Biomedical subjects

Mirjana Urosevic

Publications and source records attributed to Mirjana Urosevic.

At least 19 recordsLinked to original sources

PubMed2006

Spontaneous CD8 T cell responses against the melanocyte differentiation antigen RAB38/NY-MEL-1 in melanoma patients.

The melanocyte differentiation Ag RAB38/NY-MEL-1 was identified by serological expression cloning (SEREX) and is expressed in the vast majority of melanoma lesions. The immunogenicity of RAB38/NY-MEL-1 has been corroborated previously by the frequent occurrence of specific Ab responses in melanoma patients. To elucidate potential CD8 T cell responses, we applied in vitro sensitization with overlapping peptides spanning the RAB38/NY-MEL-1 protein sequence and the reverse immunology approach. The identified peptide RAB38/NY-MEL-1(50-58) exhibited a marked response in ELISPOT assays after in vitro sensitization of CD8 T cells from HLA-A *0201(+) melanoma patients. In vitro digestion assays using purified proteasomes provided evidence of natural processing of RAB38/NY-MEL-1(50-58) peptide. Accordingly, monoclonal RAB38/NY-MEL-1(50-58)-specific T cell populations were capable of specifically recognizing HLA-A2(+) melanoma cell lines expressing RAB38/NY-MEL-1. Applying fluorescent HLA-A2/RAB38/NY-MEL-1(50-58) multimeric constructs, we were able to document a spontaneously developed memory/effector CD8 T cell response against this peptide in a melanoma patient. To elucidate the Ag-processing pathway, we demonstrate that RAB38/NY-MEL-1(50-58) is produced efficiently by the standard proteasome and the immunoproteasome. In addition to the identification of a RAB38/NY-MEL-1-derived immunogenic CD8 T cell epitope, this study is instrumental for both the onset and monitoring of future RAB38/NY-MEL-1-based vaccination trials.

Antigen Presentation↗

PubMed2006

Anti-HIV state but not apoptosis depends on IFN signature in CD4+ T cells.

To gain insights into the molecular mechanisms underlying early host responses to HIV in the CD4(+) T cell target population, we examined gene expression in CD4(+) T cells isolated 24 h after ex vivo HIV infection of lymphocyte aggregate cultures derived from human tonsils. Gene profiling showed a distinct up-regulation of genes related to immune response and response to virus, notably of IFN-stimulated genes (ISGs), irrespective of the coreceptor tropism of the virus. This mostly IFN-alpha-dependent gene signature suggested the involvement of plasmacytoid dendritic cells, a principal component of the antiviral immune response. Indeed, depletion of plasmacytoid dendritic cells before HIV inoculation abrogated transcriptional up-regulation of several ISGs and resulted in increased levels of HIV replication. Treatment with a blocking anti-IFN-alphaR Ab yielded increased HIV replication; conversely, HIV replication was decreased in pDC-depleted cultures treated with IFN-alpha. Among up-regulated ISGs was also TRAIL, indicating a potential role of the IFN signature in apoptosis. However, a blocking anti-TRAIL Ab did not abrogate apoptosis of CD4(+) T cells in CXCR4-tropic HIV-infected cultures, suggesting the involvement of pathways other than TRAIL mediated. We conclude that acute HIV infection of lymphoid tissue results in up-regulation of ISGs in CD4(+) T cells, which induces an anti-HIV state but not apoptosis.

Antibodies, Blocking↗

PubMed2006

Melanocyte differentiation antigen RAB38/NY-MEL-1 induces frequent antibody responses exclusively in melanoma patients.

Expression pattern and immunogenicity are critical issues that define tumor antigens as diagnostic markers and potential targets for immunotherapy. The development of SEREX (serological analysis of recombinant expression libraries) has provided substantial progress in the identification of tumor antigens eliciting both cellular and humoral immune responses in cancer patients. By SEREX, we have previously identified RAB38/NY-MEL-1 as a melanocyte differentiation antigen that is highly expressed in normal melanocytes and melanoma tissues but not in other normal tissues or cancer types. In this study, we further demonstrate that RAB38/NY-MEL-1 is strongly immunogenic, leading to spontaneous antibody responses in a significant proportion of melanoma patients. The immune response occurs solely in malignant melanoma patients and was not detected in patients with other diseases, such as vitiligo, affecting melanocytes. Fine analysis of the spontaneous anti-RAB38/NY-MEL-1 antibody response reveals a polyclonal B cell recognition targeting various epitopes, although a dominant immunogenic region was preferentially recognized. Interestingly, our data indicate that this recognition is not rigid in the course of a patient's response, as the dominant epitope changes during the disease evolution. Implications for the understanding of spontaneous humoral immune responses are discussed.

