Both murine SAA1 and SAA2 yield AA amyloid in alveolar hydatid cyst-infected mice.
Amyloid susceptible C57BL/6 and partially amyloid resistant A/J mice, infected intraperitoneally with 250 alveolar hydatid cyst (AHC), the larval stage of a cestode parasite Echinococcus multilocularis, develop multiple organ amyloid deposits at approximately 1 and 4 weeks post infection (p.i.), respectively. Pooled spleens and livers from each mouse strain, at 8 and 10 weeks p.i., were used for the purification of protein AA utilizing a HiLoad Superdex 200 column equilibrated with 5 M guanidine-HCl. Protein AA from each mouse strain was separated on 16% Tris-tricine SDS-PAGE gels and immunoblotted with monospecific rabbit anti-mouse AA IgG; five and six immunoreactive AA subspecies were detected in the C57BL/6 and A/J materials, respectively. N-Terminal amino acid sequence analysis was performed on the bulk column-purified protein AA as well as on the electroblotted AA subspecies from each mouse strain. The results show a mixture of serum amyloid A1 (SAA1) and (SAA2)-derived AA protein from each mouse strain; SAA1-derived AA, although alluded to, has never been demonstrated as tissue deposits in mice. These findings suggest that the intense and persistent inflammatory processes in AHC-infected mice may have induced conversion of weakly amyloidogenic SAA1 to AA. This conversion could be detected by amino acid sequencing of electrophoretically separated AA subspecies.
Bell
A W
AW
Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada.
Chan
S L
SL
Marcantonio
D
D
Ali-Khan
Z
Z
D000595:Amino Acid Sequence; D000818:Animals; D004198:Disease Susceptibility; D004445:Echinococcosis, Pulmonary / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D007113:Immunity, Innate; D008297:Male; D051379:Mice; D008805:Mice, Inbred A; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D017421:Sequence Analysis; D000685:Serum Amyloid A Protein / Q000302:isolation & purification* / Q000378:metabolism; D013045:Species Specificity
D000685:Serum Amyloid A Protein