Anti-tumor immune responses and tumor regression induced with mimotopes of a tumor-associated T cell epitope

Mimotopes provide an alternative to natural T cell epitopes for cancer immune therapy, as they can recruit and stimulate T cell repertoires that deviate from the repertoires engaged with the tumor and exposed to disease-related immune suppression. Here, mimotopes of a shared tumor-associated T cell epitope in cutaneous lymphoma were tested for their capacities to induce clinical and immunological responses in cancer patients. The mimotope sequences had been determined by a combinatorial peptide library approach without knowledge of the corresponding natural tumor-associated antigen. Vaccination with these mimotopes together with helper T cell-inducing antigens led to complete tumor remission in the two patients tested. After each booster vaccination, enhanced frequencies of mimotope-specific CD8+ T cells were detected in the peripheral blood of the patients, and the CTL proved to be cytotoxic and tumoricidal when tested in vitro. These data provide a first indication of clinical efficacy of mimotopes in cancer patients.

Detection of Enhanced Monohydroxyeicosatetraenoic Acid and F2-Isoprostane Levels in Human Plasma Samples after Extracorporeal Photoimmunotherapy

To investigate the involvement of reactive oxygen species in extracorporeal photoimmunotherapy (photopheresis), we have introduced two highly sensitive and specific techniques for the detection and quantitative measurement of oxygenated nonenzymatically formed arachidonic acid isomers [mono-hydroxyeicosatetraenoic acids (HETEs) and F2-isoprostanes] by gas chromatography-mass spectrometry/negative ion chemical ionization (GC-MS/NICI) in plasma samples of patients suffering from cutaneous T-cell lymphoma and progressive systemic scleroderma II. The analysis of HETEs involved hydrogenation, solid phase extraction on a C18 cartridge, formation of pentafluorobenzyl bromide and trimethylsilyl ether derivatives. In the case of F2-isoprostanes, the analytical procedure was similar to that of HETEs except that the hydrogenation step was omitted. In the plasma of healthy volunteers picomole amounts of 2-, 5-, 8-12-, 15-HETEs, 8-iso-PGF(2alpha) and 9alpha,11alpha-PGF(2alpha) were quantified by using 12-hydroxy-heptadecatrienoic acid and PGF(2alpha)-d4 as internal standards of HETEs and isoprostanes, respectively. Analysis of plasma samples obtained from patients before and after extracorporeal photoimmunotherapy revealed characteristic increases in both, HETE and isoprostane levels. The enhancement of indicators of lipid peroxidation is in correspondence with a moderate loss of alpha-tocopherol, the most important lipid-soluble antioxidant in human plasma. Thus, our data confirm the involvement of lipid peroxidation in extracorporeal photoimmunotherapy.

Vaccination of patients with cutaneous T-cell lymphoma using intranodal injection of autologous tumor-lysate-pulsed dendritic cells

Cutaneous T-cell lymphoma (CTCL) is a lymphoproliferative skin disease with limited therapeutic options. Ten CTCL patients were treated with once-weekly intranodal injection of 1 x 106 mature monocyte-derived dendritic cells (DCs) pulsed with 100 microg/mL tumor lysate protein equivalent and keyhole limpet hemocyanin (50 microg/mL). Tumor-specific delayed-type hypersensitivity (DTH) reactions developed in 8 of 8 patients challenged with tumor-lysate-pulsed DCs and in 3 of 8 patients challenged with tumor lysate alone. Three of 5 patients showed significant tumor-lysate-specific increases of in vitro peripheral blood lymphocyte proliferation coinciding with increased interferon-alpha (IFN-alpha) production. Five of 10 (50%) patients had objective responses. Four patients had partial responses (PRs). Two are still in PR, and the other 2 patients had a mean PR duration of 10.5 months. One patient had a complete response (CR) for 19 months that is ongoing. The remaining 5 patients had progressive disease. In the 5 responder patients, 6.8 +/- 1.4 vaccinations were necessary to induce an objective clinical response. Response was associated with low tumor burden. Continuation of vaccinations with new tumor lysate derived from progressive lesions reinduced treatment responses in 2 patients in PR. Selected patients had massive infiltration of CD8+ and TIA+ cytotoxic T cells at the site of regressing lesions and molecular remission after therapy. Intranodal injection of autologous tumor-lysate-pulsed DCs is well-tolerated and achieves immunologic and objective clinical responses in selected CTCL patients.