Antibodies, Neoplasm↗

PubMed2006

Standard and experimental therapy in cutaneous T-cell lymphomas.

Cutaneous T-cell lymphomas are a heterogeneous group of lymphoproliferative disorders, characterized by the accumulation of clonal lymphocytes in the skin. Skin-directed therapies are the preferred first-line modalities. There are interesting new developments in topical therapy using retinoids and gene-therapy products such as adenovirus- interferon (IFN)-gamma. Systemic treatment uses biologicals such as fusion molecules, monoclonal antibodies and immune response modifiers (IFNs and retinoids), and well-tolerated antiproliferative drugs such as methotrexate. Evidence-based treatment recommendation exists but is hampered by the lack of large multicenter randomized trials.

Humans↗

PubMed2006

Pathogenesis and therapy of cutaneous lymphomas--progress or impasse?

The cutaneous environment hosts a number of hematopoietic neoplasms that are dominated by primary cutaneous (PC) T-cell lymphomas. Recent progress in molecular biology and immunology has provided tools to investigate the pathogenesis and the biology of these neoplasms. This review highlights newest findings concerning the immune biology of CD4+ CD56+ hematodermic neoplasms, and PC T-cell and B-cell lymphomas, speculating how these can be translated into more sophisticated, biology-based treatment approaches in the near future.

CD4 Antigens↗

PubMed2006

[Perspective of cutaneous lymphoma reserach].

Primary cutaneous lymphomas are characterized by an expansion of hematopoietic cells in the special microenvironment of the skin. They represent a special challenge both for researches and for clinicians who treat patients with these disorders. New research data concerning the biology of lymphocytes and the cutaneous microenvironment have increased our knowledge of these diseases in the last decades. The new WHO/EORTC classification definitely will facilitate a more detailed investigation of the various subtypes.

Biomedical Research↗

PubMed2005

Disease-independent skin recruitment and activation of plasmacytoid predendritic cells following imiquimod treatment.

BACKGROUND: Imiquimod, an immune response modifier that is used topically to treat different types of skin cancer, induces the production of proinflammatory cytokines that stimulate an antitumor immune response. We assessed characteristics of the imiquimod-induced immune activation in epithelial and lymphoproliferative neoplasias of human skin. We focused on plasmacytoid predendritic cells (PDCs), the primary producer of interferon alpha (IFN-alpha) after imiquimod activation in vitro. METHODS: We used Affymetrix oligonucleotide arrays to compare gene expression profiles from tumors from 16 patients, 10 with superficial basal cell carcinomas (sBCCs), five with cutaneous T-cell lymphomas (CTCLs), and one with Bowen's disease, before and after topical imiquimod treatment. We used quantitative immunohistochemistry with PDC-specific antibodies against BDCA-2 and CD123 to characterize the PDC population before and after imiquimod treatment in these specimens. Activation status of PDCs from four sBCC patients was assessed by intracellular IFN-alpha staining and flow cytometry. RESULTS: Expression of various IFN-alpha-inducible genes (e.g., CIG5, G1P2, OASL, IFIT1, STAT1, IFI35, OAS1, ISG20, MxA, and IRF7), the so-called IFN-alpha signature, was increased similarly in both sBCC and CTCL lesions after imiquimod treatment. PDCs were recruited and activated in both lesion types, and they produced IFN-alpha after imiquimod treatment in vivo (mean percentage of PDCs producing IFN-alpha = 14.5%, 95% confidence interval [CI] = 4.9% to 24%; range = 3.3%-27%, n = 4 lesions). Imiquimod induced similar immune activation patterns in all three diseases, and these patterns were associated with the number of PDCs recruited to the treatment site. Two imiquimod-treated sBCC patients who did not mount an inflammatory response to imiquimod and whose lesions lacked the IFN-alpha signature after treatment had fewer PDCs in treated lesions compared with other treated patients with such a response. CONCLUSIONS: Imiquimod induces immune activation patterns that relate to the number of the PDCs recruited to the treatment site, thus supporting the role of PDC in responsiveness to imiquimod in humans.

