Biomedical subjects

T Rème

Publications and source records attributed to T Rème.

21 records · Page 2Linked to original sources

PubMed1986

Mitogenic effect of PMA + IL 2 on subpopulations of corticoresistant thymocytes.

The proliferative response of subpopulations of corticoresistant thymocytes (CRT) to phorbol-12-myristate-13-acetate (PMA) + interleukin 2 (IL 2) was investigated. Thymocyte subpopulations were selected by the indirect "panning" technique, and their purity was checked by cytofluorometry. Microcultures were set up with an optimal concentration of PMA, EL4 supernatant, or pure IL 2 obtained by recombinant DNA technology (r-IL 2) in the presence or in the absence of accessory splenic adherent cells (SAC). Under these conditions, only the Lyt-2+ CRT proliferated, and this response was IL 2-dose-dependent and was increased by accessory cells. When the calcium ionophore A23187 was added to the cultures, the proliferation of L3T4+ CRT was greatly increased. These results were confirmed by cultures at limiting dilution of positively selected Lyt-2+ and L3T4+ subpopulations of CRT at optimal concentrations of PMA, r-IL 2, A23187, and accessory cells. These results are consistent with the idea that two signals are necessary to activate L3T4+ CRT, whereas only IL 2 is necessary for PMA-induced proliferation of Lyt-2+ CRT. Finally, unlike the case of lectin-induced proliferation of Lyt-2+ and L3T4+ CRT, the presence of accessory cells or cell-cell contact is important for optimal response to PMA + IL 2.

Animals↗

PubMedDate not supplied

Growth factor activity of IL-6 in the synovial fluid of patients with rheumatoid arthritis.

OBJECTIVE: We set out to determine whether the ability of synovial fluids (SF) in patients with rheumatoid arthritis (RA) to facilitate the proliferation of synovial tissue-derived fibroblastic cell lines was related to the presence of growth factors and/or cytokines. METHODS: The growth factor activity of 20 RA SF was measured by their ability to induce anchorage-independent growth of the rat NRK-49F (49F) fibroblastic strain. The presence of transforming growth factor-beta (TGF-beta) and platelet-derived growth factor (PDGF) was also assessed using neutralising anti-TGF-beta or anti-PDGF-AB mAbs. Cytokines were measured by functional assays or ELISA: RESULTS: We observed a correlation between growth factor activity and the IL-6 levels in SF. Both were correlated to the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels in SF and serum. IL-6 (at concentrations above 10(4) U/ml), synergized with growth factors in the induction of the anchorage independent (AI) growth of 49F cells. Pretreatment of SF with a neutralising anti-IL-6 mAb substantially reduced the capacity of these SF to induce AI growth of 49F cells, confirming the growth factor activity of IL-6 in this test. In contrast, IL-6 alone or in association with PDGF, epidermal growth factor (EGF) or TGF-beta had no effect on the anchored growth of synovial tissue-derived fibroblasts, and treatment of SF with a neutralising anti-IL-6 mAb did not affect their ability to increase the growth rate of synovial tissue-derived fibroblasts. CONCLUSIONS: These results strongly suggest that IL-6 is responsible for the observed correlation between the growth factor activity of SF and inflammatory indexes such as ESR and CRP. However, neither IL-6 nor PDGF were responsible for the observed positive effect of SF on synovial fibroblastic cell lines.

Adult↗

PubMedDate not supplied

Rheumatoid pericarditis: new immunopathological aspects.

Rheumatoid pericarditis (RP) is a well known extraarticular manifestation of rheumatoid arthritis (RA). It is not frequently diagnosed despite its high reported prevalence in post-mortem studies. There have been no immunohistological studies of its presence in pericardial membranes. Here we report a complete immunohistological study of two RA patients with RP complications, using a panel of monoclonal antibodies (mAbs) for the recognition of B, T, and NK cells. Both cases showed strong and almost exclusive pericardial membrane infiltration of CD8+ T-cells which was correlated with a higher than expected similar increase in the subset of peripheral blood lymphocytes (PBL). These findings suggest an important role for CD8+ T-cells in chronic RA, especially in this extraarticular manifestation of the disease.

Aged↗