Cytokine mRNA profiling of peripheral blood mononuclear cells from trypanotolerant and trypanosusceptible cattle infected with Trypanosoma congolense

Expression profiling of cytokine genes in peripheral blood mononuclear cells from Anaplasma marginale infected and healthy cattle

In this study, changes in expression profiles of genes encoding 14 cytokines (IL1A, IL1B, IL2, IL4, IL6, IL8, IL10, IL12A, IL12B, IL16, IFNA, IFNB, TGFB1, and TNFA) were investigated amongst six Anaplasma marginale infected and six healthy crossbred cattle. Health status of the animals was determined based on clinical signs, blood smear examination and molecular detection using A. marginale-specific primers. Total RNA was isolated from the peripheral blood mononuclear cells of the infected animals as well as the healthy controls, which was further reverse transcribed to cDNA. Primers for real time PCR were designed using Primer3 software and the results were analyzed by the 2-ΔΔCt method with RPS15 and GAPDH as the reference genes. The expression levels of IL1A, IL1B, IL6, IL10, IL12A, IL12B, and TNFA varied significantly between the two groups, with higher expression in the infected cattle. The transcript abundance of IL4, IL16, and TGFB1 did not vary between the diseased and healthy animals. The expression of IL2 and IL8 was higher in the healthy animals, but the results were non-significant. Taken together, this study provides evidence for difference in expression of cytokine genes in response to anaplasmosis in crossbred cattle.

Unraveling the genetic mechanisms governing the host response to bovine anaplasmosis

Bovine anaplasmosis caused by Anaplasma marginale is a tick-borne disease of livestock with widespread prevalence and huge economic implications. In order to get new insights into modulation of host gene expression in response to natural infections of anaplasmosis, this study is the first attempt that compared the transcriptome profiles of peripheral blood mononuclear cells (PBMCs) of A. marginale infected and healthy crossbred cattle. Transcriptome analysis identified shared as well as unique functional pathways in the two groups. Translation and structural constituent of ribosome were the important terms for the genes abundantly expressed in the infected as well as healthy animals. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of the differentially expressed genes revealed that immunity and signal transduction related terms were enriched for the up-regulated genes in the infected animals. The over-represented pathways were cytokine-cytokine receptor interaction and signaling pathways involving chemokines, Interleukin 17 (IL17), Tumour Necrosis Factor (TNF), Nuclear Factor Kappa B (NFKB) etc. Interestingly, many genes previously associated with parasite-borne diseases such as amoebiasis, trypanosomiasis, toxoplasmosis, and leishmaniasis were profusely expressed in the dataset of the diseased animals. High expression was also evident for the genes for acute phase response proteins, anti-microbial peptides and many inflammatory cytokines. Role of cytokines in mediating communication between immune cells was the most conspicuous gene network identified through the Ingenuity Pathway Analysis. This study provides comprehensive information about the crosstalk of genes involved in host defense as well as parasite persistence in the host upon infection with A. marginale.

Nano Copper Supplementation Increases Superoxide Dismutase and Catalase Gene Expression Profiles and Concentration of Antioxidants and Immune Variables in Sahiwal Heifers

This study was conducted to evaluate the effect of inorganic and nano copper (nanoCu) supplementation on superoxide dismutase (SOD) and catalase (CAT) gene expression, antioxidant status, and immune response in growing Sahiwal heifers. Twenty-four Sahiwal heifers were allocated at random into four groups of six heifers in each groups and fed for 120 days. Feeding regimen was similar in all the groups except that treatment groups were supplemented with 0.0 mg Cu, 10.0 mg inorganic copper (inCu), and 5.0 and 10.0 mg of nanoCu per kg dry matter (DM) in four respective groups. Feed intake and growth performance were similar in growing Sahiwal heifers fed on basal diet with or without supplemental Cu. Antioxidative variables like SOD, CAT, ceruloplasmin (Cp), total antioxidant status (TAS), and glutathione peroxidase (GSH-Px) were found higher in Cu-supplemented groups than control. Variables like malondialdehyde (MDA) and lipid peroxidation (LPO) were found lower in treatment groups than control. Total immunoglobulins (total Ig) and immunoglobulin G (IgG) were higher in treatment groups than control, although interleukin-6 (IL-6) was similar in all groups. There were upregulation of mRNA expression of SOD and CAT genes in experimental animals fed on Cu-supplemented diet while mRNA expression of interleukin-6 (IL-6) and interleukin-10 (IL-10) genes was not altered by dietary treatment. The results suggest that the level of 5-ppm nanoCu can be selected for feeding in growing cattle as it exerts similar effects as showed by 10-ppm inorganic Cu.

Can Infectious Disease Control Be Achieved without Antibiotics by Exploiting Mechanisms of Disease Tolerance?

Antimicrobial use in animal agriculture may be contributing to the emerging public health crisis of antimicrobial resistance. The sustained prevalence of infectious diseases driving antimicrobial use industry-wide suggests that traditional methods of bolstering disease resistance are, for some diseases, ineffective. A paradigm shift in our approach to infectious disease control is needed to reduce antimicrobial use and sustain animal and human health and the global economy. Targeting the defensive mechanisms that promote the health of an infected host without impacting pathogen fitness, termed “disease tolerance,” is a novel disease control approach ripe for discovery. This article presents examples of disease tolerance dictating clinical outcomes for several infectious diseases in humans, reveals evidence suggesting a similarly critical role of disease tolerance in the progression of infectious diseases plaguing animal agriculture, and thus substantiates the assertion that exploiting disease tolerance mechanisms can positively impact animal and human health.

The COMBAT project: controlling and progressively minimizing the burden of vector-borne animal trypanosomosis in Africa

Vector-borne diseases affecting livestock have serious impacts in Africa. Trypanosomosis is caused by parasites transmitted by tsetse flies and other blood-sucking Diptera. The animal form of the disease is a scourge for African livestock keepers, is already present in Latin America and Asia, and has the potential to spread further. A human form of the disease also exists, known as human African trypanosomosis or sleeping sickness. Controlling and progressively minimizing the burden of animal trypanosomosis (COMBAT) is a four-year research and innovation project funded by the European Commission, whose ultimate goal is to reduce the burden of animal trypanosomosis (AT) in Africa. The project builds on the progressive control pathway (PCP), a risk-based, step-wise approach to disease reduction or elimination. COMBAT will strengthen AT control and prevention by improving basic knowledge of AT, developing innovative control tools, reinforcing surveillance, rationalizing control strategies, building capacity, and raising awareness. Knowledge gaps on disease epidemiology, vector ecology and competence, and biological aspects of trypanotolerant livestock will be addressed. Environmentally friendly vector control technologies and more effective and adapted diagnostic tools will be developed. Surveillance will be enhanced by developing information systems, strengthening reporting, and mapping and modelling disease risk in Africa and beyond. The socio-economic burden of AT will be assessed at a range of geographical scales. Guidelines for the PCP and harmonized national control strategies and roadmaps will be developed. Gender equality and ethics will be pivotal in all project activities. The COMBAT project benefits from the expertise of African and European research institutions, national veterinary authorities, and international organizations. The project consortium comprises 21 participants, including a geographically balanced representation from 13 African countries, and it will engage a larger number of AT-affected countries through regional initiatives.

