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Results for “Leukocyte Migration-Inhibitory Factors”

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PubMed1978

Effects of cyclophosphamide on the expression and induction of delayed hypersensitivity.

Erythematous delayed reactions without induration, presumably assigned to Jones-Mote type, were characterized by the resistance to treatment with cyclophosphamide (CY) before elicitation or immunization in guinea pigs immunized with BGG in IFA or CFA. CY-treatment before elicitation converted delayed erythematous reactions from negative to positive at late intervals after immunization with BGG in IFA. Such a treatment augmented erythematous delayed reactions in animals immunized with BGG in CFA, but abolished induration at the reaction sites. CY-treatment before elicitation or immunization reduced the numbers of basophils at the reaction sites, although erythematous delayed reactions were augmented. Effector T cells responsible for delayed erythematous reaction without induration appear to persist for a long period of time after immunization in the presence of antibody production or tuberculin hypersensitivity and the expression of their function may be inhibited by suppressive mechanisms.

Animals↗
PubMed1976

Some physicochemical properties of human leucocyte migration inhibitory factor (LIF).

Leucocyte migration inhibitory factor (LIF) obtained from human lymphocytes stimulated with concanavalin A was consistently and irreversibly blocked by the serine-esterase inhibitor phenyl-methyl sulphonylfuoride (PMSF). This effect was not due to fluoride ions, hydrolysis products of PMSF or to impurities. PMSF pulse treatment of human buffy coat cells did not affect cell migration under agarose. LIF was also irreversibly destroyed by treatment with L-cysteine and 2-mercapto-ethanol, suggesting that the molecule contains disulphide linkage groups decisive for its configuration and biological activity. Di-sodium EDTA completely inhibited LIF activity but only if present during the entire migration period. Removal of EDTA before LIF assay restored LIF activity. Leucotye migration was neighter influenced by L-cysteine nor by EDTA. LIF activity was slightly diminished after treatment at 56 degrees C for 1 h and completely lost at 80 degrees C for 1/2 h. Furthermore, LIF appeared rather stable when treated at pH values between 4 and 11. These findings suggest, but do not prove, an esterase or a protease nature of human LIF.

Concanavalin A↗
PubMed1975

Properties and activities of transfer factor.

Although there is agreement that transfer factor endows skin test-negative subjects with the ability to develop the delayed allergic responses of the transfer factor donors, there is little direct information on the mechanism of this phenomenon or on the nature of the active components (s). This report reviews some of the known effects of transfer factor or immune responses and inflammation. It is concluded that transfer factor has multiple sites of action, including effects on the thymus, on lymphocyte-monocyte and/or lymphocyte-lymphocyte interactions, as well as direct effects on cells in inflammatory sites. It is also suggested that the "specificity" of transfer factor is determined by the immunologic status of the recipient rather than by informational molecules in the dialysates. Finally, it is proposed that many effects of transfer factor may be due to changes in intracellular cyclic nucleotide content, especially accumulation of cGMP, in immunologically reactive cells.

Antibody Formation↗
PubMed1979

[Kinetic differences in induction of the killers and producers of the macrophage migration inhibitory factor (MIF) in primary and secondary mixed murine leukocyte culture test].

Conditions are selected for the killer induction during primary and secondary responses in the one-way MLC, stimulated by x-irradiated or killed allogenic lymphocytes. MIF is found in the MLC culture medium as a sharp peak on the 2nd or the 3rd day of the primary reaction, or as a plato from the 1st day of the secondary reaction. In contrast, the killers are shown to be induced much later reaching their maximum on the 5th and the 4th days, respectively. If heated, instead of irradiated, allogenic lymphocytes were used for stimulation of the primary MLC reaction, the MIF-producer kinetics was not changed, but the killer induction was found to be delayed.

Animals↗
PubMed1978

The indirect assay for leukocyte migration inhibitory factor (LIF)--standardization and the effect of pH.

