EDUARDO MILTON RAMOS SANCHEZ
Projetos de Pesquisa
Unidades Organizacionais
LIM/38 - Laboratório de Epidemiologia e Imunobiologia, Hospital das Clínicas, Faculdade de Medicina
10 resultados
Resultados de Busca
Agora exibindo 1 - 10 de 10
- 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(2022) SOUZA, Carolina Menezes Suassuna de; LIMA, Ewerton de Souza; ORDONHO, Raphael Ferreira; OLIVEIRA, Bianca Rafaella Rodrigues dos Santos; RODRIGUES, Rebeca Cordeiro; MOURA, Marquiliano Farias de; LIMA, Daniel Magalhaes; BLAGITZ, Maiara Garcia; SANCHEZ, Eduardo Milton Ramos; MEDEIROS, Isac Almeida de; SOUZA, Fernando Nogueira; FERNANDES, Artur Cezar de CarvalhoThe 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 beta-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. Peripheral blood was collected 14 days prepartum (T-14), at calving (T0), and 30 days postpartum (T30) to measure the expression of PD-1 and CTLA-4 in blood T lymphocytes by flow cytometry. In addition, we collected blood at T0, 10 days after parturition (T10), and T30 to obtain serum and determine the serum concentrations of NEFA, BHB, and Hp. Endometrial cytology was performed at T10, 20 days after parturition (T20), and T30. In the present study, we observed higher expression of CTLA-4 and PD-1 in T lymphocytes at parturition and in the prepartum period, which could indicate a relationship between these immune checkpoints and immunological tolerance during gestation in dairy cattle. In addition, a negative association between the expression of these immune checkpoints prepartum or at parturition and endometrial cytology at T20 and T30 was observed, indicating the negative implications of these immune response regulators in susceptibility to infections. This finding was further corroborated by the relationship between the serum concentration of haptoglobin and the expression of CTLA-4 and PD-1 by T lymphocytes. However, we did not observe a relationship between the indicators of negative energy balance, evaluated by the serum concentrations of BHB and NEFA, and the expression of the immune checkpoint markers studied. Thus, our findings represent an initial step that paves the way for the development of new therapeutic alternatives directed by the host with the objective of increasing the resistance of dairy cattle to infections in this critical period of life.
- Effects of bovine leukemia virus infection on milk neutrophil function and the milk lymphocyte profile(2015) LIBERA, Alice Maria Melville Paiva Della; SOUZA, Fernando Nogueira de; BATISTA, Camila Freitas; SANTOS, Bruna Parapinski; AZEVEDO, Luis Fernando Fernandes de; SANCHEZ, Eduardo Milton Ramos; DINIZ, Soraia Araujo; SILVA, Marcos Xavier; HADDAD, Joao Paulo; BLAGITZ, Maiara GarciaThe effects of bovine leukemia virus (BLV) on the immune response have been extensively investigated; however, its effects on mammary gland immunity are only speculative. Although BLV has a tropism for B cells, it can affect both adaptive and innate immunities because these systems share many effector mechanisms. This scenario is the basis of this investigation of the effects of BLV on mammary gland immunity, which is largely dependent upon neutrophilic functions. Thus, the present study sought to examine neutrophilic functions and the lymphocyte profile in the milk of naturally BLV-infected cows. The viability of the milk neutrophils and the percentage of milk neutrophils that produced reactive oxygen species (ROS) or phagocytosed Staphylococcus aureus were similar between BLV-infected and BLV-uninfected dairy cows. Furthermore, the expression of CD62L and CD11b by the milk neutrophils and the percentage of milk neutrophils (CH138(+) cells) that were obtained from the udder quarters of the BLV-infected cows were not altered. Conversely, the median fluorescence intensity (MFI) representing intracellular ROS production and the phagocytosis of S. aureus, the expression of CD44 by the milk neutrophils and the percentage of apoptotic B cells were lower in the milk cells from BLV-infected dairy cows, particularly those from animals with persistent lymphocytosis (PL). The lymphocyte subsets were not different among the groups, with the exception of the percentage of CD5-/CD11b(-) B cells, which was higher in the milk cells from BLV-infected cows, particularly those with PL. Thus, the present study provides novel insight into the implications of BLV infection for mammary gland immunity.
