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S Bjercke

Publications and source records attributed to S Bjercke.

28 records · Page 2Linked to original sources

Effect of interferon gamma on expression of HLA-class II molecules on blood-derived dendritic cells.

T4 cells recognize antigen together with HLA class II molecules in the membrane of antigen-presenting cells (APC). The magnitude of the induced T cell response is in part dependent upon the quantitative expression of HLA-class II molecules in the cell membrane of the APC. We report here that recombinant interferon gamma (IFN-gamma) may enhance the expression of HLA class II molecules on the surface membrane of blood-derived dendritic cells by 30-90%.

Dendritic Cells↗

Suppressive effect of monocytes in vitro in patients with carcinoma of the uterine cervix.

The adherent cell fraction (AdC) of human peripheral blood mononuclear cells (PBM) contains two cell types of opposing function in vitro. Dendritic cells (DC) act as antigen-presenting cells (APC) in vitro, while monocytes (Mo) have a suppressive effect on antigen activation of T cells. In this report we show that patients with cervical carcinoma have a significantly increased number of suppressive Mo compared with healthy controls. The T cell response to Herpes Simplex Virus (HSV-1) and PPD was about the same in the two groups, but after removal of Mo by adherence a significantly higher T cell response was seen among the patients with advanced stage (Figo stage IIb-IVa) compared with patients in early stage (Figo stage Ia-IIa) and healthy controls. These observations indicate that patients with cervical carcinoma have an increased number of T cells reactive with HSV, and normal DC function. The relative suppression expressed on a per Mo basis was the same in all groups, which indicates that the increased suppression in the patients was caused by an increased number of Mo, and not by changes in their activation state.

Adenocarcinoma↗

Enriched Langerhans cells express more HLA-DR determinants than blood-derived adherent cells (monocytes and dendritic cells).

When used as antigen-presenting cells, enriched Langerhans cells (LC) are known to induce a stronger proliferative T-cell response towards antigens than blood-derived adherent cells (a mixture of monocytes and dendritic cells). To study the mechanism behind this difference in accessory cell function, we have compared the quantitative expression of HLA-DR molecules on LC and adherent cells (AdC), using a radioimmunoassay system. The amount of HLA-DR determinants was calculated to be 50-100 times higher on LC than on AdC.

Antigen-Presenting Cells↗

Dendritic cells and monocytes as accessory cells in T-cell responses in man. I. Phenotypic analysis of dendritic cells and monocytes.

A method is described for simple and rapid preparation of human dendritic cells (DC) and monocytes (Mo) from peripheral blood. The phenotype of enriched DC and Mo was determined and compared by means of a panel of monoclonal antibodies (Mab's). The distribution and quantitative expression of HLA class II molecules encoded by the subloci DP, DQ, and DR were the same on the two cell types. During in vitro culture a rapid decrease of class II antigens on Mo was observed, whereas the expression of class II antigens on DC was relatively stable. The absence of monocyte markers on DC may indicate that this cell type does not belong to the monocyte/macrophage cell lineage. The phenotypic analysis shows that peripheral blood DC also lack differentiation antigens expressed by epidermal Langerhans cells (OKT6) and lymph node follicular dendritic reticulum cells (DRC-1). The relationship between peripheral blood DC and tissue-localized DC thus remains unsolved. With relatively high numbers of DC now available, production of DC lineage-specific Mab's may be approached.

Antibodies, Monoclonal↗

Dendritic cells and monocytes as accessory cells in T-cell responses in man. II. Function as antigen-presenting cells.

The main antigen-presenting cells (APC) of human blood are reported to be the dendritic cells (DC), whereas monocytes (Mo) are only weakly or not at all capable of inducing T-cell immune responses to the soluble antigen purified protein derivative (PPD). In contrast, we found Mo to have a suppressive effect on the APC function of DC in vitro. Removal of Mo by adherence resulted in an increased APC activity, even though Mo produce more interleukin 1 (Il-1) than DC. Furthermore, addition of the prostaglandin synthesis inhibitor indomethacin gave rise to increased Il-1 production, HLA-class II expression, and a stronger antigen-specific T-cell response to PPD. Taken together, our studies indicate that the superior accessory cell function of DC compared with Mo in in vitro cultures may, at least partly, be attributed to the prostaglandin E2 production by Mo and more stable expression of HLA-class II molecules on DC.

Animals↗

Relative efficiency of human Langerhans' cells and blood derived dendritic cells as antigen-presenting cells.

T4 cells recognize antigens together with HLA class II molecules in the membrane of antigen-presenting cells (APC). The magnitude of the induced T cell response is in part dependent upon the APC's amount of MHC-class II molecules. Langerhans' dendritic cells (LC) express 50-100 times more HLA-DR molecules than monocytes (Mo) and blood derived dendritic cells (DC). We report here that LC are more efficient APC than DC from the same donor, indicating that the APC capacity of dendritic cells isolated from different organs is correlated to their expression of HLA class II gene products.

Antigen-Presenting Cells↗

Enriched epidermal Langerhans cells are potent antigen-presenting cells for T cells.

Human epidermis was separated from dermis by means of a suction blister device and dissociated with trypsin. The epidermal cell (Ec) suspensions contained 2-6% Langerhans cells (Lc). Using a new rosette technique for enrichment of Lc, suspensions were obtained that contained 50-92% viable Lc. Ec, enriched Lc, or peripheral blood monocytes (Mo) were cocultured with or without antigens (Candida albicans, herpes simplex virus) and autologous T lymphocytes from sensitized donors. Strong proliferative T-cell responses were obtained provided Ec, enriched Lc, or Mo were also present. Furthermore, Lc were more effective than similar numbers of Mo in inducing T-cell responses to the antigens tested, and Lc did not require the presence of significant numbers of keratinocytes to exert this function.

Antigen-Presenting Cells↗

Enrichment of human epidermal Langerhans dendritic cells.

Langerhans cells (LC) were enriched from a human epidermal cell (EC) suspension by a rosette-forming technique. First EC were sensitized with the monoclonal antibody OKT6, and then they were mixed with ox erythrocytes (ORBC) coated with affinity-purified rabbit IgG anti-mouse IgG antibodies. Rosette-forming LC were then separated from non-rosetting EC by means of Percoll flotation. After hypotonic lysis of the ORBC, the cells obtained had a viability greater than 90%, and 67-98% of the viable cells were OKT6-positive. In functional studies the enriched cells were strongly stimulatory for allogeneic lymphocytes and were able to function as antigen-presenting cells for the T-cell response to the soluble antigen purified protein derivative.

Animals↗

HLA-DR-expressing Langerhans'-like cells in vaginal and cervical epithelium.

Sections of ethanol-fixed, paraffin-embedded tissue specimens from human vagina and exocervix were stained by an indirect immunofluorescence method with a rabbit antiserum to HLA-DR antigens. A specific staining of cells having a dendritic appearance were seen. The cells were randomly distributed, mainly in the parabasal cell-layer of the stratified squamous epithelium. The number of dendritic cells was 1-3% of all cells in the cervical epithelium and 1-5% of the cells in the vaginal epithelium. Most probably these cells are Langerhans' cells.

Adult↗