The idiotypic response to ferredoxin in mice

These investigations define a new protein idiotypic system-:- that of Clostridium pasteurianum ferredoxin (Fd). Previous studies from our laboratory have shown that the response to Fd, a small, non-mammalian electron transport protein is controlled by H-2K/I-A linked loci in mice and is almost a unideterminant response in H-2[sup k] mice. Strains of mice varying in Igh, Igl, and H-2 loci were immunized with Fd. Their Fd-immune sera were tested by inhibition in the ELISA with four specific anti-(anti-Fd)- idiotypes produced in rabbits to the purified, pooled anti-Fd sera from four different strains of mice. Major idiotypes were observed reproducibly in the anti-Fd responses of AKR/J, RF/J, and B10.BR/SnJ mice, while the anti-A/J idiotype did not reproducibly inhibit a high frequency of A/J anti-Fd antisera. Significant differences were observed between the levels of inhibition of pooled or individually analyzed anti-Fd antisera from the same mice. Further experiments showed that anti-Fd antisera from B10.BR mice have a high frequency of cross-reactivity with AKR/J anti-Fd idiotypes as do RF/J, C58/J, C3H/HeJ and CBA/J antisera. C58/J, C57BR/cdJ, and RF/J antisera also cross-react significantly with A/J anti-Fd idiotypes. Curiously, A/J and AKR/J anti-Fd antisera are not inhibited with anti-RF idiotype, and AKR anti-Fd antisera are not inhibited with anti-B10.BR idiotype. The idiotype profile of monoclonal anti-Fd antibodies was studied. The results demonstrated interstrain idiotypic cross-reactivity that paralled the results obtained with the serum antibodies of the appropriate mouse strain. These data, with the data from experiments utilizing serum antibodies do not demonstrate a correlation between idiotypic cross-reactivity and Igh or Igl allotypes. H-2 genes were observed to vary the pattern of idiotype expression in BIO recombinant mice, but no correlation between H-2 genes and idiotype expression could be observed. These results demonstrate that the anti-Fd response in H-2 mice is very complex with many intra and interstrain cross-reactive idiotypic families. Confirmatory results from 2-D electrophoretic analyses show-the presence- of many light chains in the anti-Fd response: These data are discussed in the context of existing hapten, carbohydrate, and protein antigenic systems, as well as in the context of current theories of idiotypic structure and antibody cross-reactivity.Science, Faculty ofMicrobiology and Immunology, Department ofGraduat

Diagnosis of ectopic tissue versus contamination by genetic fingerprinting in a routine surgical pathology specimen

A 62-year-old woman presented with recurring right upper quadrant pain and underwent a routine laparoscopic cholecystectomy. A large gallstone was found impacted in the fundus of the gall bladder. Interestingly, aside from noting mild inflammation of the gall bladder wall, microscopic examination of the specimen identified 2 fragments of benign thyroid tissue. Given the routine nature of the surgical procedure and lack of abnormality detected during the operation, the attending pathologist suspected extraneous tissue contamination ("floater") of the pathology specimen and submitted the block and slides to Molecular Pathology. The thyroid tissue-containing fragments and gallbladder wall were independently isolated and subjected to genetic fingerprinting using a standard forensic DNA identification panel. All fragments showed the identical fingerprint, strongly suggesting that they belonged to the same patient. The results indicated that the thyroid tissue was from an ectopic rest adjacent to the gall bladder, which has been reported only very rarely in the previous literature and illustrates the unusual use of molecular genetic testing to confirm the presence of ectopic tissue versus contamination. (c) 2007 Elsevier Inc. All rights reserved