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Overcoming the systemic administration of chemotherapy to reduce drug toxicity and the application of personalised medicine are two of the major challenges in the treatment of cancer. To this aim, efforts are focused on finding novel nanomaterials for the targeted administration of drugs and bioactive molecules in the tumor sites. DNA-based hydrogels are promising candidates for these applications. However, while such materials are fairly known from a structural and physical standpoint, their effects on cell cultures are far less investigated. Here, we studied the biological response of three different cell lines (clear cell renal cell carcinoma 786-O, lung adenocarcinoma H1975 and glioblastoma U87MG) to the treatment with DNA-GEL – a DNA-based hydrogel composed of interacting DNA nanostars. Additionally, we investigated the structural modification of DNA-GELs under cell culture conditions. The results we collected show a cell type specificity of the response, with interesting implications for future applications.

Recently, a number of reports have described dominant C3 deposits in renal biopsies of patients with infection-related glomerulonephritis (GN). While acute post-infectious GN and membranoproliferative GN are commonly characterized by immune deposits containing C3 and/or C4, the absence of immunoglobulin (Ig) and/or immune complexes at light or electron microscopy is a rather unusual observation. Dominant C3 deposition is believed to result from the alternative pathway of complement activation via the C3bBb “tickover” convertase. The actual occurrence of C3 glomerulopathy could be underestimated, since infection-related GN often quickly subsides without the need for a renal biopsy. A more thorough understanding of the pathways that lead to complement assembly and deposition within the kidney is needed to support a new classification of complement-related lesions, including entities such as dense deposit disease, (atypical) hemolytic-uremic syndrome, dominant C1q, CFHR5, C4d, and C3 glomerulopathies. We will briefly review recent work in this area, focusing on GN with selective complement C3 deposits.

Denosumab (Dmab) and zoledronic acid (ZOL) are antiresorptive agents, with different mechanisms of action, that are indicated for delaying the onset of skeletal-related events in patients with bone metastases from solid tumors. Clinical and preclinical data suggest that ZOL may have also anti-angiogenic activity; however, the effects of Dmab (a fully humanized antibody against the receptor activator of nuclear factor kappa B ligand) on angiogenesis are largely unknown. The objective of this study was to compare the potential anti-angiogenic activity of Dmab with that of ZOL in preclinical models. Dmab (0.31 to 160 μM) had no effect on the viability of human MDA-MB-436 and CG5 breast cancer cells or human umbilical vein endothelial cells (HUVECs) and no effect on tubule formation or invasion of HUVECs. In contrast, ZOL (0.31 to 160 μM) decreased the viability of breast cancer and HUVECs in a time- and concentration-dependent manner and also inhibited HUVEC tubule formation and invasion. In vivo, ZOL (20 μg/mouse for three times a week for three consecutive weeks) inhibited angiogenesis in Matrigel plugs and inhibited the growth and neo-angiogenesis of CG5 xenografts in athymic nude mice. In contrast, Dmab (10 mg/Kg twice a week for 4 consecutive weeks) had no effect on Matrigel vascularization or xenograft growth in this model. These findings support the potential antiangiogenic and anticancer activity of ZOL in vitro and in vivo and further suggest that Dmab does not have antiangiogenic activity. Additional studies are needed to elucidate the potential anticancer activity of Dmab.

Regulatory T cells (TRcells) play a crucial role in the regulation of intestinal inflammation. To examine the pathogenetic relevance of TRcells in inflammatory bowel disease (IBD), we evaluated their frequency in peripheral blood and inflamed and noninflamed mucosae of pediatric patients with IBD and age-matched controls without IBD; we also characterized the immune profile of the inflammatory infiltrate in the different phases of the disease. Circulating TRcells were investigated on peripheral blood mononuclear cells by fluorescence-activated cell sorting analysis; mucosal TRcells and inflammatory cell populations were investigated by immunohistochemistry on bioptic specimens. FOXP3 messenger RNA expression levels were confirmed using real-time polymerase chain reaction. FOXP3+ TRcells were significantly increased in the intestinal lesions of patients with active IBD, and returned to normal levels in posttherapy remission phase. At variance, circulating TRcell frequency was elevated in patients with IBD independently of disease activity, as it persisted in the remission phase. A selective imbalance in the frequency of CD4+ T and natural killer cell subsets characterized the abundant inflammatory infiltrate of active intestinal lesions, and also persisted, at a lower level, in noninflamed mucosae of patients in the remission phase. TRcell frequency is differently regulated in mucosal tissues and at the systemic level during the distinct phases of pediatric IBD. The inactive stage of pediatric IBD is characterized by an incomplete normalization of the immune profile, independently of the clinical efficacy of the therapy. The pediatric, early-onset condition may represent a privileged observatory to dissect the immune-mediated pathogenetic mechanisms at the basis of the disease.

