ABSTRACT
The lupus band is the result of immune complex deposition along the dermo-epidermal junction; such complexes are formed in situ by the interaction of antinuclear antibodies with their respective autoantigens. Dermal autoantigens are released after sun exposure, concurrently a heat shock protein production take place and would participate in autoantigen transfer to the dermo-epidermal junction. In this work the presence of Hsp70 along with the lupus band was investigated by immunofluorescence in twenty SLE skin biopsies. Immune deposits were mainly composed by IgM, IgG and C3 and were found in all lupus biopsies at the dermo-epidermal junction. Immunoreagents were also present into papillary vessels and, with less extent, into epidermal keratinocytes. Hsp70 was present in 60% of lupus biopsies, and was mainly distributed along dermo-epidermal junction and around papillary vessels. Furthermore, by double fluorescence labelling assays, we found that immuno-reactants are co-localized with Hsp70. Our results suggest that Hsp70 would shuttle autoantigens to the dermo-epidermal junction.
Subject(s)
Antigen-Antibody Complex/analysis , Autoantigens/metabolism , HSP70 Heat-Shock Proteins/physiology , Lupus Erythematosus, Systemic/immunology , Skin/immunology , Adolescent , Adult , Antigen-Antibody Complex/immunology , Autoantibodies/analysis , Autoantigens/analysis , Biopsy , Female , HSP70 Heat-Shock Proteins/analysis , HSP70 Heat-Shock Proteins/immunology , Humans , Keratinocytes/immunology , Keratinocytes/metabolism , Male , Protein Transport , Skin/radiation effects , SunlightABSTRACT
AIM: Assess the expression of FasL, Bax, TNFa and IL-6, genes in salivary glands of primary Sjögren patients. METHODS: Twenty minor salivary glands from patients with primary Sjögren syndrome were studied by in situ hybridization with cDNA fluorescent probes. An equal number of control biopsies were included. RESULTS: Sjögren salivary glands differentially display the inflammatory cytokines and pro-apoptotic mRNAs as follows: mononuclear infiltrating cells exhibited IL-6 and TNFa, whereas the ductal epithelium and acinary cells mainly expressed FasL and Bax. Control biopsies were negative. CONCLUSION: Present data suggest that local production of inflammatory cytokines would induce the Fas and Bax pathways committing the ductal epithelium and the acinary cells to apoptosis.
Subject(s)
Apoptosis/genetics , Membrane Glycoproteins/genetics , Proto-Oncogene Proteins c-bcl-2 , Proto-Oncogene Proteins/genetics , Salivary Glands, Minor/metabolism , Sjogren's Syndrome/genetics , Adult , Fas Ligand Protein , Female , Gene Expression Regulation , Humans , Male , Membrane Glycoproteins/metabolism , Middle Aged , Proto-Oncogene Proteins/metabolism , RNA, Messenger/metabolism , Sjogren's Syndrome/metabolism , Tumor Necrosis Factor-alpha/metabolism , bcl-2-Associated X ProteinABSTRACT
The Ro complex is composed of three ribonucleoproteins of 60, 54, and 52 kDa. The Ro60 is associated with the 1-5 hYRNAs. Autoantibodies against Ro are found in sera from lupus patients. Lupus frequently presents in female patients during childbearing years and transplacental passage of maternal anti-Ro/La autoantibodies has been implicated in triggering neonatal lupus and congenital heart block (CHB). Since expression of Ro ribonucleoproteins occurs before the onset of CHB, epitope spreading of Ro hYRNAs could arise during cardiac ontogeny, thus maternal autoantibodies would damage a previously developed AV node. To explore the cardiac ontogeny of Ro hYRNAs, embryonic and adult tissues were obtained from legal autopsies. In situ hybridization using oligonucleotides for hY1, hY3, hY4, hY5, and Ro60 was performed on sections of cardiac tissue; their corresponding cDNAs were amplified by RT-PCR. The principal results were as follows: expression of hY4/5RNAs was greater in fetal tissues from 8-12 weeks of development. The subcellular distribution of hYRNAs in embryonic tissues was nucleocytoplasmic, whereas in the adult heart it was cytoplasmic. In conclusion, hYRNAs expression occurs during early cardiac development.
Subject(s)
Atrioventricular Node/chemistry , Autoantigens/genetics , RNA, Ribosomal, 5S/analysis , RNA, Small Cytoplasmic , Ribonucleoproteins/genetics , Adult , Atrioventricular Node/embryology , Fetus/chemistry , Gene Expression Regulation, Developmental , Humans , In Situ Hybridization , Oligonucleotide Probes , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
These studies were carried out to examine the presence of the inflammatory cytokines IL-6 and TNFalpha in kidneys of patients with lupus nephritis as an indicator of their possible role in its pathogenesis. A total of 19 kidney biopsies from patients with type III or IV lupus nephritis were processed by direct immunofluorescence using monoclonal anti-IL-6 and TNFalpha antibodies. Local expression of these genes was demonstrated both by in situ hybridization and by reverse transcriptase-PCR amplification of total RNA isolated from kidney tissue. Fifty-two percent of the biopsies exhibited IL-6 and TNFalpha deposited along the glomeruli and tubules; in situ expression of these cytokines was demonstrated in 6 biopsies with type IV, and 1 with type III nephritis. Inflammatory cytokines are actively synthesized in the kidneys of patients with lupus nephritis and therefore, may play a role in its pathogenesis.
