ANTIBODY-RESPONSES OF CHICKENS TO INOCULATION WITH MYCOPLASMA-GALLISEPTICUM MEMBRANE-PROTEINS IN IMMUNOSTIMULATING COMPLEXES

Membrane proteins of Mycoplasma gallisepticum (MG) strain R were extra cted with the detergent Mega-10 and incorporated into immunostimulatin g complexes (ISCOMs). A membrane protein of approximately 64 kD (p64) molecular weight was a major component of MG ISCOMs. Six-week-old spec ific-pathogen-free leghorn chickens were inoculated by various routes (subcutaneous; combined intranasal and eyedrop; and combined subcutane ous, intranasal, and eyedrop) with 10 mu g MG proteins in ISCOMs, or i noculated subcutaneously with 10 mu g MG proteins in Freund's adjuvant . Subcutaneous inoculation of MG ISCOMs, or MG Freund's adjuvant resul ted in higher sere-positive rates (detected by enzyme-linked immunosor bent assay) in serum and respiratory tract washings, compared to combi ned routes of MG ISCOM inoculation. In chickens inoculated subcutaneou sly with MG ISCOMs antibodies were first detected at 31 days postinocu lation (PI) and the seropositive rate peaked at 56 days PI. Sere-posit ive rates started to decline at day 64 PI. In the Freund's adjuvant gr oup, MG antibodies were first detected at day 21 PI, and the seroposit ive rate peaked at day 39 PI and did not decline. MG antibodies were d etected by ELISA in upper respiratory tract and tracheal washes from c hickens inoculated subcutaneously with MG ISCOMs and MG Freund's adjuv ant. Immunoblots to MG strain R whole cell proteins showed that respir atory tract washings and sera from chickens inoculated subcutaneously with MG ISCOMs contained immunoglobulins to MG proteins, with a promin ent reaction to p64.