The cytotoxic reactivity and sialic acid content of human lymphoid cells

Characterization of active T cells in CSF and blood in multiple sclerosis patients and controls

In thirty-two patients with multiple sclerosis (MS), significantly lower percentages of active T cells--that is, lymphocytes which have been incubated at 37 degrees C for 1 h before 5 min rosetting with sheep erythrocytes--were found in cerebrospinal fluid (CSF) than in blood, whereas the reverse was observed in twenty of twenty-two patients with other neurological diseases (OND). No significant difference was found between percentages of active T cells in blood in MS, OND, and healthy controls. Lymphocytes from MS CSF are extensively temperature-labile when examined under different test conditions; without incubation at 37 degrees C for 1 h, active T cell percentages in CSF of both patients with MS and OND were, in fact, higher than in peripheral blood. The mitogen response patterns of enriched active T cells and unseparated lymphocytes from peripheral blood did not discriminate between patients with MS and healthy controls. Although active T cell values have been shown to correlate with cell-mediated immunocompetence, they have not yet been defined functionally. One of the explanations for the present findings could be that lymphocytes themselves in MS patients' CSF are at least partly virus-infected.

Neuraminidase and tumor immunotherapy

Preliminary results of first clinical studies with the enzyme neuraminidase call attention to a new kind of cancer treatment. This promising approach to tumor immunotherapy was entered into the clinical phase as a consequence of successful experimental studies in tumor-bearing mice, rats and dogs. In this review, the presently known and essential results of experimental and clinical studies on tumor immunotherapy by means of neuraminidase are presented as well as some necessary and critical considerations in this context. Moreover, out of a broad variety of results of biochemical and biological in vitro studies, it was attempted to select the more essential knowledge which could contribute to a better understanding of the still rather unclear in vivo mode of action of the enzyme neuraminidase. In a first brief paragraph (1.0), the biochemically characteristic data of the enzyme neuraminidase is presented. In the second section (2.0), the basic knowledge about the effects of neuraminidase on cell behavior is rather amply contained. Here, on the one hand, the biophysical and biochemical alterations are mentioned, the so-called ""unmasking'' effects are reconsidered and, on the other hand, the effects on the immunologically responding cell are discussed. In a third section (3.0), the diverse findings from animal experiments using neuraminidase-treated tumor cells are confronted, whereby tumor transplantation experiments and tumor therapy experiments are dealt with separately. The last section (4.0) reports about the first clinical studies with neuraminidase-treated autologous as well as homologous tumor cells, which partly brought about rather surprising and astonishing success. On the basis of recent findings by the study group of the authors, the more prior and sometimes discrepant results of various groups are critically considered. The problems of alteration of antigenicity and of other properties of cells through splitting off membrane-bound neuraminic acid, the facts of adjuvanticity of neuraminidase itself, the relation of successful therapy to dose dependency as well as the relation of undesirable methods for tumor mass reduction to the immunological responsiveness of the tumor bearer were especially looked into.

[The effext of papain, neuraminidase and AET on the behavior of lymphocytes in cytotoxicity tests]

The influence of papain, neuraminidase and AET to lymphocytes is reported. All three substances strengthen the lymphocytotoxic reaction in low concentrations or by short incubation time and lower it in higher concentrations or longer incubation since. Membrane changes by these three substances are reversible under defined conditions.