Plant-based production of highly potent anti-HIV antibodies with engineered posttranslational modifications
Advaita Acarya Singh, Ofentse Jacob Pooe, Lusisizwe Kwezi, Therese Lotter-Stark, Stoyan Stoychev, Kabamba Alexandra, Isak B. Gerber, Jinal N. Bhiman, Juan Vorster, Michael Pauly, Larry Zeitlin, Kevin J. Whaley, Lukas Mach, Herta Steinkellner, Lynn Morris, Tsepo L. Tsekoa, Rachel Chikwamba
Abstract
Broadly neutralising antibodies (bNAbs) against human immunodeficiency virus type 1 (HIV-1), such as CAP256-VRC26 are being developed for HIV prevention and treatment. These Abs carry a unique but crucial post-translational modification (PTM), namely O-sulfated tyrosine in the heavy chain complementarity determining region (CDR) H3 loop. Several studies have demonstrated that plants are suitable hosts for the generation of highly active anti-HIV-1 antibodies with the potential to engineer PTMs. Here we report the expression and characterisation of CAP256-VRC26 bNAbs with posttranslational modifications (PTM). Two variants, CAP256-VRC26 (08 and 09) were expressed in glycoengineered Nicotiana benthamiana plants. By in planta co-expression of tyrosyl protein sulfotransferase 1, we installed O-sulfated tyrosine in CDR H3 of both bNAbs. These exhibited similar structural folding to the mammalian cell produced bNAbs, but non-sulfated versions showed loss of neutralisation breadth and potency. In contrast, tyrosine sulfated versions displayed equivalent neutralising activity to mammalian produced antibodies retaining exceptional potency against some subtype C viruses. Together, the data demonstrate the enormous potential of plant-based systems for multiple posttranslational engineering and production of fully active bNAbs for application in passive immunisation or as an alternative for current HIV/AIDS antiretroviral therapy regimens.