Plasma cell antibody repertoire analysis following administration of meningococcal polysaccharide and protein-polysaccharide conjugate vaccines: evidence of distinct patterns of B cell activation

Vaccines against N.meningitidis have been developed from the plain capsular polysaccharide, (T-independent antigen), and by covalently linking the polysaccharide to a protein carrier to from a polysaccharide-protein conjugate (T-dependent antigen). To investigate differences in the immune response to these two vaccine types, plasma cells were isolated 7 days following administration of meningococcal serogroup ACWY polysaccharide and conjugate vaccines. Additionally, naive, marginal zone, IgM memory and IgG memory B cell subsets were isolated at baseline. Next-generation sequencing was used to obtain B cell receptor sequence data from all populations.