Possible involvement of IL-12 expression by Epstein-Barr virus in Sjögren syndrome.

AIM: To determine the correlation between interleukin 12 (IL-12) expression and Epstein-Barr virus (EBV) in Sjögren syndrome. METHODS: Indirect immunohistochemical technique, enzyme linked immunosorbent assay (ELISA), and immunoblot analysis were used to investigate IL-12 expression by EBV activation, using 13 surgical specimens and four B cell lines. RESULTS: Marked expression of IL-12 was found in the epithelial cells and the infiltrating B cells of salivary gland tissues from patients with Sjögren syndrome (six of 10 cases), but not in those from normal individuals (none of three cases). A striking topographic correlation between IL-12 and EBV was found. In addition, levels of IL-12 production by B cell lines were clearly enhanced by EBV activation in vitro. CONCLUSIONS: IL-12 expression closely reflects the intracellular event of EBV activation in Sjögren syndrome, and may contribute to the T helper cell type 1 (Th1) cytokine overexpression seen in this disease.

Retrovirus in salivary glands from patients with Sjögren's syndrome.

AIMS: To investigate the possibility of an immune response to retroviral antigens or of detecting retrovirus in Sjögren's syndrome. METHODS: Retroviruses were sought in labial salivary glands and peripheral blood mononuclear cells from patients with Sjögren's syndrome by immunoblotting assay, immunohistochemical assay, polymerase chain reaction (PCR), reverse transcriptase (RT) activity assay, and transmission electron microscopy. RESULTS: Sera from five of 15 patients with Sjögren's syndrome (33%) reacted against p24 group specific antigen (gag) of human immunodeficiency virus (HIV). Labial salivary gland biopsy specimens from seven of the 15 patients with Sjögren's syndrome (47%) contained an epithelial cytoplasmic protein reactive with a monoclonal antibody to p24 of HIV. PCR was performed to detect HIV and human T lymphotropic virus type I (HTLV-I) genes from salivary gland tissues and peripheral blood mononuclear cells from patients with Sjögren's syndrome. Mn2+ dependent, Mg2+ independent RT activity was detected in the salivary gland tissues in three of 10 patients. A-type-like retroviral particles were observed in epithelial cells of salivary glands by transmission electron microscopy. Target genes for HIV and HTLV-I were not found in any of the salivary gland tissues or peripheral blood mononuclear cells from Sjögren's syndrome patients. CONCLUSIONS: The data suggest the presence of an unknown retrovirus similar to HIV in the salivary gland which might be involved in the pathogenesis of a subpopulation in Sjögren's syndrome.

Cytotoxicity reactions against target cells infected with rabies virus.

Some aspects of the cytotoxicity reactions were studied in the rabies system. The antibody-dependent complement cytotoxicity (ADC), the cellular cytotoxicity (CC), and the antibody-dependent cellular cytotoxicity (ADCC) are shown, being the cytotoxic effect as evidenced by the 51Cr released from the cells infected with the Pasteur strain of rabies virus. Some parameters such as time of cellular infection, the amount of infected cells, the concentration of complement, and the incubation time of the ADC reaction, which help to increase the performance of this reaction, are discussed. The detection and the level of the cellular response against the Pasteur strain of rabies virus in immunized mice is shown. Evidence is presented that in the ADCC test, specific human antibodies and non-immune human lymphoid cells are able to mediate in vitro lysis of cells infected with rabies virus. A comparison of the ADCC test with serum neutralization and immunoenzymatic tests is shown.