Exposure to Apoptotic Activated CD4+ T Cells Induces Maturation and APOBEC3G- Mediated Inhibition of HIV-1 Infection in Dendritic Cells

Dendritic cells (DCs) are activated by signaling via pathogen-specific receptors or exposure to inflammatory mediators. Here we show that co-culturing DCs with apoptotic HIV-infected activated CD4+ T cells (ApoInf) or apoptotic uninfected activated CD4+ T cells (ApoAct) induced expression of co-stimulatory molecules and cytokine release. In addition, we measured a reduced HIV infection rate in DCs after co-culture with ApoAct. A prerequisite for reduced HIV infection in DCs was activation of CD4+ T cells before apoptosis induction. DCs exposed to ApoAct or ApoInf secreted MIP-1α, MIP-1β, MCP-1, and TNF-α; this effect was retained in the presence of exogenous HIV. The ApoAct-mediated induction of co-stimulatory CD86 molecules and reduction of HIV infection in DCs were partially abrogated after blocking TNF-α using monoclonal antibodies. APOBEC3G expression in DCs was increased in co-cultures of DCs and ApoAct but not by apoptotic resting CD4+ T cells (ApoRest). Silencing of APOBEC3G in DC abrogated the HIV inhibitory effect mediated by ApoAct. Sequence analyses of an env region revealed significant induction of G-to-A hypermutations in the context of GG or GA dinucleotides in DNA isolated from DCs exposed to HIV and ApoAct. Thus, ApoAct-mediated DC maturation resulted in induction of APOBEC3G that was important for inhibition of HIV-infection in DCs. These findings underscore the complexity of differential DC responses evoked upon interaction with resting as compared with activated dying cells during HIV infection

A General Strategy to Endow Natural Fusion-protein-Derived Peptides with Potent Antiviral Activity

Fusion between the viral and target cell membranes is an obligatory step for the infectivity of all enveloped virus, and blocking this process is a clinically validated therapeutic strategy

Early adolescents' HIV-related knowledge, attitudes and behaviour in Finland

‘The definitive version is available at www.blackwell-synergy.com '. Copyright Blackwell Publishing [Full text of this article is not available in the UHRA]Finland had a relatively low rate of HIV infection during the first 17 years of the epidemic, which began in 1980. Similar to other developed countries around the world, information about the infection has been readily available, and this helped to reduce the occurrence of HIV contagion, particularly among adolescents, a group that is responsible for 50% of HIV infections worldwide. This small-scale study investigated HIV-related knowledge, attitudes, and behaviour among a group of 171 youths aged 13–16 years in suburban schools in southern Finland. Knowledge levels were relatively low and the disease was somewhat stigmatized, but homosexuality was less stigmatized than in other developed countries. The results suggest that Finnish adolescents need to be better informed about HIV and AIDS. Schools and school nurses could play a crucial role in providing information about this incurable disease.Peer reviewe