Regulatory T cells (TRcells) play a crucial role in the regulation of intestinal inflammation. To examine the pathogenetic relevance of TRcells in inflammatory bowel disease (IBD), we evaluated their frequency in peripheral blood and inflamed and noninflamed mucosae of pediatric patients with IBD and age-matched controls without IBD; we also characterized the immune profile of the inflammatory infiltrate in the different phases of the disease.

Background. A 54-year-old man with multiple myeloma underwent peripheral blood stem cell transplantation (PBSCT) with cells donated by his human leukocyte antigen (HLA)-identical sister. Eight months after PBSCT, the patient experienced chronic graft-versus-host disease with skin involvement (generalized erythema), mucosal ulceration, sicca syndrome, and elevated liver enzymes. Two years after PBSCT, the patient developed nephrotic syndrome with massive proteinuria, which required hospitalization.Investigations. Physical examination, blood and urine analyses, liver function tests, 24 h urinary albumin excretion and renal biopsy.Diagnosis. Focal segmental glomerulosclerosis as a complication of graft-versus-host disease.Management. Prednisone, ciclosporin and an angiotensin-converting-enzyme inhibitor.

In planning treatment of a gastric neoplasm in a patient previously treated for lobular breast carcinoma, it is important to differentiate a primary gastrointestinal tract tumor from a metastatic form. We report a case of a breast lobular carcinoma metastatic to the stomach. The patient underwent a subtotal gastrectomy for symptomatic disease. Although gastric symptoms appeared 14 years after the breast carcinoma, immunohistochemical analysis of the surgical specimen helped to establish that the gastric lesion, thought to be primary, was effectively a metastatic repetition of the breast neoplasm. To better define treatment in a gastric neoplasm patient previously treated for breast carcinoma, the preoperative diagnosis should rule out a metastatic disease. The patient described received an adjuvant chemotherapy according to breast cancer protocol after gastric resection for symptomatic disease. The patient is still alive and undergoing chemotherapy for peritoneal carcinosis.

Secreted protein, acidic and rich in cysteine (SPARC), also known as osteonectin or BM-40, is a Ca2+-binding matricellular glycoprotein involved in development, wound healing, and neoplasia. However, the role of SPARC in tumors is ill defined mostly because it is expressed by both tumor and stromal cells, especially inflammatory cells. We analyzed the respective roles of host- and tumor-derived SPARC in wild-type and congenic SPARC knockout (SPARC−/−) mice on a BALB/c genetic background injected into the mammary fat pad with SPARC-producing mammary carcinoma cells derived from c-erB2 transgenic BALB/c mice. Reduced tumor growth but massive parenchyma infiltration, with large areas of necrosis and impaired vascularization were observed in SPARC−/− mice. Immunohistochemical analysis showed a defect in collagen type IV deposition in the stroma of lobular tumors from SPARC−/− mice. Chimeric mice expressing SPARC only in bone marrow–derived cells were able to organize peritumoral and perilobular stroma, whereas reciprocal chimeras transplanted with bone marrow from SPARC−/− mice developed tumors with less defined lobular structures, lacking assembled collagen type IV and with a parenchyma heavily infiltrated by leukocytes. Together, the data indicate that SPARC produced by host leukocytes, rather than the tumor, determines the assembly and function of tumor-associated stroma through the organization of collagen type IV.

The interaction between FasL on tumor cells and Fas on lymphocytes may represent a tumor immune escape mechanism. We explored FasL expression and function in human urinary bladder transitional cell carcinomas (TCCs). FasL expression was observed in situin 45% of TCCs (n= 45) and was absent in normal urothelium (n= 20). A correlation existed between FasL expression and high tumor grade (0% in G1, 14% in G2, and 75% in G3; P< 0.0001) and stage (13% in superficial Ta-T1 versus81% in invasive T2-T4; P< 0.0001). FasL function was shown by the ability of two FasL-positive primary culture TCC cell lines (established from two FasL-positive invasive TCCs) to induce Fas-mediated killing not only of conventional Fas-sensitive targets (such as Jurkat cells or phytohemagglutinin-lymphoblasts), but also of autologous T lymphocytes generated in a mixed lymphocyte tumor-cell culture. In addition, an association between FasL expression by TCC cells and activated caspase-8, -9, and -3 expression by interferon-γ-producing CD8-positive tumor-infiltrating lymphocytes was observed in situ. Our results show a functional expression of TCC-expressed FasL that correlates with tumor progression. These results suggest that TCC-expressed FasL may induce apoptosis of anti-tumor T lymphocytes in vivo, providing new insights on the mechanisms involved in bladder TCC progression.

