Small ruminant lentivirus infection influences expression of acute phase proteins and cathelicidin genes in milk somatic cells and peripheral blood leukocytes of dairy goats

Effect of Supplementation with Curcuma longa and Rosmarinus officinalis Extract Mixture on Acute Phase Protein, Cathelicidin, Defensin and Cytolytic Protein Gene Expression in the Livers of Young Castrated Polish White Improved Bucks

Goats are an excellent animal model for research on some physiological and pathophysiological processes in humans. The search for supplements that prevent homeostasis disorders and strengthen the immune system is necessary to reduce the risk of many diseases in both humans and animals. The aim of the study was to analyze the effect of supplementation with a mixture of dried extracts of Curcuma longa and Rosmarinus officinalis on the expression of acute-phase protein (SAA, HP, CRP, LALBA, AGP, CP, FGA, FGB, and FGG), cathelicidin (BAC5, BAC7.5, BAC3.4, MAP28, MAP34, and HEPC), beta-defensin-1 (GBD1, DEFB1), and beta-defensin-2, and cytolytic protein (LIZ and LF) genes in the livers of young castrated bucks of the Polish White Improved breed. The higher expression of LF in the control group suggests that it is important for the first line of hepatic immune defense and its expression is downregulated by the mixture of turmeric and rosemary extracts; thus, the spice-herb mixture mutes its activity. The lower expression of FGB and the higher expression of BAC5 genes in the livers of healthy, young castrated bucks who were administered the supplement suggest the silencing effects of the mixture on the acute-phase response and the stimulating effect on the antimicrobial activity of the immune system.

Functional Analyses of Three Targeted DNA Antimicrobial Peptides Derived from Goats

With the increase in drug-resistant bacteria, new antibacterial drugs have emerged as a prominent area of research and development. Antimicrobial peptides (AMPs), as innate immune agents, have garnered significant attention due to their potent, rapid, and broad-spectrum antibacterial activity. This study focused on investigating the functionality of three AMPs (CATH 1, CATH 2, and MAP34-B) derived from goat submandibular glands. Among these AMPs, CATH 2 and MAP34-B exhibited direct antibacterial activity against both Gram-negative and Gram-positive bacteria, primarily targeting the bacterial membrane. Additionally, these two AMPs were found to have the potential to induce reactive oxygen species (ROS) production in bacterial cells and interact with bacterial genome DNA, which may play a crucial role in their mechanisms of action. Furthermore, both CATH 1 and CATH 2 demonstrated significant antioxidant activity, and all three AMPs exhibited potential anti-inflammatory activity. Importantly, the cytotoxic activity of these AMPs against mammalian cells was found to be weak, and their hemolytic activity was extremely low. Overall, the characteristics of these three AMPs found in goat submandibular glands offer new insights for the study of host protection from an immunological perspective. They hold promise as potential candidates for the development of novel antibacterial agents, particularly in the context of combating drug-resistant bacteria.

miRNA expression patterns in blood leukocytes and milk somatic cells of goats infected with small ruminant lentivirus (SRLV)

The study aims to determine the selected miRNAs expression in milk somatic cells (MSC) and blood leukocytes (BL) of SRLV-seronegative (SRLV-SN) and SRLV-seropositive (SRLV-SP) goats. A functional in silico analysis of their target genes was also conducted. MiR-93-5p and miR-30e-5p were expressed only in BL, while miR-144 was expressed only in MSC, regardless of SRLV infection. In the SRLV-SP goats, higher miR-214-3p and miR-221-5p levels were found in the MSC than in the BL. Only miR-30e-5p was influenced by the lactation stage in BL in both groups, while only miR-93-5p was altered in BL of SRLV-SN goats. The target gene protein products exhibited contradictory functions, protecting the host from virus on the one hand and assisting viruses in their life cycle on the other. The differential expression of the miRNAs observed between the MSC and BL of SRLV-SP goats may suggest that the local immune response to the infection in the udder differs from the systemic response, and acts independently. Some miRNAs demonstrated different expression between lactation stages. It may be influenced by the metabolic burden occurring in early lactation and its peak. Some of the studied miRNAs may influence viral infection by regulating the expression of their target genes.

Antimicrobial peptides: mechanism of action, activity and clinical potential

The management of bacterial infections is becoming a major clinical challenge due to the rapid evolution of antibiotic resistant bacteria. As an excellent candidate to overcome antibiotic resistance, antimicrobial peptides (AMPs) that are produced from the synthetic and natural sources demonstrate a broad-spectrum antimicrobial activity with the high specificity and low toxicity. These peptides possess distinctive structures and functions by employing sophisticated mechanisms of action. This comprehensive review provides a broad overview of AMPs from the origin, structural characteristics, mechanisms of action, biological activities to clinical applications. We finally discuss the strategies to optimize and develop AMP-based treatment as the potential antimicrobial and anticancer therapeutics.

