Inhibition of HIV-1 Disease Progression by Contemporaneous HIV-2 Infection

Correlates of T-cell–mediated viral control and phenotype of CD8+ T cells in HIV-2, a naturally contained human retroviral infection

“…Furthermore, recent data have suggested that preceding HIV-2 infection can limit the rate of disease progression and HIV-1 viral evolution following HIV-1 superinfection. 6 As crossreactive HIV-2 Gag-specific cytotoxic T-lymphocyte responses 7,8 are a possible explanation for these observations, characterization of CD8 1 T cells in HIV-2-infected subjects could aid our understanding of what would be required of a vaccine that could successfully contain HIV-1 via induction of T-cell responses.…”

Update on HIV-1 and HIV-2 Dual Infection

“…Two studies in Guinea-Bissau found conflicting results: (1) among 285 HIV-2-and 53 dual-infected patients, there found no difference in mortality with follow-up to 19 years in rural Caio (van Tienen et al 2011), and (2) among 223 patients that included 32 dually infected (14.3 %), it was suggested that being infected with HIV-1 and HIV-2 is associated to a slower rate of disease progression particularly in patients in whom HIV-2 infection preceded HIV-1 infection. These observations in a cohort with a long follow-up (approximately 20 years) showed that HIV-2 has an inhibitory effect of the rate of HIV-1 disease progression (Esbjornsson et al 2012). In this latter study, the rate in CD4+ T-cell percentage was similar with 1 infection only and dual infection, with an average decline of 1.2 % per year (P ¼ 0.36, with the use of a mixed model with interaction term removed).…”

“…In this latter study, the rate in CD4+ T-cell percentage was similar with 1 infection only and dual infection, with an average decline of 1.2 % per year (P ¼ 0.36, with the use of a mixed model with interaction term removed). However, the CD4+ T-cell percentage was significantly higher in participants with dual infection (31.3 %) than in those with HIV-1 infection only (23.3 %) (P < 0.001) (Esbjornsson et al 2012). …”

HIV-2 Interaction with Target Cell Receptors, or Why HIV-2 is Less Pathogenic than HIV-1

“…This equilibrium is clearly much well preserved in HIV-2 than in HIV-1 infection and it is paradoxical that the study of HIV-2 interaction with host cells remains poorly explored and sometimes neglected. Interestingly, a recent report indicates that a pre-existing infection by HIV-2 appears to inhibit the rate of HIV-1 disease progression [76], together with higher CD4+ T-cell counts and lower viral diversity of HIV-1. This apparent protective effect of HIV-2 may be explained by several viral and immunological mechanisms, namely the higher immunosupression of surface glycoprotein of HIV-2 compared to HIV-1 counterpart [77], or the ability of HIV-2 Nef protein to promote the downmodulation of TCR-CD3 from the surface of CD4+ T-cells [78] and thus the impairment of immunological synapse, established between these lymphocytes and antigen presenting cells (i.e.…”