Productive HIV-2 infection in the brain is restricted to macrophages/microglia.
OBJECTIVE
HIV-2 can use a broader range of co-receptors than HIV-1 in vitro, and is less dependent on CD4 for infection. The aim of this study was to detect productive HIV-2 infection in the brain and investigate whether HIV-2 has an expanded tropism for brain cells in vivo, in comparison with HIV-1, which productively infects macrophages/microglia.


METHODS
Brain samples taken at autopsy from eight patients who died from AIDS, six HIV-2 and two HIV-1/HIV-2 dually seropositive, with HIV encephalitis (HIVE), collected in Abidjan, Côte d'Ivoire in 1991, were examined for the presence and localization of productive HIV-2 infection.


METHODS
Using immunohistochemistry, the presence of HIV-2 p26 in formalin-fixed, wax-embedded brain tissue sections was investigated. Double-staining with glial fibrillary acidic protein (GFAP), CD45- and CD68-specific antibodies was performed to identify infected cell types.


RESULTS
HIV-2 p26 was detected in brain tissue from four of the HIV-2 cases and one of the dually infected individuals. The productively infected cells were either microglia or infiltrating macrophages.


CONCLUSIONS
The productively infected cells in the brains of HIV-2 infected individuals are macrophages/microglia. No evidence was found for productive infection of astrocytes, neurons or oligodendrocytes. Thus, the broader in vitro cell tropism, promiscuous coreceptor usage and relative independence of CD4 by HIV-2 compared to HIV-1 does not broaden its range of target cells in the brain.
Mörner
Andreas
A
Department of Immunology and Molecular Pathology, University College London, UK.
Thomas
J Alero
JA
Björling
Ewa
E
Munson
Philippa J
PJ
Lucas
Sebastian B
SB
McKnight
Aine
A
D015526:AIDS Dementia Complex / Q000276:immunology / Q000821:virology*; D000328:Adult; D015703:Antigens, CD / Q000032:analysis; D015214:Antigens, Differentiation, Myelomonocytic / Q000032:analysis; D001921:Brain / Q000276:immunology / Q000821:virology*; D005260:Female; D015683:Gene Products, gag / Q000032:analysis*; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis; D015488:HIV Antigens / Q000032:analysis*; D015497:HIV-1; D015498:HIV-2; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D017493:Leukocyte Common Antigens / Q000032:analysis; D008264:Macrophages / Q000821:virology*; D008297:Male; D017628:Microglia / Q000821:virology*; D008875:Middle Aged; D054301:gag Gene Products, Human Immunodeficiency Virus; D000097382:CD68 Molecule
D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D015683:Gene Products, gag; D005904:Glial Fibrillary Acidic Protein; D015488:HIV Antigens; D017493:Leukocyte Common Antigens; D054301:gag Gene Products, Human Immunodeficiency Virus; C067980:CD68 antigen, human; D000097382:CD68 Molecule; C065558:gag protein p26, Human immunodeficiency virus