Global Transcriptomic Profiling of Bovine Endometrial Immune Response In Vitro. I. Effect of Lipopolysaccharide on Innate Immunity

The dysregulation of endometrial immune response to bacterial lipopolysaccharide (LPS) has been implicated in uterine disease and infertility in the postpartum dairy cow, although the mechanisms are not clear. Here, we investigated whole-transcriptomic gene expression in primary cultures of mixed bovine epithelial and stromal endometrial cells. Cultures were exposed to LPS for 6 h, and cellular response was measured by bovine microarray. Approximately 30% of the 1006 genes altered by LPS were classified as being involved in immune response. Cytokines and chemokines (IL1A, CX3CL1, CXCL2, and CCL5), interferon (IFN)-stimulated genes (RSAD2, MX2, OAS1, ISG15, and BST2), and the acute phase molecule SAA3 were the most up-regulated genes. Ingenuity Pathway Analysis identified up-regulation of many inflammatory cytokines and chemokines, which function to attract immune cells to the endometrium, together with vascular adhesion molecules and matrix metalloproteinases, which can facilitate immune cell migration from the tissue toward the uterine lumen. Increased expression of many IFN-signaling genes, immunoproteasomes, guanylate-binding proteins, and genes involved in the intracellular recognition of pathogens suggests important roles for these molecules in the innate defense against bacterial infections. Our findings confirmed the important role of endometrial cells in uterine innate immunity, whereas the global approach used identified several novel immune response pathways triggered by LPS in the endometrium. Additionally, many genes involved in endometrial response to the conceptus in early pregnancy were also altered by LPS, suggesting one mechanism whereby an ongoing response to infection may interfere with the establishment of pregnancy

Acute BVDV infection inhibits expression of interferon-stimulated genes during pregnancy recognition in bovine endometrium

Bovine viral diarrhea virus (BVDV) can evade host detection by downregulation of interferon signaling pathways. Infection of cows with noncytopathic (ncp) BVDV can cause early embryonic mortality. Upregulation of type I interferon stimulated genes (ISGs) by blastocyst-secreted interferon tau (IFNT) is a crucial component of the maternal recognition of pregnancy (MRP) in ruminants. This study investigated the potential of acute BVDV infection to disrupt MRP by modulating endometrial ISG expression. Endometrial cells from 10 BVDV-free cows were cultured and treated with 0 or 100 ng/ml IFNT for 24 h in the absence or presence of ncpBVDV infection to yield four treatment groups: CONT, ncpBVDV, IFNT, or ncpBVDV+IFNT. ncpBVDV infection alone only upregulated TRIM56, but reduced mRNA expression of ISG15, MX2, BST2, and the proinflammatory cytokine IL1B. As anticipated, IFNT treatment alone significantly increased expression of all 17 ISGs tested. In contrast to the limited effect of ncpBVDV alone, the virus markedly inhibited IFNT-stimulated expression of 15 ISGs tested (ISG15, HERC5, USP18, DDX58, IFIH1, IFIT1, IFIT3, BST2, MX1, MX2, RSAD2, OAS1Y, SAMD9, GBP4, and PLAC8), together with ISG15 secreted protein. Only TRIM56 and IFI27 expression was unaltered. IL1B expression was reduced by the combined treatment. These results indicate that acute ncpBVDV infection may decrease uterine immunity and lead to MRP failure through inhibition of IFNT-stimulated endometrial ISG production. This in turn could reduce fertility and predispose cows to uterine disease, while evasion of the normal uterine immune response by ncpBVDV may contribute to maintenance and spreading of this economically important disease

Importance of Viral Disease in Dairy Cow Fertility

Many viral diseases are endemic in cattle populations worldwide. The ability of many viruses to cross the placenta and cause abortions and fetal malformations is well understood. There is also significant evidence that viral infections have additional actions in dairy cows, which are reflected in reduced conception rates. These effects are, however, highly dependent on the time at which an individual animal first contracts the disease and are less easy to quantify. This paper reviews the evidence relating to five viruses that can affect fertility, together with their potential mechanisms of action. Acute infection with non-cytopathic bovine viral diarrhea virus (BVDV) in mid-gestation increases abortion rates or causes the birth of persistently infected calves. BVDV infections closer to the time of breeding can have direct effects on the ovaries and uterine endometrium, which cause estrous cycle irregularities and early embryo mortality. Fertility may also be reduced by BVDV-induced immunosuppression, which increases the susceptibility to bacterial infections. Bovine herpesvirus (BHV)-1 is most common in pre-pubertal heifers, and can slow their growth, delay breeding, and increase the age at first calving. Previously infected animals subsequently show reduced fertility. Although this may be associated with lung damage, ovarian lesions have also been reported. Both BHV-1 and BHV-4 remain latent in the host following initial infection and may be reactivated later by stress, for example associated with calving and early lactation. While BHV-4 infection alone may not reduce fertility, it appears to act as a co-factor with established bacterial pathogens such as Escherichia coli and Trueperella pyogenes to promote the development of endometritis and delay uterine repair mechanisms after calving. Both Schmallenberg virus (SBV) and bluetongue virus (BTV) are transmitted by insect vectors and lead to increased abortion rates and congenital malformations. BTV-8 also impairs the development of hatched blastocysts; furthermore, infection around the time of breeding with either virus appears to reduce conception rates. Although the reductions in conception rates are often difficult to quantify, they are nevertheless sufficient to cause economic losses, which help to justify the benefits of vaccination and eradication schemes