Adjuvants, Immunologic↗

PubMed2005

CD4+CD56+ hematodermic neoplasms bear a plasmacytoid dendritic cell phenotype.

CD4+CD56+ hematodermic neoplasms (HNs) with initial presentation in the skin are characterized by highly aggressive behavior and poor prognosis. Recent studies indicate that malignant cells, which are devoid of common T-, B-, NK-, and myeloid lineage markers, may be of plasmacytoid dendritic cell (pDC) origin. We undertook a study to assess the expression of several pDC-associated molecules on a series of 5 CD4+CD56+ HN cases. CD123 was expressed in all 5 cases, with some heterogeneity in individual cases. All but one case revealed fine membranous BDCA-2 staining of the dermal infiltrate. pDC-like phenotype of the malignant infiltrating cells was confirmed by costaining of BDCA-2+ cells with CD123 and CD4. MxA protein, representing the surrogate marker for lesional type I interferon activity, was expressed in 4 of 5 evaluated cases. Our findings further substantiate the putative pDC origin of CD4+CD56+ HNs.

Adult↗

PubMed2005

Expression of melanoma-associated antigens in melanoma cell cultures.

The efficiency of melanoma immunotherapy appears to depend on both melanoma- and immune system-specific factors. Melanoma-specific factors include melanoma-associated antigen (MAA) expression as well as HLA class I molecule expression. We investigated the expression of five MAA - Melan-A/MART-1, tyrosinase, gp100, MAGE-1 and MAGE-3 - by means of FACS analysis in 50 melanoma cell cultures and compared them to the cultures of human foreskin-derived melanocytes and melanoma cell line UKRV-Mel2. Melan-A, tyrosinase and gp100 expression was frequently reduced in melanoma cell cultures, compared to that in foreskin melanocytes, whereas MAGE-1 and MAGE-3 expression showed variable degree of upregulation, compared to that in foreskin melanocytes. The expression of all tested MAA demonstrated high interindividual variability. We further show that cell cultures derived from the same tissue sample are oligoclonal in nature, by demonstrating the presence of up to three cell populations bearing distinct MAA profile. Analysing samples derived from the same patient but each at a different time point, we show that MAA expression profile changes over time either in positive (increase) or in negative (decrease) direction. Finally, we demonstrate that brain metastasis-derived cell cultures significantly overexpress Melan-A and MAGE-3, compared to primary tumours and other metastatic sites (P-value range: 0.05-0.001). Elucidation of the MAA expression patterns and the kinetics within the same patient as well as during the course of the disease may help improve current and develop new immunotherapeutic strategies.

Adult↗

PubMed2004

Induction of genes mediating interferon-dependent extracellular trap formation during neutrophil differentiation.

Interferons (IFNs) are cytokines that possess potent anti-viral and immunoregulatory activities. In contrast, their potential role(s) in anti-bacterial defense and neutrophil activation mechanisms is less well explored. By comparing gene expression patterns between immature and mature human neutrophils, we obtained evidence that intracellular proteases and other anti-bacterial proteins are produced at earlier stages of maturation, whereas the genes for receptors and signaling molecules required for the release of these effector molecules are preferentially induced during terminal differentiation. For instance, mature neutrophils strongly expressed genes that increase their responses to type I and type II IFNs. Interestingly, granulocyte/macrophage colony-stimulating factor was identified as a repressor of IFN signaling components and consequently of IFN-responsive genes. Both IFN-alpha and IFN-gamma induced strong tyrosine phosphorylation of STAT1 in mature but not in immature neutrophils. Functional in vitro studies suggested that IFNs act as priming factors on mature neutrophils, allowing the formation of extracellular traps upon subsequent stimulation with complement factor 5a (C5a). In contrast, both IFN-alpha and IFN-gamma had only little capacity to prime immature cells in this system. Moreover, both IFNs did not have significant anti-proliferative effects on immature neutrophils. These data contribute to our understanding regarding changes of gene expression during neutrophil differentiation and IFN-mediated anti-bacterial defense mechanisms.