The COMBAT project: controlling and progressively minimizing the burden of vector-borne animal trypanosomosis in Africa

Vector-borne diseases affecting livestock have serious impacts in Africa. Trypanosomosis is caused by parasites transmitted by tsetse flies and other blood-sucking Diptera. The animal form of the disease is a scourge for African livestock keepers, is already present in Latin America and Asia, and has the potential to spread further. A human form of the disease also exists, known as human African trypanosomosis or sleeping sickness. Controlling and progressively minimizing the burden of animal trypanosomosis (COMBAT) is a four-year research and innovation project funded by the European Commission, whose ultimate goal is to reduce the burden of animal trypanosomosis (AT) in Africa. The project builds on the progressive control pathway (PCP), a risk-based, step-wise approach to disease reduction or elimination. COMBAT will strengthen AT control and prevention by improving basic knowledge of AT, developing innovative control tools, reinforcing surveillance, rationalizing control strategies, building capacity, and raising awareness. Knowledge gaps on disease epidemiology, vector ecology and competence, and biological aspects of trypanotolerant livestock will be addressed. Environmentally friendly vector control technologies and more effective and adapted diagnostic tools will be developed. Surveillance will be enhanced by developing information systems, strengthening reporting, and mapping and modelling disease risk in Africa and beyond. The socio-economic burden of AT will be assessed at a range of geographical scales. Guidelines for the PCP and harmonized national control strategies and roadmaps will be developed. Gender equality and ethics will be pivotal in all project activities. The COMBAT project benefits from the expertise of African and European research institutions, national veterinary authorities, and international organizations. The project consortium comprises 21 participants, including a geographically balanced representation from 13 African countries, and it will engage a larger number of AT-affected countries through regional initiatives.

Effects of Red Ginseng Byproducts on Rumen Fermentation, Growth Performance, Blood Metabolites, and mRNA Expression of Heat Shock Proteins in Heat-Stressed Fattening Hanwoo Steers

The objective of this study was to evaluate the effects of dietary supplementation with red ginseng byproduct (RGB) on rumen fermentation, growth performance, blood metabolites, and mRNA expression of heat shock proteins (HSP) in fattening Hanwoo steers under heat stress. Two experimental total mixed rations (TMR) were prepared: (1) a TMR meeting the requirement of fattening beef having an average daily gain (ADG) 0.8 kg/day (CON) and (2) a TMR that included 2% RGB on a dry matter (DM) basis (GINSENG). In vitro rumen fermentation and in vivo growth experiments were conducted using two experimental diets. A total of 22 Hanwoo steers were distributed to two treatments (CON vs. GINSENG) in a completely randomized block design according to body weight (BW). The experiment was conducted during the summer season for five weeks. The final BW, ADG, DM intake, and feed conversion ratio did not differ between treatments in the growth trial. In the mRNA expression results, only HSP 90 showed an increasing tendency in the GINSENG group. The use of 2%DM RGB did not improve the growth performance or alleviate heat stress in fattening Hanwoo steers during the summer season.

Effects of intra-articular inoculation with Mycoplasma bovis on immunological responses in calf joints

Mycoplasma arthritis that caused by Mycoplasma bovis exhibit severe lameness. This disease is difficult to cure with antibiotics, but the detailed pathological mechanisms have not been fully clarified. In this study, we examined the effects of intra-articular inoculation with M. bovis on immunological responses in calf joints. We inoculated three calves each with M. bovis or phosphate buffer saline (control) into the right stifle joint and dissected them at 15 days postinoculation. Mycoplasma bovis-inoculated calves exhibited swelling of the stifle joint, increases in synovial fluid, fibrin deposition, and cartilage thinning. Intracellular M. bovis was detected in synovial tissues analyzed by immunohistochemistry and transmission electron microscopy. Messenger RNA expressions of interleukin (IL)-1β, IL-6, IL-8, IL-12p40, and IL-17A in synovial fluid cells and synovial tissues from M. bovis-inoculated calves were significantly higher than those from control calves. Protein levels of these cytokines in synovial fluid from M. bovis-inoculated calves were markedly higher than those from control calves. Our study clarified that inoculation with M. bovis into the stifle joint induced the production of inflammatory cytokines by synovial fluid cells and synovial tissues, causing a severe inflammatory response in joints. Additionally, M. bovis could invade cells in synovial tissues, which may have aided it in evading antibiotics and host immune surveillance.

Occurrence of foamy macrophages during the innate response of zebrafish to trypanosome infections

A tightly regulated innate immune response to trypanosome infections is critical to strike a balance between parasite control and inflammation-associated pathology. In this study, we make use of the recently established Trypanosoma carassii infection model in larval zebrafish to study the early response of macrophages and neutrophils to trypanosome infections in vivo. We consistently identified high- and low-infected individuals and were able to simultaneously characterise their differential innate response. Not only did macrophage and neutrophil number and distribution differ between the two groups, but also macrophage morphology and activation state. Exclusive to high-infected zebrafish, was the occurrence of foamy macrophages characterised by a strong pro-inflammatory profile and potentially associated with an exacerbated immune response as well as susceptibility to the infection. To our knowledge, this is the first report of the occurrence of foamy macrophages during an extracellular trypanosome infection.

Bovine trypanosomosis: Prevalence and vector distribution in Sadi Chanka district, Kellem Wollega zone, Oromia regional state, Ethiopia

Bovine trypanosomosis remains an important livestock disease constraint, which is threatening livestock health and production, despite ongoing tsetse and trypanosomosis control efforts in Sadi Chanka district, Kellem Wollega zone, Oromia regional state, Ethiopia. A cross-sectional study was conducted in May 2018, to determine the prevalence of bovine trypanosomosis and distribution of the vectors of disease in Sadi Chanka district, Western Ethiopia. A total of 370 blood samples were collected from randomly selected local Horro and Abigar cattle breeds covering five villages of the district. The collected samples were examined using buffy coat microscopy and Giemsa-stained thin blood smear techniques. In this study, 12.4% (95% CI: 12.3-12.4) of the animals were found to be infected with trypanosomes. The study showed that 69.6% of trypanosome infections were caused by T. congolense followed by 26.1% T. vivax and 4.3% mixed T. congolense and T. vivax. In the present study, the association of bovine trypanosomosis was assessed in releation to body condition scores, sex, and age of cattle, and a significant association (P < 0.05) was observed between body condition scores. However, significant differences were not observed between sex and age categories (P > 0.05). The Mean Packed Cell Volume (PCV) of infected (21.6%) and non-infected (24.5%) groups of cattle had significant variation (P < 0.05). In an entomological survey, a total of 616 flies were trapped, of which 280 (45.5%) were Glossina and the remaining 336 (54.5%) were Stomoxys, Tabanus, and Haematopota. The apparent density of Glossina, Stomoxys, Tabanus, and Haematopota was 3.5, 3.1, 0.7 and 0.4 fly per trap per day, respectively. This study generated basic scientific data on the epidemiology of bovine trypanosomosis and its vectors in Sadi Chanka district, which can be used in planning the control of bovine trypanosomosis in the area.

