Dendritic cells (DCs) are considered to be promising adjuvants for inducing immunity to cancer. We used mature, monocyte-derived DCs to elicit resistance to malignant melanoma. The DCs were pulsed with Mage-3A1 tumor peptide and a recall antigen, tetanus toxoid or tuberculin. 11 far advanced stage IV melanoma patients, who were progressive despite standard chemotherapy, received five DC vaccinations at 14-d intervals. The first three vaccinations were administered into the skin, 3 × 106 DCs each subcutaneously and intradermally, followed by two intravenous injections of 6 × 106 and 12 × 106 DCs, respectively. Only minor (less than or equal to grade II) side effects were observed. Immunity to the recall antigen was boosted. Significant expansions of Mage-3A1–specific CD8+ cytotoxic T lymphocyte (CTL) precursors were induced in 8/11 patients. Curiously, these immune responses often declined after the intravenous vaccinations. Regressions of individual metastases (skin, lymph node, lung, and liver) were evident in 6/11 patients. Resolution of skin metastases in two of the patients was accompanied by erythema and CD8+ T cell infiltration, whereas nonregressing lesions lacked CD8+ T cells as well as Mage-3 mRNA expression. This study proves the principle that DC “vaccines” can frequently expand tumor-specific CTLs and elicit regressions even in advanced cancer and, in addition, provides evidence for an active CD8+ CTL–tumor cell interaction in situ as well as escape by lack of tumor antigen expression.

Dendritic cell (DC) vaccination, albeit still in an early stage, is a promising strategy to induce immunity to cancer. We explored whether DC can expand Ag-specific CD8+ T cells even in far-advanced stage IV melanoma patients. We found that three to five biweekly vaccinations of mature, monocyte-derived DC (three vaccinations of 6 × 106 s.c. followed by two i.v. ones of 6 and 12 × 106, respectively) pulsed with Mage-3A2.1 tumor and influenza matrix A2.1-positive control peptides as well as the recall Ag tetanus toxoid (in three of eight patients) generated in all eight patients Ag-specific effector CD8+ T cells that were detectable in blood directly ex vivo. This is the first time that active, melanoma peptide-specific, IFN-γ-producing, effector CD8+ T cells have been reliably observed in patients vaccinated with melanoma Ags. Therefore, our DC vaccination strategy performs an adjuvant role and encourages further optimization of this new immunization approach.

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Granuloma annulare (GA) is a chronic inflammatory disorder of unknown aetiology, which is characterized clinically by erythematous plaques preferentially localized to the distal extremities, although disseminated variants exist. In light of the chronic relapsing nature of GA and lack of satisfactory treatment options, we initiated treatment with infliximab in a patient with chronic disseminated GA that was recalcitrant to standard treatment. The 59-year-old female patient with insulin-dependent diabetes had experienced GA lesions for more than 4 years despite various systemic and topical treatments. Systemic glucocorticoids were not a therapeutic option because of the preexisting unstable insulin-dependent diabetes. Infliximab was administered intravenously at 5 mg kg(-1) day(-1) at weeks 0, 2 and 6 and thereafter at a monthly interval for an additional 4 months. Most of the GA plaques resolved within 4-6 weeks, leaving postinflammatory brownish macules. Newly arising plaques disappeared within 2 weeks and new GA lesions were not observed during the entire observation period of more than 16 months. Infliximab may be an additional option in the treatment of recalcitrant forms of GA as well as in other chronic granulomatous skin disorders, such as sarcoidosis and necrobiosis lipoidica.

Key Points• ONTAK blocks DC maturation by coreceptor downmodulation and inhibition of Stat3 phosphorylation to induce a tolerogenic phenotype.• ONTAK kills activated CD4T cells but stimulates antiapoptosis in resting T reg by engagement and stimulation through CD25.

Anticancer immune therapies aim at the induction of tumor-specific T cells, which ultimately should kill tumor cells. The effector cells should, therefore, not only exert cytotoxic activity but also home to and infiltrate the tumor site. Hence, monitoring of immune modulating therapies should not be restricted to the circulating pool of peripheral blood mononuclear cells (PBMC) but also include tumor-infiltrating lymphocytes (TIL), as well as the correlation of these findings to the clinical course. We report here on the longitudinal immunologic workup of a melanoma patient who developed remarkably potent ex vivo detectable antimelanoma cytotoxic T-cell (CTL) responses after vaccinations with autologous peptide-pulsed dendritic cells. Such potent CTL responses to multiple tumor antigens have, to the best of our knowledge, not been described previously in melanoma patients, neither spontaneously nor after any therapy. This patient first experienced a transient response to therapy but finally succumbed to disease progression and died. Progression was associated with the decline of the numbers of tumor-reactive T cells in circulation and at skin metastases in addition to the loss of MHC class I antigens. The immunologic analysis revealed that fully functional tumor-specific T cells were present in the peripheral blood of this patient during the phase of a relatively stable disease, and in situ tetramer staining demonstrated that these cells were also accumulated at cutaneous and visceral tumor sites. Furthermore, comparative clonotype mapping of PBMC and TIL depicted an overlapping TCR repertoire usage among these 2 compartments. Since strong CTL responses as observed in this patient are the goal of cancer vaccination but are so far only rarely observed, the thorough analysis of patients exhibiting either exceptional clinical and/or immunologic responses appears critical to understanding how vaccine therapies work and can be further improved. © 2004 Wiley-Liss, Inc. Key words: dendritic cells; multimeric peptide/MHC-complex; T-cell receptor; cutaneous lymphocyte antigen; vaccinationImmune therapy for tumor patients aims at harnessing the immune system to fight cancer. Indeed, clinical trials have already shown that tumor-specific T cells can be induced even in advanced cancer patients. 1,2 The induction of tumor-specific T cells, however, is not necessarily associated with a clinical response. 3 A major obstacle in evaluating the success of a cell-based immunotherapy lies in the fact that systemic immune responses detected in the blood may not reflect the actual situation in the tumor. 4 Thus, we performed a thorough immunologic workup of a melanoma patient receiving DC vaccinations as well as other anticancer therapies such as isolated limb perfusion, surgery and chemotherapy. Initially, this patient experienced an objective clinical response followed by a phase of stability, which were associated with vigorous tumor-specific T-cell responses. However, despite an ongoing therapy, we observed the cessation of these...

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.