- Milk lymphocyte profile and macrophage functions: new insights into the immunity of the mammary gland in quarters infected with Corynebacterium bovis(2021) SILVA, Vitoria M.; SOUZA, Marina T.; BLAGITZ, Maiara G.; SOUZA, Fernando N.; BATISTA, Camila F.; ALVES, Alexandre J.; FERNANDES, Artur C. C.; SANCHEZ, Eduardo M. R.; ORDINOLA-RAMIREZ, Carla M.; COSTA, Luciana da; LIBERA, Alice M. M. P. DellaBackgrounds 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. The percentages of macrophages and lymphocytes were identified by flow cytometry using monoclonal antibodies. Macrophage viability, RONS production, and S. aureus phagocytosis were evaluated by flow cytometry. Results Milk samples from quarters infected with C. bovis showed a lower percentage of macrophages but an increased number of milk macrophages per mL and a higher percentage of macrophages that produced intracellular RONS and phagocytosed S. aureus. No effect of C. bovis infection on macrophage viability was found. Udder quarters infected by C. bovis showed a higher percentage of T cells and CD4(+) T lymphocytes, but no effect was found on the percentage of CD8(+) CD4(-) T, CD8(-) CD4(-) T, or B lymphocytes. Conclusions Thus, our results corroborate, at least in part, the finding that intramammary infections by C. bovis may offer protection against intramammary infections by major pathogens.
- Immunological implications of bovine leukemia virus infection(2017) BLAGITZ, M. G.; SOUZA, F. N.; BATISTA, C. F.; AZEVEDO, L. F. F.; SANCHEZ, E. M. R.; DINIZ, S. A.; SILVA, M. X.; HADDAD, J. P.; LIBERA, A. M. M. P. DellaThis study examined neutrophil and monocyte functions and the blood lymphocyte profile of naturally BLV-infected cows with or without persistent lymphocytosis (PL). The percentage of neutrophils and monocytes that phagocytosed Staphylococcus aureus was lower in BLV-infected dairy cows, particularly those with PL. The relative percentage of CD44(+) monocytes and neutrophils and CD11b expression by neutrophils was also lower in BLV-infected dairy cows with PL. A correlation between the percentage of CD11b(+) neutrophils and that produced reactive oxygen species (ROS) was found. Furthermore, the percentage of CD44(+) monocytes was positively correlated with the percentage of monocytes that phagocytosed S. aureus and the same phenomenon was observed for neutrophils. In BLV-infected dairy cows, particularly those with PL, inhibition of monocyte and neutrophil apoptosis was observed. Additionally, the percentage of neutrophils producing ROS was lower in BLV-infected cows with PL, in contrast to higher intensity of intracellular production of ROS by monocytes. The result from the lymphocyte immunophenotyping of BLV-infected cows with PL was an increase in B cells, mainly B CD5(+) CD11b(+), due to the apoptosis inhibition. In conclusion, this study provides novel insight into the implications of BLV infection for cattle, which can include the dysfunction of blood monocytes and neutrophils.
- Milk Macrophage Function in Bovine Leukemia Virus-Infected Dairy Cows(2021) LIMA, Ewerton de Souza; BLAGITZ, Maiara Garcia; BATISTA, Camila Freitas; ALVES, Alexandre Jose; FERNANDES, Artur Cezar de Carvalho; SANCHEZ, Eduardo Milton Ramos; TORRES, Hugo Frias; DINIZ, Soraia Araujo; SILVA, Marcos Xavier; LIBERA, Alice Maria Melville Paiva Della; SOUZA, Fernando Nogueira deThe 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. Furthermore, BLV-infected dairy cows had a higher frequency of viable milk macrophages, while healthy animals had a tendency toward a higher percentage of apoptotic milk macrophages. The percentage of milk macrophages that phagocytosed Staphylococcus aureus in seronegative animals was higher than that in BLV-infected dairy cows. No effect of BLV infection on the intracellular RONS production and the intensity of phagocytosis by milk macrophages was observed. Thus, this study provides new insights into the implications of BLV infections in the bovine mammary gland.