In the indirect assay for leukocyte migration inhibitory factor (LIF), lymphokine-rich supernatants were obtained by culture of stimulated lymphocytes and then tested for LIF activity in agarose plates using purified granulocytes as target cells. Studies on the standardization of the conditions under which LIF acts on the target cells are described, with emphasis on the use of "standard" supernatants of known LIF activity and the influence of pH on the action of LIF and the sensitivity of the assay. The observation that LIF activity is reduced when the ambient pH falls below 7.2 is suggested as an explanation firstly for the "escape" phenomenon seen particularly in capillary tube assays for LIF, and secondly for the reduced sensitivity of the capillarly tube assay in comparison with the corresponding agarose plate assay.

Granulocytes↗
PubMed2026

MIF-CD74 axis facilitates MDSC infiltration in the tumor microenvironment of pancreatic ductal adenocarcinoma.

Immune checkpoint inhibitors show insufficient efficacy against pancreatic ductal adenocarcinoma (PDAC). The tumor microenvironment (TME) has a remarkable influence on responsiveness to cancer immunotherapy. The aim of this study was to investigate immunosuppressive characteristics of TME in PDAC tissues. The flow cytometry (FCM) of PDAC surgical specimens revealed that the profile of tumor-infiltrating leukocytes was classified into myeloid cell- and T-cell-dominant subtypes; the myeloid subtype was associated with poorer patient outcomes. Myeloid-derived suppressor cells (MDSCs) showed the highest hazard ratio among various myeloid cell types. Single-cell RNA sequencing and FCM revealed that most MDSCs, but not lymphocytes, in PDAC tissues characteristically express CD74. Macrophage migration inhibitory factor (MIF), a CD74 ligand, was highly expressed in cancer-associated fibroblasts (CAFs) and cancer cells. Spatial transcriptomics demonstrated that the MIF-CD74+ myeloid cell interaction was recognized in CAF-dominant areas in PDAC tissue. CAFs expressing immune suppressor molecules such as MFAP5 and LRRC15 were consistent with MIF+ CAFs. Furthermore, MIF+ CAFs enhanced the migratory activity of MDSCs and promoted MDSC induction and activation. In the murine model, MDSCs were significantly increased in MIF-expressing PDAC tumors, as were CD74+ M-MDSCs per M-MDSC, confirming in vivo interaction between CD74 and MIF. MDSCs play a crucial role in creating an immunosuppressive TME in PDAC; the MIF-CD74 axis drives interactions between MDSCs and CAFs.

Humans↗
PubMed1979

Abrogation of cell-mediated immunity by a serum blocking factor isolated from patients with infectious mononucleosis.

Lymphocytes from 80% of patients with infectious mononucleosis in this study failed to produce macrophage migration-inhibition factor in response to partially purified early antigen of Epstein-Barr virus or to tetanus toxoid, whereas lymphocytes from normal subjects did produce this lymphokine. Subsequent analysis of serum from the patients with infectious mononucleosis revealed a serum factor that completely abrogated antigen-specific inhibition of migration by human leukocytes as well as lymphocyte blastogenesis. The serum blocking factor was present in sera from 11 (73%) of 15 patients with infectious mononucleos but only in sera from two (13%) of 15 normal subjects. Samples of serum from five of the patients with infectious mononucleosis and five normal subjects were fractionated with use of Sephadex G-200 gel filtration, and the eluants were assayed for several substances known to inhibit cell-mediated immunity. Serum blocking factor activity could be demonstrated only in fractionated sera from patients with infectious mononucleosis. The serum blocking factor is postulated to be either a soluble immune complex or some as yet unidentified immunoregulatory globulin contained in the IgG fraction of human serum.

Antigen-Antibody Complex↗
PubMed1976

Leukocyte migration inhibitory factor (LMIF) production in unidirectional mixed lymphocyte cultures.

Puromycin treatment of lymphocytes was used to develop a one-way test for leukocyte migration inhibitory factor (LMIF) production in the mixed lymphocyte culture (MLC) reaction. Lymphocytes incubated with this protein synthesis inhibitor induced a vigorous mediator production by nontreated allogeneic cells, being themselves unable to respond to stimulator cells. When puromycin-treated cells were stimulated with the mitogens PHA, ConA, or PWM, overall protein and DNA synthesis were significantly decreased with concomitant abolishment of LMIF production. Viability of stimulator lymphocytes was found to be essential for generation of the mediator in MLC reaction.

Cell Survival↗
PubMed1976

[Effect of synovial fluid from rheumatoid arthritis patients on leukocyte migration].