Our aim was 2-fold: to investigate the role of α-tocopherol supplementation on the antitumor activity of DDP and to evaluate the effect of α-tocopherol on the survival and neurotoxicity of DDP-treated mice. Experiments performed on the M14 human melanoma line demonstrated that α-tocopherol supplementation did not influence the efficacy of DDP; the inhibition of cell survival and of the in vivo tumor growth after treatment with α-tocopherol and DDP combination was similar to that observed after DDP alone. Conversely, α-tocopherol was also able to increase survival of mice treated with a high dose of DDP. While DDP alone produced death in about 70% of mice, the combination reduced deaths to about 30%. Analysis of oxidative stress markers and peroxidative damage in organs indicated that the protective effect of α-tocopherol was mainly related to its antioxidant activity. A significant increase in the concentration of TBARS and decreased PUFAs and catalase activity were observed after DDP treatment, while with α-tocopherol the levels of these markers were comparable to those observed in untreated mice. Histologic analysis performed on peripheral nerve revealed that α-tocopherol also protected mice from severe neurologic damage induced by DDP treatment. In conclusion, our results demonstrate that α-tocopherol protects against the systemic toxicity and neurotoxicity induced by DDP without interfering with its antitumor activity and suggest that this combination is a promising strategy to improve the therapeutic index of DDP-based chemotherapy. © 2003 Wiley-Liss, Inc.

The glycolipid α-galactosylceramide (α-GalCer), ligand of NKT cells, has been recently shown to induce antitumor immunity in mice through the induction of IL-12 production by dendriticcells. In the present study we compared α-GalCer and rIL-12 antitumor activities in the treatment of hepatic metastases of the C-26 murine colon carcinoma. We show that in immunocompetent mice the two molecules display similar efficacy, whereas in mice knockout (KO) for β2-microglobulin (β2m), IFN-γ or IL-12p40, α-GalCer antitumor activity is severely impaired. Conversely,in all such KO mice, rIL-12 retains its efficacy. In this context, the IL-12 effect relies on NK cell function since it is abrogated by antibodies to NK1.1, expressed by both NK and NKT cells, but not in β2m KO mice that lack NKT and CD8 T cells, but have a perfectly functional NK cell population. Furthermore, in IFN-γ and IL-12p40 double KO mice, exogenous rIL-12 completely loses antitumor efficacy, suggesting the existence of an IFN-γ-independent IL-12 effect that does require the presence of endogenous IL-12p40 chain.

In the last 10 years, evidence has accumulated that overexpression of Met protein is a distinguishing feature of almost every case of well‐differentiated papillary carcinoma. Increased expression of the protein is probably due to enhanced transcription of the METgene and/or to post‐transcriptional mechanisms. So far, alterations of the METgene have not been recognized, but evidence has been provided that activated RASand RETcan cause accumulation of METRNA. Thus, the possibility exists that dysregulation of METis the final result of different molecular pathways capable of inducing thyroid cell transformation; RETrearrangements might account for some of the cases, but the demonstration that the majority of papillary carcinomas do not have recognized alterations of the RETgene strongly suggests that METgene dysregulation can also be achieved through other molecular pathways. Dysregulation of METcauses marked accumulation of Met protein in tumour cells that is promptly detected by immunohistochemistry. Thus, overexpression of Met protein might represent an immunohistochemical marker of papillary carcinoma, potentially helpful in problematic cases, but caution is required; moderate expression of Met protein is observed in non‐neoplastic thyroid diseases, such as Graves' and Hashimoto's thyroiditis, and reagents active on paraffin sections may have a low affinity and/or low specificity for Met protein, leading to artifactual staining. Met protein‐positive papillary carcinoma cells may produce hepatocyte growth factor (HGF) and may activate HGF through the urokinase‐type plasminogen activator (uPA) bound to urokinase‐type plasminogen activator receptor (uPA‐R). Thus, papillary carcinoma cells possess the molecular machinery necessary for a productive HGF/Met interaction. In vitrostudies have demonstrated that HGF enhances the motility and invasiveness of tumour cells and induces the synthesis and release of chemokines active in the recruitment of dendritic cells. These observations provide a rational basis for the understanding of two distinguishing features of papillary carcinoma. First, the tumour is often characterized by early metastatic spread to regional lymph nodes and by multifocal involvement of the gland, which suggests highly invasive behaviour. Second, a prominent peritumoural inflammatory reaction is often observed, which suggests cross‐talk between tumour cells and the immune system. Copyright © 2001 John Wiley & Sons, Ltd.

