In order to investigate whether previous findings of ubiquitous skin papillomavirus infection in Caucasians apply to populations from other parts of the world, skin swab samples from Bangladesh, Japan, Ethiopia and Zambia were analysed in parallel with Swedish samples. The prevalence of HPV DNA in the material from Bangladesh was 68 %, Japan 54 %, Ethiopia 52 %, Zambia 42 % and Sweden 70 %. A great multiplicity of genotypes was demonstrated by the finding of 88 HPV types or putative types in 142 HPV DNA-positive samples in total. Double or multiple genotypes were frequently found in the same sample. The most prevalent HPV type was HPV-5, with an overall prevalence of 6?5 %. This was also the only type that was found in samples from all of the countries in the study. The results presented show that commensal skin HPV infections have a worldwide distribution with a very broad spectrum of genotypes.

The mechanisms of cadmium-metallothionein (CdMT) uptake and toxicity in proximal tubule (PT) cells are not well understood. The effects of 10 microM CdCl2 or Cd7MT-1 (MT-1 saturated with 10 microM CdCl2) on 109Cd2+ uptake, viability, and MT levels of cultured rat PT cells were investigated. Apical 109Cd2+ uptake was measured in confluent monolayers, apoptosis was assessed with Hoechst 33342, and intracellular MT levels were monitored by immunofluorescence and quantitative morphometry. 109Cd2+ uptake into PTC increased over time and plateaued at 24 h. 109Cd7MT-1 uptake was delayed but reached a similar magnitude after 40 h. With Cd2+, apoptosis occurred within 4 h, peaked at 24 h, and declined at 48-72 h. Cd7MT-1 induced apoptosis after 24-36 h, reaching similar levels as with Cd2+ after 48 h. Cd2+ and Cd7MT-1 significantly increased intracellular MT immunoreactivity after 20 and 4 h, respectively. The weak base chloroquine and the inhibitor of phosphatidylinositol 3-kinases, LY-294002, selectively inhibited the effects of Cd7MT-1 on MT immunoreactivity and apoptosis. PT cells accumulated 109Cd7MT-1 in membrane vesicles associated with the late endo/lysosomal marker LAMP1 but less with the early endosomal marker Rab5a, which was abolished by chloroquine or LY-294002. Thus development of apoptosis followed the uptake kinetics of Cd2+ and Cd7MT-1. Endo/lysosomal inhibitors prevented uptake of Cd7MT-1 into endo/lysosomes and apoptosis but had no effect on these parameters with Cd2+, suggesting that apoptosis of PT cells is triggered by free cytosolic Cd2+, either by direct apical transport or by translocation of free Cd2+ from endo/lysosomes after endocytosis of Cd7MT-1.

To avoid immune escape by down-regulation or loss of Ag by the tumor cells, target Ags are needed, which are important for the malignant phenotype and survival of the tumor. We could identify a CD4+ T cell epitope derived from the human melanoma-associated chondroitin sulfate proteoglycan (MCSP) (also known as high m.w.-melanoma-associated Ag), which is strongly expressed on >90% of human melanoma lesions and is important for the motility and invasion of melanoma cells. However, MCSP is not strictly tumor specific, because it is also expressed in a variety of normal tissues. Therefore, self tolerance should prevent the induction of strong T cell responses against these Ags by vaccination strategies. In contrast, breaking self tolerance to this Ag by effectively manipulating the immune system might mediate antitumor responses, although it would bear the risk of autoimmunity. Surprisingly, we could readily isolate CD4+ Th cells from the blood of a healthy donor-recognizing peptide MCSP693–709 on HLA-DR11-expressing melanoma cells. Broad T cell reactivity against this Ag could be detected in the peripheral blood of both healthy donors and melanoma patients, without any apparent signs of autoimmune disease. In some patients, a decline of T cell reactivity was observed upon tumor progression. Our data indicate that CD4+ T cells are capable of recognizing a membrane glycoprotein that is important in melanoma cell function, and it may be possible that the sizable reactivity to this Ag in most normal individuals contributes to immune surveillance against cancer.

Melanoma-associated chondroitin sulfate proteoglycan (MCSP) (also known as high molecular weight-melanoma-associated antigen) represents an interesting target antigen for cancer immunotherapy which is expressed on human melanomas and other tumors such as breast carcinomas, gliomas, neuroblastomas and acute leukemias. MCSP seems to play an important functional role in melanoma as it is involved in tumor cell migration, invasion and angiogenesis. In this study, we isolated CD4 1 T helper cells from the blood of a healthy donor, recognizing a peptide from the MCSP core protein presented by HLA-DBR1*1101 molecules. T cell reactivity against the identified peptide could be detected in the blood of healthy donors and melanoma patients. MCSP specific T cells from the blood of a patient could be readily expanded by repeated peptide stimulation and recognized MCSP and HLA-DR expressing tumor cells. Our findings suggest that vaccination against MCSP helper T cell epitopes might be a promising approach to fight melanoma. ' 2008 Wiley-Liss, Inc. Key words: MCSP; melanoma; peptide; T helper cells; tumor antigenFollowing the identification of tumor-associated antigens recognized by T cells on human tumor cells, numerous clinical vaccination studies have been performed in patients with metastatic melanoma. Accompanied by an improvement of vaccine approaches including new adjuvants such as CpG oligonucleotides and further development in the field of immuno-monitoring, the induction of antigen-specific T cell responses in the blood of tumor patients has been demonstrated in a number of studies. However, significant tumor regressions, especially complete responses in patients with visceral metastases have been observed infrequently, and in most studies overall response rates did not exceed 10%. 1 One obstacle might be immune escape by downregulation or complete loss of antigen expression as many antigens identified so far do not play an essential functional role for the tumor. [2][3][4] To overcome this it would be particularly important to choose a suitable target antigen for vaccination therapy, which should be broadly expressed and functionally relevant for the tumor. On our search for suitable target antigens for the active-specific immunotherapy of melanoma, we focused on the human melanoma-associated chondroitin sulfate proteoglycan (MCSP), also known as high molecular weight-melanoma-associated antigen, which has been shown to be expressed in the majority of human melanoma lesions and cultured cells with a limited expression in normal tissues. 5,6 In addition, MCSP expression was found in uveal melanoma, which is refractory to standard chemotherapy. 7 MCSP represents an unique glycoprotein-proteoglycan complex, with a 250 kDa core glycoprotein to which, via serine residues, the larger than 450 kDa proteoglycan component is attached. 8 MCSP has been implicated for some time in numerous aspects of melanoma cell biology, including adhesion, spreading and migration. In fact, melanoma cell adhesion, chemotactic responses to fi...