A multi-farm assessment of Greek black pig genetic diversity using microsatellite molecular markers.

Local breeds are important for the maintenance of genetic diversity and future food security. Nowadays, the worldwide distribution of pigs is dominated by a few breeds, tending towards a severe loss of pig biodiversity. Thus, it is critical to maintain distinct populations of pig breeds. The Greek black pig, a breed raised locally and known for the high quality of its meat for cured products, is the only traditional indigenous pig breed reared in Greece. We investigated the genetic diversity, based on microsatellite analysis, of the Greek black pig and evaluated its genetic uniqueness. One hundred and three pigs from 12 Greek farms were analyzed using 11 microsatellites. The total number of alleles amounted to 135, with a mean number of alleles per locus of 12.27, ranging between 10 and 16 alleles. The observed heterozygosity ranged from 0.363 to 0.825 per locus. The expected heterozygosity ranged from 0.471 to 0.707. The inbreeding coefficient ranged from -0.329 to 0.229. We conclude that the Greek black pig, despite its low population size, has a high degree of genetic variability, which will be useful for breeding programs aimed at maintaining long-term survival of this ancient breed.

Analysis of parotid glands of primary Sjögren's syndrome patients using proteomic technology reveals altered autoantigen composition and novel antigenic targets.

Sjögren's syndrome (SS) is an autoimmune disease characterized by lymphocytic infiltration, destruction of the salivary and lacrimal glands and production of autoantibodies against a variety of cellular proteins. The aberrant immune response against these autoantigens may begin or extend to other proteins that are not yet defined. Several studies have shown that autoantibody production is taking place in the affected salivary glands. In the present study, using proteomic approaches, we aimed to: (a) identify new autoantigens in the salivary glands of primary SS (pSS) patients and (b) evaluate the epigenetic changes of known autoantigens. Total parotid gland extracts of pSS patients were analysed using two-dimensional gel electrophoresis, sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblot with pSS patients' sera or purified autoantibodies and immunoprecipitation using homologous IgG. Identification of the unknown proteins was performed using mass spectrometry (MS). Immunoblot analysis on two-dimensional gels using purified anti-La/SSB antibodies revealed that pSS salivary glands contain high levels of post-translationally modified La/SSB autoantigen, while the native form of the protein is recognized faintly, in contrast to normal controls. Moreover, salivary glands of pSS patients contain post-translationally modified actin that becomes immunogenic in the microenviroment of the affected tissue. The alteration of the physicochemical properties of self-proteins could thus contribute to the break of immune tolerance against them.

Cross-reaction between antibodies to the major epitope of Ro60 kD autoantigen and a homologous peptide of Coxsackie virus 2B protein.

Coxsackie virus RNA has recently been detected in biopsy specimens of minor salivary glands from patients with primary Sjögren's Syndrome (pSS). A peptide derived from Coxsackie virus 2B protein (pepCoxs) presents 87% sequence homology with the 222-229 region of the major linear B-cell epitope of Ro60 kD autoantigen (pep216-232). Synthetic peptides corresponding to pep216-232: (216)KALSVETEKLLKYLEAV(232) and pepCoxs: (31)MVTSTITEKL LKNLVKI(47), were prepared. Sera from 42 patients with pSS and 43 patients with systemic lupus erythematosus (SLE) as well as sera from 27 healthy individuals (normal controls) and sera from 30 patients with rheumatoid arthritis (disease controls) were tested against the two homologous peptides. Twenty-five percent of SLE sera and 33.3% of pSS sera reacted against pep216-232, whereas 28% of SLE sera and 37% of pSS sera recognized the pepCoxs. The sera reacting with pep216-232 were apparently the same as those reacting with pepCoxs. Normal sera and disease control sera presented only a limited reactivity against both peptides (ranging from 3.7% to 10%). Both peptides reacted more prominently with anti-Ro/La (+) sera from pSS patients. Thus, pep216-232 was recognized by 17% of the anti-Ro (+) sera and by 42% of the anti-Ro/La (+) sera, whereas pepCoxs was recognized by 28.5% and 38% of the a-Ro(+) and a-Ro/La(+) sera, respectively. Purified anti-pep216-232 antibodies readily reacted with both peptides while inhibition experiments revealed the specificity of this reaction. These results suggest a possible cross-reaction between antibodies to the major linear B-cell epitope of Ro60 kD autoantigen and the homologous pepCoxs in pSS patients. This cross-reaction might potentially play a role in autoantibody formation and the perpetuation of the autoimmune response against Ro/SSA and La/SSB.