Periparturient blood T-lymphocyte PD-1 and CTLA-4 expression as potential predictors of new intramammary infections in dairy cows during early lactation (short communication).

Background: The periparturient period in dairy cows is marked by immunosuppression which increases the likelihood of infectious disorders, particularly also mastitis. An in-depth understanding of peripartum leukocyte biology is vital for the implementation of highly successful post-partum disease prevention measures. Immune checkpoint molecules, such as programmed death 1 (PD-1) and cytotoxic T-lymphocyte antigen 4 (CTLA-4), are critical inhibitory receptors expressed on immune cells, particularly T cells, that drive immunosuppressive signaling pathways.

Corrigendum to "Genetic diversity and iron metabolism of Staphylococcus hominis isolates originating from bovine quarter milk, rectal feces, and teat apices" (J. Dairy Sci. 105:9995-10006).

Staphylococcus chromogenes TA showed significantly lower growth under iron-deprived conditions, and adding an iron supplement (lactoferrin or ferritin) resulted in no improvement in growth; in contrast, growth of S. chromogenes IM was significantly recovered with ferritin iron supplementation. OnlyStaphylococcus hominis strains originating from quarter milk were able to significantly utilize ferritin as an iron source to reverse the growth inhibition caused by chelating agent 2,2'-bipyridyl in varying degrees.

Phenotypic and genotypic assessment of iron acquisition in diverse bovine-associated non-aureus staphylococcal strains.

Although the role of iron in bacterial infections has been well described for Staphylococcus (S.) aureus, iron acquisition in (bovine-associated) non-aureus staphylococci and mammaliicocci (NASM) remains insufficiently mapped. This study aimed at elucidating differences between four diverse bovine NASM field strains from two species, namely S.

Metabolites of non-aureus staphylococci affect the ability of Staphylococcus aureus to adhere to and internalize into bovine mammary epithelial cells.

This study investigated whether cell-free supernatants (SN) from four bovine non-aureus staphylococcal (NAS) isolates prevent Staphylococcus aureus adhesion to and internalization into bovine mammary epithelial cells (MAC-T cells) and if so, to determine whether such effects were potentially associated with the S. aureus accessory gene regulator (agr) system. Overall, we demonstrated that all SN obtained from the NAS isolates promoted adhesion of a S.

Comparison of non-aureus staphylococcal and mammaliicoccal species found in both composite milk and bulk-tank milk samples of dairy cows collected in tandem.

Non-aureus staphylococci and the closely related mammaliicoccal species (NASM) are the most common causes of bovine subclinical mastitis on modern dairy farms and are highly prevalent in bulk-tank milk. The purpose of this study was to determine the distribution of NASM in both composite cow milk (CCM) and bulk-tank milk (BTM) samples collected in tandem in commercial Flemish dairy herds and to estimate the origin of the different (subgroups of) NASM species present in BTM by applying strain typing (random amplification of polymorphic DNA or random amplified DNA [RAPD]). A single cross-sectional sampling was performed over 5 herds that volunteered to participate in the study.

The bovine leukemia virus infection prolongs immunosuppression in dairy cows during the periparturient period by sustaining higher expression of immunological checkpoints in T cells.

Bovine leukemia virus (BLV) is caused by a deltaretrovirus and has been associated with immunosuppression as well as comorbidities such as bovine mastitis, the costliest disease in the dairy sector. However, no previous study has explored at the synergistic immunosuppressive effect of the peripartum period with an immunosuppressive viral disease such as BLV. Thus, our study explored the effect of BLV infection in the periparturient period on the expression of PD-1 and CTLA-4 in blood T lymphocytes, and the impact of BLV infection on the rate of new intramammary infections during the early lactation.

Bovine-associated staphylococci and mammaliicocci trigger T-lymphocyte proliferative response and cytokine production differently.

We examined whether distinct staphylococcal and mammaliicoccal species and strains trigger B- and T-lymphocyte proliferation and interleukin (IL)-17A and interferon (IFN)-γ production by peripheral blood mononuclear cells in nulliparous, primiparous, and multiparous dairy cows. Flow cytometry was used to measure lymphocyte proliferation with the Ki67 antibody, and specific monoclonal antibodies were used to identify CD3, CD4, and CD8 T lymphocyte and CD21 B lymphocyte populations. The supernatant of the peripheral blood mononuclear cell culture was used to measure IL-17A and IFN-γ production.

Feeding reduced levels of trace minerals in proteinate form and selenium-yeast to transition cows: Performance, trace minerals, and antioxidant status, peripheral neutrophil activity, and oocyte quality.

