However, after infection or treatment with H. polygyrus AgS, F9 or F17, the percentage of apoptotic cells decreased. The percentage of apoptotic CD8+ cells remained
unchanged. Taken together, during infection and after cell activation by TCR and CD28 receptors, H. polygyrus antigens reduced both the proliferation and apoptosis of CD4+cells. Seventeen fractions were separated from the somatic homogenate of the H. polygyrus complete antigen with molecular range from 11 to 130 kDa and differences in activity between fractions were observed in cell culture. In naïve mice, the percentage of apoptotic cells decreased after stimulation of MLN cells with AgS (from 51% to 34.9%) and with antigenic fractions (Figure 4a). Infection buy Torin 1 with H. polygyrus also significantly reduced the percentage of apoptotic cells. Spontaneous apoptosis in RPMI medium decreased from 51% https://www.selleckchem.com/products/z-vad-fmk.html in uninfected mice to 22,8% after infection and only 6.3% of CD4+ cells were in apoptosis after stimulation with F9. The percentage of apoptotic cells was reduced in all examined populations
of T cells; CD4+CD25−, CD4+CD25hi, CD3+CD8+ in MLN (Figure 4b). Cells isolated on day 12 post infection responded distinctly to complete antigen (AgS) and to each antigen fraction. Treatment of cells with fraction F9, F13 and F17 deeply reduced apoptosis. In contrast, when fractions F6 and F19 were added, the percentage of apoptotic cells increased (data not shown). The lowest level of apoptosis was observed in CD3+CD4+ population. Only 5% of cells underwent apoptosis after treatment with fraction F9. Apoptosis of CD4+CD25hi and CD3+CD8+ cells was higher, 30% and 18% respectively, but was still lower in infected than in control mice (Figure 4b). Fraction F9 contrary to F17, was the most potent to reduce the percentage of apoptotic cells of infected mice. Overall, H. polygyrus somatic antigen and its fractions inhibited apoptosis Tyrosine-protein kinase BLK both in naïve and infected mice. To examine apoptosis signalling pathways, apoptosis of MLN cells was induced by dexamethasone (DEX), a synthetic corticosteroid and by rTNF-α,
and the percentage of apoptotic cells was evaluated both in uninfected and infected mice. All examined cell populations were sensitive to DEX which induced apoptosis (Figure 5). In naïve mice, 60% of CD4+ cells were apoptotic and only AgS inhibited cell death; fractions F9 and F17 even increased the percentage of apoptotic cells. Response of CD4+CD25hi cells was also significant and after treatment with DEX more than 80% of cells underwent apoptosis. After infection with H. polygyrus apoptosis of these cells was reduced by 40% and even by 60% after restimulation with the nematode antigens. CD3+CD8+ cells were less sensitive to DEX and approximately 60% of cells were apoptotic. Apoptosis of these cells was inhibited both in control and infected mice after exposition to H. polygyrus antigens.