The effect of single-nucleotide polymorphism in the promoter region of bovine alpha-lactalbumin (LALBA) gene on LALBA expression in milk cells and milk traits of cows

Polymorphisms of milk protein genes have been proposed as candidate markers for dairy production traits in cattle. In the present study, a polymorphism was detected in the 5'-flanking (promoter) region of the bovine alpha-lactalbumin (LALBA) gene, a T/C transition located at nucleotide -1,001 relative to the transcription start site g.-1001T > C (NC_037332.1:g.31183170T > C), which is recognizable with PstI restriction endonuclease. In silico analyses showed that this mutation created novel retinoid X receptor alpha and vitamin D receptor transcription factor binding sites. Real-time PCR found that cows with different genetic variants of the promoter demonstrated different levels of expression of LALBA mRNA in milk somatic cells (MSCs). The TT genotype cows demonstrated low expression, whereas those with CT demonstrated much higher expression (P < 0.05). ELISA analysis found milk LALBA protein levels also differed between the TT and CT cows (P < 0.05) and that these levels were not correlated with the mRNA abundance in MSC. Association analysis found that the g.-1001T > C polymorphism in the promoter region of the LALBA gene influenced milk production traits in Polish Holstein-Friesian cows. High daily milk yield and dry matter yield, and high lactose yield and concentration were associated with the TT genotype. The TT genotype cows also had a lower number of somatic cells in the milk, considered as an indicator of udder health status. Therefore, the TT genotype could be more desirable from the breeder's perspective.

A Comparison of Oxidative Stress Biomarkers in the Serum of Healthy Polish Dairy Goats with Those Naturally Infected with Small Ruminant Lentivirus in the Course of Lactation

The present study examines the effects of natural infection by small ruminant lentivirus (SRLV) in the two most common goat breeds in Poland, i.e., Polish white improved and polish fawn improved. It focuses on biomarkers of oxidative stress, oxidatively modified proteins and antioxidant defenses, ceruloplasmin level as an acute phase protein, and the activities of antioxidant enzymes in the goat serum. It was conducted on 24 goats divided into two equal groups: one SRLV-seropositive (SRLV-SP) and another SRLV-seronegative (SRLV-SN). Both groups were identical in terms of breed and parity. Despite infection, the SRLV-SP goats demonstrated no symptoms of caprine arthritis-encephalitis. In addition, the SRLV-SP goats did not reveal pronounced dysfunctions in oxidative stress biomarkers in the serum compared to the SRLV-SN animals. However, both groups demonstrated elevated levels of the aldehydic and ketonic derivatives of oxidatively modified proteins during the lactation period. In addition, both groups retained a high total antioxidant capacity in serum despite the decrease of enzyme antioxidant defenses throughout the 200-day lactation period.

Does Small Ruminant Lentivirus Infection in Goats Predispose to Bacterial Infection of the Mammary Gland? A Preliminary Study

Simple Summary

The health and functionality of the mammary gland are important factors in animal welfare and milk production. Inflammation of the udder is associated with reduced milk yield and dairy product quality. Even though mastitis is usually caused by bacterial, fungal, or algae infections, some studies have suggested that infection with small ruminant lentivirus (SRLV), causing caprine arthritis-encephalitis (CAE), can also cause mastitis in small ruminants. Its pathophysiology is not, however, fully understood. Therefore, the aim of this study was to determine whether seropositive goats were more susceptible to bacterial infections of the udder than uninfected goats. A higher prevalence of pathogenic bacteria was identified only in seropositive goats in the 5th or further lactation. This indicates that a relationship may exist between a long-lasting SRLV infection and decreased resistance of the udder to bacterial infections, even though the seropositive goats enrolled in this study had no clinical signs of CAE.

Abstract

The aim of this study was to determine whether asymptomatic small ruminant lentivirus seropositive (SRLV-SP) goats were more susceptible to bacterial infection of the udder when lactating by comparing the presence and species of pathogenic bacteria in their milk with the values for seronegative goats (SRLV-SN). Milk samples were collected during morning milking on days 20, 40, 60, 150, and 210 of lactation for three consecutive years and subjected to bacteriological examination. Staphylococcus caprae and S. xylosus were the most frequent strains identified in both SRLV-SP and SRLV-SN goats. The prevalence of pathogenic bacteria was the highest in the 1st lactation, regardless of SRLV status. Moreover, the prevalence of pathogenic bacteria was significantly higher in SRLV-SP goats, but only those in the 5th or further lactation (p = 0.010). This suggests a relationship between long-lasting SRLV infection and susceptibility to bacterial infections of the udder.