Characterization of bovine ileal epithelial cell line for lectin binding, susceptibility to enteric pathogens, and TLR mediated immune responses

In this study, primary and immortalized bovine intestinal epithelial cells (BIECs) were characterized for the expression of surface carbohydrate moieties. Primary BIEC-c4 cells showed staining greater than 90 % for 16 lectins but less than 50 % staining for four lectins. Immortalized BIECs showed significantly different lectin binding profile for few lectins compared to BIEC-c4 cells. BIEC-c4 cells were studied for infectivity to E. coli, Salmonella enterica, bovine rotavirus, bovine coronavirus, and bovine viral diarrhea virus. Bovine strain E. coli B41 adhered to BIEC-c4 cells and Salmonella strains S. Dublin and S. Mbandaka showed strong cell invasion. BIEC-c4 cells were susceptible to bovine rotavirus. LPS stimulation upregulated IL-10, IL-8, and IL-6 expression and Poly I:C upregulated TLR 8 and TLR 9 expression. This study provides important knowledge on the glycoconjugate expression profile of primary and immortalized BIECs and infectivity and immune responses of primary BIECs to bacterial and viral pathogens or ligands.

In Silico Identification of Novel Immunogenic Secreted Proteins of Mycoplasma bovis from Secretome Data and Experimental Verification

Mycoplasma bovis is a major pathogen, responsible for bovine respiratory diseases worldwide. The present lack of effective control measures leaves cattle owners at considerable perpetual risk of M. bovis outbreaks. In this study, we identified M. bovis secreted immunogenic proteins in silico as potential candidates for novel diagnostic agents and vaccines. We used immunoinformatics to analyze 438 M. bovis proteins previously identified with a label-free proteomics analysis of virulent M. bovis HB0801 (P1) and its attenuated P150 strains. The subcellular localization of these proteins was preliminarily screened and 59 proteins were found to be secreted extracellular proteins. Twenty-seven of these proteins contained a large number of predictive T-cell epitopes presented by major histocompatibility complex (MHC) class I and II molecules. Twenty-two of these 27 proteins had a high number of conformational B-cell epitopes, predicted from the corresponding 3D structural templates, including one unique to P1, two unique to P150, and 19 common to both strains. Five proteins were selected for further validation, and two of these, MbovP274 and MbovP570, were successfully expressed and purified. Both were confirmed to be secretory and highly immunogenic proteins that induced a mouse antibody response, reacted with cattle serum positive for M. bovis infection, and significantly increased the production of interleukin 8 (IL-8), IL-12 and interferon γ (IFN-γ) during the secretion of these three cytokines by both M. bovis mutants of these genes. These results should be useful in the development of novel immunological agents against M. bovis infection.

Effects of butyrate supplementation on blood glucagon-like peptide-2 concentration and gastrointestinal functions of lactating dairy cows fed diets differing in starch content

The objective of this study was to evaluate effects of butyrate supplementation on plasma concentration of glucagon-like peptide-2 (GLP-2), apparent total-tract digestibility, and responses to a grain challenge of lactating dairy cows fed diets differing in starch content. Eight Holstein cows averaging 58.6 ± 9.96 d in milk (4 primiparous cows fitted with rumen cannula and 4 multiparous intact cows) were blocked by parity and assigned to one of two 4 × 4 Latin squares balanced for carryover effects with a 2 × 2 factorial arrangement of treatments. Treatments were dietary starch content [20.6 vs. 27.5%, respectively, for low starch (LS) and high starch (HS)] and butyrate supplementation (butyrate vs. control) with 21-d periods. Butyrate was provided as Gustor BP70 WS (Norel, S.A., Madrid, Spain), containing 70% sodium butyrate and 30% fatty acid mixture, at 2% of dietary dry matter (providing butyrate at 1.1% of dietary dry matter), and control premix contained 70% wheat bran and 30% fatty acid mixture. Feeds, orts, and fecal samples were collected from d 17 to 19 to determine apparent total-tract nutrient digestibility. Blood and rumen fluid samples were collected on d 19. The baseline of dry matter intake (DMI) was determined as average DMI from d 17 to 19 for each cow, and cows were feed-restricted at 60% of the baseline DMI on d 20, and a grain challenge was conducted by providing steam-flaked corn grain at 0.6% of body weight, on an as-fed basis, in addition to each treatment diet on d 21, and blood and ruminal fluid samples were collected. The interaction of dietary starch content by butyrate supplementation was significant for plasma GLP-2 concentration, being greater for cows fed butyrate with the HS diet than those fed the other 3 diets. Cows fed butyrate increased n-butyrate concentration in the ruminal fluid and tended to increase dry matter and organic matter digestibility compared with the control. During the grain challenge, rumen endotoxin concentration increased over time and was higher for cows fed the HS diets compared with those fed LS diets. However, response variables related to inflammation were not affected by the grain challenge. However, serum haptoglobin, lipopolysaccharide-binding protein, and serum amyloid-A concentrations were greater for cows fed butyrate with the LS diet, but not for those fed the HS diet. These results indicate that butyrate supplementation may increase plasma GLP-2 concentration for cows fed HS diets, and total-tract digestibility regardless of dietary starch content. However, butyrate supplementation did not mitigate inflammation in this study.

Effect of Mycoplasma bovis on expression of inflammatory cytokines and matrix metalloproteinases mRNA in bovine synovial cells

Mycoplasma bovis causes chronic arthritis in calves. Mycoplasma arthritis shows severe inflammatory reactions in joints that is commonly treated with antibiotics and results in significant economic losses in the calf industry. A previous study showed that inflammatory cytokines and matrix metalloproteinases (MMPs) produced by synovial cells promote progression of the pathophysiology of bacterial arthritis. However, the mechanism underlying the pathogenesis of bovine Mycoplasma arthritis has not been fully clarified. In this study, we examined the immunologic response of bovine synovial tissue to M. bovis. We observed significant increases in expression of interleukin (IL)-1β, IL-6, IL-8, MMP-1, and MMP-3 mRNA in synovial tissue from Mycoplasma arthritis calves compared with tissues from normal calves. Expression of IL-6, IL-8, and MMP-1 mRNA was also induced in cultured synovial cells stimulated with M. bovis, but not expression of IL-1β and MMP-3 mRNA. In contrast, the culture supernatant of peripheral blood mononuclear cells stimulated with M. bovis induced marked increases in the expression of IL-1β, IL-6, IL-8, MMP-1, and MMP-3 mRNA in synovial cells. Our results indicate that inflammatory cytokines and MMPs produced by synovial cells play a key role in the pathogenesis of Mycoplasma arthritis. We suggest that interactions between synovial cells and mononuclear cells in the presence of M. bovis induce expression of these cytokines and MMPs in synovial cells, resulting in severe inflammatory reactions in the joints.

