Restriction factors in human retrovirus infections and the unprecedented case of CIITA as link of intrinsic and adaptive immunity against HTLV-1

Table 1 Restriction factors involved in human retroviruses infections

Restriction factors	Mechanism of restriction
Restriction factors	HIV-1	HTLV-1	HTLV-2
APOBEC3G	Inhibits viral transcription of Vif deficient HIV-1, by generating G to A mutations on nascent viral DNA [17]^a	No restriction [26]	nr
TRIM19/PML	Inhibits viral transcription [35]	Inhibits viral replication by targeting Tax-1 for proteasomal degradation [87]	Inhibits viral replication by targeting APH-2 for proteasomal degradation [40]
SAMHD-1	Inhibits viral transcription by depleting endogenous dNTP pool [16]	Induces apoptosis of HTLV-1 infected cells [90]	nr
Tetherin/BST2	Prevents viral particles release [15]	No restriction [91]	nr
miR-28-3p	nr	Inhibits viral transcription by targeting gag/pol mRNA [93]	nr
CIITA	Inhibits Viral trascription by targeting Tat and by recruiting RF in specific bodies [44, 101, 105]	Inhibits viral replication by targeting Tax-1 [106]	Inhibits viral replication by targeting Tax-2 [102, 103]

ISSN: 1742-4690