Table 1.

List of TDP-43 related viruses and brain involvement.

Virus	Brain Involvement
Coxsackievirus B3 (CVB3)	CNS of neonatal mice were found to be susceptible to CVB illness likely through the infection of progenitor cells [155]. CVB3 was found to be associated with aseptic meningitis in a Hong Kong population [156].
Theiler’s murine encephalomyelitis virus (TMEV)	TMEV is widely used as a model to study multiple sclerosis [39]. It can induce apoptosis, neuronophagia and inflammation in infected neurons [157].
Human immunodeficiency virus (HIV)	HIV is the etiological agent of HIV encephalitis. HIV can be carried into CNS through infected CD4+ T cells and/or monocytes and, as a result, brain macrophages and microglia are widely considered the reservoirs for persistent viral infection. When these cells are activated, they can trigger an immunological response leading to neuronal death and the consequent establishment of HIV-associated dementia (HAD) [158]. HIV is responsible for opportunistic infection in CNS of HIV-positive individuals, including cerebral toxoplasmosis, progressive multifocal leukoencephalopathy (PML), tuberculous meningitis, cryptococcal meningitis and cytomegalovirus infection [159].
Human endogenous retroviruses (HERV)	HERV endogenous expression can be induced by viral RNAs and proteins, following infection of HIV-1, HBV and influenza A viruses [160,56]. Interestingly, increased HERV-K expression has been detected in brain of ALS patients, and it was found to induce neuronal injury in a model of transgenic animals [56].
Hepatitis B virus (HBV)	Impairment of neuronal structures has been observed to occur in HBV-positive individuals with associated chronic liver dysfunction [161].
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)	Cognitive dysfunctions and encephalitis were reported in patients suffering from SAR-CoV-2 infection [162,163]. SARS-CoV-2 has been proposed to induce morphological and cellular alteration of brain structures [162].
West Nile virus (WNV)	WNV causes severe neurological illness, generally referred to West Nile neuroinvasive disease (WNND) and including West Nile encephalitis (WNE), West Nile meningitis (WNM), and West Nile paralysis (WNP) [164]. WNV infection has been linked to neuronal dysfunction, loss of synapses, and astrocytic gliosis, both in human patients and animal models [165,166,167,168].
Herpes simplex virus-2 (HSV-2)	HSV-2 has been observed to cause neurological complication and establishes latent infection in neurons of ganglia [74,169].