Salivarian Trypanosomosis: A Review of Parasites Involved, Their Global Distribution and Their Interaction With the Innate and Adaptive Mammalian Host Immune System

Salivarian trypanosomes are single cell extracellular parasites that cause infections in a wide range of hosts. Most pathogenic infections worldwide are caused by one of four major species of trypanosomes including (i) Trypanosoma brucei and the human infective subspecies T. b. gambiense and T. b. rhodesiense, (ii) Trypanosoma evansi and T. equiperdum, (iii) Trypanosoma congolense and (iv) Trypanosoma vivax. Infections with these parasites are marked by excessive immune dysfunction and immunopathology, both related to prolonged inflammatory host immune responses. Here we review the classification and global distribution of these parasites, highlight the adaptation of human infective trypanosomes that allow them to survive innate defense molecules unique to man, gorilla, and baboon serum and refer to the discovery of sexual reproduction of trypanosomes in the tsetse vector. With respect to the immunology of mammalian host-parasite interactions, the review highlights recent findings with respect to the B cell destruction capacity of trypanosomes and the role of T cells in the governance of infection control. Understanding infection-associated dysfunction and regulation of both these immune compartments is crucial to explain the continued failures of anti-trypanosome vaccine developments as well as the lack of any field-applicable vaccine based anti-trypanosomosis intervention strategy. Finally, the link between infection-associated inflammation and trypanosomosis induced anemia is covered in the context of both livestock and human infections.

Host Intracellular Signaling Events and Pro-inflammatory Cytokine Production in African Trypanosomiasis

Pathogens, such as bacteria, viruses, and parasites, possess specific molecules or proteins that are recognized by several host innate immune receptors, leading to the activation of several intracellular signaling molecules and pathways. The magnitude and quality of these events significantly affect the outcome of infection. African trypanosomes, including Trypanosoma congolense, are capable of manipulating the host immune response, including the activity of macrophages, which are the key immune cells that contribute to the immunopathogenesis of African trypanosomiasis. Although it is known that immune hyperactivation and excessive pro-inflammatory cytokine production are the hallmarks of African trypanosomiasis, the mechanisms through which these events are triggered are poorly defined. However, it is known that macrophages may play a significant role in these processes, because phagocytosis of trypanosomes by macrophages initiates intracellular signal transduction cascades that lead to the release of pro-inflammatory cytokines and alteration in cell function. This review highlights recent progress in our understanding of the innate immune receptors, signaling pathways, and transcription factors involved in T. congolense-induced pro-inflammatory cytokine production in macrophages. It will reveal the existence of complex signaling events through which the parasite modulates the host immune response, thus identifying novel targets that could aid in designing strategies to effectively control the disease.

TNF-alpha in bulls experimentally infected with Trypanosoma vivax: a pilot study

There are few studies about the immune response during trypanosomosis in cattle. The objective of this research was to evaluate the effect of experimental infection with Trypanosoma vivax (T. vivax) on serum levels of TNF-alpha in bulls and its relationship to hematocrit, body temperature and parasitemia. Two adult crossbred bulls were infected experimentally with T. vivax and two were used as controls. The bulls were evaluated during a 64 day period in terms of temperature, hematocrit, and parasitemia. Serum TNF-alpha levels were determined by ELISA, using an antibody specific for bovine. TNF-alpha in serum began rising on the seventh day after infection and reached a peak on day 40 of post-infection, then dropped. The lowest hematocrit levels corresponded to the upper levels of TNF-alpha, for each animal. In conclusion, the experimental infection of cattle with T. vivax promotes the release of TNF-alpha, demonstrating a pro-inflammatory immune response to this hemotropic parasite. Moreover, the lowest hematocrit levels coincide with high concentrations of TNF-alpha, suggesting that this cytokine can be linked to the observed anemia during the course of infection by T. vivax in cattle.

miR-466 is putative negative regulator of Coxsackie virus and Adenovirus Receptor

This study aimed at elucidating how Coxsackie B virus (CVB) perturbs the host's microRNA (miRNA) regulatory pathways that lead to antiviral events. The results of miRNA profiling in rat pancreatic cells infection models revealed that rat rno-miR-466d was up-regulated in CVB infection. Furthermore, in silico studies showed that Coxsackie virus and Adenovirus Receptor (CAR), a cellular receptor, was one of the rno-miR-466d targets involved in viral entry. Subsequent experiments also proved that both the rno-miR-466d and the human hsa-miR-466, which are orthologs of the miR-467 gene family, could effectively down-regulate the levels of rat and human CAR protein expression, respectively.

Hemophagocytic lymphohistiocytosis (HLH): A heterogeneous spectrum of cytokine-driven immune disorders

Hemophagocytic lymphohistiocytosis (HLH) comprises a group of life-threatening immune disorders classified into primary or secondary HLH. The former is caused by mutations in genes involved in granule-mediated cytotoxicity, the latter occurs in a context of infections, malignancies or autoimmune/autoinflammatory disorders. Both are characterized by systemic inflammation, severe cytokine storms and immune-mediated organ damage. Despite recent advances, the pathogenesis of HLH remains incompletely understood. Animal models resembling different subtypes of HLH are therefore of great value to study this disease and to uncover novel treatment strategies. In this review, all known animal models of HLH will be discussed, highlighting findings on cell types, cytokines and signaling pathways involved in disease pathogenesis and extrapolating therapeutic implications for the human situation.

A novel qPCR assay for the detection of African animal trypanosomosis in trypanotolerant and trypanosusceptible cattle breeds

This study was conducted to (i) determine the prevalence of African Animal Trypanosomosis (AAT) in tsetse challenged areas, (ii) compare conventional with qPCR detection systems and (iii) evaluate the host genetic background and biology as risk factors. AAT prevalence studies are often confronted with low levels of parasitaemia. Hence, we designed a novel qPCR assay using primers and species specific probes amplifying the Internal Transcribed Spacer 1 (ITS1) gene. Thereby all three AAT species could be detected simultaneously. 368 individuals from three cattle types (Baoulé, Zebu and hybrids) originating from 72 farms in Burkina Faso were analysed. Farmers were interviewed and morphometric measurements of the cattle taken. A chi-squared test and a logistic regression model were calculated to detect associations with infection. In our study, the overall rate of prevalence detected with the novel qPCR assay was 11.14%. Compared to conventional PCR we identified a concordance of 91.30%. We tested 41 animals positive for trypanosome DNA, five animals showed multiple infections. Zebus were twice as often infected (21.74%) compared to Baoulé (9.70%) and hybrids (9.57%). Trypanosoma vivax is the dominant species (9.24%), as compared to T. congolense (2.44%) and T. brucei (0.82%). The chi-squared tests linking the infection events to the breeds (Zebu vs. Baoulé and Zebu vs. hybrids) were on the border of significance. No significant association with other tested parameters could be detected. We introduce a novel qPCR technique for the fast, sensitive and simultaneous detection of the three AAT species. Our results suggest that associations with breed and infection exist since Zebu cattle are more likely to be infected compared to Baoulé and hybrids. Indigenous taurine cattle breeds, like the Baoulé, therefore provide a unique and valuable genetic resource.

