Project description:Host gene and protein expression impact susceptibility to clinical malaria, but the balance of immune cell populations, cytokines and genes that contributes to protection, remains incompletely understood. To identify determinants of host susceptibility to clinical malaria at a time when acquired immunity is developing, we analyzed peripheral blood mononuclear cells (PBMCs) collected from children who differed in susceptibility to clinical malaria, all from a small town in Mali. PBMCs were collected from children aged 4-6 years at the start, peak and end of the malaria season. We characterized the immune cell composition and cytokine secretion for a subset of 20 children per timepoint (10 children with no symptomatic malaria age-matched to 10 children with >2 symptomatic malarial illnesses), and gene expression patterns for six children (three per cohort) per timepoint. We noted higher frequency of HLA-DR+ CD4 T cells in protected children during the peak of the malaria season and comparable levels cytokine secretion after stimulation with malaria schizonts across all three time points. We also observed differences between the two groups of children in the expression of genes related to cell death and inflammation; in particular, inflammatory genes such as CXCL10 and STAT1 and apoptotic genes such as XAF1 were upregulated in susceptible children before the transmission season began. This suggests that differences in apoptotic and inflammatory gene expression patterns can predict susceptibility to clinical malaria.
Project description:In malaria-naïve individuals, P. falciparum (Pf) infection results in numerous Pf-infected red blood cells (iRBCs) that trigger systemic inflammation and fever. Conversely, repeatedly infected individuals in endemic areas are often asymptomatic and have low levels of iRBCs, even children who have yet to acquire reliably protective antibodies. The molecular mechanisms underlying these clinical observations are unclear. PBMCs collected from Malian children before the malaria season responded to iRBCs by producing pyrogenic, pro-inflammatory mediators such as IL-1β, IL-6 and TNF. However, following febrile malaria there was a marked shift in the response to iRBCs with the same children's PBMCs producing lower levels of those cytokines. These data suggest that malaria-induced epigenetic reprogramming of innate immune cells may play a role in immunity to malaria. Accordingly, age-stratified analysis of monocytes collected before the malaria season showed an inverse relationship between age and pro-inflammatory cytokine production capacity.
Project description:The Sanaria® PfSPZ Vaccine can confer sterilizing protection against liver stage infection by Plasmodium falciparum (Pf) in malaria naïve individuals. The vaccine consists of aseptically purified irradiated Pf sporozoites. Vaccinees received 3 doses of 1.8 X 106 irradiated sporozoites. Efficacy was measured by challenged by controlled human malaria infections (CHMI), and against naturally occurring Pf Infections in Malian adults during the malaria transmission season
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