Macrophage-derived chemokine (MDC)/CCL22 is a CC chemokine active on dendritic cells (DC), NK cells and Th2 lymphocytes. The present study was aimed at comprehensively investigating MDC production in vitro and in vivo. DC were the most potent producers of MDC among leukocytes tested. Endothelial cells did not produce MDC under a variety of conditions. Signals that induce maturation (lipopolysaccharide, IL-1, TNF, CD40 ligand, recognition of bacteria and yeast) dramatically augmented MDC production, and dexamethasone and vitamin D3 blocked it. Prostaglandin E2, which blocked the acquisition of IL-12 production and the capacity to promote Th1 generation, did not affect MDC production. Using mass spectrometry-based techniques, DC supernatants were found to contain N-terminally truncated forms of MDC [MDC(3–69), MDC(5–69) and MD(C7–69)] as well as the full-length molecule. In vivo, CD1a⁺, CD83⁺, MDC⁺ DC were found in reactive lymph nodes, and in Langerhans' cell histiocytosis. Skin lesions of atopic dermatitis patients showed that CD1a⁺ or CD1b⁺ DC, and DC with a CD83⁺ phenotype were responsible for MDC production in this Th2-oriented disorder. Thus, DC are the predominant source of MDC in vitro and in vivo under a variety of experimental and clinical conditions. Processing of MDC to MDC(3–69) and shorter forms which do not recognize CCR4 is likely to represent a feedback mechanism of negative regulation.

Tissue distribution of dendritic cells was investigated in eight cases of papillary carcinoma of the thyroid using immunohistochemistry. Most dendritic cells had an immature phenotype (CD1a++, CD11c+, CD40+, CD86−, HLA-DR−) and were located at the invasion edge of the tumor. This pattern of distribution was profoundly different from that of CD68+ macrophages, which were evenly distributed throughout the tumor. The ability of tumor cells to release chemotactic factors active on dendritic cells was investigated in primary cultures of the same cases of papillary carcinoma, and was compared to that of the corresponding normal thyroid cells obtained from the tumor-free contralateral lobe. Chemotactic activity of culture supernatants was tested against dendritic cells in a chemotaxis chamber. It was found that papillary carcinoma cells were active in releasing chemotactic activity, that hepatocyte growth factor (HGF; 100 ng/ml) or interleukin (IL)-1β (103U/ml) induced a fourfold increase in the amount of chemotactic activity released, and that normal thyroid cells obtained from the same patients were as effective as tumor cells. Characterization of chemokines at RNA level revealed that unstimulated cells contain large amounts of IL-8 and monocyte chemotactic protein (MCP)-1 RNAs, and that stimulation with HGF or IL-1β induced RNAs for regulated upon activation normal T expressed and secreted (RANTES), macrophage inflammatory protein (MIP)-3α, interferon-γ-inducible protein 10 (IP-10), and, to a lesser extent, MIP-1α and MIP-1β. The possibility that HGF/Met interaction has a biological role in vivowas investigated in serial sections of six tumors immunostained for CD1a+, Met protein, and HGF. It was found that all six tumors were intensely and diffusely positive for Met protein, that HGF staining was present in tumor cells of the advancing edge, and that HGF+/Met+ tumor cell nests were infiltrated by CD1a+ dendritic cells. The foregoing observations are consistent with the possibility that HGF stimulation of Met+ tumor cells is one of the molecular mechanisms involved in the recruitment of dendritic cells.

Thymic epithelial cell component originates from cranial neural crest as well as from endoderm and ectoderm of the third pharyngeal pouch and branchial cleft. Epidermal growth factor (EGF) has been previously shown to play a crucial role in directing thymic epithelial cells toward a neural-oriented cell fate. To identify genes that are involved in the EGF-induced neurotypic differentiation of the thymic stroma-derived TC-1S cell line, we studied EGF-treated and untreated cells by RNA fingerprinting PCR-based differential screening. We obtained 23 distinct sequences including 18 known genes and 5 sequences previously unreported, which are currently under characterization. Here, we describe the involvement of one of the isolated genes, the thrombospondin-1, as a mediator of the neurotypic differentiation induced by EGF in TC-1S cells. We show that thrombospondin-1 mRNA and protein levels are increased by EGF. Moreover, exogenous thrombospondin-1 is able to enhance the outgrowth of neurite-like processes as well as the expression of neurofilaments and neural cell adhesion molecule in TC-1S cells. These observations suggest that the up-regulation of thrombospondin-1 synthesis induced by EGF contributes to the differentiation choice of thymic epithelial cells toward a neural fate, reminiscent of their neural crest origin.

