An HIV-1 broadly neutralizing antibody from a clade C infected pediatric elite neutralizer potently neutralizes the contemporaneous and autologous evolving viruses

Abstract

Keywords 23 HIV-1, clade C, N332 supersite, plasma neutralization, pediatric HIV-1 bNAb, single B cell 24 sorting, elite neutralizer, SOSIP trimer, negative stain EM and 3D reconstruction 25 2 Abstract 26 27 Broadly neutralizing antibodies (bNAbs) have demonstrated protective effects against HIV-1 28 in primate studies and recent human clinical trials. Elite-neutralizers are potential candidates 29 for isolation of HIV-1 bNAbs and coexistence of bNAbs such as BG18 with neutralization 30 susceptible autologous viruses in an HIV-1 infected adult elite controller has been suggested 31 to control viremia. Disease progression is faster in HIV-1 infected children than adults. 32 Plasma bNAbs with multiple epitope specificities are developed in HIV-1 chronically 33 infected children with more potency and breadth than in adults. Therefore, we evaluated the 34 specificity of plasma neutralizing antibodies of an antiretroviral naïve HIV-1 clade C 35 chronically infected pediatric elite neutralizer AIIMS_330. The plasma antibodies showed 36 broad and potent HIV-1 neutralizing activity with >87% (29/33) breadth, median inhibitory 37 dilution (ID50) value of 1246 and presence of N160 and N332-supersite dependent HIV-1 38 bNAbs. The sorting of BG505.SOSIP.664.C2 T332N gp140 HIV-1 antigen-specific single B 39 cells of AIIMS_330 resulted in the isolation of an HIV-1 N332-supersite dependent bNAb 40 AIIMS-P01. The AIIMS-P01 neutralized 67% of HIV-1 cross-clade viruses; exhibited 41 substantial indels despite limited somatic hypermutations; interacted with native-like HIV-1 42 trimer as observed in negative stain electron microscopy and demonstrated high binding 43 affinity. In addition, AIIMS-P01 potently neutralized the coexisting and evolving autologous 44 viruses suggesting the coexistence of vulnerable autologous viruses and HIV-1 bNAbs in 45 AIIMS_330 pediatric elite neutralizer. Further studies on such pediatric elite-neutralizers and 46 isolation of novel HIV-1 pediatric bNAbs may provide newer insights to guide vaccine 47 design.48 49 Total Words: 238 50 51 3 Importance 52 53 More than 50% of the HIV-1 infections globally are caused by clade C viruses. Till date, 54 there is no effective vaccine to prevent HIV-1 infection. Based on the structural information 55 of the currently available HIV-1 bNAbs, attempts are underway to design immunogens that 56 can elicit correlates of protection upon vaccination. Here we report the isolation and 57 characterization of an HIV-1 N332-supersite dependent bNAb AIIMS-P01 from a clade C 58 chronically infected pediatric elite neutralizer. The N332-supersite is an important epitope 59 and is one of the current HIV-1 vaccine targets. AIIMS-P01 potently neutralized the 60 contemporaneous and autologous evolving viruses and exhibits substantial indels despite low 61 somatic hypermutations. Taken together with the information on infant bNAbs, further 62 isolation of bNAbs contributing to the plasma breadth in HIV-1 infected children may help to 63 better understand their development and chara...

Viral characteristics associated with sustenance of elite neutralizing activity in chronically HIV-1C infected monozygotic pediatric twins

“…MPER, RSC3 and RSC3Δ371I/P363N ELISAs were performed as described previously (16). Briefly, 96 well ELISA plates (Corning, USA) were coated with 2 µg/ml of RSC3, and RSC3Δ371I/P363N proteins and MPER-B and MPER-C peptides overnight at 4°C.…”

Broadly neutralizing plasma antibodies effective against autologous circulating viruses in infants with multivariant HIV-1 infection

“…In HIV-1 infected children, plasma bnAbs arise earlier in infection, and show higher potency and breadth compared to adults [15][16][17][18][19] . We observed the presence of cross-neutralizing antibodies in HIV-1 clade C chronically infected children 19 and recently generated a bnAb AIIMS-P01 from an elite pediatric neutralizer AIIMS_330 20 . Further, in this cohort of chronically infected children, AIIMS_329 and AIIMS_330, a pair of identical twins, showed elite plasma neutralizing activity 21 .…”

“…Studies undertaken in infants have, however, documented that HIV-1 infected infants develop potent plasma bnAbs as early as one-year post-infection 17,18 suggesting that an effective vaccine in infants may perhaps be able to trigger the immune system and elicit an early bnAb response thus providing an impetus to evaluate the antibody response in a cohort of perinatally infected infants. Moreover, the bnAbs isolated from infected children show features atypical of adult bnAbs suggesting that the factors governing bnAb induction in infants are distinct from those in adults 20,22 .…”

Effect of combination antiretroviral therapy on human immunodeficiency virus 1 specific antibody responses in subtype-C infected children

“…All plasmids were used to transform STBL3 Escherichia coli cells, followed by plasmid purification using a Qiagen plasmid isolation kit (mini-prep). Purified plasmid (5 µg) of each infectious molecular clone was expressed by transfecting HEK293T cells (ATCC) using PEI-Max transfection reagent (Polysciences), and the HIV-1 global panel of pseudoviruses was generated as described elsewhere [8,14,30]. Virus-containing supernatant was harvested at 48 h post-transfection by centrifugation and filtered through a 0.45 µm filter.…”

“…Interestingly, recent studies on HIV-1 specific immune responses have demonstrated the development of (cross-subtype) broadly neutralizing antibodies (bnAbs) in infected infants 1 year of age and understanding the responses in such infants will provide useful information towards vaccine design. Furthermore, it has been observed that select HIV-1 infected infants [12,13] and chronically infected children [9,[14][15][16][17] develop bnAb responses earlier, with higher potency and breadth than infected adults, suggesting that the pathways of eliciting antibody responses may differ between HIV-1 infected children and adults [7, 12-14, 16, 17].…”