- R-Phycoerythrin-labeled Mannheimia haemolytica for the simultaneous measurement of phagocytosis and intracellular reactive oxygen species production in bovine blood and bronchoalveolar lavage cells(2018) BATISTA, Camila F.; SOUZA, Fernando N.; SANTOS, Kamila R.; SANCHEZ, Eduardo M. Ramos; REIS, Luiza Campos; BERTAGNON, Heloisa G.; BLAGITZ, Maiara G.; GOMES, Renata C.; LAGE, Andrey P.; HEINEMANN, Marcos B.; LIBERA, Alice M. M. P. DellaThe present study aimed to validate the use of R-phycoerythrin (R-PE)-labeled Mannheimia haemolytica to simultaneously stimulate phagocytosis and intracellular production of reactive oxygen species (ROS) by blood phagocytes in bronchoalveolar lavage (BAL) fluid. Initially, R-PE-labeled M. haemolytica was inactivated using a water bath at 60 degrees C for 60 min. Afterwards, R-PE labelling of bacteria was confirmed by flow cytometry. The geometric mean fluorescence intensity of R-PE-labeled bacteria (FL2 detector, 585 +/- 42 nm) was analyzed by flow cytometry and was 41.5-fold higher than the respective unlabeled controls, confirming the success of bacterial conjugation to R-PE. Phagocytosis and intracellular production of ROS by blood neutrophils and monocytes, and by BAL CD14 macrophages, in 12 healthy 6-month-old male calves were then performed using R-PE-labeled bacteria and 2',7'-dichlorofluoresceindiacetate (DCFH-DA) as probes. Confocal microscopy was used to confirm phagocytosis of R-PE-labeled M. haemolytica by phagocytes and to exclude erroneous measurements of bacteria adhering to the leukocyte membrane. The present study showed that there is no difference in the ROS production without stimulus and in the presence of M. haemolytica by peripheral blood neutrophils and monocytes, in contrast to the increased ROS production by local alveolar macrophages upon stimulation by M. haemolytica. This emphasizes the importance of alveolar macrophages in the maintenance of homeostasis and health of the respiratory system, which can be supported during the inflammatory process by the rapid recruitment of neutrophils with high microbicidal and phagocytic capacity. The method described here provides an easy and feasible tool to measure phagocytosis and intracellular ROS production by phagocytes, especially when commonly used probes for intracellular ROS production were used, such as DCFH-DA and dihydrorhodamine 123.
- Emergence of livestock-associated Mammaliicoccus sciuri ST71 co-harbouring mecA and mecC genes in Brazil(2023) MOURA, Guilherme S. de; CARVALHO, Eneas de; SANCHEZ, Eduardo M. Ramos; SELLERA, Fabio P.; MARQUES, Michele F. S.; HEINEMANN, Marcos B.; VLIEGHER, Sarne De; SOUZA, Fernando N.; MOTA, Rinaldo A.The discovery and tracking of antimicrobial resistance genes are essential for understanding the evolution of bacterial resistance and restraining its dispersion. Mammaliicoccus sciuri (formerly Staphylococcus sciuri) is the most probable evolutionary repository of the mecA gene, that later disseminated to S. aureus. In this study, we describe the first double mecA/mecC homologue-positive non-aureus staphylococci and mammaliicocci (NASM) from the American continent, also representing the first report of mecC-positive NASM in Brazil. Two clonally related methicillin-resistant M. sciuri strains co-carrying mecA and mecC genes were isolated from the teat skin swab and milk sample collected from an ewe's left udder half. Both M. sciuri strains belonged to the sequence type (ST) 71. Besides mecA and mecC genes, the M. sciuri strains carried broad resistomes for clinically important antimicrobial agents, including & beta;-lactams, tetracyclines, lincosamide, streptogramin, streptomycin, and aminoglycosides. Virulome analysis showed the presence of the clumping factor B (clfB), ATP-dependent protease ClpP (ClpP) and serine-aspartate repeat proteins (sdrC and sdrE) virulence-associated genes. Phylogenomic analysis revealed that these M. sciuri strains are part of a globally disseminated branch, associated with farm and companion animals and even with food. Our findings suggest that M. sciuri is likely to emerge as a pathogen of global interest, carrying a broad repertoire of antimicrobial resistance genes with a remarkable co-presence of mecA and mecC genes. Finally, we strongly encourage to monitor M. sciuri under the One Health umbrella since this bacterial species is spreading at the human-animal-environment interface.