The present study has investigated the functional role of the Met receptor in primary cultures of 20 papillary carcinomas and of normal thyroid cells obtained from the same patients. Normal and tumour cells grew as adherent cells, formed a confluent monolayer after 10–20 days, had epithelial morphology, and were immunoreactive for cytokeratin, vimentin, and thyroglobulin. The potential effect of hepatocyte growth factor (HGF) on cell invasiveness was investigated in Boyden chambers, using a nucleopore filter coated with Matrigel as the barrier and HGF as the chemoattractant. Tumour cells of five out of seven cases of papillary carcinoma were more responsive to HGF than the corresponding normal cells in terms of the number of migrated cells per mm². Involvement of the Met receptor in the HGF-induced migratory response was suggested by the observation that the agonistic anti-Met monoclonal antibody (MAb) DO-24 was equally effective. HGF did not affect the proliferative activity of thyroid cells. Under the same experimental conditions, 10 per cent fetal bovine serum (FBS) induced a two-fold increase in [³H]thymidine incorporation into normal cells and tumour cells. These findings are consistent with the possibility that HGF plays a crucial role in determining the invasiveness of tumour cells in papillary carcinoma of the thyroid. Copyright © 1999 John Wiley & Sons, Ltd.

Cellular fibronectins containing the extracellular domain A or B (EDA and EDB) are particularly abundant in fetal and neoplastic tissues. The presence of EDA and EDB was investigated in 28 cases of papillary carcinoma of the thyroid using IST‐9 and BC‐1 monoclonal antibodies. Immunostaining for EDA and EDB was detected in tumour stroma, in tumour basement membranes, and in tumour blood vessels. EDA was present in 27 of the 28 cases, in 20 of which more than 75 per cent of the tumour stroma was stained. Immunostaining for EDB was detected in 23 of the 28 cases and was less pronounced than that for EDA, being present in less than 25 per cent of the tumour stroma in most cases. Reactivity for EDA/EDB was not observed in the adjacent normal thyroid in any of the cases investigated. In a group of 20 non‐papillary tumours, immunostaining for EDA was present in the stroma of three follicular carcinomas (one minimally and two widely invasive), one medullary carcinoma, and 5 of 16 follicular adenomas; expression of EDB was more restricted, being present in only the two cases of widely invasive follicular carcinoma. The presence of EDA and EDB was not correlated with the extent of fibrosis or the degree of tumour cell differentiation. Immunoreactivity was already present in microcarcinomas. These observations raise the possibility that the production of oncofetal fibronectins is an important step in papillary carcinoma tumourigenesis, perhaps facilitating adhesion and spreading of tumour cells. Copyright © 1999 John Wiley & Sons, Ltd.

The present study has investigated the functional role of the Met receptor in primary cultures of 20 papillary carcinomas and of normal thyroid cells obtained from the same patients. Normal and tumour cells grew as adherent cells, formed a confluent monolayer after 10–20 days, had epithelial morphology, and were immunoreactive for cytokeratin, vimentin, and thyroglobulin. The potential effect of hepatocyte growth factor (HGF) on cell invasiveness was investigated in Boyden chambers, using a nucleopore filter coated with Matrigel as the barrier and HGF as the chemoattractant. Tumour cells of five out of seven cases of papillary carcinoma were more responsive to HGF than the corresponding normal cells in terms of the number of migrated cells per mm2. Involvement of the Met receptor in the HGF‐induced migratory response was suggested by the observation that the agonistic anti‐Met monoclonal antibody (MAb) DO‐24 was equally effective. HGF did not affect the proliferative activity of thyroid cells. Under the same experimental conditions, 10 per cent fetal bovine serum (FBS) induced a two‐fold increase in [3H]thymidine incorporation into normal cells and tumour cells. These findings are consistent with the possibility that HGF plays a crucial role in determining the invasiveness of tumour cells in papillary carcinoma of the thyroid. Copyright © 1999 John Wiley & Sons, Ltd.

