The Expression of Major Histocompatibility Class I and Major Histocompatibility Class II on Macrophages in the Presence of Aryl Hydrocarbon Antagonist (CH-223191)

Macrophages are crucial for ridding the body of debris and foreign cells. The aryl hydrocarbon receptor (AhR) also plays a critical role in immunity. This study examined the effect of the AhR on the expression of major histocompatiability complex class I (MHCI) and MHC class II (MHCII) in two murine macrophage cell lines. This study used Raw264.7 and J774A.1 murine macrophage cell lines. The Raw264.7 cells are from male BALB/c mice while the J774A.1 cells are from female BALB/cN mice. The addition of the AhR anatagonist CH-223191 (AhRa) showed that the AhR does not significantly impact MHCI expression. However, MHCII expression was decreased by the addition of AhRa in Raw264.7 cells, while MHCII expression was significantly increased in J774A.1 cells after AhRa addition. During the course of the study, trypan blue results showed increased cell survival in classically activated macrophages. Therefore, early apopotosis, late apoptosis, and necrosis were examined by annexin V and propidium iodide analysis. Cell death analysis showed increases in late apoptosis for both cell lines after the addition of AhRa, suggesting the AhR plays a role in cell survival during macrophage activation. This study shows that even basal levels of AhR expression can impact MHCII expression and apoptosis of murine macrophages