SANTHE trainee learns new anitbody-discovery skills in US

Thursday, 16 August, 2018

Daniel Muema, SANTHE Post-doctoral trainee, is handed a farewell gift by Dr Evan Cale. It's a photograph of the VRC, signed by his host laboratory colleagues.Daniel Muema, SANTHE Post-doctoral trainee, based at the Africa Health Research Institute (AHRI), left Durban, South Africa, on the 14th of April to complete a 4-month research visit to the National Institute of Allergy and Infectious Diseases’ Vaccine Research Center (VRC) in Maryland, USA. The main objective of his visit was to acquire training on the process of isolating and expressing anti-HIV broadly neutralising monoclonal antibodies from peripheral blood mononuclear cells (PBMCs) of HIV infected individuals.

His specific objectives were to acquire training on the:

  • mapping of broadly neutralising anti-HIV antibody responses to identify targeted epitopes;
  • fluorescent activated cell sorting of HIV-specific memory B cells;
  • cloning and expression of recombinant anti-HIV monoclonal antibodies in production cell lines.

During his visit, under the guidance of Dr Nicole Doria-Rose and Dr John Mascola – his hosts, he isolated a broadly neutralising anti-HIV monoclonal antibody from the PBMCs (peripheral blood mononuclear cells) of a South African HIV-infected study participant. The antibody, named HPP-VRC47.01, had a neutralisation breadth of 48% in a panel of 27 pseudoviruses. Muema plans to ship the PCR products from that participant back home to clone more antibodies in an attempt to discover clones that have better breadth. From the same donor, he also immortalised some sorted B cells to further assess back home, to isolate more broadly neutralising monoclonal antibodies.  He also sorted, amplified and sequenced the Ig (immunoglobin) genes from a second donor and will be completing the cloning process from this donor in Durban. In summary, he learnt the entire antibody discovery pipeline and will be implementing it in Durban, South Africa.

Muema is confident that the new antibody-discovery skills he has acquired will help him in future scientific endeavours that entail studies on antibody responses in infectious diseases. Asked what this means to the general public, he says, “The training enables us to inform vaccine design. The isolated antibodies will help us identify the most useful virus targets that can be used in protective HIV vaccines. The antibodies can also be used therapeutically as drugs.”

He says during his training he also established useful connections for future collaborative work. “I am currently setting up the pipeline for isolation and characterisation of HIV broadly neutralising monoclonal antibodies in Durban. This will entail optimising protocols for single cell sorting of HIV specific B cells, PCR of immunoglobulin genes, sequencing, and cloning of monoclonal antibodies. I will train my colleagues in every aspect of this pipeline. We will apply the skills to isolate and clone monoclonal antibodies from vaccinees in a clinical trial scheduled to start in March 2019.”