African Animal Trypanosomosis (AAT) is a neglected tropical disease heavily impacting on the poor. Sensitive diagnostic tools are needed since actual parasitaemia levels can be very low, particularly in chronically infected or trypanotolerant animals. Hence, we present a novel real-time PCR (qPCR) assay for the simultaneous detection of the three AAT species (T. congolense, T. brucei and T. vivax). Thereby infected animals can be accurately detected in one step. 368 individuals from three cattle types (Baoulé, Zebu and hybrids) originating from 72 farms in Burkina Faso were analysed. Farmers were interviewed and morphometric measurements of the cattle taken to detect potential risk factors of infection. In our study, the overall rate of prevalence detected with the novel qPCR assay was 11.14% (41/368) compared to 10.87% (40/368) with conventional PCR. Zebus are most often infected (21.74%) compared to Baoulé (9.70%) and hybrid (9.57%) cattle. Except for breed, no significant correlation with other tested parameters could be detected. Baoulé show significantly less infections and therefore provide a unique and valuable genetic resource. In summary, with this novel qPCR technique the three AAT species can be simultaneously detected in a fast and sensitive manner.

Effect of avian influenza A H5N1 infection on the expression of microRNA-141 in human respiratory epithelial cells

BACKGROUND

Avian influenza remains a serious threat to human health. The consequence of human infection varies markedly among different subtypes of avian influenza viruses. In addition to viral factors, the difference in host cellular response is likely to play a critical role. This study aims at elucidating how avian influenza infection perturbs the host's miRNA regulatory pathways that may lead to adverse pathological events, such as cytokine storm, using the miRNA microarray approach.

RESULTS

The results showed that dysregulation of miRNA expression was mainly observed in highly pathogenic avian influenza A H5N1 infection. We found that miR-21*, miR-100*, miR-141, miR-574-3p, miR-1274a and miR1274b were differentially expressed in response to influenza A virus infection. Interestingly, we demonstrated that miR-141, which was more highly induced by H5N1 than by H1N1 (p < 0.05), had an ability to suppress the expression of a cytokine - transforming growth factor (TGF)-β2. This was supported by the observation that the inhibitory effect could be reversed by antagomiR-141.

CONCLUSIONS

Since TGF-β2 is an important cytokine that can act as both an immunosuppressive agent and a potent proinflammatory molecule through its ability to attract and regulate inflammatory molecules, and previous report showed that only seasonal influenza H1N1 (but not the other avian influenza subtypes) could induce a persistent expression of TGF-β2, we speculate that the modulation of TGF-β2 expression by different influenza subtypes via miR-141 might be a critical step for determining the outcome of either normal or excessive inflammation progression.

Moderate and high intensity sprint exercise induce differential responses in COX4I2 and PDK4 gene expression in Thoroughbred horse skeletal muscle

REASONS FOR PERFORMING STUDY

The role of molecular signalling pathways in the phenotypic adaptation of skeletal muscle to different exercise stimuli in the Thoroughbred horse has not been reported previously.

OBJECTIVE

To examine CKM, COX4I1, COX4I2 and PDK4 gene expression following high intensity sprint and moderate intensity treadmill exercise stimuli in skeletal muscle of Thoroughbred horses.

MATERIALS AND METHODS

Two groups of trained 3-year-old Thoroughbred horses participated. Group A (n = 6 females, n = 3 males) participated in an incremental step test (moderate intensity) to fatigue or HR(max) on a Sato high speed treadmill (distance = 5418.67 m ± 343.21). Group B (n = 8 females) participated in routine 'work' (sprint) on an all-weather gallop (distance = 812.83 m ± 12.53). Biopsy samples were obtained from the gluteus medius pre-exercise (T(0)), immediately post exercise (T(1)) and 4 h post exercise (T(2)). For physiological relevance venous blood samples were collected to measure plasma lactate and creatine kinase concentrations. Changes in mRNA expression were determined by quantitative real-time RT-PCR for creatine kinase muscle (CKM), cytochrome c oxidase subunit IV isoform 1 (COX4I1), cytochrome c oxidase subunit IV isoform 2 (COX4I2) and pyruvate dehydrogenase kinase, isozyme 4 (PDK4) genes. Statistical significance (α < 0.05) was determined using Student's t tests.

RESULTS

COX4I2 mRNA expression decreased significantly in Group A and remained unchanged in Group B between T(0) vs. T(2) (-1.7-fold, P = 0.017; -1.0-fold, P = 0.859). PDK4 mRNA expression increased significantly in Group B but not in Group A between T(0) vs. T(1) (3.8-fold, P = 0.039; 1.4-fold, P = 0.591). There were no significant changes in the expression in CKM or COX4I1 mRNA abundance in either group.

CONCLUSIONS

Different exercise protocols elicit variable transcriptional responses in key exercise relevant genes in equine skeletal muscle due to variation in metabolic demand.

The evolution of tropical adaptation: comparing taurine and zebu cattle

Beef cattle breeds consist of three major genetic subdivisions. The taurine group is adapted to temperate environments, and the zebu and Sanga groups are both adapted to tropical environments. With the advent of genotyping and sequencing technologies in agriculture, genome-wide exploration of the genetic basis for the differences in tropical adaptation has only just become possible. In this study, approximately 9000 single nucleotide polymorphism markers were genotyped on 317 animals of a selection of taurine, zebu, and composite breeds to characterize any systematic differences between these groups. We identified 91 intra-breed-class markers; 78 were polymorphic only within the zebu animals, while 13 were polymorphic only in the taurine animals. There were no fixed differences (fixed for alternate alleles between the two breed types) between zebu and taurine animals. We found 14 regions with significantly different allele frequencies between zebu and taurine animals indicative of variable selection pressure or genetic drift. We also found 12 independent regions of differential extended haplotype homozygosity (EHH), indicative of recent selection or rapid fixation of the alternate allele within a short period of time in one of the two breed classes. A preliminary functional genomics analysis of these regions pointed towards signatures of tropical attributes including keratins, heat-shock proteins and heat resistance genes. We anticipate this investigation to be a stepping-stone for future studies to identify genomic regions specific to the two cattle groups, and to subsequently assist in the discrimination between temperate and tropically adapted cattle.