Cellular fibronectins containing the extracellular domain A or B (EDA and EDB) are particularly abundant in fetal and neoplastic tissues. The presence of EDA and EDB was investigated in 28 cases of papillary carcinoma of the thyroid using IST-9 and BC-1 monoclonal antibodies. Immunostaining for EDA and EDB was detected in tumour stroma, in tumour basement membranes, and in tumour blood vessels. EDA was present in 27 of the 28 cases, in 20 of which more than 75 per cent of the tumour stroma was stained. Immunostaining for EDB was detected in 23 of the 28 cases and was less pronounced than that for EDA, being present in less than 25 per cent of the tumour stroma in most cases. Reactivity for EDA/EDB was not observed in the adjacent normal thyroid in any of the cases investigated. In a group of 20 non-papillary tumours, immunostaining for EDA was present in the stroma of three follicular carcinomas (one minimally and two widely invasive), one medullary carcinoma, and 5 of 16 follicular adenomas; expression of EDB was more restricted, being present in only the two cases of widely invasive follicular carcinoma. The presence of EDA and EDB was not correlated with the extent of fibrosis or the degree of tumour cell differentiation. Immunoreactivity was already present in microcarcinomas. These observations raise the possibility that the production of oncofetal fibronectins is an important step in papillary carcinoma tumourigenesis, perhaps facilitating adhesion and spreading of tumour cells. Copyright © 1999 John Wiley & Sons, Ltd.

We transduced BALB/c-derived C-26 colon carcinoma cells with granulocyte/macrophage colony-stimulating factor (GM-CSF) and CD40 ligand (CD40L) genes to favor interaction of these cells with host dendritic cells (DCs) and, therefore, cross-priming. Cotransduced cells showed reduced tumorigenicity, and tumor take was followed by regression in some mice. In vivo tumors were heavily infiltrated with DCs that were isolated, phenotyped, and tested in vitro for stimulation of tumor-specific cytotoxic T lymphocytes (CTLs). BALB/c C-26 carcinoma cells express the endogenous murine leukemia virus (MuLV) env gene as a tumor-associated antigen. This antigen is shared among solid tumors of BALB/c and C57BL/6 mice and contains two epitopes, AH-1 and KSP, recognized in the context of major histocompatibility complex class I molecules H-2Ld and H-2Kb, respectively. DCs isolated from C-26/GM/CD40L tumors grown in (BALB/c × C57BL/6)F1 mice (H-2d×b) stimulated interferon γ production by both anti–AH-1 and KSP CTLs, whereas tumor-infiltrating DCs (TIDCs) of BALB/c mice stimulated only anti–AH-1 CTLs. Furthermore, TIDCs primed naive mice for CTL activity as early as 2 d after injection into the footpad, whereas double-transduced tumor cells required at least 5 d for priming; this difference may reflect direct DC priming versus indirect tumor cell priming. Immunohistochemical staining indicated colocalization of DCs and apoptotic bodies in the tumors. These data indicate that DCs infiltrating tumors that produce GM-CSF and CD40L can capture cellular antigens, likely through uptake of apoptotic bodies, and mature in situ to a stage suitable for antigen presentation. Thus, tumor cell–based vaccines engineered to favor the interaction with host DCs can be considered.

In the present study we investigated the lymph node morphology and distribution of cell surface phenotypes in four cases of adult peripheral T cell lymphoma. Histologically, the tumors were classified as T zone lymphoma, T cell lymphoma with large multilobated nuclei and T cell immunoblastic sarcoma. In the T zone lymphoma the neoplastic lymphocytes were E+(90 %) and exhibited intensive focal staining for acid phosphatase (93 %) and acid esterase (92 %); the phenotype distribution revealed low expression of the T-3 antigen (49 %), selective expression of the T-4 antigen (72 %) and poor expression of T-6 (10 %) and T-10 antigens (22 %). Some of these features are present in normal and in neoplastic immature T cells. In the remaining three cases the majority of lymph node cells were E+(59–75 %), T-3+(67–80 %) and T-8+(43–55 %). A distinctive feature of the T cell immunoblastic sarcoma was the presence of high percentages of DR+cells (62 %; 63 %). Thus our results indicate that the morphological heterogeneity of peripheral T cell lymphoma is also paralleled by a variety of surface phenotypes and that phenotype studies may provide a useful contribution to identification and accurate classification of peripheral T cell neoplasms.

Metprotein encoded by METoncogene is the high affinity receptor for hepatocyte growth factor (HGF)/scatter factor (SF). HGF/SF has to be cleaved in its heterodimeric form by the urokinase‐type plasminogen activator (uPA) to become active as a ligand for Metreceptor. The expression of Metprotein and of the high affinity receptor for uPA (uPA‐R) was investigated in 39 samples of papillary carcinoma using immunohistochemistry. Reactivity for Metprotein was present in 33 of 34 tumours, mostly with a diffuse pattern of staining. Reactivity for uPA‐R was present in 78 per cent of papillary tumours and exhibited a pattern of staining similar to that of Metprotein. Staining for uPA‐R was present in 23 of 25 cases (92 per cent) of papillary carcinoma with prominent sclerosis, and in only 1 of 7 cases (14 per cent) without sclerosis. Peritumoural normal thyroid, follicular adenomas, and follicular carcinomas were negative for Metprotein and for uPA‐R. Hyperfunctioning tall thyroid cells showed weak membrane reactivity for uPA‐R and for Metprotein. The findings of immunohistochemistry were confirmed at the mRNA level using in situhybridization, since the signal for uPA‐R and MetRNAs was detected in most tumour cells of five cases of papillary carcinoma. © 1998 John Wiley & Sons, Ltd.

