Experimental autoallergic sialadenitis in the LEW rat. III. Role of CD4+ T cells in EAS induction

Experimental autoallergic sialadenitis (EAS) in the LEW rat is an induced autoimmune disease of the salivary tissues. EAS is characterized by a lymphocytic infiltration that consists of both CD4+ (helper/inducer T-cell subset) and CD8+ (cytotoxic/suppressor T-cell subset) T cells and results in the immune-mediated destruction of the exocrine salivary glands. To investigate the role that each of the T-cell subsets may have in the pathogenesis of EAS, LEW rats sensitized with WF SMG homogenate were injected with monoclonal antibodies to deplete or inactivate, in vivo, the CD4, CD5 (OX19; pan T lymphocyte), CD8, or RT6 (70% of peripheral T cells) T-cell populations. Treatment with the OX8 (CD8), OX19 (CD5), or W3/25 (CD4) only partially reduced in vivo the respective splenic or lymph node T-cell subsets when analyzed on Day 14, while treatment with DS4.23 (anti-RT6) resulted in greater than 95% depletion of RT6+ spleen and lymph node T cells. EAS incidence and severity was significantly reduced in the W3/25 (CD4) treatment group (11% incidence rate; histologic score 1.0) as compared to medium-injected controls (88% incidence rate; histologic score 2.9). Although the incidence and severity of EAS in the OX19 (71%; histologic score 1.7), OX8 (55%; histologic score 1.7), and RT6 (67%; histologic score 1.6) treatment groups appeared decreased, the reduction was not statistically significant. These results provide evidence that CD4+ T cells have an important role in EAS induction and demonstrate that in vivo treatment with anti-CD4 can ameliorate and/or prevent EAS in the LEW rat.     

Microbiological quality of drinking water from dispensers in Italy

Background  

Water coolers are popular in office buildings and commercial stores and the quality of this source of drinking water has the potential to cause waterborne outbreaks, especially in sensitive and immunocompromised subjects. The aim of this study was to determine the quality of water plumbed in coolers from commercial stores in comparison with tap water in Italy.     

Purification of recombinant human secretory phospholipase A2 (group II) produced in long-term immobilized cell culture.

Recombinant human secretory phospholipase A2 (Group II) was expressed in long-term culture of immobilized Chinese hamster ovary cells utilizing a continuous-perfusion airlift bioreactor. The bioreactor was continuously perfused with cell-culture medium supplemented with 5% fetal calf serum at an average flow rate of 5 liters/day for 30 days. Recombinant phospholipase A2, at concentrations ranging from 100 to 500 micrograms/liter, was purified to apparent homogeneity by an efficient two-step procedure involving a silica-based cation-exchange resin and hydrophobic interaction chromatography (greater than 65% recovery of phospholipase A2). The purified recombinant protein has an apparent molecular weight of 16 kDa, identical to that of purified human placental or synovial fluid phospholipase A2, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Application of the purified protein onto several different gel filtration columns resulted in elution of the protein at molecular weights corresponding to 3.1-4.7 kDa, suggesting an interaction of the protein with the column resins. However, analytical ultracentrifugation experiments revealed that the protein behaves as a monomer (13.8-14.2 kDa) over a protein concentration range of approximately 10 micrograms/ml to 5 mg/ml. With autoclaved Escherichia coli membranes as substrate, the recombinant protein has catalytic properties (pH optimum, effects of bovine serum albumin, sodium chloride concentration, and requirement for calcium) similar to those of the protein purified from human placenta.