An experiment was conducted to evaluate the effects of inorganic trace minerals (TM) and reduced levels of TM by using proteinate forms of Co, Zn, Mn, and Cu, and Se-yeast in diets of transition cows on performance, TM concentrations in colostrum, plasma, and liver, blood metabolites, antioxidant status, peripheral neutrophil activity, and oocyte quality. Thirty-two Holstein cows (22 multiparous and 10 primiparous cows) were enrolled in this study from 30 d before the expected calving date to 56 DIM. Cows were blocked according to body condition score, parity, and previous milk yield and randomly assigned to one of the following treatments: control (CON), with TM (Zn, Cu, Mn, and Co) supplied in form of sulfate and Se as sodium selenite to meet or exceed requirement estimates of the National Research Council; and proteinate trace minerals (PTM), with TM supplied bound with AA and peptides at 50% of CON levels and inorganic Se replaced with Se-yeast at 100% of CON level.

Cure-Associated Antigens Elicit Type 3 Immune Memory T Cells.

Background: is one of the most frequently major mastitis pathogens that cause clinical and subclinical mastitis worldwide. Current antimicrobial treatments are usually ineffective, and the commercially available vaccines lack proven effectiveness. The immunological response elicited by the recombinant -cure-associated proteins phosphoglycerate kinase (PGK), enolase (ENO), and elongation factor-G (EF-G) in combination with the granulocyte-macrophage colony-stimulating factor (GM-CSF) DNA vaccination was studied in this work.

Memory CD4 and CD8 T lymphocyte proliferation in vaccinated dairy cows with different histories of Staphylococcus aureus mastitis.

Staphylococcus aureus mastitis constitutes a serious threat to dairy cows. The reasons why available vaccines are not fully effective remain poorly understood; thus, in the present study, we investigated CD4 and CD8 T lymphocyte proliferation in dairy cows vaccinated with a polyvalent mastitis vaccine that had distinct precedent Staphylococcus aureus mastitis. We studied 17 S.

Genetic diversity and iron metabolism of Staphylococcus hominis isolates originating from bovine quarter milk, rectal feces, and teat apices.

Staphylococcus hominis, a member of the non-aureus staphylococci (NAS) group, is part of the human and animal microbiota. Although it has been isolated from multiple bovine-associated habitats, its relevance as a cause of bovine mastitis is currently not well described. To successfully colonize and proliferate in the bovine mammary gland, a bacterial species must be able to acquire iron from host iron-binding proteins.

Brief Research Report: Expression of PD-1 and CTLA-4 in T Lymphocytes and Their Relationship With the Periparturient Period and the Endometrial Cytology of Dairy Cows During the Postpartum Period.

The present study sought to evaluate the expression of PD-1 and CTLA-4 in blood T lymphocytes during the periparturient period and their relationship with uterine health in dairy cows, as determined by endometrial cytology and serum concentrations of β-hydroxybutyrate (BHB) and non-esterified fatty acids (NEFAs), which are indicators of a negative energy balance. The second objective of this study was to investigate whether the expression of PD-1 and CTLA-4 in T lymphocytes is associated with the serum acute phase-protein haptoglobin concentration during the periparturient period. To address these objectives, 26 clinically healthy dairy cows were used.

Corrigendum: miR-548d-3p Is Up-regulated in Human Visceral Leishmaniasis and Suppresses Parasite Growth in Macrophages.

[This corrects the article DOI: 10.3389/fcimb.2022.

miR-548d-3p Is Up-Regulated in Human Visceral Leishmaniasis and Suppresses Parasite Growth in Macrophages.

Visceral leishmaniasis caused by in Latin America progress with hepatosplenomegaly, pancytopenia, hypergammaglobulinemia, and weight loss and maybe lethal mainly in untreated cases. miRNAs are important regulators of immune and inflammatory gene expression, but their mechanisms of action and their relationship to pathogenesis in leishmaniasis are not well understood. In the present study, we sought to quantify changes in miRNAs associated with immune and inflammatory pathways using the promastigote infected- human monocytic THP-1 cell model and plasma from patients with visceral leishmaniasis.

Distinct behavior of bovine-associated staphylococci species in their ability to resist phagocytosis and trigger respiratory burst activity by blood and milk polymorphonuclear leukocytes in dairy cows.

Mastitis affects a high proportion of dairy cows and is still one of the greatest challenges faced by the dairy industry. Staphylococcal bacteria remain the most important cause of mastitis worldwide. We investigated how distinct staphylococcal species evade some critical host defense mechanisms, which may dictate the establishment, severity, and persistence of infection and the outcome of possible therapeutic and prevention interventions.

