Leukocyte Inhibitory Factor Research Articles

Delayed anaphylactoid reaction in a worker exposed to chromium

A 29-year-old male welder reported systemic reactions after exposure to chromium. Inhalation challenge testing to 29 μg/m 3 of sodium chromate aerosol resulted in late appearing systemic urticaria, angioedema, and severe bronchospasm that occurred at the same time as a threefold rise in plasma histamine. A direct leukocyte inhibitory factor test to 5.5 × 10 −6mol/L Na 2CrO 4 was positive. Although the mechanism of this reaction is unknown, the positive leukocyte inhibitory factor and the general acceptance of hexavalent chromium as a contact skin sensitizer suggest that cell-mediated mechanisms could be involved.

Immune responses during human Schistosomiasis mansoni. XI. Immunologic status of patients with acute infections and after treatment.

Sixteen patients, 8 to 30 yr of age, with acute (toxemic) phase schistosomiasis mansoni were studied immunologically within 2 to 3 mo of their exposure to Schistosoma mansoni cercariae, and were monitored after chemotherapy. Total leukocyte levels and peripheral blood eosinophilias were higher in these patients than in similar individuals with chronic schistosomiasis mansoni. In contrast to chronic patients, the eosinophilias of the acute cases were decreased rather than elevated upon treatment. Total lymphocyte population (T and B cell) percentages were not altered during acute infection. Lymphoid subset (T3+, T4+, and T8+) analysis revealed elevated levels of both T4+ and T8+ cells. In vitro blastogenic responses of peripheral blood mononuclear cells (PBMN) to heterogeneous schistosome-derived antigens (eggs, SEA; adult worms, AW; and cercariae, CERC) were evaluated. SEA responsiveness was considerably higher than that of patients with chronic S. mansoni infections. The ratios of SEA to AW responses in acute cases gave a mean of 2.0, as opposed to 0.5 for a comparable group of chronically infected patients. The sera of most acute patients already contained suppressive factors that specifically decreased schistosomal antigen-induced PBMN blastogenesis. Chemotherapy of acute cases lead to a diminution of PBMN responsiveness to SEA and CERC. Treatment of patients with chronic infections lead to the elevation of such responses. PBMN from patients with acute infections produced lymphokine leukocyte inhibition factor upon exposure of the cells to SEA but not AW. A similar pattern was true for production of the lymphokine activity mitogenic factor. Levels of antibody in sera of acutely infected patients against SEA, CERC, and AW were considerably higher than levels in sera of chronically infected patients matched for age and intensity of their infections. These high antibody titers persisted for at least 6 mo after treatment, and were unrelated to the intensity of infection. The immunologic status of these patients with acute schistosomiasis mansoni differed considerably from patients with chronic infections. These findings re-emphasize the immunoregulatory events that apparently develop upon continued exposure to schistosomes and their products during chronic infection.

Physiological studies with human leukocyte inhibitory factor.

Physiological studies with human leukocyte inhibitory factor.

Mechanism of priming of human neutrophils by a soluble lymphoblastoid cell factor.

Treatment of human neutrophils (PMN) with a cytokine-like factor in the supernatants of human lymphoblastoid cells (Raji) increased the random mobility and enhanced the migration of treated cells in response to other chemoattractants nearly 21/2-fold, although the supernatant itself was not a chemoattractant. Supernatant treatment also increased the adherence of bacteria threefold and the bacterial killing fourfold compared with PMN treated with control media. In examining the metabolic basis for the enhanced bactericidal ability, we observed a significant increase in spontaneous hexose monophosphate shunt activity of Raji cell supernatant (RS)-treated neutrophils even in the absence of additional stimuli. RS-treated PMN also had significantly enhanced production of superoxide anion and chemiluminescence response upon subsequent stimulation with a variety of soluble and particulate stimuli. Unlike other agents that prime neutrophil activation, however, the factor(s) in RS did not cause degranulation. It also differed in its ability to progressively enhance PMN functions with a longer period of preincubation (up to 3 hr). These data suggest that the RS factor(s) primes neutrophils by a unique mechanism. The neutrophil-enhancing activities of RS, which are the opposite of those activities described for leukocyte inhibitory factor, eluted off a Sephacryl S-200 column at approximately 30,000 m.w. This factor expands the relationship between neutrophils and lymphocytes, and may be a useful agent to provide valuable insights into the mechanism of respiratory burst activation and regulation.

