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Biomedical subjects

I Scher

Publications and source records attributed to I Scher.

116 records · Page 7Linked to original sources
PubMed1975

Specificity and immunosuppressive potency of a rabbit antimouse T cell-specific antiserum.

An attempt was made to prepare a specific heterologous rabbit antimouse T cell antiserum (anti-MTLA) by absorbing rabbit antimouse thymocyte globulin (ATG) with spleen cells from BALB/c TXBM mice. Cytotoxicity data showed that whereas ATG was cytotoxic to both T and B cells, anti-MTLA was highly cytotoxic to only T cells. Whereas spleen cells treated with ATG and complement (C) failed to respond in all assays studied, spleen cells treated with anti-MTLA and C: (1) responded to the B cell mitogens but failed to respond to the T cell mitogens; (2) were able to stimulate allogeneic spleen cells but failed to respond to mixed lymphocyte culture (3) failed to act as T killer cells in the CML reaction but retained their ability to kill antibody-coated target cells; and (4) did not cause a graft-versus-host reaction when injected in allogeneic mice and increased their survival significantly. Furthermore, anti-MTLA was just as immunosuppressive in vivo as ATG in its ability to suppress the immune response to sheep red blood cells and prolong skin allograft survival. Anti-MTLA was found to be different in specificities from anti-theta serum by several points: (1) it was cytotoxic for T cells from both theta-C3H and theta-AKR mice; (2) it was highly immunosuppressive in vivo when compared to anti-theta serum; (3) absorption of anti-MTLA with mouse brain did not decrease the immunosuppressive activity; and (4) rabbit antimouse brain antiserum failed to show any immunosuppressive activity. These data indicate that anti-MTLA is a specific antiserum against a unique marker on T cells distinct from the theta marker.

Animals↗
PubMed1975

The immune response to a synthetic amino acid terpolymer in man: relationship to HL-A type.

The immune response to the synthetic amino acid terpolymer (L-glutamic acid-55 L-lysine-33 L-tyrosine15)n (GLT) was studied in normal human volunteers. Delayed skin test reactivity to this antigen was seen in 34 of 61 subjects immunized with 150 mug of GLT. No antibody to GLT was detected in these responding individuals. There was a close correlation between the in vivo skin reactivity of volunteers to GLT and the ability of their lymphocytes to produce migration inhibitory factor (MIF) in response to GLT in vitro. However, a similar correlation was not seen when the in vitro proliferative response of lymphocytes to GLT, as measured by [methyl-3H] thymidine ([3H] T dR) incorporation, was assayed. HL-A typing of volunteers was studied to determine if responsiveness to GLT was correlated to HL-A type. No statistical association was seen after correction was made for the number of individual HL-A antigens.

Adolescent↗
PubMed1973

Specific murine B-cell activation by synthetic single-and double-stranded polynucleotides.

The synthetic single- and double-stranded polynucleotides, poly I, poly C, and poly I.C, were shown to induce thymidine incorporation in six inbred strains of murine spleen cells. This stimulation was shown to be secondary to B-cell activation and not due to contamination of the polynucleotides with bacterial lipopolysaccharide (LPS). The ability of poly I.C to act as a B-cell mitogen, in addition to its behavior as a thymic-independent antigen, suggested that these two phenomena may be related. The similarity of the molecular structure of poly I.C to LPS, a material which also acts as a thymic-independent antigen and a B-cell mitogen, supports the hypothesis that the polyvalent nature of these materials accounts for their functional interaction with murine B cells.

Animals↗
PubMed1972

Isolation of human synovial-fluid hyaluronate by density-gradient ultracentrifugation and evaluation of its protein content.

1. A compound of hyaluronate and protein, called hyaluronate-protein was isolated from pooled human synovial fluids by caesium chloride density-gradient ultracentrifugation. 2. The isolated hyaluronate-protein was labelled with [(125)I]iodide and the following studies were done. (a) Ultracentrifugation in caesium chloride showed that the protein moiety ((125)I counts) and hyaluronate (hexuronate) sedimented together in the middle of the gradient. (b) The labelled hyaluronate-protein was treated with trypsin, and ultracentrifugation showed that peptide fragments ((125)I counts) were dispersed throughout the gradient, indicating proteolytic digestion. Hyaluronate sedimented in the middle of the gradient. (c) The labelled hyaluronate-protein was digested with streptococcal hyaluronidase, and ultracentrifugation showed that hyaluronate fragments were dispersed throughout the gradient, indicating digestion of the polysaccharide. The protein moiety, without attached hyaluronate, now sedimented at the top of the gradient. (d) Ultracentrifugation of labelled hyaluronate-protein in 4m-guanidinium chloride showed that protein and hyaluronate sedimented together. 3. These studies confirm that hyaluronate is combined with a small quantity of protein in normal human synovial fluid. A mild method for the rapid isolation of hyaluronate-protein in good yield is described.

Centrifugation, Density Gradient↗