Table 2.

Neurodegeneration in infectious disorders in humans

Disease	Neurodegeneration	Immune involvement	References
Viral
Enteroviruses Poliovirus	Apoptosis of motor neurones	Unknown	45
Japanese B Encephalitis	Neuronal death	Increase in pro-inflammatory mediators, iNOS, COX-2, IL-6, IL-1β, TNF-α and CCL2	48
Epstein–Barr virus	Grey-matter atrophy Encephalopathy and acute quadriparesis; anterior horn cell degeneration	EBV antibodies associated with MRI markers of grey-matter damage Cellular infiltration of nerve roots Production of viral IL-10	49,50
Human herpesvirus 6	Meningoencephalitis and leucoencephalitis. Dead and dying neurons undergoing neuronophagia	Lymphocytes and microglia in the meningeal and cortical lesions	51
Cytomegalovirus	Transverse myelitis	CSF pleocytosis indicative of CNS inflammation. Unclear if neuronal damage is immune mediated	52
Rabies virus	Cognitive changes Neuronal destruction	Induces expression of HLA-G to aid latency	53
Herpes simplex virus	Cognitive changes Neuronal destruction	Induces expression of HLA-G to aid latency. Production of viral chemokine receptor analogue	53
Measles	Myelin damage	Possible autoimmunity	54
PML JC virus	Infection of oligodendrocytes, astrocytes and neurons		55
HIV	Dementia (HAD)	Infected macrophages migrate to CNS	56
Bacterial
Bacterial meningitis	Neuronal loss and damage, apoptosis	TLR-dependent activation of microglia	57
Prion disease
CJD	Apoptotic neurons	Inflammation and cytokine production in regions of apoptotic neurons	58

CJD, Creutzfeldt-Jakob disease; CNS, central nervous system; COX2, cyclooxygenase 2; CSF, cerebrospinal fluid; EBV, Epstein–Barr virus; HAD, HIV-associated dementia; HIV, human immunodeficiency virus; HLA, human leucocyte antigen; IL, interleukin; iNOS, inducible nitric oxide synthase; MRI, magnetic resonance imaging; PML, progressive multifocal leucoencephalopathy; TNF-α, tumour necrosis factor-α; TLR, toll-like receptor.