CHARACTERIZATION OF INTERTYPE SPECIFIC EPITOPES ON ADENOVIRUS HERONS

The specification and differentiation of eighteen intertype specific ( IT) epitopes of adenovirus herons defrned by monoclonal antibodies are given by two groups of hexon types: on which they ape and on which th ey are not present. The close specificity relationship among some grou ps of epitopes determined by pairwise analysis according to their pres ence on the hexon types indicate that they could be continuous (sequen tial), overlapping or discontinuous (topographic) epitopes. Based on t he identification of the hydrophilic regions and the localization of p -turns sixteen IT epitope sites were predicted on human adenovirus (HA dV) type 2 and nineteen on HAdV-41 hexon's amino acid (aa) sequences b eside the type and genus specific ones. The 16 predicted IT epitopes o n HAdV-2, hexon show good coincidency with the 14 IT epitopes demonstr ated with monoclonal antibodies (MAbs) on this hexon type. The predict ed number of common epitopes between HAdV types 2 and 41 also correspo nds well with the eight IT epitopes determined by MAbs, but the 17 pre dicted non-common epitopes indicate the possibility of the existence o f more epitopes on these hexon types. The location of the predicted ep itopes of HAdV-2 were determined by alignment of their sequence number s on the three dimensional ribbon representation of the hexon subunit. Most of the predicted IT epitopes were found between the type and gen us specific epitopes i.e. in the ''upper'' regions of pedestal domains P1 and P2 orientated toward the virion surface and in the ''lower'' p art of loop 1 region orientated inside the virion. Two peptides repres enting potential IT epitopes were synthesized corresponding to residue s 309-320 from the ''lower'' part of loop 1 and 399-408 from the ''upp er'' part of P1 region of HAdV-2 hexon. Antibodies raised against the peptide-carrier conjugates recognized different purified native hexon types in ELISA.