Mechanisms linking bovine viral diarrhea virus (BVDV) infection with infertility in cattle

Bovine viral diarrhea virus (BVDV) is an important infectious disease agent that causes significant reproductive and economic losses in the cattle industry worldwide. Although BVDV infection is known to cause poor fertility in cattle, a greater part of the underlying mechanisms particularly associated with early reproductive losses are not clearly understood. Previous studies reported viral compromise of reproductive function in infected bulls. In females, BVDV infection is thought to be capable of killing the oocyte, embryo or fetus directly, or to induce lesions that result in fetal abortion or malformation. BVDV infections may also induce immune dysfunction, and predispose cattle to other diseases that cause poor health and fertility. Other reports also suggested BVDV-induced disruption of the reproductive endocrine system, and a disruption of leukocyte and cytokine functions in the reproductive organs. More recent studies have provided evidence of viral-induced suppression of endometrial innate immunity that may predispose to uterine disease. Furthermore, there is new evidence that BVDV may potentially disrupt the maternal recognition of pregnancy or the immune protection of the conceptus. This review brings together the previous reports with the more recent findings, and attempts to explain some of the mechanisms linking this important virus to infertility in cattle

Global Transcriptomic Profiling of Bovine Endometrial Immune Response In Vitro. II. Effect of Bovine Viral Diarrhea Virus on the Endometrial Response to Lipopolysaccharide

Infection with noncytopathic bovine viral diarrhea virus (ncpBVDV) is associated with uterine disease and infertility. This study investigated the influence of ncpBVDV on immune functions of the bovine endometrium by testing the response to bacterial lipopolysaccharide (LPS). Primary cultures of mixed epithelial and stromal cells were divided into four treatment groups (control [CONT], BVDV, CONT+LPS, and BVDV+LPS) and infected with ncpBVDV for 4 days followed by treatment with LPS for 6 h. Whole-transcriptomic gene expression was measured followed by Ingenuity Pathway Analysis. Differential expression of 184 genes was found between CONT and BVDV treatments, showing interplay between induction and inhibition of responses. Up-regulation of TLR3, complement, and chemotactic and TRIM factors by ncpBVDV all suggested an ongoing immune response to viral infection. Down-regulation of inflammatory cytokines, chemokines, CXCR4, and serine proteinase inhibitors suggested mechanisms by which ncpBVDV may simultaneously counter the host response. Comparison between BVDV+LPS and CONT+LPS treatments showed 218 differentially expressed genes. Canonical pathway analysis identified the key importance of interferon signaling. Top down-regulated genes were RSAD2, ISG15, BST2, MX2, OAS1, USP18, IFIT3, IFI27, SAMD9, IFIT1, and DDX58, whereas TRIM56, C3, and OLFML1 were most up-regulated. Many of these genes are also regulated by IFNT during maternal recognition of pregnancy. Many innate immune genes that typically respond to LPS were inhibited by ncpBVDV, including those involved in pathogen recognition, inflammation, interferon response, chemokines, tissue remodeling, cell migration, and cell death/survival. Infection with ncpBVDV can thus compromise immune function and pregnancy recognition, thereby potentially predisposing infected cows to postpartum bacterial endometritis and reduced fertility

Bovine Endometrial Cells Mount Innate Immune Response to the Intracellular Ligands CL097 and Poly(dA:dT) Indicating Roles against Uterine Viruses

Uterine infection and endometritis cause infertility and economic losses in the cattle industry. The innate immune response of the endometrium is critical in the elimination of pathogenic organisms that invade the uterus in postpartum cows. This study investigated the response of bovine endometrium to synthetic intracellular ligands which activate innate immunity by stimulating similar receptors to those used to recognise the presence of some viruses. Mixed primary epithelial and stromal cell cultures were treated with 5 μg/ml of CL097 (a TLR7/8 ligand) or 2 μg/ml of poly(dA:dT) (a DNA analogue) for either 6 h or 24 h. Cellular responses were assessed by the mRNA expression of 18 immune-related genes and 3 endogenous reference genes by conventional PCR followed by qRT-PCR from four replicate experiments. Bovine endometrial cells expressed the cytosolic pattern recognition receptors (PRRs) DDX58 (RIG-I), IFIH1 (MDA5) and LRRFIP1 which act as intracellular nucleic acid sensors. Neither ligand altered the expression of the extra-cytosolic pattern recognition receptors (PRRs) TLR3, TLR4, TLR7 or TLR8 whereas poly(dA:dT) treatment increased the expression of IFIH1 and DDX58. Treated cells also responded to CL097 or poly(dA:dT) with a differential up-regulation of genes involved in innate immune response including type I interferon/antiviral response (MX1, IFNAR1), antimicrobial activity (MUC1, SLPI) and cytokine activity (TNF, IL1B, IL8). Bovine endometrial cells therefore express both cytosolic and extra-cytosolic intracellular PRRs and are able to mount an innate immune response upon stimulation with intracellular ligands. This suggests an important role for these cells in the defence against viruses that may be present in the uterus in postpartum cows

