells. In PBL obtained prior to treatment and during IL2 therapy, expression of V beta 13.1 was 0.7 and 1.8%, respectively, of the total V beta gene repertoire. Fresh vaccine-draining lymph node lymphocytes contained 5.9% of V beta 13.1-expressing T-cells. After IL2 therapy, V beta 13.1 gene expression increased to 5.4% in PBL. In the nonresponding tumor mass, the frequency of V beta 13.1 gene expression among TIL was 12%, whereas in the responding, highly infiltrated nodule, it was 28%, with a striking loss of expression of other V beta gene families. Sequencing of the amplified product of V beta 13.1 complementary DNA from the responding pulmonary metastasis showed restrictions in the complementarity-determining region 3. Thus, in vivo expansion of V beta 13.1-expressing CD4+ T-cells, possibly in response to a tumor-associated antigen, occurred in the responding tumor mass following this form of therapy and correlated with tumor course.

Natural killer (NK) cell lytic dysfunction and putative NK cell receptor expression abnormality in members of a family with chromosome 3p-linked von Hippel-Lindau disease.

UNLABELLED: BACKGROUND. Using antibodies to a putative natural killer (NK) cell receptor (pNKR), we recently cloned a novel cDNA and localized this gene to the short arm of human chromosome 3, region 3p21-3p24. Individuals susceptible to or clinically manifesting von Hippel-Lindau disease (VHL) have a genetic defect telomeric to this region on chromosome 3. This defect, resulting in VHL, is manifested by a high incidence of certain tumors. PURPOSE: Based on the location of this gene, we sought to determine if VHL patients have a defect in gene expression of pNKR. METHODS: Because of the proximity of the VHL and pNKR genetic regions, the variable expression of VHL tumors, and the ability of NK cells to target tumor cells, we investigated NK cell activity and other aspects of the immunologic status in 40 members (four branches) of a family with a high incidence of VHL tumors. RESULTS: Individuals affected with VHL and lacking in normal surface expression of pNKR had virtually no NK cell lytic activity. Analysis of genotypes and phenotypes of all subjects revealed that the greatest difference in NK cell lytic activity (P = .0002) was seen when family members exhibited both VHL and pNKR surface expression defects, compared with normal relatives who had neither defect. Furthermore, the lack of NK cell activity strongly correlated (P = .0005) with abnormal pNKR protein surface expression. Of particular interest, individuals who lacked NK cell activity had normal numbers of NK cells. In addition, analysis of leukocyte subsets indicated normal numbers of T and B cells, monocytes, and NK cells in both affected and normal individuals. CONCLUSIONS: These data indicate that although all affected individuals have the cell population responsible for NK cell activity, many have cells low in expression of pNKR and lack functional NK cell activity. Overall, these results indicate that, in addition to a predisposition to the development of neoplasms, VHL patients have a defect in a specific mechanism of natural immunosurveillance that correlates with a defect in expression of a novel large granular lymphocyte pNKR protein.

[Hippel-Lindau syndrome: morphology and immunohistochemistry of tumors related to this syndrome]. / Hippel-Lindau-Syndrom: Morphologie und immunhistochemisches Verhalten einiger dem Syndrom zugeordneter Tumoren.

Hippel Lindau syndrome (HLS), inherited as a simple dominant trait, is characterized by angiomatosis in the brain and retina, and also by cysts and tumours in various abdominal organs. Microscopically there is a striking morphological similarity between some of these tumours and especially between those in the brain (hemangioblastomas) and in the kidneys (renal cell carcinomas). Biopsy and autopsy material from two patients with HLS was examined chiefly by immunohistochemical methods, to investigate further the origin of these tumours. The cerebral hemangioblastomas of both patients showed tumour cells with a positive immunohistochemical reaction for neuron-specific enolase (NSE), suggesting a neural or neuroendocrine origin, while corresponding investigation of the kidney tumours did not produce similar clear results. Systemic immunohistochemical investigation of all tumours related to this syndrome is recommended.