Extracorporeal photopheresis reduces the number of mononuclear cells that produce pro-inflammatory cytokines, when tested ex-vivo

Extracorporeal photopheresis (ECP) has been shown to be clinically effective in the treatment of many T cell-mediated conditions. ECP's mechanism of action includes the induction of apoptosis and the release of pro-inflammatory cytokines. Recently, we have observed early lymphoid apoptosis, detectable immediately post ECP. We were interested to determine what influence ECP has on pro-inflammatory cytokine secretion at this early pre-infusion stage. Samples from 6 cutaneous T cell lymphoma (CTCL) and 5 graft versus host disease (GvHD) patients were taken pre ECP and immediately post ECP, prior to re-infusion. Following separation, the PBMCs were added to a cell culture medium and stimulated with PMA, Ionomycin, and Brefeldin A for 6 hours. Using flow cytometry, intracellular cytokine expression of IFNgamma and TNFalpha was determined in the T cell population. The monocytes were evaluated for IL6, IFNgamma, IL12, and TNFalpha. For both patient groups, the number of IFNgamma-expressing T cells fell significantly at re-infusion, whilst both T cell- and monocyte-expressing TNFalpha levels were reduced at re-infusion. All other cytokines tested showed no significant change post ECP. For GvHD, pro-inflammatory cytokines have a pathological role. Their down-regulation may have a direct clinical benefit. However, the reduction in the number of IFNgamma- and TNFalpha-expressing mononuclear cells means, at this early stage, it is unlikely that these cytokines assist in the removal of the malignant Th2 cells present in CTCL.

Papulosquamous diseases in the elderly

This article refers to papulosquamous diseases that are seen in the elderly. Many of these diseases are complex to diagnose due to the fact that they are difficult to identify, because they may resemble a similar disorder, which can be misleading. The problem that is frequently seen with these diseases is that they are commonly misdiagnosed. In this article the authors include information that will help with identifying these diseases. The authors also provide important laboratory exams that can be performed and can help guide diagnosis, as well as differential diagnosis and treatment options.

Nasal-type natural killer cell lymphoma preceded by benign panniculitis arising in an asymptomatic HTLV-1 carrier

We report a case of an Epstein-Barr virus (EBV)-associated nasal-type natural killer cell lymphoma (NKCL) preceded by benign panniculitis, which arose in a 48-year-old woman with an asymptomatic human T-cell leukemia/lymphoma virus type-1 (HTLV-1) infection. A biopsy of the initial panniculitis lesion demonstrated lobular panniculitis with a germinal center composed of benign mononuclear cells with a phenotype of CD4+CD45RO+CD5sCD3+ cCD3 epsilon + T-cell intracellular antigen-1 (TIA-1)- and granzyme B-. One year after oral prednisolone therapy, the patient developed subcutaneous nodules composed of atypical lymphoid cells with a phenotype of CD4-CD45RO+CD56+sCD3-cCD3 epsilon + (TIA-1)+ and granzyme B+. In the initial panniculitis lesion, neither EBV-encoded RNA (EBER-1) nor clonal proliferation of EBV-infected cells was identified. In later lesions, however, a large number of atypical cells were positive for EBER-1, and a clonal expansion of EBV-infected cells was detected. No clonal rearrangement of T-cell receptor-alpha, -beta, or -gamma genes was found in either specimen. This patient was an asymptomatic carrier of human T-cell leukemia/lymphoma virus type-1 (HTLV-1) without clonal integration of proviral HTLV-1 in neither the peripheral blood nor the skin lesions. These observations suggest that EBV-associated NKCL occurred subsequently in the clinical course of benign panniculitis under the influence of immunosuppression caused by prednisolone treatment and HTLV-1 infection.