Cellular Immunity to Sperm in Infertile Women

To investigate further whether immunity to sperm contributes to some cases of infertility in women, the production of leukocyte inhibitory factor by blood mononuclear cells challenged with human sperm in vitro was measured in women with infertility associated with poor results of postcoital tests or long-term unexplained infertility. Five (36%) of 14 infertile patients but none of nine fertile volunteers responded significantly to sperm in this assay. No study subject had serum IgG or IgM antibodies to sperm detected. These data provide additional evidence consistent with the possibility that cellular immunity to sperm-specific antigen(s) functions in the primary pathogenesis of infertility in some women.

Immune induction of human monocyte plasminogen activator. Characteristics of an assay for cell-mediated immunity

We characterized immunologic induction of monocyte plasminogen activator (PA) to determine whether assay for PA induction reliably detected cell-mediated immunity (CMI). Mononuclear leukocytes (MNL) were incubated in teflon-lined culture tubes for 1–4 days in the presence or absence of phytohemagglutinin-P (PHA), concanavalin A (Con A) or Candida antigen. PA activity of the monocytes in those suspensions was then measured using a micro fibrin plate assay. Monocytes in stimulated MNL had more PA activity than monocytes in unstimulated MNL. Maximal differences between stimulated and unstimulated cells were seen after 2 days of culture. Dose-response studies demonstrated that PA induction occurred at submitogenic concentrations of stimuli. Peak induction was seen using suboptimally mitogenic concentrations of PHA, Con A and Candida antigen. PA induction in response to Candida stimulation corresponded with skin test results. More than 90% of healthy adults tested had positive assays to all stimuli. LPS, in picogram concentrations, induced PA activity in the absence of lymphocytes, but such induction was prevented by polymyxin B. Supernates from activated MNL also induced PA in purified monocytes. This indirect assay of PA induction was less sensitive than direct assay of the MNL. A standard indirect assay for leukocyte inhibitory factor (LIF) was also less sensitive than the direct PA induction assay. The direct PA induction assay is sensitive and convenient and requires small volumes of blood. It may prove valuable in in vitro analysis of cell-mediated immunity in health and disease.

1019 AUTOIMMUNITY TO ARTICULAR ANTIGENS IN JUVENILE ARTHRITIS

We studied 103 JA children, 46 controls and 25 patients with osteoarticular syndromes (OAS) to determine if differences in immune reactivity characterized different onsets or outcomes. We measured cell-mediated immunity (CMI) to human collagen, proteoglycan monomer (PM) and link protein (LP). Production of leukocyte inhibitory factor by mononuclear leukocytes was assayed and correlated with HLA type. Antibodies to native type II collagen were measured in an enzyme-linked immunosorbent assay. Results were analyzed using Fisher's Exact Test. JA patients were less reactive to ConA than controls, yet were more reactive to collagen I, II and PM. JA patients did not differ from OAS patients, CMI did not correlate with onset, course, out come, ANA, RF or HLA type. Collagen antibodies were found in 23/86 JA, 1/20 OAS, and 0/31 controls (p<0.01). These antibodies, confirmed by absorption studies, distinguished erosive disease from other JA (p<0.001). CMI to articular antigens may be of pathogenetic importance in JA, but in vitro reactivity does not predict risks or complications. The presence of antibodies to native type II collagen may be of greater importance in signaling poor outcome in JA.

Leukocyte migration inhibition in recurrent aphthous ulceration.

Leukocyte inhibitory factor (LIF) production in response to streptococcal antigens and oral mucosa was examined as a possible pathogenic mechanism in recurrent aphthous ulceration (RAU). Mononuclear cells from RAU patients and controls were stimulated with antigens prepared from two species of streptococci and from oral mucosa. Candida albicans and foreskin were tested as control antigens. There were some statistically significant differences in leukocyte migration inhibition between patients and controls with some concentrations of Streptococcus sanguis (ATCC 10556) and C. albicans, and a trend toward low migration indices with oral mucosa. However, the roughly equal numbers of patients and controls responding positively to each antigen and the large background variation suggest a lack of biological significance. LIF production did not increase consistently in the early stages and did not correlate with ulcer development in patients studied sequentially. We conclude that LIF production (at least in response to the antigens tested) plays no pathogenic role in RAU. Our data do not support the hypothesis that a specific cell-mediated sensitivity to streptococcal antigens is involved in RAU.

