The contribution of peroxynitrite generation in HIV replication in human primary macrophages.
BACKGROUND
Monocytes/Macrophages (M/M) play a pivotal role as a source of virus during the whole course of HIV-1 infection. Enhanced oxidative stress is involved in the pathogenesis of HIV-1 infection. HIV-1 regulatory proteins induce a reduction of the expression and the activity of MnSOD, the mitochondrial isoform leading to a sustained generation of superoxide anions and peroxynitrite that represent important mediators of HIV-1 replication in M/M. MnTBAP (Mn(III)tetrakis(4-benzoic acid)porphrin chloride), a synthetic peroxynitrite decomposition catalyst, reduced oxidative stress subsequent to peroxynitrite generation.


RESULTS
Virus production was assessed by p24 ELISA, western blot, and electron microscopy during treatment with MnTBAP. MnTBAP treatment showed a reduction of HIV-1 replication in both acutely and chronically infected M/M: 99% and 90% inhibition of p24 released in supernatants compared to controls, respectively. Maturation of p55 and p24 was strongly inhibited by MnTBAP in both acutely and chronically infected M/M. EC50 and EC90 are 3.7 (+/- 0.05) microM and 19.5 (+/- 0.5) microM, in acutely infected M/M; 6.3 (+/- 0.003) microM and 30 (+/- 0.6) microM, in chronically infected M/M. In acutely infected peripheral blood limphocytes (PBL), EC50 and EC90 are 7.4 (+/- 0.06) microM and of 21.3 (+/- 0.6) microM, respectively. Treatment of acutely-infected M/M with MnTBAP inhibited the elevated levels of malonildialdehyde (MDA) together with the nitrotyrosine staining observed during HIV-1 replication. MnTBAP strongly reduced HIV-1 particles in infected M/M, as shown by electron microscopy. Moreover, in presence of MnTBAP, HIV-1 infectivity was reduced of about 1 log compared to control.


CONCLUSIONS
Results support the role of superoxide anions in HIV-1 replication in M/M and suggest that MnTBAP may counteract HIV-1 replication in combination with other antiretroviral treatments.
Aquaro
Stefano
S
Faculty of Pharmacy, University of Catanzaro Magna Graecia, Roccelletta di Borgia, Catanzaro, Italy. aquaro@uniroma2.it
Muscoli
Carolina
C
Ranazzi
Alessandro
A
Pollicita
Michela
M
Granato
Teresa
T
Masuelli
Laura
L
Modesti
Andrea
A
Perno
Carlo-Federico
CF
Mollace
Vincenzo
V
D002478:Cells, Cultured; D015658:HIV Infections / Q000378:metabolism / Q000821:virology; D015497:HIV-1 / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D008264:Macrophages / Q000276:immunology / Q000378:metabolism* / Q000821:virology; D008665:Metalloporphyrins / Q000378:metabolism*; D030421:Peroxynitrous Acid / Q000378:metabolism*; D014779:Virus Replication / Q000502:physiology*
D008665:Metalloporphyrins; C097284:manganese(III)-tetrakis(4-benzoic acid)porphyrin; D030421:Peroxynitrous Acid