Table 3.

Morphine suppresses immune cell function

Cell Type	Morphine effect	Reference
PBMC	suppressed activity	(Carr et al., 1993)
	Th1 → Th2 shift	(Roy et al., 2001)
	↓ superoxide production	(Peterson et al., 1987)
NK cells	suppressed activity	(Carr et al., 1993)
T cells	↓ number	(Carr et al., 1993)
	↓ IFN-γ promoter activity via ↑ cAMP	(Wang et al., 2003)
B cells	↓ mitogenic responses of splenic B cells to LPS	(Bhargava et al., 1994) (Bryant et al., 1988) (Bussiere et al., 1992)
	↓ numbers in mouse spleens	(Lefkovitz et al., 2000)
murine macrophages	↑ phagocytosis ↑ intracellular bacerial growth ↓ respiratory burst activity ↓ chemotaxis	(Tomei et al., 1997) (Perez-Castrillon et al., 1992) (Wang et al., 2005) (Martin et al., 2010)
murine splenocytes	↓ IL-1β, IL-2, TNF-α, IFN-γ, ↑ TGF-β1, IL-10 production	(Pacifici et al., 2000)
	Th1 → Th2 shift	(Roy et al., 2001)
murine thymocytes	↓ activation of IL-2 gene	(Roy et al., 1997)