Direct intralymphatic injection of peptide vaccines enhances immunogenicity

Research to enhance the efficiency of vaccines focuses mainly on improving either the adjuvant or the type and form of the antigen. This study evaluates the influence of the administration route on the efficiency of a peptide-based vaccine. Peptide vaccines are generally administered subcutaneously or intradermally, from where they must reach secondary lymphatic organs to induce an immune response. We analyzed the efficacy of peptide vaccines administered directly into a lymph node. Using a MHC class I-binding peptide from lymphocytic choriomeningitis virus, we found that intralymphatic injection enhanced immunogenicity by as much as 10(6) times when compared to subcutaneous and intradermal vaccination. Intralymphatic administration induced CD8 T cell responses with strong cytotoxic activity and IFN-gamma production that conferred long-term protection against viral infections and tumors. These results should have immediate implications for clinical immunotherapy of infectious disease and cancer.

Coexpression of CD40 and CD40 ligand in cutaneous T-cell lymphoma (mycosis fungoides)

Microarray analysis is a promising new approach for creating specific expression profiles of multiple genes simultaneously. We quantitatively analyzed differential gene expression patterns in mycosis fungoides-derived clonal T cells and autologous, identically cultured CD4+ lymphocytes using microarrays containing 588 cDNA segments from genes relevant to cell signaling, carcinogenesis, and apoptosis. Among other dissimilarities, neoplastic T cells showed coexpression of CD40 (Bp50) and CD40 ligand (gp39, CD154). These results could be corroborated by reverse transcription-PCR, immunohistochemistry, and two-color immunofluorescence staining. Our data suggest that in cutaneous T-cell lymphoma, CD40/CD40 ligand interactions might represent a paracrine loop that is crucial not only in preventing apoptosis or positively regulating growth but also in homing of neoplastic cells to the skin.

CD4 + /CD7- T cell frequency and polymerase chain reaction-based clonality assay correlate with stage in cutaneous T cell lymphomas

In cutaneous T cell lymphomas, tumor cells can be found in skin and in other compartments. A precise definition of extracutaneous spread including blood involvement is necessary for staging and treatment design. We investigated peripheral blood in 51 patients with various types of cutaneous T cell lymphomas by the analysis of blood smears for Sézary cells, the CD4 + /CD7- T helper cell frequency in the peripheral blood by fluorescence activated cell sorter analysis and by polymerase chain reaction for the T cell receptor gamma-chain followed by denaturing gradient gel electrophoresis. Eleven polymerase chain reaction products were sequenced. Thirty-five per cent of patients with stage Ia-IIb cutaneous T cell lymphomas presented a peripheral blood T cell clone. In patients with stage III-IVb cutaneous T cell lymphomas 75% were positive for clonality in the peripheral blood by polymerase chain reaction. Interestingly, three of 13 Sézary patients showed a TCR-gamma joining region pseudogene (JgammaP1/JgammaP2) usage. CD4 + /CD7- cell counts were significantly higher in patients with advanced cutaneous T cell lymphomas than in patients with early cutaneous T cell lymphomas. There was a correlation between increased percentage of circulating CD4 + /CD7- cells and detection of clonality by polymerase chain reaction (p = 0.001). There was no significant correlation between the polymerase chain reaction data and the percentage of Sézary cells on blood smears. A significant correlation between CD4 + /CD7- cells and Sézary cells was found, however. Stepwise logistic regression analysis showed that the CD4 + /CD7- cell count and clonal T cell detection in peripheral blood are independently correlated with stage. The combination of both parameters gives more information than each one separately. In conclusion, our data indicate that fluorescence activated cell sorter analysis of peripheral blood and polymerase chain reaction-based clonality assays can improve the accuracy of staging investigations in cutaneous T cell lymphomas patients.

[Current therapy concepts in cutaneous T-cell lymphomas]

Cutaneous T-cell-lymphomas (CTCL) include a group of rare diseases that are characterized by an accumulation of clonal T-lymphocytes in skin. The various disease entities may be classified by an adapted Kiel classification. For staging purposes the TNM system is most commonly used. Treatment modalities depend on the extent and the aggressiveness of the disease (low- or high-grade lymphoma) and on the individual situation of the patient. Stage-adapted therapy is currently recommended. Early stages of low-grade CTCL are successfully treated with PUVA, retinoids or interferon-alpha. Extracorporeal photopheresis is the treatment of choice in stage III patients with Sézary syndrome. Alternative therapeutic modalities for CTCL, such as radiotherapy, chemotherapy or various experimental protocols, are discussed.