Base Sequence↗

PubMed2004

Imiquimod treatment induces expression of opioid growth factor receptor: a novel tumor antigen induced by interferon-alpha?

PURPOSE: Imiquimod represents a synthetic local immune response modifier that has demonstrated efficacy in clearing basal cell carcinoma. Via interaction with Toll-like receptor 7 on immune cells, imiquimod induces local production of cytokines, such as interferon (IFN)-alpha. EXPERIMENTAL DESIGN: To more closely define and elucidate mechanisms leading to basal cell carcinoma clearance in vivo, we examined gene expression profiles of skin basal cell carcinoma before and after treatment with 5% imiquimod cream (Aldara) by using high-density oligonucleotide arrays. RESULTS: We show that imiquimod predominantly induces genes involved in different aspects of immune response. In addition to effects on immunity, imiquimod treatment modulates the expression of genes involved in the control of apoptosis and oncogenesis. Array data indicated that imiquimod treatment induces expression of opioid growth factor receptor, a molecule recently reported to be a target for antitumor antibody responses. Immunohistochemistry revealed in vivo up-regulation of opioid growth factor receptor protein on tumor and on infiltrating cells after treatment. By using basal cell carcinoma cell lines treated with IFN-alpha or imiquimod, we show that opioid growth factor receptor up-regulation is IFN-alpha-mediated, rather then directly imiquimod-mediated. By using tissue microarray containing 52 basal cell carcinomas, we demonstrate opioid growth factor receptor expression in almost half of the cases. Expression of opioid growth factor receptor correlated with a longer recurrence-free period in basal cell carcinoma that recurred after radiotherapy (Kaplan-Meier analysis, P = 0.041). CONCLUSIONS: In addition to its immunomodulatory and antiproliferative activity, opioid growth factor receptor seems to have a prognostic significance in basal cell carcinoma patients. Our data add to the growing list of basal cell carcinoma-associated tumor antigens.

Adjuvants, Immunologic↗

PubMed2004

Adenovirus-mediated intralesional interferon-gamma gene transfer induces tumor regressions in cutaneous lymphomas.

Primary cutaneous lymphomas have been successfully treated with interferons (IFNs), counterbalancing the T-helper 2 (Th2)-skewing state. We undertook a phase 1, open-label, dose-escalating trial of repeated intratumoral administration of TG1042 in patients with advanced primary cutaneous T-cell lymphomas (CTCLs) and multilesional cutaneous B-cell lymphomas (CBCLs). TG1042 is a third-generation, nonreplicating human adenovirus vector containing a human IFN-gamma cDNA insert. Nine patients (7 CTCL, 2 CBCL) were enrolled at the following TG1042 doses: 3 x 10(9), 3 x 10(10), and 3 x 10(11) total particles. Local clinical response was observed in 5 of 9 treated patients (3 patients with complete response [CR] and 2 patients with partial response [PR]). Out of these, 3 patients showed systemic CR with the clearance of other noninjected skin lesions. Clinical response lasted for a median of 3 months (range, 1-6 months). Adverse events were mostly of grades 1 and 2. Seven of 9 treated patients had a detectable TG1042-derived IFN-gamma message in injected lesions after the first treatment cycle. A TG1042-IFN-gamma message was also detectable after several treatment cycles. We demonstrate the induction of humoral immune response to lymphoma tumor-antigen se70-2 after treatment. Our study shows that intralesional injections of TG1042 are both safe and well tolerated.

Adenoviridae↗

PubMed2004

Immune activation status of CD8+ T cells infiltrating non-small cell lung cancer.

In a variety of human cancers, the presence of tumor-infiltrating T lymphocytes (TILs) is associated with tumor regression and favorable prognosis. Local interferon (IFN)-gamma secretion from activated T cells is supposed to induce a specific immune response leading to tumor-specific cytotoxicity. Nonetheless, significance and properties of TILs still remains controversial in lung cancer patients. We determined CD8+ T cell counts in 31 patients with non-small cell lung cancer (NSCLC) by immunohistochemistry, and assessed T-cell immune activation status in a subset of patients by measuring IFN-gamma mRNA expression by quantitative PCR (TaqMan). Semi-quantitative immunohistochemical analysis revealed significantly higher CD8+ T cell counts within the tumor as when compared to the invasive margin. CD8+ T cells immune activation status, represented in the IFN-gamma/CD8 mRNA ratio, correlated with the median number of CD8+ T cells presented at the tumor-host interface. Neither tumor histology and grade, nor CD8+ T cell counts and IFN-gamma/CD8 ratio could demonstrate an influence on overall survival in these patients. Our results indicate that CD8+ T cells infiltrating the tumor cell nests may be inadequately activated and thus incapable of mounting an effective anti-tumor immune response.

