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W Y Weiser

Publications and source records attributed to W Y Weiser.

27 records · Page 2Linked to original sources
PubMed1985

Antigen-dependent heterogeneity of human migration inhibitory factor.

Human migration inhibitory factor (MIF) produced by peripheral blood mononuclear cells stimulated with purified protein derivative, tetanus toxoid, streptokinase-streptodornase, or Candida albicans antigen was analyzed by gel filtration and isoelectrofocusing. In all cases, supernatants harvested after a 24-hr exposure of the mononuclear cells to the antigen yielded only one MIF species with an isoelectric point of 5. In contrast, isoelectrofocusing of supernatants obtained from cells exposed to the antigen for an additional 24 hr demonstrated that different antigens induce the elaboration of different MIF species. Streptokinase-streptodornase and tetanus toxoid induced the production of one MIF species with an isoelectric point of 5 (pH 5-MIF). Stimulation of cells with Candida antigen elaborated a MIF species with an isoelectric point of 3 (pH 3-MIF). In contrast, stimulation of cells with purified protein derivative induced the production of both pH 3-MIF and pH 5-MIF.

Antigens↗
PubMed1985

Generation of human hybridomas producing migration inhibitory factor (MIF) and of murine hybridomas secreting monoclonal antibodies to human MIF.

Human T-cell hybridomas were established by hybridization of concanavalin A (Con A)-stimulated human peripheral blood T lymphocytes with cells from a 6-thioguanine-resistant, aminopterin-sensitive mutant line designated CEM-WH4, derived from the continuously growing human T cell line, CEM. High levels of MIF activity were demonstrated in the supernatants of two hybridoma lines, T-CEMA and T-CEMB but not of CEM-WH4 when stimulated with phorbol myristate acetate and phytohemagglutinin. In comparison, MIF derived from Con A-stimulated peripheral blood mononuclear cells showed 100 times less activity. Upon isoelectrofocusing, MIF activity of T-CEMB was found exclusively between pH 4.6 and 5.3 whereas MIF derived from T-CEMA showed heterogeneity with a major peak of MIF recovered at pH 4.6-5.3 and a minor peak at pH 2.4-3.3. These molecules, however, were all found to have an apparent MW of 68,000 and were resistant to trypsin. Most of these characteristics are in accordance with second day pH 3- and pH 5-MIF derived from peripheral blood mononuclear cells. When spleen cells from BALB/c mice immunized with T-CEMB-MIF were used to fuse with NS-1 mouse myeloma cells, nine hybridomas secreting antibodies to human MIF were obtained. Clone D112 which demonstrated the highest MIF-neutralizing activity was found to neutralize MIF derived from T-CEMA, peripheral blood mononuclear cells, and a T cell line, Mo.

Animals↗
PubMed1985

Partial purification and characterization of a human lymphokine which induces antileishmanial activity in mouse macrophages.

Human blood mononuclear cells stimulated in vitro with concanavalin A secrete a lymphokine which activates mouse macrophages to kill Leishmania enriettii. Supernatants of cells cultivated for 1 day and for 2 days were analyzed for this activity after G-100 gel filtration and isoelectrofocusing. First day antileishmanial activity was found in a MW range of 23,000 with an isoelectric point of 3.6 to 4.0. Second day antileishmanial activity eluted in a peak in the MW range of 23,000 to 65,000 with an isoelectric point of 4.0 to 4.3. This activity could be completely separated from migration-inhibitory factor (MIF) after isoelectrofocusing in first day and in second day supernatants. Antileishmanial activity could be separated from interferon-gamma in first day, but not in second day supernatants.

Antiprotozoal Agents↗
PubMed1984

Dissociation of human interferon-gamma-like activity from migration-inhibition factor.

Supernatants harvested from concanavalin A-stimulated human peripheral mononuclear cells after 24 hr of incubation contain one interferon species similar to human interferon-gamma (IFN-gamma) with a pI of 4.6-5.3 (first day pH 5 IFN-gamm). In contrast, during the subsequent 24 hr of incubation two species with properties of IFN-gamma are produced with pI of 3.6-4.0 (second day pH 4 IFN-gamma) and 4.6-5.6 (second day pH 5 IFN-gamma), respectively. First day pH 5 IFN-gamma and second day pH 5 IFN-gamma have been found to differ on the basis of trypsin sensitivity. This pattern of polymorphism is similar to the pattern previously described for human migration-inhibitory factor (MIF) which can be separated into first day pH 5 MIF, second day pH 3 MIF, and second day pH 5 MIF. However, IFN-gamma-like species can be differentiated from MIF biochemically and antigenically. Fractions with second day pH 4 IFN-gamma have no MIF activity and fractions with second day pH 3 MIF contain no IFN activity. In addition, first and second day pH 5 MIF, which also contain IFN-gamma activity, can be separated from the latter by precipitation as well as neutralization with polyclonal and monoclonal anti-human MIF antibodies.

