In such cases, IL-2-mediated bystander activation of these pre-activated CD25+ CD4+ T cells by Ag-stimulated Ag-specific CD4+ memory T cells, as suggested by Di Genova et al. 12, could occur and boost suboptimal responses ABT-888 solubility dmso of the former, thus favoring chronic inflammation and immunopathology 17. Although “classic” IFN/IL-15-mediated bystander activation provides an explanation as to how resting heterologous CD8+ T cells are recruited to an ongoing immune response, the IL-2-dependent type of bystander activation focuses on recently activated CD4+ T cells. As CD4+ T cells can differentiate into many different

functional subsets and exert diverse functions 13, such CD4+ T-cell bystander activation might affect immune homeostasis in a very different way as compared with bystander activation of CD8+ T cells. Thus, it will be of interest to Peptide 17 molecular weight further investigate the fate of CD4+ T cells stimulated by IL-2-mediated bystander activation, as IL-2 is known to exert somewhat opposing functions in the immune system, being able to either promote cell survival or favor apoptosis depending on the circumstances 13. Likewise, previous work on bystander proliferation of CD4+ T cells

has also described opposing outcomes such as prolonged survival or rapid cell death 18, 19. Future studies will have to address these outstanding issues. This work was supported by a grant from the Swiss National Science Foundation (♯320000-118471). Conflict of interest: The author declares no

financial or commercial conflict of interest. See accompanying article: http://dx.doi.org/10.1002/eji.200940017 “
“Currently, placentitis, an important cause of late pregnancy loss in mares, is diagnosed by clinical signs and ultrasonography. Acute phase proteins (APP) are mainly produced and secreted by the liver in response to acute inflammatory stimuli. We hypothesized that APP are increased in mares with placentitis. Concentrations of serum amyloid A (SAA), haptoglobin (Hp), Fossariinae fibrinogen (Fb), and white blood cell counts (WBC) were determined in plasma of mares with experimentally induced placentitis and gestationally age-matched control mares. Placentitis was induced via intracervical inoculation of Streptococcus equi subspecies zooepidemicus, a common isolate from clinical cases of bacterial placentitis. Concentrations of SAA and Hp were also determined in the 10 days pre-partum in normal mares. Mares with placentitis aborted within 5–25 days after inoculation. Concentrations of SAA and Hp rapidly increased subsequent to experimental induction of placentitis and remained increased until abortion. Neither Fb nor WBC appeared to be useful markers for placentitis. Parturition did not trigger increase in either SAA or Hp in normal foaling mares.