Effect of dietary n-3 polyunsaturated fatty acid supplementation on bovine uterine endometrial and hepatic gene expression of the insulin-like growth factor system

Supplementation of cattle diets with n-3 polyunsaturated fatty acids (n-3 PUFA) has been suggested to have positive effects on fertility. In addition, the actions of the insulin-like growth factor (IGF) system both systemically and locally have been shown to influence reproductive processes. The objective of this study was to evaluate the effect of dietary n-3 PUFA supplementation on hepatic and endometrial expression of IGF signalling genes in cattle. Beef heifers were supplemented with a rumen protected source of either a saturated fatty acid (palmitic acid; CON) or high n-3 PUFA diet (n-3 PUFA) for 45 days before slaughter and tissue recovery. Transcription level of candidate IGF signalling genes was measured by reverse transcription quantitative real-time PCR (RT-qPCR) in total RNA isolated from uterine endometrial and liver tissue from seven CON and seven n-3 PUFA supplemented animals. Compared to controls, mRNA abundance in n-3 PUFA liver tissues was higher for IGF-2R, IGFBP-1 and IGFBP-5 (P < 0.05); lower for GHR-1A (P < 0.05); and unchanged for IGF-1, IGF-2, IGF-1R, IGFBP-2, IGFBP-3, IGFBP-4, IGFBP-6, ALS and GHR(total) (P > 0.05). Compared to controls, mRNA abundance in n-3 PUFA endometrial tissues was higher for IGF-2, IGF-1R, IGF-2R and IGFBP-2 (P < 0.05); lower for IGF-1, IGFBP-3 and IGFBP-6 (P < 0.05); and unchanged for IGFBP-1, IGFBP-4, IGFBP-5 and GHR(total) (P > 0.05). Thus, dietary supplementation of cattle with n-3 PUFA affects transcription of genes involved in IGF signalling, in a tissue dependent fashion.

Profiles of cytokine and chemokine gene expression in human pulmonary epithelial cells induced by human and avian influenza viruses

Influenza pandemic remains a serious threat to human health. In this study, the repertoire of host cellular cytokine and chemokine responses to infections with highly pathogenic avian influenza H5N1, low pathogenicity avian influenza H9N2 and seasonal human influenza H1N1 were compared using an in vitro system based on human pulmonary epithelial cells. The results showed that H5N1 was more potent than H9N2 and H1N1 in inducing CXCL-10/IP-10, TNF-alpha and CCL-5/RANTES. The cytokine/chemokine profiles for H9N2, in general, resembled those of H1N1. Of interest, only H1N1, but none of the avian subtypes examined could induce a persistent elevation of the immune-regulatory cytokine - TGF-β2. The differential expression of cytokines/chemokines following infection with different influenza viruses could be a key determinant for clinical outcome. The potential of using these cytokines/chemokines as prognostic markers or targets of therapy is worth exploring.

mRNA expression of genes regulating oxidative phosphorylation in the muscle of beef cattle divergently ranked on residual feed intake

Our objective was to evaluate the effects of phenotypic ranking on residual feed intake (RFI) on the transcription of genes 1) involved in the respiratory chain complex and 2) coding for transcriptional factors regulating mitochondrial biogenesis, across two contrasting diet types. Beef heifers (n = 86) fed a diet comprising 70:30 concentrate-corn silage [low forage (LF)] over a 82-day period were ranked on RFI. The 10 highest (feed inefficient, high-RFI) and 10 lowest (feed efficient, low-RFI) ranking animals were selected for the current study. Biopsies of the M. longissimus dorsi were harvested following initial selection (LF diet) and again following a 6 wk period while the animals were offered a high-forage (HF) grass silage-only diet. Real-time PCR was used to quantify mRNA transcripts of 17 genes associated with cellular energetic efficiency. The mRNA expression of UCP3 tended to be upregulated (2.2-fold, P = 0.06) for the high-RFI compared with the low-RFI animals. mRNA transcripts coding for the transcription factor PGC-1α was 1.7-fold higher (P = 0.01) in low compared with high-RFI animals. A phenotype × diet interaction was evident for the abundance of ANT1 mRNA transcript, with greater (P = 0.04) expression levels detected in the low-RFI phenotype during the HF period, but no difference (P = 0.50) between phenotypes during the LF period. A phenotype × diet interaction was also evident for COX II with greater expression levels detected (P = 0.04) in the low compared with the high RFI phenotype while on LF but not the HF diet (P = 0.22). These data suggest an association between cellular energetic efficiency and RFI in cattle.

Trypanosoma vivax infections: pushing ahead with mouse models for the study of Nagana. II. Immunobiological dysfunctions

Trypanosoma vivax is the main species involved in trypanosomosis, but very little is known about the immunobiology of the infective process caused by this parasite. Recently we undertook to further characterize the main parasitological, haematological and pathological characteristics of mouse models of T. vivax infection and noted severe anemia and thrombocytopenia coincident with rising parasitemia. To gain more insight into the organism's immunobiology, we studied lymphocyte populations in central (bone marrow) and peripherical (spleen and blood) tissues following mouse infection with T. vivax and showed that the immune system apparatus is affected both quantitatively and qualitatively. More precisely, after an initial increase that primarily involves CD4⁺ T cells and macrophages, the number of splenic B cells decreases in a step-wise manner. Our results show that while infection triggers the activation and proliferation of Hematopoietic Stem Cells, Granulocyte-Monocyte, Common Myeloid and Megacaryocyte Erythrocyte progenitors decrease in number in the course of the infection. An in-depth analysis of B-cell progenitors also indicated that maturation of pro-B into pre-B precursors seems to be compromised. This interferes with the mature B cell dynamics and renewal in the periphery. Altogether, our results show that T. vivax induces profound immunological alterations in myeloid and lymphoid progenitors which may prevent adequate control of T. vivax trypanosomosis.

Trypanosoma vivax is responsible for animal trypanosomosis, or Nagana, in cattle and small ruminants. Under experimental conditions, the outbred mouse model infected with a well studied West African T. vivax isolate reproduces the main characteristics of the infection and pathology observed in livestock. Anemia and non-specific (parasite-directed) polyclonal hypergammaglobulinemia are the most common disorders coincident with the rise in parasitemia. Our results presented here show that the decrease in peripheral B cell populations does not seem to be compensated by newly arriving B cells from the bone marrow. The infection nevertheless prompts intense production of stem cells that mature into myeloid and lymphoid precursors. In spite of this, B cell numbers are specifically reduced in the periphery as the infection progresses. Thus, negative feedback seems to be set in motion by the infection in the bone marrow, more precisely affecting the maturation of B precursors and consequently the output of mature B cells. The origin of these phenomena is unclear but this doubtless creates a homeostatic imbalance that contributes to the inefficient immune response against T. vivax infection.