Antibodies↗
PubMed1984

Modulation of eosinophil cytotoxicity by blood mononuclear cells from healthy subjects and patients with chronic schistosomiasis mansoni.

Human blood mononuclear cells in culture release a factor(s) that markedly enhances eosinophil cytotoxicity. This factor(s) stimulates eosinophils to kill Schistosoma mansoni larvae at low antibody concentrations and cell/target ratios. A study of the mononuclear cells of 78 subjects with chronic schistosomiasis mansoni and 33 controls suggests that the production of eosinophil cytotoxicity enhancing activity (ECEA) is suppressed in most patients with S. mansoni infections. Suppression of ECEA production was not observed, however, with cells from many patients with heavy infections, including patients with hepatosplenomegaly. The possible role of ECEA in the development of pathology is discussed.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1981

In vitro macrophage manifestation of cortisone-induced decrease in resistance to mouse hepatitis virus.

Genetically resistant G3H mice routinely yielded macrophages that were resistant when grown in 90% horse serum. These mice also routinely yielded macrophages that were susceptible to the same virus, MHV (PRI), in vitro after the mice had been treated with three intraperitoneal doses, of hydrocortisone. Dexamethasone and prednisolone when similarly administered also increased the susceptibility of C3H macrophages taken from the treated animal, but progesterone and testosterone did not. In addition, spleen cells from mice treated with cortisone made the resistant C3H macrophages 100 times more susceptible in vitro. Increased in vitro susceptibility induced in this way by hydrocortisone was reversed by exposure to supernatant fluid removed from cultures of concanavalin A-treated spleen cells.

Animals↗
PubMed1981

Studies on human migration inhibitory factor: characterization of three molecular species.

Human migration inhibitory factor (MIF), obtained from supernatants of peripheral blood mononuclear cells stimulated with concanavalin A, was analyzed by gel filtration, isoelectrofocusing, and CsCl density gradient centrifugation. A distinct pattern of heterogeneity was determined on the basis of its harvesting time and biochemical criteria. Supernatants from cells cultured for 1 day contained a single peak of MIF activity with an isoelectric point of 4.3 to 5.2, an apparent m.w. of 23,000, and a density of 1.314 g/ml, the same as the density of the marker protein, 125I-HSA (1st day pH 5-MIF). Furthermore, this species of human MIF was sensitive to treatment with trypsin, strongly suggesting its being a protein, but not to treatment with neuraminidase and corresponds therefore to guinea pig pH 5-MIF. However, when 2nd day supernatants were analyzed under the same conditions, 2 MIF species were found. One species with an isoelectric point of 2.4 to 3.3 had an apparent m.w. of 65,000 (2nd day 3-MIF). The other species with an isoelectric point of 4.3 to 5.6 had an apparent m.w. of 23-43,000 (2nd day pH 5-MIF). Upon centrifugation in CsCl density gradients, the density (rho 25 of 1.314 to 1.414 g/ml) of both species was found to be greater than that of the pure protein, 125I-HSA. In addition, both species were chymotrypsin and neuraminidase sensitive but not trypsin sensitive, further suggesting their glycoprotein nature.

Animals↗
PubMed1977

Blocking of in vitro and in vivo susceptibility to mouse hepatitis virus.

By pretreatment with concanavalin A (Con A) both in vivo and in vitro genetically susceptible mice and their cultured macrophages have been converted to animals and cells which are phenotypically resistant to mouse hepatitus virus (MHV). Con A at 1.0 mg/mouse decreased the mortality from 100% to less than 40% by inducing a prominent inflammatory response, increasing the number of macrophages in the virus inoculation site, and producing a population of macrophages not uniformly susceptible to the virus. In addition, mediators derived from Con A-treated spleen cells conferred resistance to normally susceptible syngeneic macrophages to 100 TCID50 of MHV.

Animals↗