TABLE 1.

Chemokines, cytokines, and other immune molecules involved in the human immune response to RSV infection^a

Immune molecule(s)	Productionb			Comments	Reference(s)d
	Respiratory tractc		Systemic
	Nasal mucosa	Lung
Th1 cytokines
IFN-γ	+	+	+	Protective
IL-12	+	+	+	Protective
IL-1α and IL-1β	+		+	Deleterious
IL-2	+	+	+	No reported association with severity
TNF-α	+	+	+	Deleterious
IL-18	+			Protective
sCD25			+	Deleterious
Th2 cytokines
IL-4	+	+	+	Deleterious
IL-6	+	+	+	Variable association with severity (see text)
IL-9	+	+		No reported association with severity
IL-10	+	+	+	Variable association with severity (see text)
IL-13	+	+	+	No reported association with severity
Other cytokines
IL-8	+	+	+	Deleterious: neutrophil chemoattractant
IL-17A	+	+		Variable association with severity (see text)
IL-33	+			No reported association with severity	130
Chemokines
CCL-2 (MCP-1)	+	+		Deleterious
CCL-3 (MIP-1α)	+	+		Deleterious
CCL-4 (MIP-1β)	+			Variable association with severity (see text)
CCL-5 (RANTES)	+	+		Protective
CXCL-10 (IP-10)	+		+	Deleterious
Eotaxin	+	+		Deleterious
Other
IFN-λ	+			Deleterious despite stimulating ISG expression	159, 160
IFN-α	+		+	No reported association with severity	158
G-CSF	+		+	Circulating levels are higher in infants with RSV LRTI requiring ventilation	18, 105
Soluble ICAM-1	+		+	Levels in nasal fluid positively correlate with severity	40, 124, 126
Substance P	+	+		Lower concentrations associated with increased severity	106
MBL			−	No reported association with severity	44
Cathelicidin LL-37	+			Protective: in human exptl infection, higher constitutive nasal levels are associated with reduced development of infection	177
Olfactomedin 4			+	Greater expression in PBMC was associated with need for ventilation in RSV LRTI	19
Surfactants A, B, D		−	+	The pulmonary level of surfactant A and measurable surfactant activity increase during recovery	178–181
MMP-9, MMP-3, PGP		+		Elevated pulmonary levels in ventilated infants are associated with hypoxia and acute lung injury	182–184
KL-6			+	Circulating levels are greater in infants with RSV LRTI requiring ventilation	185
sTRAIL		+		No reported association with severity	186

^aAbbreviations: CCL, C-C motif chemokine ligand; CXCL, C-X-C motif chemokine ligand; G-CSF, granulocyte colony-stimulating factor; ICAM, intercellular adhesion molecule; IFN, interferon; IL, interleukin; IP-10, IFN-γ-inducible protein-10; ISG, interferon-stimulated gene; MBL, mannose binding lectin; MCP-1, monocyte chemoattractant protein-1; MIP, macrophage inflammatory protein; MMP, matrix metalloproteinase; PGP, proline-glycine-proline (the product of MMP hydrolysis of collagen); RANTES, regulated on activation, normal T expressed and secreted; sTRAIL, soluble TNF-related apoptosis-inducing ligand; TIMP, tissue inhibitor of metalloproteinase; TNF, tumor necrosis factor.

^b+, increased production; −, reduced production.

^cNasal mucosa, measurements made in nasal fluid or nasopharyngeal aspirate; lung, measurements made in bronchoalveolar lavage fluid or tracheal aspirate.

^dReferences are provided for molecules not discussed in detail in the text.