Search

Acute‐phase neutralizing antibody (NAb) passive immunization in simian immunodeficiency virus (SIV)‐infected rhesus macaques (Macaca mulatta) can confer stringent viremia control with T‐cell augmentation. In one NAb‐infused SIV partial controller, we identify chronic‐phase Nef‐specific CD107a+ CD4+ T‐cell response maintenance, implicating that NAb infusion modulates long‐term T‐cell responses even within viremic control. [ABSTRACT FROM AUTHOR]

We hypothesised that CD8 SP + sp T cells have a greater cytotoxic potential in ITP patients who do not have detectable autoantibodies, compared to patients with autoantibodies. Autoantibody-negative ITP patients were not more likely to have high CD107a expression compared to autoantibody-positive patients (OR: 0-6, 95% CI: 0-1-3-5). Since CD107a expression in ITP patients was comparable with non-ITP, it is unclear whether the enhanced cytotoxic potential of CD8 SP + sp T cells in ITP is disease-specific. Whether or not ITP patients have CD8 SP + sp T cells specific to platelet autoantigens remains to be determined. [Extracted from the article]

The purpose of this study was to monitor abundance and activation of local CD8β-expressing T-cell populations during Eimeria tenella infections of naïve chickens and chickens immune by previous infections. Chickens were infected with E. tenella up to three times. Caecal T-cell receptor ( TCR) γ/δ- CD8β+ cells (cytotoxic T lymphocytes; CTL) and TCRγ/δ+ CD8β+ cells were characterized with respect to activation markers (blast transformation, CD25 and cell surface CD107a). Cells were also induced to degranulate in vitro as a measure of activation potential. Major findings included a prominent long-lasting, up to 6 weeks, increase in the proportion of CTL among caecal CD45+ cells in the later stages after primary E. tenella infection. These CTL also showed clear signs of activation, that is blast transformation and increased in vitro induced degranulation. At second and third E. tenella infection, chickens showed strong protective immunity but discrete signs of cellular activation were observed, for example increased in vitro induced degranulation of CTL. Thus, primary E. tenella infection induced clear recruitment and activation of local CTL. Upon subsequent infections of strongly immune chickens cellular changes were less prominent, possibly due to lower overall numbers of cells being activated because of the severe restriction of parasite replication. [ABSTRACT FROM AUTHOR]