Neutrophil functions and serum IgG in growing foals.

The research paper examines the development of functional capacities of neutrophils, which are critical components of the immune system, in young foals from birth to eight months. It specifically looks at their ability to eliminate bacterial infections and how this is affected by the concentration of serum IgG, a type of antibody, in their bodies.

Research Objectives and Methodology

• The study’s main objective was to understand the development of phagocytic and killing capacities, and CD18 expression, of neutrophils in foals. These are critical components for battling infections in the body.
• The researchers collected blood samples from six Standardbred foals at seven different time-points between the ages of 2 to 56 days, and then once per month. They also compared the cells from these samples with those obtained from 16 mature horses.
• The neutrophils’ capacity to engulf yeast cells, otherwise known as phagocytosis, was assessed using flow cytometry. These cells were first opsonised with mature pooled serum, autologous serum, or anti-yeast IgG.
• The neutrophils’ ability to destroy bacteria (killing capacity) was evaluated through chemiluminescence, which measures the oxidative burst associated with the destruction of the engulfed cells.
• Finally, the concentration of serum IgG was evaluated using radial immunodiffusion. Serum IgG plays a critical role in immunity against bacterial infections.

Key Findings

• The research found that the neutrophils’ phagocytic ability in young foals was impaired until the age of three weeks when autologous serum was used as an opsonin.
• The killing capacity of the neutrophils was initially low, but it was similar to or higher than that of mature horses after three months.
• The concentration of serum IgG decreased from 10 g/l at two days to 5 g/l at two months and then slowly increased to 10 g/l by the end of the study.
• The study finds that these results could partially explain the increased susceptibility of young horses to bacterial infections.

Significance of the Study

• This investigation offers valuable insights into the development and functioning of the immune system in young foals.
• Understanding the vulnerability of young horses to bacterial infections could help in the development of veterinary practices aimed at boosting immunity in these animals.
• Further, enhancing our understanding of immunity in horses can potentially be utilised in comparative immunology research or studies focusing on human immunity.