Table 1.

Comparison of herpesviral latency reservoirs, latent transcripts, and inducers of lytic reactivation.

Sub Family	Virus	Cell Tropism	Latent Reservoir	Major Latent Transcripts	Inducers of Lytic Cycle
Alphaherpesvirinae	HSV1 HSV2	neurons fibroblasts	neurons	LATs: sRNA1 and 2, lncRNAs, miRNAs	immunosuppression, stress, UV hypoxia local tissue trauma hypothermia and hyperthermia cytokines and prostaglandins * hormonal changes NGF withdrawal Dexamethasone, NaBu
	VZV	neurons	neurons	ORF63 VLT	immunosuppression, stress, UV NGF withdrawal PI3K inhibitor, NaBu
Betaherpesvirinae	HCMV	fibroblasts PBMCs macrophages dendritic cells endothelial cells	CD34+ HSCs CD33+ myeloid progenitors CD14+ monocytes NSCs	UL138, UL111A LUNA US28 IE1x4 lncRNA2.7 and 4.9 UL144	immunosuppression proinflammatory cytokines * differentiation of cells allogeneic T-cell activation TPA
	HHV-6 HHV-7	T cells	CD34+ HSCs PBMCs	HHV-6: H6LTs:ORF99, ORF142, ORF145 U94 miR-U86 HHV-7: no data available	immunosuppression infection with other pathogen * (HHV-6B) T-cell activation (HHV-7) TPA (HHV-6A/6B, HHV-7), TSA (HHV-6A)
Gammaherpesvirinae	EBV	B cells epithelial cells	B cells	Latency I: EBNA1 Latency II: EBNA1 and LMP1 and/or 2 Latency III: EBNA1, 2, 3a, 3c, 3b, LP and LMP1, 2a and 2b	immunosuppression, stress, chemotherapy, radiotherapy, hypoxia infection with other pathogen * prostaglandins * BCR crosslinking, TPA, NaBu, TSA
	KSHV	B cells endothelial cells	B cells	LANA (ORF73) vCyc (ORF72) vFLIP (ORF71) Kaposins vIRF3 (PEL and MCD) miRNAs	immunosuppression, UV proinflammatory cytokines * hypoxia infection with other pathogen * TPA, NaBu, TSA, VPA

* For more detailed description please see text Section 4. Virus reactivation. HSV—herpes simplex virus; VZV—varicella zoster virus; HCMV—human cytomegalovirus; HHV—human herpesvirus; EBV—Epstein–Barr virus; KSHV—Kaposi sarcoma-associated herpesvirus; PBMCs—peripheral blood mononuclear cells; HSCs—haematopoietic stem cells; NSCs—neural stem cells; NPCs—neural progenitor cells; NGF—nerve growth factor; NaBu—sodium butyrate; PI3K—phosphoinositide 3-kinase; TPA-12-O—tetradecanoylphorbol-13-acetate; TSA—trichostatin A; BCR—B-cell receptor; VPA—valproic acid; LATs—latency associated transcripts; ORF—open reading frame; VLT—VZV latency-associated transcript; LUNA—latency unique nuclear antigen; EBNA—Epstein–Barr nuclear antigen; LMP—latency-associated membrane proteins; LANA—latency-associated nuclear antigen; vFLIP—viral FLICE inhibitory protein; vCyc—viral cyclin; PEL—primary effusion lymphoma; MCD—multicentric Castleman’s disease.