19 Leukocyte inhibitory factor(LIF) potentiation of f-met-leu-phe induced chemotaxis and superoxide (O 2−) generation

19 Leukocyte inhibitory factor(LIF) potentiation of f-met-leu-phe induced chemotaxis and superoxide (O 2−) generation

Demonstration of leukocyte inhibitory factor in human schistosomiasis mansoni and its evaluation from patients in an endemic setting

Leukocyte migration inhibitory Factor (LIF) is produced by the peripheral blood mononuclear cells (PBMN) of most patients with Schistosoma mansoni infection upon their exposure to soluble egg antigens (SEA). PBMN of some patients also respond to adult worm (SWAP) antigens by LIF production. LIF is stable at 37°C for 60 min but is sensitive to heating at 56°C for even 30 min. The serine protease inhibitor PMSF destroyed LIF activity at concentrations of 10 −2 to 10 −3 M. Concanvalin A stimulated production of detectable levels of LIF by 8 hr, while SEA and SWAP did so by 15 and 39 hr, respectively. PBMN of healthy normal controls did not produce LIF upon exposure to SEA or SWAP. PBMN of a few field controls (stool negative subjects from an endemic area) produced detectable LIF activity when exposed to SEA or SWAP. PBMN from most infected (stool positive) patients from an endemic area produced LIF when exposed to SEA and only occasionally did so to SWAP. Previous studies have shown that most often only the PBMN of former, cured patients, and not chronically infected patients, produce the lymphokine activity termed mitogenic factor (MF). The current data indicate that because LIF is primarily produced by actively infected patients, its production may be controlled by different immunoregulatory mechanisms. Furthermore, although most SEA-related responses are highly immunoregulated in active, chronically infected patients, SEA appears to be a better stimulus for patient PBMN production of LIF than SWAP.

Lymphokine production and lymphocyte subpopulations in patients with head and neck squamous carcinoma.

Prior studies of impaired cellular immune reactivity in patients with head and neck squamous carcinoma (HNSC) suggest that immune deficiency associated with tumor growth may be related, in part, to alterations in immunoregulatory functions. To determine if production of soluble mediators of the immune response (lymphokines) is impaired in patients with HNSC, leukocyte migration inhibition in response to phytohemagglutinin was assessed in 32 patients with HNSC and 29 normal subjects and was correlated with levels of specific peripheral blood lymphocyte subpopulations to determine if quantitative levels of immunoregulatory lymphocyte subpopulations were related to in vitro lymphokine production. In the patients with cancer, leukocyte inhibitory factor production was consistently and significantly impaired and was directly related to levels of T4-positive (helper/inducer) lymphocytes. Substantial differences in levels of individual subpopulations were not detected among normal subjects and patients with cancer; however, the mean T4/T8 ratio was substantially increased in the patients with cancer. The findings confirm and extend prior observations of impaired cellular immune mechanisms in patients with HNSC and suggest that impaired lymphokine production may be related to quantitative and qualitative alterations in lymphocyte subpopulations.

Effect of bacterial lipopolysaccharide on bovine polymorphonuclear neutrophil migration in vitro

The in vitro effects of Escherichia coli 026:B6 lipopolysaccharide (LPS) on random migration of bovine polymorphonuclear neutrophils (PMN) was investigated. Treatment of peripheral blood leukocytes (PBL) with LPS significantly inhibited PMN migration. These inhibitions were observed at a threshold concentration of 5.0 μg/2.0 × 10 6 PBL. PMN migration inhibition was eliminated in PBL by the addition of polymyxin B, which binds the Lipid A moiety of LPS. Treatment of isolated PMNs with LPS significantly enhanced migration. Enchanced migrations were observed at threshold concentration of 2.5 μg/4.0 × 10 6 PMN. Collectively these findings indicate that the inhibition was caused by leukocyte inhibitory factor (LIF) production in PBL cultures, whereas enhancement was probably caused by PMN activation. These results provide further insight into the effects of LPS on in vitro bovine PMN migration by its distinct actions on different cells of PBL.