Colonization and local host response following intramammary Staphylococcus chromogenes challenge in dry cows.

Although extensive research has been performed on bovine non-aureus staphylococci (NAS), several aspects such as bacteria-host interaction remain largely unstudied. Moreover, only a few mastitis pathogen challenge studies in cows have been conducted in the dry period, an important period that allows intramammary infection (IMI) to cure and new IMI to occur. We challenged 16 quarters of 4 Holstein Friesian cows at dry off with 100; 100 000 or 10 000 000 CFU of the udder-adapted S.

Bovine-associated non-aureus staphylococci suppress Staphylococcus aureus biofilm dispersal in vitro yet not through agr regulation.

Biofilm formation is a significant virulence factor in Staphylococcus (S.) aureus strains causing subclinical mastitis in dairy cows. A role of environmental signals and communication systems in biofilm development, such as the agr system in S.

Protection-Related Type 3 Cell-Mediated Immune Response Elicited by Recombinant Proteins and GM-CSF DNA Vaccine.

mastitis remains a major challenge for dairy farming. Here, 24 mice were immunized and divided into four groups: G1: control; G2: Granulocyte Macrophage Colony-Stimulating Factor (GM-CSF) DNA vaccine; G3: F0F1 ATP synthase subunit α (SAS), succinyl-diaminopimelate (SDD), and cysteinyl-tRNA synthetase (CTS) recombinant proteins; and G4: SAS+SDD+CTS plus GM-CSF DNA vaccine. The lymphocyte subpopulations, and the intracellular interleukin-17A (IL-17A) and interferon-γ production in the draining lymph node cells were immunophenotyped by flow cytometry.

Milk lymphocyte profile and macrophage functions: new insights into the immunity of the mammary gland in quarters infected with Corynebacterium bovis.

Backgrounds: The present study explored the viability of bovine milk macrophages, their intracellular production of reactive oxygen and nitrogen species (RONS), and their phagocytosis of Staphylococcus aureus, as well as the profile of lymphocytes, from healthy udder quarters and udder quarters infected by Corynebacterium bovis. The study included 28 healthy udder quarters from 12 dairy cows and 20 udder quarters infected by C. bovis from 10 dairy cows.

Milk Macrophage Function in Bovine Leukemia Virus-Infected Dairy Cows.

The implications of bovine leukemia virus (BLV) on innate and adaptive immune responses have been widely investigated; however, the effects of BLV on mammary gland immunity require further investigation. The present study investigated the viability, phagocytic capacity, and intracellular production of reactive oxygen and nitrogen species (RONS) by macrophages in milk samples from dairy cows naturally infected with BLV with or without persistent lymphocytosis (PL). No effect of BLV infection in the overall number of macrophages per milliliter and in the percentage of viable macrophages among overall milk viable cells was found.

Metabolites of bovine-associated non-aureus staphylococci influence expression of Staphylococcus aureus agr-related genes in vitro.

Communications via quorum sensing (QS) between non-aureus staphylococci (NAS) and Staphylococcus (S.) aureus in the bovine mammary gland remains largely unexplored. We determined whether 34 S.

Immune response in nonspecific mastitis: What can it tell us?

We analyzed a large number of immune response parameters from quarter milk samples with distinct bacteriological and quarter somatic cell count (qSCC) statuses. Furthermore, we sought to explore and identify displayed immune response patterns in milk samples from mammary glands with nonspecific mastitis. Thus, 92 quarter milk samples from 28 cows were stratified into 4 groups, as follows: (1) 49 culture-negative control quarters with a low qSCC (<1 × 10 cells/mL) from 19 dairy cows (so-called healthy quarters); (2) 15 culture-negative quarters with high qSCC (>2 × 10 cells/mL; so-called quarters with nonspecific mastitis) from 10 dairy cows; (3) 8 culture-positive quarters with low qSCC (noninflammatory quarters with low qSCC) from 5 dairy cows; and (4) 20 culture-positive quarters with high qSCC (so-called truly infected quarters) from 8 dairy cows.

Comparison of antibody repertories against Staphylococcus aureus in healthy and infected dairy cows with a distinct mastitis history and vaccinated with a polyvalent mastitis vaccine.

Staphylococcus aureus is one of the pathogens most frequently isolated from cases of mastitis worldwide. To decrease the effect of S. aureus mastitis in dairy farming, alternative strategies for controlling mastitis are needed that depend on a better knowledge of cow-to-cow variations in S.