A primary cutaneous non-T, non-B CD4+, CD56+ lymphoma

BACKGROUND

Cutaneous lymphomas are heterogeneous clonal lymphoproliferative disorders originating from B or T lymphocytes.

OBSERVATION

We describe a patient with a unique primary cutaneous lymphoma characterized by a bruise-like aspect of the skin lesions, a CD4+, CD43+, CD56+, CD2-, CD3-, CD8-, T-cell receptor-negative phenotype of the medium-sized to large lymphoid tumor cells and an undetermined genotype (T-cell receptor beta and immunoglobulin heavy chain in germline configuration, no clonal T-cell receptor gamma population as detected after analysis with polymerase chain reaction combined with denaturing gradient gel electrophoresis) and fast relapse after radiotherapy.

CONCLUSIONS

This non-B, non-T cutaneous lymphoma cannot be classified by any current lymphoma classification. It seems to represent a new disease entity with peculiar clinical, histologic, and molecular features.

Major histocompatibility complex class I molecule serves as a ligand for presentation of the superantigen staphylococcal enterotoxin B to T cells

Superantigens, such as staphylococcal enterotoxin B (SEB), elicit a strong proliferative response in T cells when presented in the context of major histocompatibility complex (MHC) class II molecules. We observed a similar T-cell response, when MHC class II-negative epidermal cell lines were employed as antigen-presenting cells. Immunoprecipitation studies indicated that the ligand to which SEB bound had a molecular mass of 46 kDa. Radiolabeled SEB could be immunoprecipitated from isolated membrane proteins on the SCC13 epidermal cell line with a monoclonal antibody directed against the MHC class I molecule, and transfection of the K-562 cell line with MHC class I molecules showed a 75% increased SEB-binding capacity compared with the nontransfected MHC class I- and class II-negative counterpart. In functional studies, antibodies to the MHC class I molecule inhibited T-cell proliferation by at least 50%. From these studies, we conclude that MHC class I molecules on malignant squamous cell carcinomas serve as ligands for SEB, which, given the appropriate costimulatory signals, is sufficient to allow for superantigen-induced T-cell proliferation.

Reduced growth factor requirements and accelerated cell-cycle kinetics in adult human melanocytes transformed with SV40 large T antigen

Melanomas develop with high frequency in transgenic mice in which oncogenic sequences of the SV40 DNA tumor virus have been specifically targeted to melanocytes. To investigate the role of SV40 in melanomagenesis, cultured human melanocytes were transformed with a retroviral shuttle vector encoding the SV40 large T antigen and examined for changes in cell-cycle kinetics and growth-factor dependence. Colonies expressing the viral oncogene were morphologically indistinguishable from their non-T-antigen-transformed counterparts. Also like normal melanocytes, the infected cells remained anchorage dependent and non-tumorigenic in nude mice. However, T-antigen-positive cultures exhibited significantly accelerated population doubling times, increased saturation densities with highly confluent monolayers and a three- to fourfold extended life span. Most interestingly, cell-cycle analysis revealed a measurable shift from quiescent to cycling cells in T-antigen-expressing cultures and an acquired ability to progress more rapidly through G1. Moreover, T-antigen-positive melanocytes proliferated in the absence of PMA and required markedly reduced levels of exogenous bFGF. These studies indicate that the viral oncogen of simian virus 40 provides melanocytes with distinct growth advantages that may render these cells unusually susceptible to additional environmental challenges necessary for full expression of the malignant phenotype.

The prognosis of primary and metastasising melanoma. An evaluation of the TNM classification in 2,495 patients

The prognostic value of the TNM classifications of the UICC dated 1978 and 1987, was investigated in a population of 2,495 patients who were followed up over the long term. In the case of primary melanoma, Breslow's tumour thickness proved to be the most powerful predictor of patient survival in multivariate analysis, while the significance of Clark's level ranged after that of both localisation of the primary tumour and the sex of the patient. The continuous proportional relationship between tumour thickness and risk of death makes it possible to regrade thickness groups. Grading cutoffs at 1, 2 and 4 millimetres, with no account being taken of depth of invasion, proved to be particularly favourable for a classification in accordance with prognostic criteria. In advanced stages of the disease, the outcome of locoregional and distant metastasis is significantly different; and furthermore in the case of locoregional metastasis, in-transit and satellite metastases exert a significantly better prognosis than regional lymph node involvement. Isolated juxtaregional lymph node metastases occurred primarily or during the course of the observation period in only 19 patients of our group, and, in comparison with visceral metastases, proved to have only an insignificantly better prognosis. For this reason, it would appear meaningful to assign them to a common stage. On the basis of these results, proposals are made for modifications of the TNM classification.