CD4/CD8 Ratio Recovery Among People Living With HIV Starting With First-Line Integrase Strand Transfer Inhibitors: A Prospective Regional Cohort Analysis.

BACKGROUND: We evaluated trends in CD4/CD8 ratio among people living with HIV (PLWH) starting antiretroviral therapy (ART) with first-line integrase strand transfer inhibitors (INSTI) compared with non-INSTI-based ART, and the incidence of CD4/CD8 ratio normalization. METHODS: All PLWH enrolled in adult HIV cohorts of IeDEA Asia-Pacific who started with triple-ART with at least 1 CD4, CD8 (3-month window), and HIV-1 RNA measurement post-ART were included. CD4/CD8 ratio normalization was defined as a ratio ≥1. Longitudinal changes in CD4/CD8 ratio were analyzed by linear mixed model, the incidence of the normalization by Cox regression, and the differences in ratio recovery by group-based trajectory modeling. RESULTS: A total of 5529 PLWH were included; 80% male, median age 35 years (interquartile range [IQR], 29-43). First-line regimens were comprised of 65% NNRTI, 19% PI, and 16% INSTI. The baseline CD4/CD8 ratio was 0.19 (IQR, 0.09-0.33). PLWH starting with NNRTI- (P = 0.005) or PI-based ART (P = 0.030) had lower CD4/CD8 recovery over 5 years compared with INSTI. During 24,304 person-years of follow-up, 32% had CD4/CD8 ratio normalization. After adjusting for age, sex, baseline CD4, HIV-1 RNA, HCV, and year of ART initiation, PLWH started with INSTI had higher odds of achieving CD4/CD8 ratio normalization than NNRTI- (P < 0.001) or PI-based ART (P = 0.015). In group-based trajectory modeling analysis, INSTI was associated with greater odds of being in the higher ratio trajectory. CONCLUSIONS: INSTI use was associated with higher rates of CD4/CD8 ratio recovery and normalization in our cohort. These results emphasize the relative benefits of INSTI-based ART for immune restoration.

Identification of conserved motifs in the West Nile virus envelope essential for particle secretion.

BACKGROUND: Enveloped viruses utilize cellular membranes to bud from infected cells. The process of virion assembly and budding is often facilitated by the presence of certain conserved motifs within viral proteins in conjunction with cellular factors. We hence examined the West Nile Virus (WNV) Envelope protein for the presence of any such motifs and their functional characterization. RESULTS: We identified conserved 461PXAP464 and 349YCYL352 motifs in the WNV envelope glycoprotein bearing resemblance to retroviral late domains. Disruptive mutations of PXAP to LAAL and of the highly conserved Cys350 in the YCYL motif, led to a severe reduction in WNV particle production. Similar motifs in case of retroviruses are known to interact with components of host sorting machinery like PXAP with Tsg101 and YXXL with Alix. However, in the case of WNV, siRNA mediated depletion of Alix or Tsg101 did not have an effect on WNV release. Molecular modeling suggested that while the 461PXAP464 motif is surface accessible and could potentially interact with cellular proteins required for WNV assembly, the 349YCYL352 motif was found to be internal with Cys350 important for protein folding via disulphide bonding. CONCLUSIONS: The conserved 461PXAP464 and 349YCYL352 motifs in the WNV envelope are indispensable for WNV particle production. Although these motifs bear sequence similarity to retroviral late domains and are essential for WNV assembly, they are functionally distinct suggesting that they are not the typical late domain like motifs of retroviruses and may play a role other than Alix/Tsg101 utilization/dependence.