Further purification of neutrophil migration inhibition factor from T lymphocytes (NIF-T): Evidence that NIF-T and leukocyte inhibitory factor (LIF) are immunologically distinct

Neutrophil migration inhibition factor from T lymphocytes (NIF-T) purified by antibody affinity chromatography and gel filtration chromatography was radioiodinated and identified as a 26,000-MW protein by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). NIF-T was identified by elution of biological activity from gel fractions and selective adsorption of a radioiodinated mediator by HL60 cells differentiated in the presence of dimethyl sulfoxide (DMSO) to develop receptors for NIF-T. A goat neutralizing antibody for NIF-T neutralized and immunoprecipitated migration inhibition activity in the conditioned medium from Mo T-lymphoblast cells and human peripheral blood lymphocytes (PBL) cultured with concanavalin A (Con A), but not from RPMI 1788 B-lymphoblast cells with leukocyte migration inhibitory factor (LIF) activity. These studies distinguish NIF-T both chemically and immunologically from LIF.

Recognition of leukotriene B 4 by a unique subset of human T-lymphocytes

Leukotriene (LT) B 4, but not 12(S)-LTB 4 or LTC 4, inhibits the generation of the lymphokine-designated leukocyte inhibitory factor by purified human T-lymphocytes. LTB 4 coupled to fluorescein-labeled human serum albumin interacts specifically with approximately 11% of the T-lymphocytes as assessed by fluorescence-activated flow cytometry. The LTB 4-reactive T-lymphocytes are distributed between the suppressor-cytotoxic (14%) and helper-inducer (8%) subsets, which were identified concurrently by phycoerythrin-labeled monoclonal antibodies to subset-specific antigens. LTB 4, but not 12(S)-LTB 4 or LTC 4, significantly enhances the proliferation of mitogen-stimulated purified suppressor-cytotoxic T-lymphocytes at concentrations of 10 −12M to 10 −6M and significantly inhibits the proliferation of mitogen-stimulated purified helper-inducer T-lymphocytes at concentrations of 10 −8M to 10 −6M, as assessed by the uptake of [ 3H]thymidine. The net effect of LTB 4 on blood T-lymphocytes is immunosuppression that may be expressed in some human hypersensitivity and inflammatory diseases.

Cell-mediated immunity to cytomegalovirus (CMV) and herpes simplex virus (HSV) antigens in the acquired immune deficiency syndrome: interleukin-1 and interleukin-2 modify in vitro responses.

Peripheral blood lymphocytes (PBL) were obtained from five patients with the acquired immune deficiency syndrome (AIDS), six homosexual males with lymphadenopathy, and five normal heterosexual controls. Modulation of virus-specific immunity was assayed in vitro by measuring the lymphocyte blastogenic response and the production of lymphokine (leukocyte inhibition factor; LIF) by PBL stimulated with herpes simplex virus (HSV) or cytomegalovirus (CMV) antigens in the presence or absence of interleukin-1 (IL-1) and interleukin-2 (IL-2). PBL from the control and lymphadenopathy subjects responded to both antigens in the lymphocyte transformation assay (LT) measured on day 7, and the responses were significantly enhanced in cultures grown in the presence of antigen and IL-2 (1 U/ml). PBL from the AIDS patients were unresponsive, but responsiveness was restored by the addition of IL-2. The addition of IL-1 (0.02 micrograms/ml) to antigen-stimulated PBL cultures failed to enhance the proliferative responses in all three study groups. LIF production was assayed in the supernatants from day 1 PBL cultures. LIF was not produced by PBL from AIDS patients grown in the presence of viral antigens, whereas three of five patients from the lymphadenopathy group, and three of five control subjects gave rise to positive responses. The addition of IL-1 to the antigen-stimulated cultures enhanced LIF production in the control and lymphadenopathy groups but not in the AIDS patients. The addition of IL-2 did not modulate LIF production by antigen-stimulated PBL from the control or AIDS patients while suppressing the LIF response of the similarly stimulated PBL from the lymphadenopathy patients.

Evaluation of blocking mechanisms against immunological responses in patients with laryngeal carcinoma.

The specific tumor-induced leukocyte inhibition factor (LIF) production in laryngeal cancer patients has been investigated before and after the removal of adherent cells in order to evaluate the existence of a suppressor activity; 20 patients served as subject. The LIF production, after challenging the lymphocytes with 3MKC1 autologous tumor extracts, was significant in 12 patients and showed a further significant increase after the removal of adherent cells. In 3 patients with no previous significant LIF production, there was a conversion to significance when the adherent cells were removed. The other patients did not show any significant variation. These data seem to suggest the existence of a suppressor activity exerted by adherent cells in laryngeal cancer patients on LIF production.

