S2c). FcγRIIIB was expressed by a smaller percentage of CD4+ T cells (Fig. S2). The examination of three independent fields of cells expanded using anti-CD3 and anti-CD28 showed that a total of 49% of cells expressed FcγRIIIA, 27% expressed FcγRIIIB and 22% stained for MRs. Treatment of the cells with TCC, ICs purified from SLE patients (SLE–ICs) or TCC together with ICs did not alter the
protein pattern of immunoprecipitates beta-catenin pathway generated using anti-FcγRIIIA/B (Fig. S7). Western analysis of immunoprecipitates obtained using monoclonal anti-FcγRIIIA/B from naive CD4+ T (CD45RA+) cells showed protein bands migrating at the molecular weights of 26–29 kD that correspond to a previously reported molecular mass for FcγRIIIA and B
(Fig. S6) [29]. In naive CD4+ T cells, an additional band at approximately 34 kD was also observed (Fig. S6). The FcγRIIIA consists of 254 amino acids with a predicted molecular mass of 29 kD (Accession no. P08637-1) and FcRIIIB consists of 233 amino acids with a predicted molecular mass of 26 kD (Accession no. P75015-1). In addition to the light and heavy chains of immnoglobulins, faint protein bands at 72, 98 and 130 kD were also observed. These proteins were also observed in the immunoprecipitates prepared from Jurkat cells. Jurkat cells are used traditionally to study T cell activation (Fig. S6). To further confirm the presence of FcγRIIIA/B in the CD4+ T cells, we analysed the presence of RNA Dapagliflozin transcripts by RT–PCR. The RT–PCR analysis of the total RNA isolated from both selleck chemicals peripheral CD4+ T cells and naive CD4+ T cells using a primer set designed from the gene ID NM_001127596·1 (FCGRA) and a second primer set published recently [27] showed the presence of appropriate-sized products for the FcγRIII gene. These FcγRIII transcripts were
also amplified from the total leucocyte RNA. Negative controls without the template RNA did not show the PCR amplification product. Both CD4+ T cells (not shown) and naive CD4+ T cells showed transcripts for the FcγRIIIA/B gene. Jurkat cells also demonstrated these RNA transcripts (Fig. 4). The sequencing of PCR-amplified cDNA confirmed it to be the FcγRIIIA/B gene product. The staining pattern of FcRγ chain in T cells showed them to be present in microclusters, a pattern that is observed for TCR signalling proteins in activated CD4+ T cells (Fig. 3a). The treatment of cells with purified ICs triggered the microclusters to move towards one side of the cell due to capping (Fig. 3a). The presence of TCC during IC treatment further enhanced staining for the FcRγ chain. We observed that the ICs and TCC treatment triggered migration of these receptors into MRs (Figs 5 and S5). We have observed previously that the assembly of non-lytic C5b-9 using purified C5b-6, C7, C8 and C9 labelled with AlexaFluor® 594 trigger MR aggregation beneath C5b-9 deposits (Fig. S4). In quiescent cells, both FcγRIIIB and the FcγRIIIA were not observed in the MRs.