A possible origin of emerged HIV-1 after interrupting anti-retroviral therapy

Phylogenetic Analyses Comparing HIV Sequences from Plasma at Virologic Failure to Cervix Versus Blood Sequences from Antecedent Antiretroviral Therapy Suppression

Identifying tissue sources of HIV that rebound following "failure" of antiretroviral therapy (ART) is critical to evaluating cure strategies. To assess the role of the uterine cervix and peripheral blood mononuclear cells (PBMC) as viral reservoirs, nearest-neighbor phylogenetic analyses compared genetic relatedness of tissue sequences during ART suppression to those detected in plasma at viral rebound. Blood and genital tract specimens from a natural history cohort of HIV-infected women were collected over 5 years. HIV DNA sequences extracted from PBMC and cervical biopsies during ART suppression and plasma RNA from rebound (defined as HIV RNA >3 log₁₀ copies/mL) were derived by single-genome amplification. Phylogenetic and nearest-neighbor analyses of HIV env sequences and drug resistance in pol sequences were compared between tissues. Nine instances of plasma viral rebound (median HIV RNA 3.6 log₁₀ c/mL; IQR: 3.1-3.8) were detected in 7 of 57 women. Nearest-neighbor analyses found rebound plasma sequences were closer to uterine cervical sequences in 4/9 (44%), closer to PBMC in 3/9 (33%), and ambiguous in 2/9 (22%) cases. Rebound plasma clades (n = 27) shared identical sequences in seven instances with the cervix versus two with PBMC. Novel drug resistance mutations were detected in 4/9 (44%) rebounds. The observed tendency for greater sharing of identical HIV variants and greater nearest-neighbor association between rebounding plasma and uterine cervical versus PBMC sequences suggests that the uterine cervix may be a relevant HIV reservoir. The cervix, a readily accessible tissue in women that can be repeatedly sampled, could help assess the HIV reservoir when evaluating cure strategies.

Suppression of R5-type of HIV-1 in CD4+ NKT cells by Vδ1+ T cells activated by flavonoid glycosides, hesperidin and linarin

We established transfectants expressing T cell receptors (TCRs) either for Vγ1 and Vδ1 (1C116) or for Vγ2 and Vδ2 (2C21) using the TCR-deficient Jurkat T cell line J.RT3-T3.5. The amount of IL-2 secreted from these γδ T cell clones accurately indicated TCR-dependent stimulation. Clone 2C21 was specifically stimulated by previously reported ligands for Vγ2Vδ2 (Vδ2)-TCR such as isopentenyl pyrophospate (IPP), ethylamine, or risedronate. In contrast, clone 1C116 was strongly stimulated through the Vγ1Vδ1 (Vδ1)-TCR by flavonoid glycosides such as hesperidin and linarin, having both rutinose at the A ring and methoxy (-OCH3) substitution at the B ring. Additionally, hesperidin and linarin showed stimulatory activity for peripheral blood mononuclear cell (PBMC)-derived T cells expressing Vδ1-TCR; these activated Vδ1⁺ T cells also secreted IL-5, IL-13, MIP-1α, MIP-1β and RANTES. Such PBMC-derived Vδ1⁺ T cells stimulated by hesperidin and linarin suppressed R5-HIV-1-NL(AD8) viral replication in CD4⁺ NKT cells in a dose-dependent manner. To the best of our knowledge, this is the first demonstration that flavonoid glycosides activate functional Vδ1⁺ T cells.