PH-DEPENDENT AGGREGATION AND SECRETION OF SOLUBLE MONOMERIC INFLUENZAHEMAGGLUTININ

We previously reported the expression of soluble A/Victoria/3/75 (H3N2 ) hemagglutinin in insect cells and the molecular and immunological st ructure of an aggregated fraction, only observed in cell supernatant w hen expression was performed at low pH [23]. Here we report that besid es this aggregated a monomeric and possibly a trimeric structure is de tected in cell supernatant, irrespective of the pH of the medium. Evid ence is presented that the aggregated fraction is generated out of mon omeric HA0s molecules due to a low intracellular pH encountered during secretion.