Project description:Class-switching to IgG2a/c in mice is a hallmark response to intracellular pathogens. T cells can promote class-switching and the predominant pathway for induction of IgG2a/c antibody responses has been suggested to be via stimulation from Th1 cells. We previously formulated CAF®01 (cationic liposomes containing dimethyldioctadecylammonium bromide (DDA) and Trehalose-6,6-dibehenate (TDB)) with the lipidated TLR7/8 agonist 3M-052 (DDA/TDB/3M-052), which promoted robust Th1 immunity in newborn mice. When testing this adjuvant in adult mice using the recombinant Chlamydia trachomatis (C.t.) vaccine antigen CTH522, it similarly enhanced IgG2a/c responses compared to DDA/TDB, but surprisingly reduced the magnitude of the IFN-g+ Th1 response in a TLR7 agonist dose-dependent manner. Single cell RNA-sequencing revealed that DDA/TDB/3M-052 liposomes initiated early transcription of class-switch regulating genes directly in pre-germinal center B cells. Mixed bone marrow chimeras further demonstrated that this adjuvant did not require Th1 cells for IgG2a/c switching, but rather facilitated TLR7-dependent T-bet programming directly in B cells. This study underlines that adjuvant-directed IgG2a/c class-switching in vivo can occur in the absence of T cell help, via direct activation of TLR7 on B cells and positions DDA/TDB/3M-052 as a powerful adjuvant capable of eliciting type I-like immunity in B cells without strong induction of Th1 responses.
Project description:Tobacco smoking generates deleterious effects on human semen quality but mechanisms by which cigarettes smoking can impact spermatogenesis are poorly understood. Recent works have shown that spermatozoa RNAs can be used to understand mechanisms involved in tobacco induced spermatogenesis impairment. We performed a prospective study of 8 smoker and 8 non-smoker patients in an university hospital. All patients were selected according to an occupational exposure standardized questionnaire and the sperm parameters. We performed gene expression and miRNA microarrays using RNA extracts from spermatozoa of 8 smokers and 8 non-smokers. Quantification of selected miRNA was performed using quantitative RT-PCR. We show that 16 genes were differentially expressed between smokers and non-smokers, of which 5 were upregulated and 11 were down regulated in smokers. 23 microRNAs were differentially expressed, of which 16 were upregulated and 7 were down regulated in smokers. Quantitative RT-PCR confirmed the down regulation in smokers for 3 microRNAs. Moreover in smokers, one of the upregulated genes is a putative target for one down regulated microRNA. This is a preliminary and innovating study on spermatozoa RNA extracts in the field of infertility. This preliminary study shows that large scale approaches are non invasive diagnostic tools that may help elucidate the mechanisms that mediate the response to tobacco smoke exposure on human spermatogenesis. This could be used to design biomarkers of human spermatogenetic damage, and help elucidate the fine regulatory mechanisms that mediate responses to environmental agent exposure during human spermatogenesis.
Project description:Tobacco smoking generates deleterious effects on human semen quality but mechanisms by which cigarettes smoking can impact spermatogenesis are poorly understood. Recent works have shown that spermatozoa RNAs can be used to understand mechanisms involved in tobacco induced spermatogenesis impairment. We performed a prospective study of 8 smoker and 8 non-smoker patients in an university hospital. All patients were selected according to an occupational exposure standardized questionnaire and the sperm parameters. We performed gene expression and miRNA microarrays using RNA extracts from spermatozoa of 8 smokers and 8 non-smokers. Quantification of selected miRNA was performed using quantitative RT-PCR. We show that 16 genes were differentially expressed between smokers and non-smokers, of which 5 were upregulated and 11 were down regulated in smokers. 23 microRNAs were differentially expressed, of which 16 were upregulated and 7 were down regulated in smokers. Quantitative RT-PCR confirmed the down regulation in smokers for 3 microRNAs. Moreover in smokers, one of the upregulated genes is a putative target for one down regulated microRNA. This is a preliminary and innovating study on spermatozoa RNA extracts in the field of infertility. This preliminary study shows that large scale approaches are non invasive diagnostic tools that may help elucidate the mechanisms that mediate the response to tobacco smoke exposure on human spermatogenesis. This could be used to design biomarkers of human spermatogenetic damage, and help elucidate the fine regulatory mechanisms that mediate responses to environmental agent exposure during human spermatogenesis.