Influence of dilution on the chemotactic properties of cotyledon suspensions.

In this study the influence of dilution of cotyledon suspensions on the chemotactic stimulus was investigated. When the concentration of the chemotactic stimulus is reduced, the activity of the leucocytes is reduced as well. Dilutions of retained placenta cotyledon suspensions showed an increase in leucocyte activity. This may indicate the existence of a leucocyte inhibition factor in the retained placenta cotyledon.

Indirect Leukocyte Migration Inhibition in Breast Cancer and Benign Breast Disease Patients by Mouse Mammary Tumor Virus Grown in Feline Kidney Cells

Indirect migration inhibition assays were performed with normal and mammary tumor-bearing C3H/HeN mice and patients with breast disease to assess cellular immunity against three different mouse mammary tumor virus (MTV) preparations grown in feline kidney cell cultures and against a mouse-derived MTV preparation. MTV obtained after passage through feline kidney cells and the mouse-derived MTV were capable of eliciting macrophage migration inhibitory factor production by mouse spleen cells obtained from normal or mammary tumor-bearing C3H/HeN mice, thus demonstrating a similar degree of antigenicity of these preparations. In experiments with human breast cancer patients' leukocytes, leukocyte inhibitory factor (LIF) was produced by 32-50% of these patients in response to the mouse-derived MTV or to three different MTV preparations obtained after passage through feline kidney cells. A significant proportion (31-54%) of benign breast disease patients also reacted with both the mouse-derived and feline-derived MTV preparations. Patients with both malignant and benign breast disease, however, had a significantly different (P less than .05) pattern of reactivity to mouse- and feline-derived MTV preparations from that observed with normal donors. Finally, some LIF activity was also observed (but not statistically significant with the use of nonparametric analysis methods) when feline leukemia virus was used as antigen with these patients. The data suggest that both breast cancer and benign breast disease patients were reactive against antigens largely specific for MTV in the feline cells and, presumably, were not reactive against feline cellular components, although the second possibility cannot be completely ruled out.

Amiodarone-induced Hypersensitivity Pneumonitis: Evidence of an Immunological Cell-Mediated Mechanism

Interstitial pneumonitis developed in a patient who had received a cumulative dose of 985 g of amiodarone in nine years. No other cause for pneumonitis was found. The following findings favor an immunologic mechanism of hypersensitivity due to amiodarone: positive skin and basophil degranulation tests with amiodarone; lymphocytosis and inverted ratio of helper/suppressor T lymphocytes in bronchoalveolar lavage fluid; secretion of leukocyte inhibitory factor, as shown by the inhibition of migration of peripheral blood leukocytes; and positive lymphoblastic transformation in the presence of amiodarone.

Supernatant derived from a human hepatocellular carcinoma cell line (PLC/PRF/5) activates a population of T-suppressor cells.

Harvest fluid derived from a primary hepatocellular carcinoma cell line (PLC/PRF/5) inhibited the incorporation of 3H-thymidine into PHA-activated human lymphocytes. A similar effect was observed when lymphocytes were pre-incubated with the tumour supernatant and washed prior to mitogen activation. Not only did the tumour supernatant inhibit 3H-thymidine incorporation by mitogen-activated lymphocytes, but it also inhibited production of the lymphokine leucocyte inhibitory factor (LIF). In experiments designed to establish whether a component of the tumour harvest fluid was activating a population of suppressor cells, normal mononuclear (MN) cells were treated with the PLC/PRF/5 or embryonic fibroblast supernatant for 48 h, after which they were washed and added to normal mitogen-activated lymphocyte cultures. Only cells pretreated with the PLC/PRF/5 supernatant suppressed mitogenesis. The cell responsible for the suppressor effect was a T cell, which after a further 24 h in culture liberated a suppressor factor responsible for inhibiting lymphocyte function. Although the nature of the factor/s in the PLC/PRF/5 supernatant responsible for activation of the T-suppressor cell population is unknown, it is suggested that this mechanism may be important in protecting the tumour from the immune response.