Table 1 Effects of virus infections on AHR signaling pathways

RNA

ZIKV

Promote the synthesis of AHR endogenous ligand Kyn by upregulating IDO1 and TDO2, thereby activating the AHR signaling pathway

Inhibit IFN-I expression and reduce the body's antiviral ability; at the same time, after activation of AHR, it can inhibit the NF-κB signaling pathway to limit the intrinsic immunity driven by PML protein, which is conducive to the replication of ZIKV in vivo

[24]

SARS-CoV-2

Promote the synthesis of AHR endogenous ligand Kyn via promoting the expression of IFN-β、γ to upregulate IDO1, thereby activating the AHR signaling pathway

Stimulate mucins production, thereby promoting hypoxia by hindering O₂ diffusion at alveolar sites; on the other hand, AHR activation, in turn, promotes virus replication

[57]

[59]

HCV

Activate the AHR signaling pathway by upregulating the AHR endogenous ligand Kyn

After activation of AHR, the expression of its downstream target gene CYP1A1 increases, promoting the formation of LDs and accumulation of liver fat, which is closely related to the progression of HCC

[62]

IAV

Possibly activate the AHR signaling pathway by upregulating Kyn levels

Diminish host responses and reduce cytotoxic T lymphocytes production, thereby reducing cellular antiviral immunity

[102]

HTLV-1

AHR is activated, but the exact mechanism is unknown

Facilitate HTLV-1 plus-strand transcription and control viral latency-reactivation switching

[104]

HIV-1

In the lymphocyte, AHR activation promotes HIV-1 infection and reactivation; in the macrophage, AHR activation causes a block to HIV-1 replication

In the lymphocyte, AHR directly binds to the HIV-1 5′-LTR; in the macrophage, AHR activation surpresses the transcription of CDK1, CDK2, resulting in dNTP depletion and antiviral effects

[70, 71]

DNA

EBV

EBV-encoded EBNA3 facilitates the role of the AHR pathway by promoting AHR nuclear translocation in B lymphocytes;

EBV-encoded LMP1 affects AHR signaling pathway by activating NF-κB in B lymphocytes;

EBV-encoded LMP2A suppresses the role of the AHR pathway through the ERK signal pathway in EBV-associated gastric cancer

In B lymphocytes, EBNA3 activates AHR, which in turn promotes EBV to enter the lytic phase, and it is conducive to virus replication;

In gastric cancer cells, inhibition of AHR by LMP2A favors EBV to maintain a latent state

[72]

[78]

[93]

HCMV

Increase Kyn levels by promoting Kyn synthesis and inhibiting Kyn metabolism in fibroblasts, thereby activating the AHR signaling pathway

AHR activation following HCMV infection, in turn, promotes efficient production of viral progeny;

And it promotes HCMV-Induced G1/S block to cell cycle progression, thereby preventing cell proliferation and preserving metabolic resources for viral progeny

[100]