Differential levels of mRNA transcripts encoding immunologic mediators in mammary gland secretions from dairy cows with subclinical environmental Streptococci infections

Dry-off, and the period around parturition, are associated with increased susceptibility to intramammary infections in dairy cows. The immunological profiles of mammary gland secretions during these periods are not well described. The objective of the present study was to better characterize association(s) between chronic subclinical Environmental Streptococci infections at dry-off and relative levels of mRNA transcripts encoding multiple immunologic mediators present in cells derived from mammary gland secretions at dry-off and continuing through parturition. The chronic subclinical bacterial infections in the present study were characterized by multiple isolations of Streptococcus species and elevated SSC for a minimum of three weeks prior to dry-off. The majority of differences between principal and control quarters were identified at dry-off. Transcript levels of IL-17, IL2Rα and iNOS were increased while pro-inflammatory cytokine IL-6, and the regulatory cytokine IL-10, were reduced. Following antibiotic treatment of mammary glands, IL-17 transcripts remained elevated over the course of the study, indicative of a persistent insult. IL-4 transcript levels were modestly elevated at 7 days following dry-off and significantly elevated at 14 days, consistent with activated T(H)1 and T(H)2 lymphocytes in the principal quarters, respectively. From a temporal perspective, transcript levels of IL-8 decreased in all animals through the dry-off period animals and returned to pre-dry-off levels at parturition; levels of iNOS peaked at parturition. Five of the six principal cows experienced recurrent bacterial mastitis during the subsequent lactation; four were in the same quarter as was initially infected with Streptococcus and three of these four were due to coliforms. Taken together, this apparent chronic susceptibility of select mammary glands to bacterial infection would suggest a physiologic and/or immunologic dysfunction. Identification of factor(s) that contribute to the predisposition of mammary glands to developing mastitis should facilitate development of new control strategies.

Peripheral and gastrointestinal immune systems of healthy cattle raised outdoors at pasture or indoors on a concentrate-based ration

Background

Despite an increasing preference of consumers for beef produced from more extensive pasture-based production systems and potential human health benefits from the consumption of such beef, data regarding the health status of animals raised on pasture are limited. The objective of this study was to characterise specific aspects of the bovine peripheral and the gastrointestinal muscosal immune systems of cattle raised on an outdoor pasture system in comparison to animals raised on a conventional intensive indoor concentrate-based system.

Results

A number of in vitro functional tests of immune cells suggested subtle differences between the animals on the outdoor versus indoor production systems. There was a decrease in the number of neutrophils and monocytes engaged in phagocytosis in outdoor cattle (P < 0.01 and P < 0.05, respectively) in comparison to those indoors. Following mitogen stimulation, a lower level of interferon-γ was produced in leukocytes from the outdoor animals (P < 0.05). There was evidence of a gastrointestinal nematode infection in the outdoor animals with elevated levels of serum pepsinogen (P < 0.001), a higher number of eosinophils (P < 0.05) and a higher level of interleukin-4 and stem cell factor mRNA expression (P < 0.05) in the outdoor animals in comparison to the indoor animals. Lower levels of copper and iodine were measured in the outdoor animals in comparison to indoor animals (P < 0.001).

Conclusion

Despite distinctly contrasting production systems, only subtle differences were identified in the peripheral immune parameters measured between cattle raised at pasture in comparison to animals raised on a conventional intensive indoor concentrate-based production system.

Role for parasite genetic diversity in differential host responses to Trypanosoma brucei infection

The postgenomic era has revolutionized approaches to defining host-pathogen interactions and the investigation of the influence of genetic variation in either protagonist upon infection outcome. We analyzed pathology induced by infection with two genetically distinct Trypanosoma brucei strains and found that pathogenesis is partly strain specific, involving distinct host mechanisms. Infections of BALB/c mice with one strain (927) resulted in more severe anemia and greater erythropoietin production compared to infections with the second strain (247), which, contrastingly, produced greater splenomegaly and reticulocytosis. Plasma interleukin-10 (IL-10) and gamma interferon levels were significantly higher in strain 927-infected mice, whereas IL-12 was higher in strain 247-infected mice. To define mechanisms underlying these differences, expression microarray analysis of host genes in the spleen at day 10 postinfection was undertaken. Rank product analysis (RPA) showed that 40% of the significantly differentially expressed genes were specific to infection with one or the other trypanosome strain. RPA and pathway analysis identified LXR/RXR signaling, IL-10 signaling, and alternative macrophage activation as the most significantly differentially activated host processes. These data suggest that innate immune response modulation is a key determinant in trypanosome infections, the pattern of which can vary, dependent upon the trypanosome strain. This strongly suggests that a parasite genetic component is responsible for causing disease in the host. Our understanding of trypanosome infections is largely based on studies involving single parasite strains, and our results suggest that an integrated host-parasite approach is required for future studies on trypanosome pathogenesis. Furthermore, it is necessary to incorporate parasite variation into both experimental systems and models of pathogenesis.

Divergent antimicrobial peptide (AMP) and acute phase protein (APP) responses to Trypanosoma congolense infection in trypanotolerant and trypanosusceptible cattle

African animal trypanosomiasis (AAT) is endemic across Sub-Saharan African and is a major constraint to livestock production. The ability of certain cattle breeds to remain productive despite infection is known as trypanotolerance; however, the underlying immune mechanisms contributing to this trait remain poorly understood. Antimicrobial peptides (AMPs) and acute phase proteins (APPs) are evolutionarily conserved effector molecules of the innate immune system that have important roles in the resolution of infection and activation of the adaptive immune response. Expression levels of AMP genes (TAP, LAP, BNBD4, DEFB1, DEFB5 and LEAP2) and APP genes (HP, CP, AGP, LBP, SAA3 and CRP) were investigated using real time quantitative reverse transcription PCR (qRT-PCR) in peripheral blood mononuclear cells (PBMC) isolated from two breeds of African cattle (trypanotolerant N'Dama and trypanosusceptible Boran), experimentally infected with Trypanosoma congolense. Haptoglobin and serum amyloid A (SAA) were also measured in plasma using quantitative protein assays. Results demonstrated that tracheal antimicrobial peptide (TAP) gene expression increased by 32-fold in Boran, compared to only 3-fold in N'Dama, by 14 days post-infection (dpi) and rising to 136-fold at 29 dpi in Boran, compared to 47-fold in N'Dama (P<0.05). Protein expression levels of SAA are elevated in N'Dama, rising to 163 microg/ml at 14 dpi compared with 72 microg/ml in Boran. The SAA expression profile mirrors the wave of parasitaemia detected in N'Dama. Seven single nucleotide polymorphisms (SNPs) were identified in the promoter regions of the SAA3 and SAA4 genes, which are predicted to affect transcription factor binding and thereby contributing to the differential patterns of expression detected between the breeds. Whereas elevated TAP expression is a conserved component of the innate immune response to infection in both breeds, higher SAA expression levels may contribute toward trypanotolerance in N'Dama.