A 16-yr-old white female was affected by continuous fever, pancytopenia with relative increase of T-8 lymphocytes, severe bone marrow hypoplasia, generalized lymphadenomegaly and splenomegaly. A first lymph node biopsy, obtained at the onset of the disease, was involved by a paracortical tumor with some S-100+ “lymphocyte-like” cells in the neoplastic areas; in the cell suspension, 70–80% of cells were E4 + /E37 + lymphocytes with prevalent expression of the T-8 phenotype (52%). A second lymph node biopsy, obtained five months later, was involved by a diffuse proliferation of S-100 + cells with high mitotic activity; in the cell suspension, the majority of cells were E-/T-11+/ T-3+/T-8+. At the TEM level, the neoplastic cells were characterized by regular or indented nuclei with finely dispersed chromatin and by regular or indented nuclei with finely dispersed chromatin and by irregular cytoplasmic profiles with thick pseudopodia-like projections. The possibility is discussed that this neoplasm may share some similarities with the T-γ lymphoma being part of a poorly described group of tumors with intermediate features between T cell lymphoma and malignant histiocytosis.

Human monocytes cultured with granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-13 for 7 days differentiate into cells with the morphology and function of dendritic cells (DC). We have investigated the effect of IL-10 on this differentiation pathway. In the presence of IL-10 cells did not develop DC morphology, did not express CD1a and had lower levels of MHC class II. IL-10 promoted the differentiation of large cells with the morphology, cytochemistry and membrane phenotype of macrophages, including staining for nonspecific esterase and high levels of CD14, CD16 and CD68. The effect of IL-10 was dose dependent and was best appreciated when the cytokine was added at the initiation of the culture, as addition on day 3 was less inhibitory. When added to already differentiated DC on day 6, IL-10 caused only a modest reduction of MHC class II and CD1a expression, and no acquisition of the macrophage markers CD14, CD16 and CD68. Prolonged incubation up to 5 days with IL-10 did not induce a shift of differentiated DC to macrophages. On the other hand, the macrophages obtained by culturing for 7 days with GM-CSF+IL-13+IL-10 did not shift to DC upon removal of IL-10 for up to 3 days. Thus, the effect of IL-10 on monocyte differentiation, occurs only at the precursor level and confers an irreversible phenotype. From a functional point of view, cells cultured in the presence of IL-10 were poor stimulators of allogeneic cord blood T cells in mixed lymphocyte reaction (MLR) and presented tetanus toxin (TT) to specific T cell lines with much less efficiency than control DC. In contrast, IL-10-cultured DC showed 7 times greater endocytosis of FITC-dextran. This increased endocytosis was mostly mediated via the mannose receptor, as demonstrated by blocking with unlabeled mannose. In conclusion, IL-10 inhibits DC differentiation from monocytes and, in a substantial proportion of the cells, promotes the differentiation to mature macrophages. Intriguingly, IL-10 inhibits antigen presentation while it stimulates endocytic activity.

S-100 protein is an immunohistochemical marker for a subset of dendritic cells, the interdigitating reticulum cells (IDRCs), which are mainly located in T-dependent areas of lymphoid tissues. In the present study we have investigated the distribution of S-100-positive cells in lymph nodes, spleen, thymus and peripheral blood of normal subjects. Immunoreactivity for S-100 protein was demonstrated in large cells with dendritic morphology and in small lymphocyte-like cells present in the lymph node paracortex, thymic medulla, splenic periarterial lymphatic sheaths (PALS) and in peripheral blood. S-100-positive lymphocyte-like cells were frequently detected around high endothelial venules (HEV) and were present in numbers comparable to those of S-100-positive IDRCs. Immunoelectron microscopy confirmed the existence of positive cells with lymphoid morphology and revealed that the intracellular distribution of the immunoreaction product was similar in lymphoid and dendritic cells. Further characterization of S-100-positive cells demonstrated that both lymphoid and dendritic cells were unreactive with a large panel of monocytic and macrophage markers.

