An in vitro model to study the effect of antibodies and cell receptor analogues on meningococcal adherence to human oroepithelial cells.

We have investigated different experimental schedules to achieve adherence of Neisseria meningitidis group B to cultured and buccal epithelial cells (BEC) and the effect of antibodies and receptor analogues on bacterial adherence. No adherence of meningococcus was observed when HeLa, HEp-2 or KB cells were used, but high rates of adherence to BEC occurred. The effect of antibodies on bacterial adherence was studied in assays carried out in the presence of saliva and serum collected from convalescing children with meningococcal meningitis and children vaccinated with VAMENGOC B-C. Both saliva and serum from the convalescent patients inhibited the adherence of meningococci, but saliva and serum from vaccinated children did not, corroborating our previous data of a poor antibody response induced by this vaccine. Human colostrum did not affect meningococcal adherence despite the presence of antibodies to N. meningitidis detected by ELISA. Inhibition of adherence by sera from an immunized horse, rabbits and mice, as well as by cell receptor analogues (outer-membrane complex and purified polysaccharide C), was observed. Our results show that up to now BEC continue to be the best cells to study meningococcal adherence and the effect of adherence inhibitors.(AU)