Biomedical subjects

M Rosenkoetter

Publications and source records attributed to M Rosenkoetter.

4 recordsLinked to original sources

PubMed1984

Low T8 antigen density on lymphocytes in active multiple sclerosis.

The median fluorescence intensity of peripheral blood T8+ (T-suppressor/cytotoxic) cells in patients with active (relapsing or progressive) or stable multiple sclerosis (MS) and in control subjects was determined with a fluorescence-activated cell sorter using an indirect immunofluorescence assay. Median fluorescence intensity was significantly lower in patients with active MS than in controls. No differences in median fluorescence intensity were found between patients with stable MS and controls. Analysis of T8+ cells that had been modulated in vitro with OKT8 indicated that the resultant reduction in the median T8 antigen density per cell resulted in fewer T8+ cells being enumerated when the fluorescence-activated cell sorter was used than when a fluorescence microscope was used. Reduced median T8 antigen density on cells as found in active MS may contribute to the apparent underrepresentation of circulating T-suppressor cells in such patients and may be associated with reduced suppressor cell function.

Adult↗

PubMed1984

Multiple sclerosis: relation of in vitro IgG secretion to T suppressor cell number and function.

The proportion of MS patients whose pokeweed mitogen-stimulated mononuclear cells (MNCs) secreted greater than 1,000 ng/ml IgG per 10(6) cells (ie, "high responders") was increased compared with controls. The suppressor effect mediated by a constant number of T8+ cells from high responders, both MS and control, on IgG secretion by standard T helper (T4+) plus B-cell cultures was significantly lower than that for the same number of T8+ cells from "low responders." The proportion of T8+ cells within MNCs from MS patients did not correlate with levels of IgG secretion. Our results indicate that high levels of IgG secretion by MNCs, an occurrence overrepresented in the MS population, is significantly influenced by functional properties of T suppressor cells.

Adolescent↗

PubMed1984

T cell regulation of polyclonally induced immunoglobulin secretion in humans.

We measured the pokeweed mitogen (PWM)-induced secretion of IgG by the unfractionated mononuclear cells (MNC) of young adult donors, and correlated the results with the functional activity of cell suspensions enriched for T helper (T4+) and T suppressor/cytotoxic (T8+) cells. The distribution of IgG levels secreted by MNC differs from a Gaussian curve, implying that the group is composed of distinct heterogeneous populations. When donors were compared who were judged to be very low responders or very high responders on the basis of IgG secretion levels by MNC (less than 700 ng/ml or greater than 2500 ng/ml), no differences were found in the capacity of T4+-enriched cells to support PWM-driven IgG secretion by a common B cell pool. In contrast, the addition of 0.2 X 10(5) T8+ cells from these low responders to PWM-stimulated cultures of 0.5 X 10(5) T4+ cells plus 0.5 X 10(5) B cells resulted in significantly less IgG secretion (389 +/- 121 ng/ml) than did the addition of the same number of T8+ cells from the high responders (2241 +/- 548 ng/ml, p less than 0.01). Normalized percent suppression by T8+ cells was higher in low responders than in high responders (77.0 +/- 9.9% vs 33.0 +/- 8.5%, p less than 0.01). Both high and low responders markedly suppressed IgG secretion when 0.5 X 10(5) T8+ cells were added. No correlation was found either between proportion of T3+, T8+, T4+, or M1+ cells within the MNC population and levels of IgG secretion by MNC or between T8+ numbers and levels of suppression induced by a constant number of T8+-enriched cells. Our data indicate that differences in the functional activity of T8+ cells, rather than quantitative differences, account for the wide range of PWM-induced IgG secretion by MNC.

Adult↗

PubMed1983

Modulation of T lymphocyte differentiation antigens: influence of aging.

In vitro modulation of human T lymphocyte surface differentiation antigens T3, T8, and T4, by their respective monoclonal antibodies, was studied as a function of donor age. Kinetic studies performed on lymphocytes from young adults indicated that modulation is dependent on concentration of antibody used and duration of culture. OKT3 modulates T3 rapidly (maximum at less than 24 hr) and relatively completely (79% at the highest concentration of antibody used). By 48 hr, regeneration of the T3 antigen is apparent. T8 modulation by OKT8 is slower (continued modulation at 48 hr) and less complete than is T3 modulation by OKT3. OKT4 does not modulate the T4 antigen. In elderly individuals modulation of T3 by OKT3 is preserved whereas modulation of T8 by OKT8 is significantly reduced (24 +/- 8% at 48 hr vs 53 +/- 4% for young controls). These observations document further age-related changes in properties of human T suppressor cells.

Adult↗