Table 2.

CD4 T cell effector functions in herpes viral infections.

Viral infection	CD4 T cell effector function
	Direct antiviral effector function of CD4 T cells	Support of CD8 T cell responses	Support of humoral responses
HSV	IFNγ (Chan et al., 2011)	Support of immigration into infected tissue via IFNγ-dependent mechanism (Nakanishi et al., 2009); support entry into draining lymph node (Kumamoto et al., 2011); priming of CD8 T cells and function (IFNγ and TNF secretion but not cytotoxicity) (Jennings et al., 1991; Rajasagi et al., 2009)	Antibodies mediate limited control (Chan et al., 2011)
VZV		Support CD8 T cells in SVV infected animals (Haberthur et al., 2011)	Protective role of passively transferred antibodies (Gershon et al., 1974; Zaia et al., 1983); support of isotype-switched antibodies in SVV infected animals (Haberthur et al., 2011)
MCMV	IFNγ (Jonjic et al., 1990; Lucin et al., 1992; Polic et al., 1996; Walton et al., 2011a)	Memory inflation and maintenance of functionality (Snyder et al., 2009; Walton et al., 2011b); help likely provided by IL-2 secretion (Walton et al., 2011b)	Support of isotype-switched antibodies (Jonjic et al., 1989); antibodies inhibit viral dissemination during acute viral replication and reactivation (Jonjic et al., 1994; Polic et al., 1998; Klenovsek et al., 2007; Wirtz et al., 2008)
HCMV	IFNγ (Sester et al., 2001; Gamadia et al., 2003; Nebbia et al., 2008); cytotoxicity (Tazume et al., 2004; van Leeuwen et al., 2004, 2006; Casazza et al., 2006; Delmas et al., 2007; van de Berg et al., 2008)	In transplant recipients (Walter et al., 1995; Einsele et al., 2002); in HIV patients (Komanduri et al., 2001a)	Administration of HCMV antibodies is beneficial in some cases (Yeager et al., 1981; Snydman et al., 1987; Fowler et al., 1992; Guglielmo et al., 1994; Messori et al., 1994; Harrison et al., 1995; Munoz et al., 2001)
MHV-68	IFNγ (Dutia et al., 1997; Sarawar et al., 1997; Sparks-Thissen et al., 2005; Tsai et al., 2011)	Progressive loss of virus-specific CD8 T cells in absence of CD4 T cell (Cardin et al., 1996); increased suppressive IL-10-producing and PD-1+ CD8 T cells in absence of CD4 T cells (Dias et al., 2010; Molloy et al., 2011)	Protective role of antibodies in lytic viral replication (Wright et al., 2009) and in recrudescence (Gangappa et al., 2002; Kim et al., 2002)
EBV	Soluble factors (Nagy et al., 2012); cytotoxicity (Khanolkar et al., 2001; Sun et al., 2002; MacArthur et al., 2007; Haigh et al., 2008)		B cell deficiency lack of viral persistence but also reservoir (Faulkner et al., 2000)