Gene Expression Profile in Peripheral Blood Nuclear Cells of Small Ruminant Lentivirus-Seropositive and Seronegative Dairy Goats in Their First Lactation

Simple Summary

Caprine arthritis encephalitis, caused by small ruminant lentivirus (SRLV), is a disease that develops with various signs in adult goats, e.g., arthritis, mastitis, and progressive weight loss, while in goat kids, the disease presents with only neuropathy and extremely rarely. The disease results in reduced milk production and economic losses in herds of goats. Previously described changes in single gene expression do not fully explain all the processes occurring in the infected goats. Therefore, the present study describes the first use of a transcriptomic array designed specifically for goats in Poland. Its aim was to investigate the gene expression profiles of peripheral blood nuclear cells from SRLV-seropositive and SRLV-seronegative goats using a custom-made Capra hircus gene expression array. Just four genes out of ~50,000 were found to have differential expression; moreover, changes in their expression suggest an active inflammatory mechanism in SRLV-seropositive goats at the early stage of SRLV infection.

Abstract

The immune response to a viral antigen causes inflammatory cell infiltration to the tissue, which creates a suitable environment for the replication of the virus in macrophages, and the recruitment of more monocytes to the site of infection, or latently infected monocytes. The aim of the study was to analyze the transcriptomic profile of peripheral blood nuclear cells isolated from SRLV-seropositive and SRLV-negative goats at the peak of their first lactation. SRLV-seropositive goats were probably infected via colostrum. Custom transcriptomic microarrays for goats were designed and developed, namely the Capra hircus gene expression array, which features ~50,000 unique transcripts per microarray. Only four genes were differentially expressed, with up-regulated expression of the GIMAP2, SSC5D and SETX genes, and down-regulated expression of the GPR37 gene in SRLV-seropositive vs. SRLV-seronegative goats. However, in an RT-qPCR analysis, the result for the SETX gene was not confirmed. The differences in the expressions of the studied genes indicate an active inflammatory process in the SRLV-seropositive goats at the early stage of infection.

Acute phase protein expressions in secretory and cistern lining epithelium tissues of the dairy cattle mammary gland during chronic mastitis caused by staphylococci

Background

Mastitis is the most common disease in dairy cattle and the costliest for the dairy farming industry, as it lowers milk yield and quality. Mastitis occurs as a result of interactions between microorganisms and the individual genetic predispositions of each animal. Thus, it is important to fully understand the mechanisms underlying these interactions. Elucidating the immune response mechanisms can determine which genetic background makes an animal highly resistant to mastitis. We analyzed the innate immune responses of dairy cows naturally infected with coagulase-positive staphylococci (CoPS; N = 8) or coagulase-negative staphylococci (CoNS; N = 7), causing persistent mastitis (after several failed treatments) vs. infection-free (i.e., healthy [H]; N = 8) dairy cows. The expressions of the acute phase protein genes serum amyloid A3 (SAA3), haptoglobin (HP), ceruloplasmin (CP) genes in the tissues most exposed to pathogens— mammary gland cistern lining epithelial cells (CLECs) and mammary epithelial cells (MECs)—were analyzed.

Results

We found constitutive and extrahepatic expressions of the studied genes in both tissue types. HP expression in the MECs of the CoPS-infected group was higher than in the H group (p ≤ 0.05). Moreover, higher SAA3 expression in the CoPS and CoNS groups than in the H group (p = 0.06 and 0.08, respectively) was found. No differences between SAA3 and HP in CLECs were revealed, regardless of the pathogen type. However, higher expression of CP (p ≤ 0.05) in the CoPS group than in the H group was noted.

Conclusions

The expressions of selected acute phase proteins were similar between CLECs and MECs, which means that CLECs are not only a mechanical barrier but are also responsible for the biological immune response. Our findings agree with the results of other authors describing the immunological response of MECs during chronic mastitis, but the results for CLECs are novel.

