Expression of procoagulant activity by equine lung macrophages: stimulation by blood lymphocytes.

This research article discovers how procoagulant activities (PCA) in horse lung macrophages are increased by blood lymphocytes. The study determines that this may contribute to the monitoring processes of cell-mediated immunity in horses.

Research Findings

The main findings from the research study are:

• Increases in Procoagulant Activities (PCA) in equine lung macrophages were driven by blood lymphocytes.
• Blood lymphocytes stimulated these increases after being prestimulated themselves with phytohaemagglutinin for 48 to 72 hours.
• The research observed that prestimulated lymphocyte suspensions expressed PCA, though the source of this was attributed to contaminating monocytes.
• The possibility remains that non-adherent cells from the stimulated lymphocytes could have affected adherent macrophages, and these cells within the lymphocyte suspensions might have contributed to the PCA expressed.

Stimulation Methodology and Results

• When equine lung macrophages were stimulated for 24 hours by supernatants of phytohaemagglutinin-prestimulated blood lymphocytes, a significantly larger increase in PCA was observed in comparison to stimulation with phytohaemagglutinin alone.
• From this, the researchers hypothesize that cytokines from the lymphocyte cultures might have triggered or enhanced the induction of PCA.
• However, when lung cell preparations were directly stimulated with phytohaemagglutinin for 48 hours, a progressive increase of PCA was only observed in two out of the five specimens tested.
• Failing to induce PCA in three specimens could be due to the lack of sufficient T cells within the adherent lung cell preparations.

Research Conclusions

• In conclusion, it was hypothesized that the PCA response of equine lung macrophages could be stimulated by lymphocytes.
• As a result, PCA could be a useful tool for monitoring the process of cell-mediated immunity in horses.