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Biomedical subjects

R H Weisbart

Publications and source records attributed to R H Weisbart.

8 recordsLinked to original sources
PubMed1992

An antibody that binds a neutrophil membrane protein, ERp72, primes human neutrophils for enhanced oxidative metabolism in response to formyl-methionyl-leucyl-phenylalanine. Implications for ERp72 in the signal transduction pathway for neutrophil priming.

Human neutrophils are primed by cytokines for enhanced oxidative metabolism in response to chemotactic factors, but the signal transduction pathways for cytokine activation and priming are unknown. Neutrophil priming may play an important role in mechanisms of host defense and inflammatory responses associated with autoimmune diseases. A rabbit antibody was produced that reacted with human neutrophils and induced priming in response to the chemoattractant, FMLP. The protein responsible for neutrophil priming in response to binding antibody was identified in a neutrophil cDNA library by expression cloning. The cloned protein absorbed the neutrophil-priming activity from rabbit serum. Furthermore, antibody priming activity was recovered by elution from the cloned protein. The gene for the protein associated with neutrophil priming was sequenced and identified as the endoplasmic reticulum protein, ERp72, which contains three copies of the active site sequences of protein disulfide isomerase. The antibody that primed neutrophils was shown to bind ERp72 in neutrophil membranes by immunoprecipitation of the same 72-kDa protein from neutrophils as a known antibody to ERp72. These studies implicate ERp72 in the signal transduction pathway for priming human neutrophils.

Amino Acid Sequence↗
PubMed1979

Neutrophil migration-inhibition activity produced by a unique T lymphoblast cell line.

Fifteen lymphoblast cell lines, including B cell, T cell, Null cell, and myeloblast cells, were examined for the production of human neutrophil migration-inhibition activity. Only one T lymphoblast cell line established from a patient with hairy cell leukemia produced a neutrophil migration-inhibition factor spontaneously and after stimulation with Con A and PHA.

B-Lymphocytes↗
PubMed1978

Cellular collaboration in the production of human leucocyte migration inhibition factor.

The participation of cell subpopulations in the expression of leucocyte migration inhibition factor (LMIF) in response to Concanavalin A and Protein A was evaluated for cells isolated from the peripheral blood of five healthy subjects. LMIF activity could not be attributed to the function of T cells, B enriched cells, or monocytes acting alone, or to a combination of B enriched cells and monocytes. The LMIF response was the result of a collaborative event that occurred between T cells and B enriched cells, or between T cells and monocytes.

B-Lymphocytes↗
PubMed1977

A microassay for leukocyte migration: analysis of its reproducibility.

A reliable microassay for human leukocyte migration is described by which 50 to 100 assays can be performed each day in quadruplicate with the number of indicator cells obtainable from 10 to 20 ml of peripheral blood. The reproducibility of this method is demonstrated with respect to the variability among replicate test wells (including reading), the variability among different test readers, the variability among replicate cultures, and the variability of using indicator cells from different subjects. A microculture system is described that requires only 75,000 mononuclear cells to consistently produce detectable polymorphonuclear leukocyte migration inhibition factor in response to PPD. The reproducibility of this culture system is demonstrated with respect to the variability of lymphocyte responsiveness on repetitive testing in the same individuals.

Antigens↗
PubMed1976

Lymphocyte response to IgG in patients with ankylosing spondylitis and their families.

Lymphocyte responsiveness to IgG was measured by an agarose method in nine patients with ankylosing spondylitis (AS), one patient with Reiter's Syndrome (RS), and thirty-six of their family members. Similar studies were also performed in five patients with rheumatoid arthritis (RA) and twenty-nine of their first degree relatives as well as in seven control families (twenty-seven subjects). Lymphocytes from the ten spondylitic patients and twenty-four of thirty-six family members responded in vitro to autologous IgG. Although most of these subjects had the histocompatibility antigen, B27, there was no association between B27 and response to IgG. Four of the five patients with RA and twenty of their twenty-nine first degree relatives responded in vitro to IgG, whereas only six of twenty-seven control family members gave a positive reaction. There was no difference in the incidence of antiglobulins (detected by agglutination tests) in the family members of patients with AS and RA or in control family members. These data indicate that lymphocyte responsiveness to IgG is the only aberrant immune response thus far described which is shared by patients with AS and RA and their family members.

Adolescent↗
PubMed1975

Cellular immunity to intrinsic factor in pernicious anemia.

Cellular immunity to hog intrinsic factor was detected by a modified agarose-leukocyte migration test in 18 patients with pernicious amemia. Lymphocytes from 17 out of 18 patients with pernicious anemia gave positive responses to a concentrate of hog intrinsic factor; the intrinsic factor present in 1 mg. of this concentrate bound 128 ng. of vatamin B12. Six patients with atrophic gastritis, 7 with regional enteritis, and 9 out of 10 healthy adults did not respond to this preparation. No correlation existed between the presence of serum autoantibodies to intrinsic factor and in vitro lymphocyte responsiveness to intrinsic factor. The results demonstrate that cellular immunity to intrinsic factor concentrates is present in the majority of patients with pernicious anemia.

Adult↗
PubMed1975

Human polymorphonuclear leucocyte migration inhibitory factor. Evidence for antigen dependency.

Sudies were performed on human polymorphonuclear leucocyte migration inhibitory factor (PMN-MIF) to determine its antigen dependence. PMN-MIF produced by lymphocytes in response to purified protein derivative or coccidiodin was measured in an agarose gel system with buffy coat leucocytes as indicator cells. PMN-MIF activity contained in the lymphocyte supernatants uniformly disappeared when the supernatants were diluted 1:50 with medium; the inhibitory activity was only restored when the diluted supernatants were reconstituted with specific antigen. PMN-MIF isolated by polyacrylamide gel electrophoresis showed the same properties as PMN-MIF present in whole supernatants. This factor consistently migrated in the albumin region on gel electrophoresis. These data indicate that human PMN-MIF is antigen-dependent.

Antigens↗