Rational Engraftment of Quaternary-Interactive Acidic Loops for Anti-HIV-1 Antibody Improvement.
Broadly neutralizing antibodies (bNAbs) are the focus of increasing interest for human immunodeficiency virus type 1 (HIV-1) prevention and treatment. Although several bNAbs are already under clinical evaluation, the development of antibodies with even greater potency and breadth remains a priority. Recently, we reported a novel strategy for improving bNAbs against the CD4-binding site (CD4bs) of gp120 by engraftment of the elongated framework region 3 (FR3) from VRC03, which confers the ability to establish quaternary interactions with a second gp120 protomer. Here, we applied this strategy to a new series of anti-CD4bs bNAbs (N49 lineage) that already possess high potency and breadth. The resultant chimeric antibodies bound the HIV-1 envelope (Env) trimer with a higher affinity than their parental forms. Likewise, their neutralizing capacity against a global panel of HIV-1 Envs was also increased. The introduction of additional modifications further enhanced the neutralization potency. We also tried engrafting the elongated CDR1 of the heavy chain from bNAb 1-18, another highly potent quaternary-binding antibody, onto several VRC01-class bNAbs, but none of them was improved. These findings point to the highly selective requirements for the establishment of quaternary contact with the HIV-1 Env trimer. The improved anti-CD4bs antibodies reported here may provide a helpful complement to current antibody-based protocols for the therapy and prevention of HIV-1 infection.IMPORTANCE Monoclonal antibodies represent one of the most important recent innovations in the fight against infectious diseases. Although potent antibodies can be cloned from infected individuals, various strategies can be employed to improve their activity or pharmacological features. Here, we improved a lineage of very potent antibodies that target the receptor-binding site of HIV-1 by engineering chimeric molecules containing a fragment from a different monoclonal antibody. These engineered antibodies are promising candidates for development of therapeutic or preventive approaches against HIV/AIDS.
['Liu|Qingbo|Q|', 'Zhang|Peng|P|', 'Miao|Huiyi|H|', 'Lin|Yin|Y|', 'Kwon|Young Do|YD|', 'Kwong|Peter D|PD|0000-0003-3560-232X', 'Rikhtegaran-Tehrani|Zahra|Z|', 'Seaman|Michael S|MS|', 'DeVico|Anthony L|AL|', 'Sajadi|Mohammad M|MM|', 'Lusso|Paolo|P|0000-0002-2813-4081']
D000911:Antibodies, Monoclonal D001665:Binding Sites D001666:Binding Sites, Antibody D000080908:Broadly Neutralizing Antibodies D015704:CD4 Antigens D000939:Epitopes D015483:HIV Antibodies D015699:HIV Envelope Protein gp120 D015658:HIV Infections D015497:HIV-1 D006801:Humans D008958:Models, Molecular D009154:Mutation D011485:Protein Binding D015202:Protein Engineering D055503:Protein Multimerization D021122:Protein Subunits
neutralizing antibodies human immunodeficiency virus prevention mutagenesis protein structure-function recombinant protein production retroviral therapy viral envelope