CD8-Positive T-Lymphocytes↗

PubMed2004

Expression of Melan-A/MART-1 in primary melanoma cell cultures has prognostic implication in metastatic melanoma patients.

The lack of melanoma-associated antigen (MAA) expression has been associated with the reduced overall survival in melanoma patients. In order to investigate whether the MAA expression detected on cell cultures established from melanoma patients might relate to the overall survival in these patients, we screened primary cell cultures derived from 37 melanoma metastases for the expression of five known MAA: Melan-A, tyrosinase, gp-100, MAGE-1 and MAGE-3 by polymerase chain reaction (PCR) and fluorescence-activated cell sorting (FACS). MAA expression detected by PCR was found at a high percentage in evaluated melanoma cell lines: 25 of 28 (89%) were positive for Melan-A, 22 of 28 (79%) were positive for tyrosinase, 26 of 28 (93%) were positive for gp-100, and 18 of 28 (64%) were positive for MAGE-3 expression. Using the FACS method the percentage of MAA-positive cell lines was much lower: 14 of 31 (45%) cell lines were positive for Melan-A, eight of 31 (26%) were positive for tyrosinase, 13 of 31 (42%) were positive for gp-100, six of 31 (19%) were positive for MAGE-1, and 14 of 31 (45%) were positive for MAGE-3 expression. Kaplan-Meier survival analysis demonstrated that the patients whose cell lines were positive for Melan-A expression by PCR had significantly longer overall survival time as Melan-A PCR-negative cases (P=0.0038). This could not be shown for any of the markers tested by FACS. Our results suggest that the expression of Melan-A/MART-1 in patient-derived cell cultures may help to identify a group of melanoma patients with prolonged survival.

Adult↗

PubMed2004

Role of imiquimod in skin cancer treatment.

Cancer of the skin is by far the most common form of all cancers. Given the increasing incidence of skin cancer worldwide, it seems feasible to reconsider the treatment options available for dealing with this growing problem. Despite the lower costs associated with classical methods such as surgery and radiotherapy, immune response modifiers such as imiquimod appear to be good candidates for the future given their good cosmetic effects, the possibility of treating large areas, and the simpleness of patient-applied treatment with a cream formulation. This article reviews current literature on the use of imiquimod in the treatment of nonmelanoma and melanoma skin cancer.

Administration, Cutaneous↗

PubMed2003

Superficial radiotherapy for patients with basal cell carcinoma: recurrence rates, histologic subtypes, and expression of p53 and Bcl-2.

BACKGROUND: The histologic subtype of a basal cell carcinoma (BCC) may be an important factor for the success of a certain treatment modality. In the current article, the authors report recurrence rates among patients with BCC after superficial radiotherapy as well as Bcl-2 and p53 expression levels stratified by BCC subtype. METHODS: The authors performed a retrospective study of 175 BCCs in 148 patients (64 female patients and 84 male patients; mean age, 69 years) who were treated with radiotherapy. According to their histologic patterns, BCCs were classified as nodular (n = 103), superficial (n = 25), and sclerosing (n = 47). In addition, six patients with metatypic BCC were reviewed. Bcl-2 and p53 protein expression was examined on a tissue microarray of 60 BCC samples (18 nodular tumors, 12 superficial tumors, and 30 sclerosing tumors). RESULTS: The estimated 5-year recurrence rate for all patients with BCC was 15.8%: 8.2% for patients with the nodular subtype, 26.1% for patients with the superficial subtype, and 27.7% for patients with the sclerosing subtype (Kaplan-Meier analysis: P = 0.055). The median follow-up was 48 months. The mean time to recurrence was 20 months, and 86.4% of all recurrences occurred within 3 years after treatment. No gender-specific differences were observed. In addition, one of six metatypic BCCs recurred. Nuclear p53 immunoreactivity and low Bcl-2 expression were significantly correlated with the sclerosing subtype. Overall, 61.5% of patients developed additional neoplasms during follow-up (76 developed additional BCCs, 15 developed squamous cell carcinomas, and 6 developed Bowen disease). CONCLUSIONS: The sclerosing subtype of BCC was a risk factor for recurrence after radiotherapy. In contrast, excellent results were achieved for patients with predominant nodular subtype. Nevertheless, radiotherapy may be the therapy of choice for patients with all BCC subtypes, depending on the individual patient's characteristics. Expression analyses confirmed that p53 and Bcl-2 levels may be used as indicators for the aggressiveness of a BCC subtype. Due to the high incidence of additional skin malignancies, patients with BCC need careful follow-up.