By means of the migration inhibition test, the influence of the synovial fluid of rheumatoid arthritis patients on normal blood lymphocytes was investigated. There was the hypothesis that the migration inhibitory factor is already formed in the synovial membrane of rheumatoid arthritis patients. In 35 cases a migration inhibition could be demonstrated, in 3 cases the migration of normal lymphocytes remained uninfluenced, in 6 cases a migration enhancement occurred. The demonstration of the rheumatic factor in the synovial fluids used was partly positive, partly negative. Especially the demonstration of a migration enhancement--this phenomenon could be reproduced repeatedly--cannot yet be interpreted unequivocally and requires further investigations.

Arthritis, Rheumatoid↗
PubMed1976

Antibodies to guinea pig lymphokines. IV. Suppression of the mixed leukocyte culture reaction by anti-lymphokine globulin.

An antiserum, (anti-lymphokine globulin, ALyG) directed against highly purified products of activated lymphocytes, inhibits the proliferation of responding cells in guinea pig mixed leukocyte cultures ((MLC). This serum recognizes three newly synthesized lymphocyte products (one of them being migration inhibition factor (MIF) which are involved in the mediation of delayed hypersensitivity reactions in vivo. Since ALyG does not appear to contain cytotoxic antibodies against guinea pig lymphocyte antigens and its inhibitory activity cannot be removed by absorption with lymphoid cells it seems likely that the inhibition of MLC reactivity is not mediated by the lysis of stimulator or responder cells and its target is not the lymphocyte per se but possibly some factor elaborated during MLC response. By contrast, antisera with specificity for histocompatibility (H) antigens can inhibit the MLC when the appropriate H antigens are present on the responding and/or stimulating cell population. However, this inhibitory of the antisera can be effectively absorbed with lymphoid cells bearing the appropriate H antigens. The addition of ALyG even 48 hr after the initiation of culture results in a marked inhibition of MLC reactivity. This finding is consistent with the elaboration of a mitogenic factor or signal during the first 48 hr of culture and the delivery of this signal to the responding cell population. Thus, ALyG does not appear to interfere with the synthesis of this factor but must be present after its release in order to block responder cell proliferation. Furthermore, the stimulatory effect of this MLC mitogenic factor, but not of PPD-induced mitogenic factor on "third party" cells can be completely inhibited when the cells are cultured in the presence of ALyG. These findings suggest that the MLC-mitogenic factor in this system is identical to or cross-reactive with one or both of the newly synthesized molecules recognized by the ALyG.

Animals↗
PubMed1977

[In vitro liberation of lymphocytic factors inhibiting migration of human leukocytes induced by gold, cadmium and mercury chlorides].

The presence of 300 microgram gold and cadmium and 10 microgram mercury chloride per millitre of survival medium, during the process of T.I.M.L., results in the release by human lymphocytes of soluble factors which inhibit migration of leucocytes (L.I.F. and M.I.F.). This stimulation of cellular immunity suggests that the anti-infectious therapeutic effect of gold and mercury inorganic salts results from activation of the histiocytary system, through the release of these lymphokins.

Cadmium↗
PubMed1977

[The inhibitor factor of leukocyte migration in acne vulgaris].

The inhibition factor of the leukocytic migration was studied in 26 patients with Acne Vulgaris, stages III and IV, being positive in all the cases. The LIF positive shows the mobilisation of lymphocytic population, answering an active and constant immunologic conflict. As the PA is antigenic, because it produces a blastification (TTL positive), we can say that it acts as antigen provoking immunologic mechanisms with help to explain the inflammatory process at the pilosebaceous follicle in the AV.

Acne Vulgaris↗
PubMed1979

Studies of assay conditions for macrophage migration from an agarose droplet.

The agarose microdroplet method is a relatively simple and economic technique to determine migration inhibition of leukocytes or macrophages in vitro. In the present study, further cultural and technical requirements of this method for the determination of macrophage migration inhibition have been defined: influence of macrophage handling before the assay, kinetics of migration and dependence on the pH of the medium. Considering defined conditions, the agarose microdoplet assay gives highly reliable and reproducible results. In comparative experiments, it proved to be as sensitive and valid as the capillary tube technique.

Animals↗