Due to their genetic proximity to humans and availability of outbred populations, non-human primates (NHP) play an important role in biomedical research and the development of new biologics and vaccines. Importantly, however, in-depth studies of NHP immunoglobulin repertoires have identified substantial differences compared to human populations, including greater levels of genetic diversity both within and between animals. Currently, how these differences influence macaque antibody responses is not well understood.
To develop a greater understanding of the extent to which macaque antibody responses resemble that of humans, we compared B cell receptor (BCR) sequences and antigen binding sites of anti-SARS-CoV-2 spike antibodies isolated from convalescent humans and a vaccinated pigtail macaque. A greater number of immunoglobulin gene segments were utilised in the polyclonal SARS-CoV-2 Spike antibody response by a single macaque compared to six convalescent humans. Nonetheless, macaque RBD-specific antibodies targeted similar epitopes as human RBD antibodies.
In this study, we demonstrate broad similarities but also clear differences in serological responses between species. This highlights the need for further characterisation of macaque antibody repertoires and how it relates to human immunity in order to maximise the insights from such a precious resource.