Immunotherapy is a promising approach for the management of malignancies. It may be particularly useful for tumors that do not respond to conventional therapies, such as many metastatic cancers. The efficacy of immunotherapy will depend on many factors, one of which is the immunocompetence of the host. Patients with large primary tumors frequently are immunosuppressed, making them poor candidates for immunotherapy. Although a few studies have reported that surgical removal of primary tumor reverses immunosuppression, it is not known whether metastatic disease in postsurgery patients inhibits this recovery. To determine the role of metastatic disease, we examined tumor-free mice versus mice with primary tumor and metastatic disease versus mice whose primary tumors were removed surgically but who had metastatic disease. We have used the mouse 4T1 mammary carcinoma, a BALB/c-derived transplantable tumor that shares many characteristics with human breast cancer and is an established model for spontaneous, metastatic cancer. Cell-mediated and humoral adaptive immunity, as measured by rejection of allogeneic tumor, antigen-specific T-cell proliferation, and antigenspecific antibody responses, was suppressed in 4T1-bearing nonsurgery mice relative to tumor-free mice. Surgical removal of primary tumor resulted in rebounding of antibody and cell-mediated responses, even in mice with metastatic disease. Macrophage activity, as measured by lipopolysaccharide responsiveness, and dendritic cell function, as measured by nominal and alloantigen presentation, were not suppressed in tumorbearing mice. Therefore, the presence of primary tumor suppresses T-cell and antibody responses; however, surgical removal of primary tumor restores immunocompetence even when disseminated metastatic disease is present.

A number of biological activities have been ascribed to the major green tea polyphenol epigallocatechin-3-gallate (EGCG) to explain its chemopreventive properties. Its antioxidant properties emerge as a potentially important mode of action. We have examined the effect of EGCG treatment on the damaging oxidative effects of UVA radiation in a human keratinocyte line (HaCaT). Using the ROS-sensitive probes dihydrorhodamine 123 (DHR) and 2 ,7 -dichlorodihydrofluorescein diacetate (DCFH-DA), we detected a reduction in fluorescence in UVA-irradiated (100 kJ/m 2 ) cells in the case of the former but not the latter probe after a 24-hr treatment with EGCG (e.g., 14%, [p < 0.05] after 10 M EGCG). In the absence of UVA, however, both DHR and DCFH detected a pro-oxidant effect of EGCG at the highest concentration used of 50 M. Measurements of DNA damage in UVA-exposed cells using the single cell gel electrophoresis assay (comet assay) also showed the protective effects of EGCG. A concentration of 10 M EGCG decreased the level of DNA single strand breaks and alkali-labile sites to 62% of the level observed in non-EGCG, irradiated cells (p < 0.001) with a 5-fold higher concentration producing little further effect. Correspondingly, EGCG ablated the mutagenic effects of UVA (500 kJ/m 2 ) reducing an induced hypoxanthine-guanine phosphoribosyl transferase (HPRT) mutant frequency of (3.39 ؎ 0.73) ؋ 10 ؊6 to spontaneous levels (1.09 ؎ 0.19) ؋ 10 ؊6 . Despite having an antiproliferative effect in the absence of UVA, EGCG also served to protect against the cytotoxic effects of UVA radiation. Our data demonstrate the ability of EGCG to modify endpoints directly relevant to the carcinogenic process in skin. © 2002 Wiley-Liss, Inc. Key words: epigallocatechin-3-gallate; antioxidant; ultraviolet AThere has been considerable recent interest in the chemopreventive properties of the polyphenols or catechins of green tea that have been shown to inhibit tumorigenesis in a variety of organs in rodent models. 1-3 The major polyphenol component by mass, (Ϫ)-epigallocatechin-3-gallate (EGCG) is an effective protectant against the mutagenicity of a number of chemical carcinogens including benzo[a]pyrene (B[a]P), aflatoxin B1 and 3-hydroxyamino-1-methyl-5H-pyrido [4,3-b]indole. 4 -6 EGCG, together with other green tea polyphenols also exhibits growth inhibitory properties in a variety of tumour cell lines. 7-9 Several mechanisms have been proposed by which these compounds exert their anti-tumorigenic action: these include the blockade of growth factors binding to their receptors, 10 phosphorylation (activation) of mitogen-activated protein kinases (MAPKs) 11,12 possibly resulting in the observed induction of Phase II drug-metabolizing enzymes, 13,14 and the generation of oxidative stress leading to apoptosis. 7,9 In the face of an oxidative challenge, however, it is now well documented that green tea catechins act as antioxidants. For example, EGCG abrogates oxidation by hydrogen peroxide both in a cell free system 15 and in terms of DNA single-s...

