Table 1.

Cytokines examined in porcine reproductive and respiratory syndrome (PRRS) and their role in the immunopathogenesis of the disease.

Cytokine	Role in PRRS	References
IL-1	Chemotaxis of monocytes and neutrophils	Thanawongnuwech et al. (2001)
	Early upregulation in BALF and in the lung parenchyma	Labarque et al. (2003)
	Poor and delayed enhancement in serum	Van Gucht et al. (2003)
		Gómez-Laguna et al., 2010b, Gómez-Laguna et al., 2010c
		Renukaradhya et al. (2010)
		García-Nicolás et al. (2011)
IL-6	Induction of acute phase proteins	Asai et al. (1999)
	Upregulation in situ in the lung parenchyma	Gómez-Laguna et al. (2010b)
TNF-α	Inhibition of PRRSV replication	López-Fuertes et al. (2000)
	Induction of acute phase proteins	Gómez-Laguna et al. (2010b)
	Downregulated in PRRSV-infected PAMs	Albina et al. (1998)
IFN-α	Correlation between virus specific IFNα-SCs and IFNγ-SCs	Van Reeth et al. (1999)
	Interference with PRRSV replication	Royaee et al. (2004)
	Downregulation in PRRSV-infected PAMs and/or PBMCs
IFN-γ	Inhibition PRRSV replication	Bautista and Molitor, 1999
	Enhancement by PRRSV vaccination with IL-12 or IFN-α	Foss et al. (2002)
	Delayed onset of PRRSV specific IFNγ-SCs	Meier et al. (2003)
	Higher expression with highly virulent PRRSV strains	Thanawongnuwech et al. (2003)
		Díaz et al., 2005, Díaz et al., 2006
IL-10	Correlation with the expression of PRRSV in the lung	Díaz et al. (2006)
	Inhibition of the expression of IFN-γ and other cytokines	Gómez-Laguna et al. (2010b)
TGF-β	Induction of regulatory T cells after PRRSV-2 infection	Silva-Campa et al. (2009)
	Correlation with the expression of PRRSV in the lung	Gómez-Laguna et al. (2012a)

IL, interleukin; BALF, bronchoalveolar lavage fluid; TNF, tumour necrosis factor; PRRSV, porcine reproductive and respiratory syndrome virus; PAMs, porcine alveolar macrophages; IFN, interferon; SC, secreting cells; PBMCs, peripheral blood mononuclear cells; TGF, transforming growth factor; PRRSV-2, porcine reproductive and respiratory syndrome virus type 2.