Adult↗

PubMed2003

Primary cutaneous CD8+ and CD56+ T-cell lymphomas express HLA-G and killer-cell inhibitory ligand, ILT2.

Primary cutaneous lymphomas constitute a spectrum of diseases characterized by a clonal accumulation of lymphocytes in the skin. Cutaneous T-cell lymphomas of the cytotoxic phenotype, including CD8+ and CD56+ lymphomas, are rare entities that have only been recently recognized and characterized. These lymphomas often show an aggressive clinical course. We investigated the expression of human leukocyte antigen G (HLA-G) and interleukin 10 (IL-10) in conjunction with expression of HLA-G killer-cell inhibitory receptor ligand immunoglobulin-like transcript 2 (ILT2) in 3 CD56+CD4+ and 4 CD8+ cutaneous T-cell lymphomas. HLA-G expression was detected in 2 of 3 lymphomas of the CD56+CD4+ type and in all lymphomas of CD8+ type. It is of note that CD56+CD4+ lymphomas displayed stronger HLA-G reactivity. The expression of IL-10 matched the expression of HLA-G. Together with the expression of IL-10, HLA-G might be one of the factors accounting for the evasion of immunosurveillance, thus contributing to aggressive phenotype of these lymphoma entities.

Adult↗

PubMed2003

Mechanisms underlying imiquimod-induced regression of basal cell carcinoma in vivo.

BACKGROUND: Imiquimod is a local immune response modifier that has demonstrated potent antiviral and antitumor activity. It enhances innate and acquired immune responses via endogenous cytokine production and has proven efficacious in clearing superficial basal cell carcinoma (sBCC). OBJECTIVE: To evaluate the mechanisms by which topical imiquimod treatment leads to sBCC clearance in vivo. DESIGN: A pilot, open-label, nonrandomized study. SETTING: Zurich, Switzerland. PATIENTS: Six persons 18 years or older who had nonrecurrent primary tumors that had not undergone previous biopsy or treatment but were suitable for treatment by surgical excision. The tumors were located on the scalp, extremities, or trunk; had a minimum diameter of 1 cm and a maximum diameter of 2 cm; and were clinically and histologically consistent with sBCC. INTERVENTIONS: Daily application of 5% imiquimod cream 5 times per week for a maximum of 6 weeks. When the tumor began to show signs of erosion, it was surgically excised. OUTCOME MEASURES: Parameters reflecting tumor apoptotic status (Bcl-2), expression of death receptors (Fas and Fas ligand [FasL]), intercellular adhesion molecule (ICAM) 1, immunosuppressive microenvironment (interleukin 10), and antigen presentation machinery (transporter associated with antigen presentation [TAP] 1) before and after imiquimod treatment were evaluated. The changes in the interferon gamma messenger RNA (mRNA) levels relative to CD4 and CD8 mRNA were assessed using quantitative polymerase chain reaction. RESULTS: Tumor cells became more susceptible to apoptosis through decreased Bcl-2 expression after treatment with 5% imiquimod cream. Inflammatory infiltrate developed rapidly (within 3 to 5 days after treatment initiation) and was associated with the enhanced expression of ICAM-1. This early response tended to be a mixed cellular response of macrophages and lymphocytes. Interferon gamma was produced by CD4 and CD8 T cells. Imiquimod treatment induced a massive increase in macrophage peritumoral and intratumoral infiltration. Interleukin 10 was produced by infiltrating cells but was not produced by tumor cells. Tumor expression of TAP-1 and Fas/FasL appeared to be unaffected in the first 5 days of treatment.

ATP Binding Cassette Transporter, Subfamily B, Mem↗