Autoimmunity results from a breakdown in tolerance mechanisms that regulate autoreactive lymphocytes. We recently showed that during innate immune responses, secretion of IL-6 by dendritic cells (DCs) maintained autoreactive B cells in an unresponsive state. In this study, we describe that TLR4-activated DCs from lupus-prone mice are defective in repressing autoantibody secretion, coincident with diminished IL-6 secretion. Reduced secretion of IL-6 by MRL/lpr DCs reflected diminished synthesis and failure to sustain IL-6 mRNA production. This occurred coincident with lack of NF-κB and AP-1 DNA binding and failure to sustain IκBα phosphorylation. Analysis of individual mice showed that some animals partially repressed Ig secretion despite reduced levels of IL-6. This suggests that in addition to IL-6, DCs secrete other soluble factor(s) that regulate autoreactive B cells. Collectively, the data show that MRL/lpr mice are defective in DC/IL-6-mediated tolerance, but that some individuals maintain the ability to repress autoantibody secretion by an alternative mechanism.

The ability to induce antibody responses to pathogens while maintaining the quiescence of autoreactive cells is an important aspect of immune tolerance. During activation of Toll-like receptor-4 (TLR4), dendritic cells (DCs) and macrophages (MFs) repress autoantibody production through their secretion of IL-6 and soluble CD40L (sCD40L). These soluble mediators selectively repress B cells chronically exposed to antigen, but not naïve cells, suggesting a means to maintain tolerance during TLR4 stimulation, yet allow immunity. In this study, we identify TNFα as a third repressive factor, which together with IL-6 and CD40L, account for nearly all the repression conferred by DCs and MFs. Like IL-6 and sCD40L, TNFα did not alter B cell proliferation or survival. Rather, it reduced the number of antibody secreting cells. To address whether the soluble mediators secreted by DCs and MFs functioned in vivo, we generated mice lacking IL-6, CD40L and TNFα. Compared to wildtype mice, these mice showed prolonged anti-nuclear antibody responses following TLR4 stimulation. Further, adoptive transfer of autoreactive B cells into chimeric IL-6-/- × CD40L-/- × TNFα-/- mice showed that pre-plasma cells secreted autoantibodies independent of germinal center formation or extrafollicular foci. These data indicate that in the absence of genetic predisposition to autoimmunity, loss of endogenous IL-6, CD40L, and TNFα promotes autoantibody secretion during TLR4 stimulation.

Summary.  Inhibitors are a serious complication, considerably increasing the morbidity, mortality and cost of treatment in this patient group [1]. The challenge of treating people with haemophilia (PWH) with inhibitors can be met by a well‐coordinated multidisciplinary team specialized in haemophilia. Each treatment centre must run a screening programme to detect inhibitors within their population and develop protocols to treat these patients. The treatment centre in Buenos Aires developed a screening programme that tests all our patients twice a year, ensuring early detection of inhibitors and early treatment of complications. In 2006, we analysed the quality of life (QOL) of non‐inhibitor patients and compared it with inhibitor patients detected by this programme and found no differences in QOL measured by the SF36 questionnaire and no differences in school absenteeism [2]. When diagnosis of the inhibitor does not come from a screening programme, its presence is suspected upon a lack of response to conventional replacement therapy for musculoskeletal bleeding, losing the ‘golden moment’ of treatment. This complication is much more serious when facing a traumatic bleed. In this situation, the lack of early diagnosis can lead to permanent damage or even death. Due to the cost of bypassing factors and the lack of experience of the medical team in the treatment of patients with inhibitors, many treatments that would improve the QOL of patients are instituted in an insufficient manner. Therefore, patients with haemophilia and inhibitors are often untreated or undertreated in their community. Orthopaedic surgeons and physiotherapists play a key role in the treatment of these patients and should be included in therapeutic decision making and most specifically in the postoperative treatment of patients with haemophilia and inhibitors. It is important that these patients have quick access to a trained therapeutic team in order to obtain an early diagnosis and treatment plan to prevent the evolution of the pathological process. Early treatment is cost‐effective in maintaining and improving the QOL of patients. Experience in patients with haemophilia and inhibitors is not very extensive. Today, this situation is changing, with several treatment centres beginning to perform surgeries in these most complex patients, giving them a chance to improve their QOL. This article presents the experience of experts from various fields involved in treating patients with inhibitors from a developed and developing world perspective.