Objective. To examine the expression of molecules known to participate in early T cell receptor (TCR)/CD3 signaling in peripheral blood (PB) T lymphocytes from patients with systemic lupus erythematosus (SLE).Methods. Signaling molecules were analyzed by immunoprecipitation and Western blotting of unstimulated PB T lymphocyte cell lysates from SLE patients, non-SLE disease controls, and healthy controls. Flow cytometry was used for analysis of the expression of membrane markers in intact cells.Results. PB T lymphocytes from SLE patients showed diminished levels of TCR chains. This was not due to trapping of these molecules in the cytoskeleton, nor was it dependent on the presence of monocyte/macrophages. There was normal expression of CD3 chains and normal assembly of TCR/CD3 complexes in membranes. We observed a lack of expression of TCR chains in in vitro cultures of SLE T cells, and reversal of the defective expression in some patients by culturing T cells in the presence of NH 4 Cl.Conclusion. Blood lymphocytes from SLE patients have a diminished expression of TCR chains that may be related to enhanced degradation in the lysosomal compartment. The defective expression of these molecules may alter signal transduction via the CD3 pathway and contribute to abnormal T cell responses in T lymphocytes from SLE patients.

Trichomonas vaginalis can be grown in cell culture. We studied the growth kinetics of T. vaginalis in McCoy cell culture compared with that in a conventional broth medium (Diamond TYI-S-33 medium supplemented with 10% heat-inactivated bovine serum [TYI]). In the presence of McCoy cells and two parts cell culture medium to one part TYI, a peak concentration of 2 x 106 to 6 x 106 T. vaginalis per ml was consistently achieved with inocula as low as three T. vaginalis cells per ml. Without cells, this medium did not support growth of T. vaginalis. T. vaginalis in TYI in 1-ml vials with or without McCoy cells demonstrated poor growth. In tubes containing 10 ml of TYI, inocula grew to 2 x 106 to 6 x 106 T. vaginalis per ml, but at least 3 x 101 T. vaginalis per tube was required to initiate growth. Thus, in vitro, cell culture was more sensitive than TYI broth in detecting low numbers of T. vaginalis. In a subsequent clinical comparison of broth and cell culture for isolation of T. vaginalis from 188 vaginal specimens and 21 urethral specimens from men, the results were in agreement for 206 specimens (98.6%). There were no situations in which culture was negative and a saline preparation showed motile trichomonads. For women, using a positive culture as the indicator of true positivity, the sensitivity of detection of T. vaginalis was 83% with the Pappenheim stain and 77% with saline preparations. In tests with a limited number of men, the Pappenheim stain was neither sensitive nor specific for detection of T. vaginalis in comparison with cultures or saline preparations. These studies show that cell culture can be used for isolation of T. vaginalis from clinical specimens; it gave results comparable to those of broth culture for the group of mainly symptomatic womèn. Further studies should be performed to determine its utility in clinical populations such as asymptomatic women and men with and without symptoms, in which T. vaginalis is more likely to be present in low nuffibers.

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Entamoeba histolytica, the protozoan responsible for human amoebiasis, has a complex genome, whose linear chromosomes and DNA circles have so far eluded detailed analysis. We report the detection by transmission electron microscopy of nuclear vesicles (0.05-0.3 microm in diameter) carrying DNA in E. histolytica trophozoites. In late anaphase many of these nuclear vesicles were found to be organized in structures of approximately 2.5 x 1 microm, in association with chromosomes and microtubules. In glutaraldehyde-fixed and detergent-treated trophozoites, nuclear vesicles displayed a non-membranous envelope. Binding of phosphotungstate stain and recognition by serum from patients with systemic lupus erythematosus indicated that these vesicles contain DNA. Similar DNA carrier vesicles were found in the cytoplasm and in the E. histolytica kinetoplast-like organelle (EhkO). By Feulgen staining, we detected DNA carrier vesicles entering or leaving the nuclei, suggesting a structural relationship between the nuclear vesicles and the vesicles present in the EhkOs.

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