Antifungal susceptibility and test for cure of candida species among vulvovaginal candidiasis patients in a secondary care hospital, Nigeria

Background: Antimicrobial resistance among Candida species is an intense public health concern. The aim of the study was to determine the antifungal susceptibility pattern and test for cure of Candida species among women of child bearing age who visited the General Hospital Onitsha, Nigeria with symptoms suggestive of Vulvovaginal Candidiasis (VVC).Materials and Methods: Eight hundred and seventy six female patients participated in the study of which high vaginal swabs were collected and evaluated mycological by standard microbiological methods: microscopic examination and culture using sabouraud dextrose agar (SDA). Susceptibility of isolates to 4 antifungal agents was tested using agar dilution method. Clinicomycological evaluation was also performed among the patients.Result: Higher minimum inhibitory concentration (MIC) to azole antifungals was observed predominantly among non-albicans Candida species increasingly involved in VVC. The rate of mycological resolution was higher than symptomatic relief at 2 weeks after treatment with antifungal drug.Conclusion: Efficacious treatment of VVC requires an adequate knowledge of the causative agents and more importantly the antimicrobial to which they exhibit high susceptibility.Keywords: Vulvovaginal Candidiasis, Clinico- mycology, Antimicrobial resistance, Candida speciesSusceptibilite antifonique et test pour la cure d'especes de candida entre les patients de candidases vulvovaginales dans un hopital de soins secondaires, NigeriaContexte: La résistance aux antimicrobiens chez les espèces de Candida est un problème de santé publique intense. L'objectif de l'étude était de déterminer le schéma de susceptibilité aux antifongiques et le test de guérison des espèces de Candida parmi les femmes en âge de procréer qui ont visité l'hôpital général de Onitsha, au Nigeria, avec des symptômes suggérant une candidose vulvovaginale (VVC).Matériaux et méthodes: huit cent soixante-seize six patientes ont participé à l'étude des prélèvements vaginaux élevés collectés et évalués par mycologie par méthodes microbiologiques standard: examen microscopique et culture à l'aide de la gélose sabouraud dextrose (SDA). La susceptibilité des isolats à 4 agents antifongiques a été testée en utilisant une méthode de dilution en agar. Une évaluation clinico-mycologique a également été réalisée chez les patients.Résultat: une concentration minimale minimale d'inhibition (MIC) en anatoxines azoliques a été observée principalement chez les espèces non-albicans Candida de plus en plus impliquées dans VVC. Le taux de résolution mycologique était plus élevé que le soulagement symptomatique à 2 semaines après le traitement par un médicament antifongique.Conclusion: Un traitement efficace de la VVC nécessite une connaissance adéquate des agents causaux et, plus important encore, des antimicrobiens auxquels ils présentent une forte susceptibilité.Mots-clés: Candidiase Vulvovaginale, Clinico-mycologie, Résistance Antimicrobienne, Espèces Candid

BVDV alters uterine prostaglandin production during pregnancy recognition in cows

Embryonic mortality in cows is at least in part caused by failure of pregnancy recognition (PR). Evidence has shown that bovine viral diarrhoea virus (BVDV) infection can disrupt pregnancy. Prostaglandins (PG) play important roles in many reproductive processes, such as implantation. The aim of this study was to investigate the effect of BVDV infection on uterine PG production and PR using an in vitro PR model. Bovine uterine endometrial cells isolated from ten BVDV-free cows were cultured and treated with 0 or 100ng/mL interferon-τ (IFNT) in the absence or presence of non-cytopathic BVDV (ncpBVDV). PGF2α and PGE2 concentrations in the spent medium were measured using radioimmunoassays, and in the treated cells expression of the genes associated with PG production and signalling was quantified using qPCR. The results showed that the IFNT challenge significantly stimulated PTGS1 and PTGER3 mRNA expression and PGE2 production; however, these stimulatory effects were neutralised in the presence of ncpBVDV infection. ncpBVDV infection significantly increased PTGS1 and mPGES1 mRNA expression and decreased AKR1B1 expression, leading to increased PGE2 and decreased PGF2α concentrations and an increased PGE2:PGF2α ratio. The other tested genes, including PGR, ESR1, OXTR, PTGS2, PTGER2 and PTGFR, were not significantly altered by IFNT, ncpBVDV or their combination. Our study suggests that BVDV infection may impair PR by (1) inhibiting the effect of IFNT on uterine PG production and (2) inducing an endocrine switch of PG production from PGF2α to PGE2 to decrease uterine immunity, thereby predisposing the animals to uterine disease