Complement dependent trapping of infectious HIV in human lymphoid tissues.

Objectives: HIV-1 bound extracellularly to follicular dendritic cells (FDC) in germinal centers (GC) of lymphoid tissues (LT) represents the largest viral reservoir in HIV-infected individuals; however there is no direct evidence as to whether HIV trapped in human GC remains infectious. In the GC, complement receptors and Fc gamma receptors have been suggested to participate in trapping of HIV; therefore, the relative contribution of complement- and Fc gamma receptors in binding HIV on LT was investigated and the infectivity of this virus was tested.

Design: As it is difficult to isolate FDC without contaminations of productively infected cells, HIV was detached from LT of HIV positive individuals using antibodies blocking complement- and Fc gamma receptors.

Phenotypic characterization and distribution of dendritic cells in parotid gland tumors.

Evidence on the relationship between the infiltration of dendritic cells (DCs) and prognosis in head and neck tumors exists. Interestingly, only limited information is available regarding the maturation state and distribution of DCs in parotid gland tumors. The purpose of our study was therefore to extend these observations and to investigate in more detail the density and distribution of mature DCs and Langerhans cells (LCs) in parotid gland tumors.

Maturation of dendritic cells in the presence of living, apoptotic and necrotic tumour cells derived from squamous cell carcinoma of head and neck.

Dendritic cells (DC) have been recently used as vaccines for stimulation of tumour-specific immunity in various types of cancer. Since data about interactions of DC with tumour cells derived from head and neck cancer are not available, in our study we investigated the effects of head and neck squamous cell carcinoma (HNSCC) cell lines on the maturation of DC. We found that immature DC efficiently internalise necrotic cells, but not living and apoptotic tumour cells.

Pharmacodiagnostic value of the HER family in head and neck squamous cell carcinoma.

Two protooncogene products, EGFR (Her-1, c-erbB-1) and HER2 (Her-2/neu, c-erbB-2), have been reported to be frequently overexpressed in head and neck squamous cell carcinoma (HNSCC). In order to identify patients who may benefit from targeted cancer treatment for these two molecules, we determined the expression status of EGFR and HER2 in 129 HNSCC tumor specimens. Two pharmacodiagnostic kits (EGFR pharmDx and HercepTest) were used to identify HNSCC tumors that overexpress EGFR or HER2.

Immunosuppressive effects of soluble factors secreted by head and neck squamous cell carcinoma on dendritic cells and T lymphocytes.

Recent observations suggest that the inability of the immune system to mount an effective immune response against head and neck squamous cell carcinoma (HNSCC) could be a result of the immunosuppression mediated through soluble factors that are secreted by tumour cells. Therefore, we investigated the effects of conditioned medium obtained from cultures of HNSCC cell lines (HNSCC-CM) on the function of dendritic cells (DC) and T cell immune response. In our study, we could not observe any inhibitory effect of HNSCC-CM on the maturation and the cytokine secretion pattern of DC.