Lymphoma of the skin

This chapter describes the various ways in which the non-Hodgkin's lymphomas can involve the skin, how these diseases should be assessed, standard treatments available in 2002, and new directions in research. The goal of the session is to succinctly review recent developments in lymphoma classification and treatment as they apply to the unique aspects of lymphoma when manifest in the skin. In Section I, Dr. Eric Hsi reviews the special characteristics of the lymphomas seen when they proliferate in the skin and the application of the new World Health Organization classification system to the cutaneous lymphomas, emphasizing the unique challenges of recognizing and correctly classifying these diseases. He summarizes the evidence in favor of including the skin lymphomas in the overall lymphoma classification scheme and concludes with a practical description of the specific skin lymphoma entities. In Section II, Dr. Joseph Connors describes the current optimal treatment of the B-cell lymphomas when they present in or metastasize to the skin. Building on the classification scheme described by Dr. Hsi, Dr. Connors outlines a treatment approach based on current understanding of pathophysiology of these diseases and application of each of the effective modalities available for cutaneous lymphoma including radiation, chemotherapy, and immunotherapy. In Section III, Dr. Francine Foss concludes the session with a discussion of the different T-cell lymphomas that start in or spread to the skin concentrating on mycosis fungoides, cutaneous anaplastic large cell lymphoma and peripheral T-cell lymphoma. She includes comments on the newer anti-T-cell chemo- and immuno-therapeutics focusing on agents and techniques specific for cutaneous T-cell lymphomas.

Therapy of cutaneous lymphoma--current practice and future developments

Cutaneous lymphomas include various types of clonal lymphoproliferative disorders. The adequate treatment approach depends on the exact diagnosis and should be non-aggressive in most cases. In early stages, local approaches such as UV or radiotherapy are preferred. In advanced stages, systemic drugs such as interferon-alpha or bexarotene can be administered. Experimental approaches for cutaneous lymphomas include vaccination and gene therapy.

Monitoring the decrease of circulating malignant T cells in cutaneous T-cell lymphoma during photopheresis and interferon therapy

BACKGROUND

The prognosis of patients with stage IV cutaneous T-cell lymphoma (CTCL) is grim and therapeutic options are limited. Treatment of advanced-stage CTCL is aimed at suppressing the dominant T-cell clone, which is typically present in the skin, peripheral blood, and lymph nodes.

OBSERVATIONS

We detected the expansion of 1 T-cell clone expressing the T-cell receptor V beta 14 in the peripheral blood of a patient with stage IVA CTCL. Before initiation of combination therapy with photopheresis and low-dose interferon alpha, the dominant T-cell clone represented 84% of the total T-cell population. After successful therapy, this clone showed a dramatic decrease to 6% of the T-cell population after 6 months of treatment. This reduction in the percentage of the malignant T-cell population in response to therapy was paralleled by clinical skin improvement from initial generalized erythroderma to undetectable skin disease.

CONCLUSIONS

This case demonstrates that response to combination treatment with photopheresis and low-dose interferon alpha in patients with advanced CTCL may be accurately and quantitatively followed up by monitoring the percentage of the malignant T-cell clone (when identifiable) within the total circulating T-cell population by flow cytometry.

Cutaneous extranasal NK/T-cell lymphoma

Malignant neoplasm from natural killer (NK) cells are characterized by their positivity for CD56 and absence of monoclonal TCR gene rearrangement. We present the case of a 54-year-old man with a fungous mass in his left flank whose histological examination was consistent with cutaneous extranasal T/NK cell lymphoma. We review the literature and also discuss the prognosis and treatment of this variety of lymphoma.

Early reduction in number of T cells producing proinflammatory cytokines, observed after extracorporeal photopheresis, is not linked to apoptosis induction

Immediately following ECP, a significant number of lymphocytes become apoptotic and the number of T cells producing TNFalpha and IFNgamma is reduced. This study sought to determine if the cytokine down-regulation was a direct consequence of apoptosis induction.

METHODS

Samples were obtained from 6 graft versus host disease (GvHD) and 5 cutaneous T cell lymphoma (CTCL) patients immediately pre-ECP and from the leucocyte collection bag following 8-MOP/UVA exposure, but prior to re-infusion. Separated peripheral blood mononuclear cells (PBMC) were placed in cell culture and stimulated for 6 hours with phorbol myristate acetate (PMA), Ionomycin and Brefeldin A. Using flow cytometry, T cells were identified by CD3 expression and apoptotic T cells sub-selected by Annexin V staining. Both apoptotic and non-apoptotic T cells were evaluated for their intracellular expression of IL2, IL4, IL10, IFNgamma and TNFalpha.

RESULTS

Neither patient group demonstrated a significant change in IL4 or IL10 expression post ECP. However the number of T cells expressing IL2, IFNgamma and TNFalpha was reduced in both the Annexin V-positive and -negative T cell populations (P <.05). The nonapoptotic T cells from GvHD patients demonstrated the greatest reduction in cytokine expression.

