The effects of polyhexamethyleneguanidine-phosphate on T cell subtypes in the blood

抄録

Polyhexamethyleneguanidine-phosphate (PHMG-p) is a lung toxicant and can reach the whole body by inhalation. Inhalation exposure to PHMG-p causes effects on the lymphocyte percentage in the blood, but the effect on the ratio of T cell subtypes is not known. Therefore, we aimed to determine the change in ratio of the T cell subtype and T cell differentiation-related genes by PHMG-p exposure. PHMG-p was instilled intratracheally in mice, and the lungs, thymus, and blood were collected. We analyzed histology in the lung and thymus, the T cell subtype by flow cytometry in the blood, and gene expression in the thymus. In the lungs, PHMG-p induced varying degrees of damage, ranging from inflammatory cell infiltration to granulomatous inflammation/fibrosis. There was a decrease in lymphocyte number in the blood as well as a change in the T cell subtype ratio (CD4:CD8) in the group administering PHMG-p. In addition, there was observed in the alteration of T cell differentiation-related genes in the thymus. These results indicate that PHMG-p alters T cell subtypes in the blood by regulating T cell differentiation-related genes. Collectively, we suggest that the damage caused by PHMG-p is not limited only to the lungs and can affect the immune response of the whole body via the change in the T cell ratio, which is a key cell in the immune system.