Immune response of the XXXX to particulate (red blood cell) antigens.

@entity4186 @entity742 @entity1573 @entity4601 @entity6514 @entity11230
Young ducklings were inoculated intravenously (IV) twice with either @entity1573 or @entity742 red blood cells (CRBC, SRBC). Breeder @entity4186 were inoculated IV twice with an increased dose of CRBC. Sera of these actively immunized @entity4186 and sera of day-old ducklings from the CRBC-inoculated breeder @entity4186 were tested for @entity11230 in direct-hemagglutination ( @entity4601 ) tests. The young ducklings and the breeders responded with very low @entity4601 titers to CRBC and SRBC. Although ducklings inoculated with CRBC developed a true secondary response to a second CRBC inoculation, ducklings inoculated with SRBC failed to develop elevated titers after a second of SRBC inoculation. Half the breeders failed to develop higher titers to a second CRBC inoculation. Sera from the majority of day-old ducklings hatched from eggs laid after one inoculation of the breeders had no or only minimal @entity4601 activity. Sera of ducklings hatched from eggs laid after the second inoculation had somewhat higher @entity4601 titers, and in greater proportion. Still, many of those duckling sera had no or minimal @entity4601 titers. Results with Sephadex G-200 fractions indicated that hemagglutinins after one inoculation resided primarily in @entity4186 immunoglobulin M (DIgM). Sera of @entity4186 inoculated twice with CRBC had hemagglutinating activity in DIgG, too. Hemagglutinating activity was demonstrated in both @entity6514 -sensitive (DIgM) and -resistant (DIgG) antibodies. The conspicuously low titers in all @entity4601 -positive sera agree with results of previous studies, suggesting that DIg's are deficient in immunological reactions requiring functional bivalency.