CONCLUSIONS

Since proinflammatory cytokines play a major role in the pathology of GvHD, their down-regulation post-ECP may produce a direct clinical benefit. The lowest number of IL2-, IFNgamma- and TNFalpha-expressing T cells occurred within the apoptotic population; however, Annexin V-negative T cells also demonstrated a marked reduction post-ECP. However, the lack of an increase in IL4 and IL10 expression indicates that this process was not a consequence of skewing toward a Th2 cytokine profile.

Tumor-specific antigens in cutaneous T-cell lymphoma: expression and sero-reactivity

Cutaneous T-cell lymphoma (CTCL) is a heterogeneous group of extra-nodal non-Hodgkin lymphomas with primary manifestation in the skin with poor treatment options in the advanced stages. As basis for future immune-therapeutic strategies we have investigated the possible expression of tumor-specific targets in CTCL focusing mainly on so-called cancer-germline genes. cDNAs derived from 20 CTCL tissues and 4 CTCL cell lines were tested with 15 gene-specific and 4 gene family-specific primers by RT-PCR and confirmative Northern blotting. The most frequently detected mRNAs were LAGE-1 (55% with only partial coexpression of the splicing variants), cTAGE-1 (35%), MAGE-A9 (27%) and the GAGE-3-7 group (35%). Furthermore, we could detect NY-ESO-1 (21%) and a MAGE-A subgroup (15%), whereas sub-specification of the latter proved absence of MAGE-A1, -A2, -A3, -A6 and -A12. SCP-1 was found in only one specimen and a several antigens could not been detected in any tumor tissue or cell line (MAGE-B, GAGE-1,2,8 and all 4 RAGE genes). 90% of all CTCL samples were positive for at least 1 of the frequent mRNAs in RT-PCR (LAGE-1, NY-ESO-1, cTAGE-1, MAGE-A9, or GAGE-3to7). Using a secondary SEREX approach we could detect sero-reactivity in sera of CTCL patients against recombinant cTAGE-1 (10/29), GAGE (3/19), MAGE-A1 (1/18), -A3 (1/18), -A6 (2/18) and -A9 (4/18) protein, but not against LAGE-1a, MAGE-A4b or MAGE-A12 protein (n = 19). We conclude, that certain cancer-germline genes can be detected frequently in CTCL and are able to elicit a systemic immune response. These candidate genes might therefore be promising targets for immunotherapeutic interventions in CTCL.

Bexarotene gel: a new skin-directed treatment option for cutaneous T-cell lymphomas

Cutaneous T-cell lymphomas (CTCLs) are a relatively uncommon group of lymphoproliferative disorders in which a malignant population of T cells is localized to the skin at presentation. Of the 4 classic CTCL phases (patches, infiltrated plaques, tumors, Sézary syndrome), the majority of patients present with early stage patch or plaque disease, which can usually be effectively managed using skin-directed therapies. Traditional skin-directed therapies include topical corticosteroids, topical chemotherapeutic agents (mechlorethamine, carmustine), electron beam therapy (local and total skin), and phototherapy (UV-A, UV-B). Each of these has demonstrated efficacy in early stage disease; however, with the exception of topical corticosteroids, all have some disadvantages and are associated with significant adverse events, particularly secondary skin malignancies and skin damage. Bexarotene is a synthetic retinoid analog that selectively activates retinoid X receptors. In clinical trials, bexarotene gel demonstrated efficacy for the topical treatment of cutaneous lesions in patients with stage IA or IB CTCL who have refractory or persistent disease following other therapies or who cannot tolerate other therapies. Initial evidence indicates that bexarotene gel may be active as first-line therapy in early stage disease. Its role in combination with other treatments remains to be determined. Topical bexarotene gel is generally well tolerated and offers patients greater convenience compared with traditional skin-directed therapies, with a flexible administration regimen. The availability of bexarotene gel provides patients and physicians with a new skin-directed treatment option for early stage CTCL.

