Submitted to: World Veterinary Poultry Association
Publication Type: Abstract Only
Publication Acceptance Date: August 18, 1997
Publication Date: N/A
Technical Abstract: R2 antiserum was used to detect endogenous avian leukosis virus (ALV-E) in plasma of chickens. R2 reactivity was monitored by hemagglutination (HA) of red blood cells (RBC); and by flow cytometry (FC). Test RBC were incubated with plasma, washed, and suspended in diluted R2 antiserum. HA was assessed based on RBC sedimentation patterns. For FC, the cells were washed again and then incubated with fluorescinated goat anti-chicken immunoglobulin. After washing 5 - 10,000 cells were analyzed by FC, and the mean channel fluoresence (MCF) was defined. The results of primary interest were those for plasma on RBC of chickens from two lines that lack ALV-E, but that differ for susceptibility to ALV-E; i.e. line 15B1 [susceptible to ALV-E and ALV-B], as opposed to line 0 [resistant to ALV-E but susceptible to ALV-B]. Using plasma from chickens with ALV-E envelope expression (lines 100B, 15I5, or 0.44-21), weak HA occurred with RBC from chickens of line 15B1, but not line 0. However, if plasma was from lines lacking ALV-E expression [72 or C which are resistant to ALV-E and ALV-B, or 0], no HA was seen. FC results confirmed the weak HA, but these could be quantified by a specific binding ratio. R2 antiserum was also used to predict ALV-E susceptibility in 0X0.44-21 F2 chickens that lacked ALV-E. If R2 antiserum reacted to a F2 chickens RBC + plasma from ALV-E envelope expressing chickens, but not to the RBC + plasma of congenic lines lacking ALV-E expression, then the F2 chicken was assigned the ALV-E susceptibility genotype. However, if the F2 chickens RBC + both types of plasma were negative for R2 reactivity the chicken was resistant to ALV-E. Thus, R2 antisera may be used to quantitate ALV-E envelope expression in plasma, and to identify chickens resistant to ALV-E.