Seminal fluid factors modulate the female immune response at conception to facilitate embryo implantation and reproductive success. Whether sperm affect this response has not been clear. We evaluated global gene expression by microarray in the mouse uterus after mating with intact or vasectomized males. Intact males induced greater changes in gene transcription, prominently affecting pro-inflammatory cytokine and immune regulatory genes, with TLR4 signaling identified as a top-ranked upstream driver. Recruitment of neutrophils and expansion of peripheral regulatory T cells were elevated by seminal fluid of intact males. In vitro, epididymal sperm induced IL6, CXCL2, and CSF3 in uterine epithelial cells of wild-type, but not Tlr4 null females. Collectively these experiments show that sperm assist in promoting female immune tolerance by eliciting uterine cytokine expression through TLR4-dependent signaling. The findings indicate a biological role for sperm beyond oocyte fertilization, in modulating immune mechanisms involved in female control of reproductive investment.

There is a real need for simple structures that define a β-strand conformation, a secondary structure that is central to peptide-protein interactions. For example, protease substrates and inhibitors almost universally adopt this geometry on active site binding. A planar pyrrole is used to replace two amino acids of a peptide backbone to generate a simple macrocycle that retains the required geometry for active site binding. The resulting β-strand templates have reduced peptide character and provide potent protease inhibitors with the attachment of an appropriate amino aldehyde to the C-terminus. Picomolar inhibitors of cathepsin L and S are reported and the mode of binding of one example to the model protease chymotrypsin is defined by X-ray crystallography.

Animal models of cystic fibrosis (CF) are essential for investigating disease mechanisms and trialing potential therapeutics. This study generated two CF rat models using clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic repeatseassociated protein 9 gene editing. One rat model carries the common human Phe508del (DF508) CF transmembrane conductance regulator (CFTR) mutation, whereas the second is a CFTR knockout model. Phenotype was characterized using a range of functional and histologic assessments, including nasal potential difference to measure electrophysiological function in the upper airways, RNAscope in situ hybridization and quantitative PCR to assess CFTR mRNA expression in the lungs, immunohistochemistry to localize CFTR protein in the airways, and histopathologic assessments in a range of tissues. Both rat models revealed a range of CF manifestations, including reduced survival, intestinal obstruction, bioelectric defects in the nasal epithelium, histopathologic changes in the trachea, large intestine, and pancreas, and abnormalities in the development of the male reproductive tract. The CF rat models presented herein will prove useful for longitudinal assessments of pathophysiology and therapeutics.

To support embryo implantation, the female reproductive tract must provide a tolerogenic immune environment. Seminal fluid contact at conception contributes to activating the endometrial gene expression and immune cell changes required for robust implantation, influencing not only the quality of the ensuing pregnancy but also the health of offspring. miRNAs are small non-coding RNAs that play important regulatory roles in biological processes, including regulation of the immune environment. miRNAs are known to contribute to gene regulation in pregnancy and are altered in pregnancy pathologies. Recent studies indicate that miRNAs participate in establishing immune tolerance at conception, and may contribute to the regulatory effects of seminal fluid in generating tolerogenic dendritic cells and T regulatory cells. This review highlights those miRNAs implicated in programming immune cells that are critical during the peri-conception period and explores how seminal fluid may regulate female tract miRNA expression following coitus.

Paternal experiences and exposures prior to conception can influence fetal development and offspring phenotype. The composition of seminal plasma contributes to paternal programming effects, through modulating the female reproductive tract immune response after mating. To investigate whether paternal obesity affects seminal plasma immune-regulatory activity, C57Bl/6 male mice were fed an obesogenic high fat diet (HFD) or control diet (CD) for 14 weeks. While HFD consumption caused only minor changes to parameters of sperm quality, the volume of seminal vesicle fluid secretions was increased by 65%, and the concentrations and total content of immune-regulatory TGFB isoforms were decreased by 75-80% and 43-55% respectively. Mating with BALB/c females revealed differences in the strength and properties of the post-mating immune response elicited. Transcriptional analysis showed >300 inflammatory genes were similarly regulated in the uterine endometrium by mating independently of paternal diet, but 13 were dysregulated by HFD-fed compared to CD-fed males. Seminal vesicle fluid factors reduced in HFD-fed males, including TGFB1, IL10, and TNF, were amongst the predicted upstream regulators of differentially regulated genes. Additionally, the T cell response induced by mating with CD-fed males was blunted after mating with HFD-fed males, with 27% fewer CD4 + T cells, 26% fewer FOXP3 +CD4 + regulatory T cells (Treg) cells, and 19% fewer CTLA4 + Treg cells, particularly within the NRP1 + thymic Treg cell population. These findings demonstrate that an obesogenic high fat diet alters the composition of seminal vesicle fluid and impairs seminal plasma capacity to elicit a favorable pro-tolerogenic immune response in females at conception.