Cutaneous T-cell lymphoma

Cutaneous T-cell lymphoma (CTCL) is a neoplasm of helper T cells whose first manifestations usually appear in the skin. The various forms of CTCL are distinguished by both clinical features and histopathology. Early on, the diagnosis may be difficult to establish because of its numerous, and often non-specific, clinical presentations. Further, the pathological findings of early lesions may lack the diagnostic features observed in well-developed or advanced disease. The diagnosis of CTCL must be considered in any patient with a chronic, therapy-resistant condition of the skin. In patients with non-specific histological findings, a high index of suspicion and multiple biopsies may eventually lead to a diagnosis of CTCL. Once the diagnosis of CTCL is established, accurate staging is essential both for its effect on treatment decisions and for its prognostic value. In general, CTCL is a chronic, slowly progressive disease with a long evolution. The development of tumours is a poor prognostic sign, as is erythroderma. The Sezary syndrome is a distinct form of erythrodermic CTCL that is characterized by exfoliative erythroderma, lymphadenopathy, lymphocytosis, intense pruritus, and circulating large, abnormal lymphocytes (Sezary cells). When death does occur, it is most often due to septicemia. Treatment of CTCL must be tailored to the individual patient. The most commonly employed treatment options are photochemotherapy and topical chemotherapy.

Extracorporeal photochemoimmunotherapy in cutaneous T-cell lymphoma

Extracorporeal photochemotherapy was originally conceived for the treatment of cutaneous T-cell lymphoma (CTCL) and as well as other T-cell mediated diseases. Evidence collected in the past 17 years has demonstrated that this treatment modality can have a very significant effect on the course of a subset of CTCL patients. The evidence available is positive but for a variety of reasons has been controversial within the medical community. A number of very well-designed multi-center trials which have been lacking since the first publication by Edelson et al. are being carried out so that hopefully a number of open questions will be resolved with greater clarity in the coming years. The fact remains that this innovative approach for the treatment of CTCL and T-cell mediated diseases has certainly opened new avenues of therapy and thought in photoimmunology and photomedicine. Clearly the very low side effect profile of this therapy has made it more attractive than the chemotherapeutic and immunosuppressive substances that are presently available or in experimental protocols. If and when the mechanisms of action are fully understood and appropriate studies investigating different treatment schedules and different combination therapies and modifications of its present form are performed the place of photopheresis in the therapeutics of CTCL as well as other T-cell mediated diseases and oncology will be better placed.

Massive immune hemolysis after non-myeloablative allogeneic peripheral blood stem cell transplantation with minor ABO-incompatibility

A 35-year-old male, blood group B, Rh(D)+ type, received an allogeneic peripheral blood stem cell (PBSC) transplant after a non-myeloablative regimen of fludarabine and cyclophosphamide for resistant gammadelta cutaneous T-cell lymphoma (CTCL). The donor was his HLA-identical brother, blood group O, Rh(D)+ type. Graft-versus-host disease (GVHD) prophylaxis was performed with cyclosporine alone. On day +8, massive immune hemolysis occurred, followed by acute renal failure. Hemodialysis was performed eight times until recovery of renal function on day +24. The risk of delayed immune hemolysis after non-myeloablative allogeneic PBSC transplantation with minor ABO-incompatibility must be considered.

Treatment of cutaneous T cell lymphoma with extracorporeal photopheresis induces Fas-ligand expression on treated T cells, but does not suppress the expression of co-stimulatory molecules on monocytes

Following extracorporeal photopheresis (ECP), lymphocytes become apoptotic and upregulate class I MHC antigenic peptides. Conversely, ECP treated monocytes demonstrate activation markers and have an increased avidity for the phagocytosis of apoptotic T cells. Processing of apoptotic T cells by monocytes, following ECP, is thought to induce an immunomodulatory response, which targets untreated, but clonal T cells. Recently we detected apoptotic lymphocytes immediately post ECP. Although enhanced CD95 (Fas) expression has been observed 24 h post ECP, CD95 and Fas-ligand (Fas-L) expression have not been determined at this very early apoptotic stage. Exposure of monocytes to UV has previously suppressed expression of the co-stimulatory molecules required for the presentation of processed antigens to T cells. Our data demonstrate no increase in CD95 or Fas-L expression on T cells tested immediately following ECP. However, the number of T cells expressing Fas-L significantly increased 24 h post ECP (P<0.005). The expression of the co-stimulatory molecules, CD54, CD80 and CD86, remained unaltered on monocytes treated by ECP. Although the mechanism responsible for early induction of lymphocyte apoptosis remains unclear, the later apoptosis involves Fas-L expression. The maintenance of co-stimulatory molecules, on treated monocytes, indicates that they retain the ability to induce an immunomodulatory response.