- The bovine leukemia virus infection prolongs immunosuppression in dairy cows during the periparturient period by sustaining higher expression of immunological checkpoints in T cells(2023) NASCIMENTO, Alice Maria Melo do; SOUZA, Carolina Menezes Suassuna de; OLIVEIRA, Ana Claudia Dumont; BLAGITZ, Maiara Garcia; SANCHEZ, Eduardo Milton Ramos; LIBERA, Alice Maria Melville Paiva Della; LEITE, Ricardo de Miranda Henriques; FERNANDES, Artur Cezar de Carvalho; SOUZA, Fernando NogueiraBovine 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. Here, we found that BLV-infected dairy cows always had a statistically significant higher expression of CTLA-4 and PD-1 in blood T cells. Furthermore, our findings indi-cated that BLV infection prolongs immunosuppression in dairy cows during the periparturient period by sus-taining higher expression of immunological checkpoints in T cells. In addition, BLV-infected dairy cows have a higher rate of new intramammary infections during early lactation. Thus, our study provides new insights of the immunosuppressive effect of BLV on the most critical period of the cows' life with marked detrimental effect on protective T-cell immunity and comorbidities, such as bovine mastitis.
- Letters to the editor: A comment on ""Control of bovine mastitis in the 21st century: Immunize or tolerate?""(2019) SOUZA, Fernando N.; SANCHEZ, Eduardo M. R.; LIBERA, Alice M. M. P. Della; HEINEMANN, Marcos B.
- Memory CD4+ and CD8+ T lymphocyte proliferation in vaccinated dairy cows with different histories of Staphylococcus aureus mastitis(2022) SOARES, Thais C. S.; SANTOS, Kamila R.; LIMA, Daniel M.; MAIA, Raysa Brenda M.; RAMOS-SANCHEZ, Eduardo M.; REIS, Luiza C.; GIDLUND, Magnus; CUNHA, Adriano F. da; ORDINOLA-RAMIREZ, Carla M.; CERQUEIRA, Monica M. O. P.; HEINEMANN, Marcos B.; LIBERA, Alice M. M. P. Della; GOTO, Hiro; SOUZA, Fernando N.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. aureus-infected dairy cows (11 vaccinated and six unvaccinated) and eight vaccinated healthy dairy cows with no previous S. aureus mastitis infections. Flow cytometry was used to assess lymphocyte proliferation using an anti-Ki67 antibody, and monoclonal antibodies were used to identify T cell subsets. S. aureus-infected cows exhibited reduced overall lymphocyte proliferation, including CD4(+) T lymphocyte proliferation, and memory lymphocyte proliferation in response to S. aureus isolate stimulus. Immunization did not influence the expansion of blood lymphocyte populations. Furthermore, CD8(+) T cells, memory CD8(+) T lymphocytes, and effector memory CD8(+) T lymphocytes displayed reduced proliferation 21 days after the third vaccine dose compared with before vaccination at time zero. The present data demonstrates an overall negative regulation of the T-cell response suggesting its detrimental impact leading to the persistence of S. aureus intramammary infections. Furthermore, the lack of vaccination effect on T-cell mediated immunity (e.g., proliferation) may be related to poor vaccine efficacy.