Alterations in oxidative gene expression in equine skeletal muscle following exercise and training

Intense selection for elite racing performance in the Thoroughbred horse (Equus caballus) has resulted in a number of adaptive physiological phenotypes relevant to exercise; however, the underlying molecular mechanisms responsible for these characteristics are not well understood. Adaptive changes in mRNA expression in equine skeletal muscle were investigated by real-time qRT-PCR for a panel of candidate exercise-response genes following a standardized incremental-step treadmill exercise test in eight untrained Thoroughbred horses. Biopsy samples were obtained from the gluteus medius before, immediately after, and 4 h after exercise. Significant (P < 0.05) differences in gene expression were detected for six genes (CKM, COX4I1, COX4I2, PDK4, PPARGC1A, and SLC2A4) 4 h after exercise. Investigation of relationships between mRNA and velocity at maximum heart rate (VHR(max)) and peak postexercise plasma lactate concentration ([La]T(1)) revealed significant (P < 0.05) associations with postexercise COX4I1 and PPARCG1A expression and between [La]T(1) and basal COX4I1 expression. Gene expression changes were investigated in a second cohort of horses after a 10 mo period of training. In resting samples, COX4I1 gene expression had significantly increased following training, and, after exercise, significant differences were identified for COX4I2, PDK4, and PPARGC1A. Significant relationships with VHR(max) and [La]T(1) were detected for PPARGC1A and COX4I1. These data highlight the roles of genes responsible for the regulation of oxygen-dependent metabolism, glucose metabolism, and fatty acid utilization in equine skeletal muscle adaptation to exercise.

Transcriptional profiling of cattle infected with Trypanosoma congolense highlights gene expression signatures underlying trypanotolerance and trypanosusceptibility

Background

African animal trypanosomiasis (AAT) caused by tsetse fly-transmitted protozoa of the genus Trypanosoma is a major constraint on livestock and agricultural production in Africa and is among the top ten global cattle diseases impacting on the poor. Here we show that a functional genomics approach can be used to identify temporal changes in host peripheral blood mononuclear cell (PBMC) gene expression due to disease progression. We also show that major gene expression differences exist between cattle from trypanotolerant and trypanosusceptible breeds. Using bovine long oligonucleotide microarrays and real time quantitative reverse transcription PCR (qRT-PCR) validation we analysed PBMC gene expression in naïve trypanotolerant and trypanosusceptible cattle experimentally challenged with Trypanosoma congolense across a 34-day infection time course.

Results

Trypanotolerant N'Dama cattle displayed a rapid and distinct transcriptional response to infection, with a ten-fold higher number of genes differentially expressed at day 14 post-infection compared to trypanosusceptible Boran cattle. These analyses identified coordinated temporal gene expression changes for both breeds in response to trypanosome infection. In addition, a panel of genes were identified that showed pronounced differences in gene expression between the two breeds, which may underlie the phenomena of trypanotolerance and trypanosusceptibility. Gene ontology (GO) analysis demonstrate that the products of these genes may contribute to increased mitochondrial mRNA translational efficiency, a more pronounced B cell response, an elevated activation status and a heightened response to stress in trypanotolerant cattle.

Conclusion

This study has revealed an extensive and diverse range of cellular processes that are altered temporally in response to trypanosome infection in African cattle. Results indicate that the trypanotolerant N'Dama cattle respond more rapidly and with a greater magnitude to infection compared to the trypanosusceptible Boran cattle. Specifically, a subset of the genes analyzed by real time qRT-PCR, which display significant breed differences, could collectively contribute to the trypanotolerance trait in N'Dama.

Dietary n-3 polyunsaturated fatty acids alter the expression of genes involved in prostaglandin biosynthesis in the bovine uterus

Nutrition plays a critical role in the regulation of cow fertility. There is emerging evidence that dietary long chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) may act as specific regulators of some reproductive processes. In vitro studies suggest that the n-3 PUFAs, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) may play pivotal roles by suppressing the synthesis of uterine prostaglandin F(2alpha) (PGF(2alpha)) which is centrally involved in the control of the bovine oestrous cycle and in early embryo survival. The objective of the current study was to determine the effect of dietary inclusion of n-3 PUFA on uterine endometrial mRNA expression of key genes regulating PGF(2alpha) biosynthesis. Beef heifers were fed either a low (CON; n=10) or high (HIGH PUFA; n=10) n-3 PUFA diet for 45 days and endometrial tissues were harvested following slaughter. Following analysis, tissues within each dietary group were ranked on the basis of their PUFA concentrations and the highest (n=7) and lowest (n=7) within each of HIGH PUFA and CON, respectively, were used in gene expression studies. Endometrial n-3 PUFA concentrations were more than two-fold higher (P<0.05) and EPA concentrations alone more than seven-fold higher (P<0.01) in the HIGH PUFA than the CON group. Endometrial concentrations of arachidonic acid, were lower (P<0.001) in the tissues from HIGH PUFA than those from the CON group. Total RNA was isolated from all endometrial tissues and real-time reverse transcription (RT) PCR conducted to compare the relative expression of 11 genes with known involvement in uterine biosynthesis of 2-series prostaglandins. Expression of mRNA for prostaglandin E synthase (PGES) and peroxisome proliferator-activated receptors, PPAR alpha and delta was increased (P<0.05) while mRNA expression of phospholipase A(2) (PLA(2)) was decreased (P=0.06) in the HIGH PUFA endometrial tissues. Expression of genes coding for the oxytocin receptor (OTR), phospholipase C (PLC), cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), PGE(2) 9-ketoreductase (9-KPR), prostaglandin F synthase (PGFS), and the nuclear transcription factor, PPAR gamma was not different (P>0.05) between HIGH PUFA and CON tissues. Overall the results indicate that key genes regulating uterine PGF(2alpha) biosynthesis can be regulated by dietary inclusion of LC n-3 PUFA which may influence uterine function and embryo survival.

Reference gene selection for real-time rtPCR in human epidermal keratinocytes

BACKGROUND

RNA interference represents a powerful tool with which to achieve suppression of specific target mRNA. Real-time rtPCR is a useful technique for assessing levels of mRNA expression. Critically, for real-time rtPCR to yield meaningful results, it is necessary to normalise expression of the gene of interest to stably expressed endogenous control genes.

OBJECTIVES

The study involved establishing expression profiles for 11 housekeeping genes in human epidermal keratinocyte cell lines determining their relative stability. Furthermore, the effect of the presence of shRNA on these expression profiles has been established.

METHODS

Keratinocytes were transfected using lipid-based transfection or AMAXA nucleofection. Real-time rtPCR was used to establish RNA expression levels. Data analysis was carried out using geNORM.

RESULTS

When using HaCaT or adult NHEK cells any combination of 8 of the housekeeping genes would be appropriate for normalisation. In contrast, with juvenile NHEK cells only 4 of the housekeeping genes were found to be sufficiently stable to be deemed appropriate for normalisation of expression data. Furthermore data demonstrated that the expression of housekeeping genes may sometimes be affected by the induction of the RNAi pathway.

CONCLUSIONS

The data obtained highlight the importance of characterising housekeeping gene expression profiles in each specific cell type prior to choosing a set of housekeeping genes for expression studies. The results from this study are applicable to researchers working with human epidermal keratinocytes and the experimental approach is more broadly applicable to any researcher carrying out real-time rtPCR.