The effect of the subclinical small ruminant lentivirus infection of female goats on the growth of kids

A longitudinal observational study was carried out to evaluate the influence of prenatal exposure to small ruminant lentivirus(SRLV)-infected does on the body weight (BWT) of young kids. The study was carried out in years 2001–2017 in the research dairy goat herd. Goats in the herd were regularly serologically tested and individuals showing clinical signs of caprine arthritis-encephalitis (CAE) were promptly culled. As a result all goats enrolled in the study were asymptomatic. Moreover, kids were weaned immediately after birth, fed on bovine colostrum and kept in strict separation from mothers to prevent SRLV lactogenic transmission. Kids were weighed immediately after birth, and then 1–3 times within the first 3 months of life. In total 620 goat kids were weighed at least once, excluding weighing at birth, providing 992 BWT records. The mixed linear model including four variables fitted as random effects (doe, kid, the year of kid’s birth and the exact age of a kid at weighing) and four potential confounders fitted as fixed effects (parity, kid’s sex, litter size and birth body weight) was developed and showed that BWT was not significantly associated with SRLV serological status of a doe, regardless of the time for which does had been infected before the delivery of the kid (p = 0.242). This study provides strong evidence that kids born to SRLV-infected does grow equally well as kids from uninfected does, provided that the lactogenic viral transmission is prevented by maintaining strict separation between the offspring and mothers. This observation is important for choosing the most optimal strategy of CAE control in a goat herd.

The expression of cytokines in the milk somatic cells, blood leukocytes and serum of goats infected with small ruminant lentivirus

Background

The present study aimed to determine the expression of cytokines, which is associated with the immunological response of dairy goats against small ruminant lentivirus (SRLV). The study was conducted on 26 dairy goats in their second to sixth lactation, which were divided by breed and parity into two groups: SRLV naturally infected (N = 13) and non-infected (N = 13) animals. All goats in the study were asymptomatic. The milk and blood samples, which served as studied material were taken on days 7, 30, 120 and 240 of the lactation. The gene and protein expression of several cytokines was studied using Real-Time PCR and ELISA methods.

Results

INF-β and INF-γ expression was down-regulated in the milk somatic cells (MSC) of SRLV-infected goats. However, an increased concentration of INF-β was observed in the MSC in SRLV-infected goats, while INF-γ expression was not observed in both SRLV-infected and non-infected animals The SRLV-infected goats also displayed decreased expression of IL-1α, IL-1β, IL-6 and INF-γ genes in the blood leukocytes,with IL-1α, IL-1β and IL-6 protein levels also being decreased in the sera. TNF-α was the only gene that demonstrated increased expression in both the MSC and the blood of infected animals; however, no such overexpression was observed at the protein level.

Conclusions

SRLV probably influences the immune system of infected animals by deregulating of the expression of cytokines. Further, epigenetic studies may clarify the mechanisms by which SRLV regulates the gene and protein expression of the host.

The impact of organic vs. inorganic selenium on dairy goat productivity and expression of selected genes in milk somatic cells

The aim of this study was to determine the effect of diet supplemented with selenized yeast (Se-yeast) on milk yield and milk composition of goats and expression of casein and mammary-gland-immune system genes in milk somatic cells (MSC). Twenty-four dairy goats in their second to fourth lactations were divided into control and experimental groups, balanced according to lactation number and breed (Polish White or Fawn Improved). Morning milk and blood samples were collected four times during lactation (on the 21st, 70th, 120th, 180th day after kidding). The control and experimental groups were fed diets with 0.7 mg inorganic Se/goat/day (sodium selenite) or 0.6 mg organic Se/goat/day (selenized yeast), respectively. Milk, fat and protein yields during lactation as well as average somatic cell count, fat, protein and lactose contents in milk were evaluated. Microelements in milk and blood serum and biochemical parameters in blood serum were determined at the beginning and the end of the experiment. The expression levels of the genes encoding αS1-casein (CSN1S1), αS2-casein (CSN1S2), κ-casein (CSN3), interleukin 8 (IL-8), serum amyloid A3 (SAA3), interleukin 1β (IL-1β), bactenecin 7.5 (BAC7.5), bactenecin 5 (BAC5), β2-defensin (GBD2), hepcidin (HAMP), chemokine 4 (CCL4), tumour necrosis factor α (TNFα), toll-like receptor 2 (TLR2), cathelicidin-7 (MAP34) and cathelicidin-6 (MAP28) were determined in MSC. Milk, fat, and protein yields were higher and somatic cell count (SCC expressed as natural logarithm) was lower in the milk of goats fed organic Se. The Se concentration in milk was twice as high in the organic vs. inorganic treatment groups at the end of the experiment, while there were no differences in studied biochemical parameters between groups. The transcript levels of CSN1S2 and BAC7.5 were higher and IL-8 was lower in MSC of Se-yeast treated groups. Such results may indicate better health status of mammary glands of goats treated with organic Se as well as positive impact of selenized yeast on the goat's milk composition. Differences in the IL-1β and IL-8 transcript levels were also noted between the stages of lactation, with the highest expression at the peak of lactation (day 70), highlighting the metabolic burden at this time. We concluded that the Se-yeast supplementation improved the productivity and health status of goats and could have significant economic impact on farmer's income.