Evolution of phagocytic function in monocytes and neutrophils blood cells of healthy calves

• Grant number: 15/19793-6
• Support Opportunities: Regular Research Grants - Publications - Scientific article
• Start date: November 01, 2015
• End date: April 30, 2016
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Clinics and Surgery
• Principal Investigator: Alice Maria Melville Paiva Della Libera
• Grantee: Alice Maria Melville Paiva Della Libera
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The immune system of newborn calves is immature and must mature gradually. Understanding how this immunity is established may define different profiles. Twelve healthy calves were monitored during eight time periods to assess the innate immune system during the first trimester of life. Blood samples were collected, and the blood phagocytes, identified by the expression of CD14 and CH138 surface molecules, were evaluated for phagocytic functionality (Staphylococcus aureus and Escherichia coli stained with propidium iodide) and the intracellular production of reactive oxygen species (2Œ,7Œ-dichlorofluorescin diacetate (DCFH-DA) oxidation). Functional changes in the CD14+ and CH138+ cells occurred at 40 days of age, with sporadic increases in phagocytosis intensity and reactive oxygen species production, and decreased phagocytosis occurred at 60 days of age. Therefore, fewer phagocytes were active from 40 days of age, although those that were active performed their roles with greater efficacy. That change presumably occurred because the calf phagocytes began to support the immune response without the influence of passive immunity. The animals failed to reach the stability needed to complete the maturation of the innate immune response by 90 days of age. These data are applicable for healthy calves only. (AU)