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Broad and potent neutralizing antibodies (bnAbs) with multiple epitope specificities evolve in HIV-1 infected children. Herein, we studied two antiretroviral naïve chronically HIV-1C in fected monozygotic pediatric twins AIIMS_329 and AIIMS_330 with potent plasma bnAbs. Elite plasma neutralizing activity was observed since initial sampling at 78 months in AIIMS_330 and persisted throughout, while in AIIMS_329 it was seen at 90-months of age after which potency decreased overtime. We evaluated potential viral characteristics associat ed with varied immune profile by generating single genome amplified pseudoviruses. The AIIMS_329 viruses generated from 90-month time point were neutralization sensitive to bnAbs and contemporaneous plasma antibodies, while viruses from 112-month and 117-month timepoints were resistant to most bnAbs and contemporaneous plasma. AIIMS_329 viruses developed resistance to plasma nAbs plausibly by N160-glycan loss, V1- and V4- loop lengthening. The viruses generated from AIIMS_330 (at 90 and 117-months) showed varied susceptibility to bnAbs and autologous contemporaneous plasma antibodies while the viruses of 112-month timepoint, at which plasma nAb specificities mapped to the V2-glycan, V3-glycan and CD4bs, were resistant to contemporaneous plasma antibodies as well as to most bnAbs. Chimeric viruses were constructed from 90-month time-point PG9 sensitive AIIMS-329 and AIIMS_330 viruses with swapped V1V2 regions of their respective evolved viruses (at 112 and 117-month), that led to higher resistance to neutralization by PG9 and autologous plasma antibodies. We observed evolution of a viral pool in AIIMS_330 donor, comprising of plasma antibody neutralization sensitive or resistant diverse autologous viruses that may have contributed to development and maintenance of elite neutralizing activity. [ABSTRACT FROM AUTHOR]

Broadly neutralizing antibodies (bNAbs) have demonstrated protective effects against HIV-1 in primate studies and recent human clinical trials. Elite neutralizers are potential candidates for isolation of HIV-1 bNAbs. The coexistence of bNAbs such as BG18 with neutralization-susceptible autologous viruses in an HIV-1-infected adult elite controller has been suggested to control viremia. Disease progression is faster in HIV-1-infected children than in adults. Plasma bNAbs with multiple epitope specificities are developed in HIV-1 chronically infected children with more potency and breadth than in adults. Therefore, we evaluated the specificity of plasma neutralizing antibodies of an antiretroviral-naive HIV-1 clade C chronically infected pediatric elite neutralizer, AIIMS_330. The plasma antibodies showed broad and potent HIV-1 neutralizing activity with -87% (29/33) breadth, a median inhibitory dilution (ID50) value of 1,246, and presence of N160 and N332 supersite-dependent HIV-1 bNAbs. The sorting of BG505.SOSIP.664.C2 T332N gp140 HIV-1 antigen-specific single B cells of AIIMS_330 resulted in the isolation of an HIV-1 N332 supersite-dependent bNAb, AIIMS-P01. The AIIMS-P01 neutralized 67% of HIV-1 cross-clade viruses, exhibited substantial indels despite limited somatic hypermutations, interacted with native-like HIV-1 trimer as observed in negative stain electron microscopy, and demonstrated high binding affinity. In addition, AIIMS-P01 neutralized the coexisting and evolving autologous viruses, suggesting the coexistence of vulnerable autologous viruses and HIV-1 bNAbs in the AIIMS_330 pediatric elite neutralizer. Such pediatric elite neutralizers can serve as potential candidates for isolation of novel HIV-1 pediatric bNAbs and for understanding the coevolution of virus and host immune response. [ABSTRACT FROM AUTHOR]