Met protein encoded by MET oncogene is the high affinity receptor for hepatocyte growth factor (HGF)/scatter factor (SF). HGF/SF has to be cleaved in its heterodimeric form by the urokinase-type plasminogen activator (uPA) to become active as a ligand for Met receptor. The expression of Met protein and of the high affinity receptor for uPA (uPA-R) was investigated in 39 samples of papillary carcinoma using immunohistochemistry. Reactivity for Met protein was present in 33 of 34 tumours, mostly with a diffuse pattern of staining. Reactivity for uPA-R was present in 78 per cent of papillary tumours and exhibited a pattern of staining similar to that of Met protein. Staining for uPA-R was present in 23 of 25 cases (92 per cent) of papillary carcinoma with prominent sclerosis, and in only 1 of 7 cases (14 per cent) without sclerosis. Peritumoural normal thyroid, follicular adenomas, and follicular carcinomas were negative for Met protein and for uPA-R. Hyperfunctioning tall thyroid cells showed weak membrane reactivity for uPA-R and for Met protein. The findings of immunohistochemistry were confirmed at the mRNA level using in situ hybridization, since the signal for uPA-R and Met RNAs was detected in most tumour cells of five cases of papillary carcinoma. © 1998 John Wiley & Sons, Ltd.

We analyzed the ability of interferon (IFN)-γ knockout mice (GKO) to reject a colon carcinoma transduced with interleukin (IL)-12 genes (C26/IL-12). Although the absence of IFN-γ impaired the early response and reduced the time to tumor onset in GKO mice, the overall tumor take rate was similar to that of BALB/c mice. In GKO mice, C26/IL-12 tumors had a reduced number of infiltrating leukocytes, especially CD8 and natural killer cells. Analysis of the tumor site, draining nodes, and spleens of GKO mice revealed reduced expression of IFN- inducible protein 10 and monokine induced by γ-IFN. Despite these defects, GKO mice that rejected C26/IL-12 tumor, and mice that were primed in vivo with irradiated C26/IL-12 cells, showed the same cytotoxic T lymphocyte activity but higher production of granulocyte/macrophage colony–stimulating factor (GM-CSF) as compared with control BALB/c mice. Treatment with monoclonal antibodies against GM-CSF abrogated tumor regression in GKO but not in BALB/c mice. CD4 T lymphocytes, which proved unnecessary or suppressive during rejection of C26/IL-12 cells in BALB/c mice, were required for tumor rejection in GKO mice. CD4 T cell depletion was coupled with a decline in GM-CSF expression by lymphocytes infiltrating the tumors or in the draining nodes, and with the reduction and disappearance of granulocytes and CD8 T cells, respectively, in tumor nodules. These results suggest that GM-CSF can substitute for IFN-γ in maintaining the CD8–polymorphonuclear leukocyte cross-talk that is a hallmark of tumor rejection.

lnterleukin-1 (IL-1) profoundly affects a number of functions of vascular cells. Two distinct IL-1 receptors (IL-1R) are expressed on different cell types: the 80 Kd IL-1R, on T cells and fibroblasts, and the 68 Kd IL-1RIIon B cells and myelomonocytic cells. The presence and functionality of IL-1R on vascular cells has been investigated by using polyoma-transformed mouse endothelial cell (EC) lines (sEnd.1 and tEnd.1). These cells expressed specific and saturable binding sites for IL-1 (1,273 sites per cell with kd 9.5 × 10-11mol/Lfor sEnd.1, and 771 sites per cell with kd 8.5 × 10-11mol/L for tEnd.1, with radioiodinated IL-1α as ligand). Binding of IL-1 was also evident at single cell level by autoradiography. By cross-linking studies, the molecular weight of the IL-1 binding protein on EC was approximately 80 Kd. This was confirmed by the presence in EC of mRNA for the 80 Kd IL-1 R1. The IL-1R1on EC was apparently functional, since EC responded to IL-1 with IL-6 mRNA expression and IL-6 bioactivity production. These results were extended to human EC and vascular smooth muscle cells, which were also found to express mRNA for IL-1 R,.

Freshly obtained normal lymphoid cells kill certain tumor target cells in vitro. Using peripheral-blood lymphocytes (PBLs) and the human tumor target cell line BT-20, we have defined a tumor necrosis factor (TNF)-dependent, cell-mediated cytotoxic mechanism that is homologous to the murine natural cytotoxic (NC) cell activity. Human NC cell activity was detected in freshly isolated PBLs and was augmented by short in vitro pulses with recombinant human interleudin-2 but not with recombinant human alfa interferon. Monoclonal anti-TNF antibodies inhibited the killing of the target cells. The independence of interferon and the mediation of killing by TNF distinguish human NC cell activity from natural killer and lymphokine-activated killer cell activitoes. [J Natl Cancer Inst 1988;80:1035–1038]