A random nanopeptide phage library was used to screen a pool of immunoglobulin fractions obtained from rheumatoid arthritis (RA) patients. After three rounds of panning, random individual phages were selected by their capacity to react with individual sera from RA patients. By sequencing the inserts corresponding to the peptides displayed on the surface of the phages, we found that phages displaying particular peptides were overrepresented in the selected libraries. The peptides displayed by these phages were: pep1 = Ala-Asp-Gly-Gly-Ala-Gln-Gly-Thr-Ala; pep2 = Pro-Gly-Pro-Ser-Arg-Ala-His-Phe-Leu; pep3 = Leu-Ser-Ser-Arg-Glu-Pro-Gln-Ala-Arg; pep4 = Arg-Leu-Thr-Arg-Glu-Leu-Tyr-Ala-Gln and pep5 = Tyr-Thr-Gln-Lys-His-Gln-Ala. The percentage of sera positive for pep1 was higher in RA patients as compared to the normal adults (p < 0.0004) and the reacting antibody was mainly of IgG isotype. The specificity of binding to the phage displaying pep1 was confirmed by competition experiments using both isolated phages and a synthetic peptide. Interestingly, a mutated phage displaying only Ala-Asp-Gln-Gly-Thr-Ala had no significant reactivity with the sera, indicating that the amino acids (Gly-Gly-Ala) of pep1 are the vital for the binding. Taken together this study demonstrates that it is possible to select specific ligands from a random phage library using sera from RA patients. In addition, this approach could be useful for identifying peptide antigens that might be part of causitive agents in autoimmune diseases.

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Cancer immunotherapy relies on the identification and characterization of tumour antigens that can be recognized by effector T cells. Here, we used a proteomics-based approach to identify tumour antigens recognized by serum antibodies from patients with breast cancer. Specific reactivity against a set of spots was identified and their identity was revealed by MALDI-TOF peptide mass fingerprinting. They include disintegrin and metalloprotease 10, aldolase A, ß-ATPase F1, heat shock protein 27, deaminase, pyruvate dehydrogenase protein X component, and Vimentin. Western blot analysis using recombinant proteins expressed in E. coli confirmed the specific reactivity with patient sera. Several tumour antigens were expressed on the surface of the T7 phage and shown to trigger specific immune responses in BALB/c mice following oral immunisation. Furthermore, these immune responses inhibited tumour growth and metastasis of the 4T1 mammary adenocarcinoma cell line. Collectively, the present data indicate that proteomics-based strategy can identify tumour antigens whose surface display on phages or bacteria can provide an effective strategy for mucosal cancer vaccines. In addition, arrayed phage-displayed tumour antigens could be useful as a serum-based screening test for the detection of several tumour antigens.

Objective-To measure Proteus mirabilis and Escherichia coli antibody levels in patients with rheumatoid arthritis (RA) during treatment by vegetarian diet. Methods-Sera were collected from 53 RA patients who took part in a controlled clinical trial of fasting and a one year vegetarian diet. P mirabilis and E coli antibody levels were measured by an indirect immunofluorescence technique and an enzyme immunoassay, respectively. Results-The patients on the vegetarian diet had a significant reduction in the mean anti-proteus titres at all time points during the study, compared with baseline values (all p < 0.05). No significant change in titre was observed in patients who followed an omnivorous diet. The decrease in anti-proteus titre was greater in the patients who responded well to the vegetarian diet compared with diet nonresponders and omnivores. The total IgG concentration and levels of antibody against E coli, however, were almost unchanged in all patient groups during the trial. The decrease from baseline in proteus antibody levels correlated significantdy (p < 0.001) with the decrease in a modified Stoke disease activity index. Conclusion-The decrease in P mirabilis antibody levels in the diet responders and the correlation between the decrease in proteus antibody level and decrease in disease activity supports the suggestion of an aetiopathogenetic role for P mirabilis in RA.(Ann Rheum Dis 1995; 54: 221-224) Proteus mirabilis, a common cause of urinary tract infection, has been suggested to be of importance in RA.' Increased proteus antibody levels have been found in patients with RA compared with healthy controls and patients with ankylosing spondylitis, sarcoidosis, and systemic lupus erythematosus,'-3 although one study found no correlation between levels of antibodies to Proteus and the Stoke disease activity index.4In the present study we have examined the association between disease activity and proteus antibodies in RA patients during a controlled clinical trial of fasting and a one year vegetarian diet.5 We also measured IgG antibodies to Escherichia coli, and total IgG concentration, to test the species specificity of any changes in antibody titres. Patients and methods PATIENT POPULATION AND STUDY DESIGNDetails of the RA patients who took part in this controlled clinical trial of fasting and a one year vegetarian diet have been given elsewhere.5 Briefly, 53 patients were allocated randomly to a treatment group (n = 27) or a control group (n = 26). The patients in the treatment group were sent to a health farm for a period of four weeks. During the first seven to 10 days at the health farm the patients fasted; during the subsequent 3-5 months the patients followed a gluten free vegan diet (a vegetarian diet without milk and dairy products), followed by a lactovegetarian diet during the remaining nine months of the study period.5 The patients in the control group had a four week stay at a convalescent home, and they continued to follow their normal omnivorous diet throughout the whole study ...

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