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To determine the role of endogenous migration-inhibitory factor (MIF) in the development of protective immunity against cutaneous leishmaniasis, we analyzed the course of cutaneous Leishmania major infection in MIF gene-deficient mice (MIF(-/-)) and wild-type (MIF(+/+)) mice. Following cutaneous L. major infection, MIF(-/-) mice were susceptible to disease and developed significantly larger lesions and greater parasite burdens than MIF(+/+) mice. Interestingly, antigen-stimulated lymph node cells from MIF(-/-) mice produced more interleukin-4 (IL-4) and gamma interferon (IFN-gamma) than those from MIF(+/+) mice, although the differences were statistically not significant. IFN-gamma-activated resting peritoneal macrophages from MIF(-/-) mice showed impaired macrophage leishmanicidal activity and produced significantly lower levels of nitric oxide and superoxide in vitro. The macrophages from MIF(-/-) mice, however, produced much more IL-6 than macrophages from wild-type mice. These findings demonstrate that endogenous MIF plays an important role in the development of protective immunity against L. major in vivo. Furthermore, they indicate that the susceptibility of MIF(-/-) mice to L. major infection is due to impaired macrophage leishmanicidal activity rather than dysregulation of Th1 and Th2 responses.

In this study, in vitro cell-mediated immune response was analysed in 150 healthy Nigerians between 6 and 95 years old by the leukocyte migration inhibitory factor (L-MIF) test. Lymphocytes were activated with the mitogen concanavalin A and candida, measles virus and mycobacterial antigens. Nonspecific cellular immune capacity was studied by the Nitroblue tetrazolium (NBT) test. Numerical estimates of leukocytes and lymphocyte subpopulations were done. Mean L-MIF activity obtained with the four lymphocyte activators decreased with rising age indicating a progressive decline in cellular immune function with age. There was no significant age-related change in formazan positivity rate for both unstimulated and stimulated NBT tests. No age-related change in number was observed for any of the leucocyte and lymphocyte subpopulations. These results show that cell-mediaging response in Nigerians immunity declines, but phagocyte function is unchanged during aging. Lymphocyte depletion or numerical alteration in resting T cell subsets could not be demonstrated to be responsible for depressed cell-mediated immunity in aging Nigerians.

We have previously reported that cancer chemotherapy prior to lymphokine activated-killer (LAK) cell-transfer gave synergistic increase in therapeutic effects of LAK adoptive immunotherapy on transplanted tumors, BMT-11 fibrosarcoma and 3LL lung carcinoma, in C57 BL/6 mice, and that transferred LAK cell-accumulation into tumor tissues was enhanced by treatment with anti-cancer drugs. The author tried to analyze mechanisms responsible for the enhanced LAK cell-accumulation into tumor tissues after chemotherapy by under agarose migration assay and LAK migration inhibitory assay. The author detected a chemotactic factor for LAK cells (LAK-attractant) and a migration inhibitory factor for LAK cells (LAK-MIF) in the conditioned medium of tumor tissues from mice treated with various anti-cancer drugs, which was not found in that of untreated tumor tissues. Since mRNA expression for transforming growth factor-beta 1 (TGF-beta 1) was found to enhance in tumor tissues after chemotherapy through RT-PCR, the author examined a possible participation of TGF-beta 1 as LAK-attractant in tumor tissues of mice treated with cyclophosphamide. Recombinant human TGF-beta 1 showed LAK-attractant activity, and anti-TGF-beta 1 antibody inhibited LAK-attractant activity in the conditioned medium. These findings indicate that TGF-beta 1 produced in tumor tissues of mice treated with anti-cancer drugs may be one of LAK-attractants. On the other hand, LAK-MIF activity was concentrated in the fraction of less than 3kDa which is a smaller molecule than that of TGF-beta 1. These findings suggest that both TGF-beta 1 and LAK-MIF produced in tumor tissues after chemotherapy contributed to the enhanced accumulation of transferred LAK cells into tumor tissues after the chemotherapy.

The past several years have produced a dramatic increase in our understanding of the steps involved in the infiltration of leukocytes into inflamed tissues. At least four major families of adhesion molecules: the selectins, sialomucins, integrins, and Ig supergene family CAMs have been identified; and their interactions are being elucidated. The role of the leukocyte beta 2 and alpha 4 integrins and the selective use of these integrins by leukocytes for migration into inflamed tissues in various organs is presented.

Analyses of leucocyte migration activating factor (LMAF) and leucocyte migration inhibitory factor (LMIF), and measurements of interleukin-2 (IL-2) and interferon-gamma (IFN gamma) were performed after stimulation of suspected agents in 25 patients thought to be hypersensitive to antibacterial agents in order to clarify the pathogenic mechanism. The leucocyte migration inhibition test (LMIT) was negative in 6 patients. LMAF was detected in 11 patients and LMIF in 8 patients. IL-2 values (M +/- SE) were 6.23 +/- 1.33 BRPM u/ml in the LMIT-negative group, 17.67 +/- 1.68 BRPM u/ml in the LMAF-positive group and 7.98 +/- 0.26 BRPM u/ml in the LMIF-positive group. The LMAF-positive group was found to have a significantly higher level of production of IL-2 (p < 0.005) than the other groups. Moreover, mathematical analysis revealed a positive correlation between the leucocyte migration indices and IL-2 in the LMAF-positive group (r = 0.75, p < 0.01). IFN gamma was detected in only 3 patients (16% of the LMIT-positive patients), i.e., in 2 patients in the LMAF-positive group and one patient in the LMIF-positive group. The patient in the LMIF-positive group was found to have lower IFN gamma values than the patients in the LMAF-positive group. Moreover, examination of the effects of IL-2 and IFN gamma on leucocyte migration revealed that IL-2 or IFN gamma and LMAF or LMIF were not exactly the same.(ABSTRACT TRUNCATED AT 250 WORDS)

To identify factors contributing to the pathogenesis of autoimmune chronic active hepatitis (CAH) healthy relatives of 13 patients with the disorder were followed prospectively for 4 years. 58 relatives were monitored for various serological markers and for T-lymphocyte migration inhibitory activity every 2 months. 3 cases of subclinical acute hepatitis A occurred during the study. In 2 of the 3 subjects, before hepatitis A virus (HAV) infection, there was a defect in suppressor-inducer T lymphocytes specifically controlling immune responses to the asialoglycoprotein receptor, an antigen expressed on the hepatocyte surface. In these 2 subjects, specific helper T cells and antibodies to the asialoglycoprotein receptor persisted and increased after acute hepatitis A, and autoimmune CAH type 1 developed within 5 months. Thus, in susceptible individuals HAV is a trigger for autoimmune CAH.

We prepared supernatants of Concanavalin-A activated human lymphocytes containing high titers of leukocyte migration inhibition factor (LIF). A pool of these supernatants was filtered thorough sephadex 6-100 as well as a pool of supernatants from parallel non activated cultures. A migration assay was carried out for each activated fraction, using as control migration the same fraction from non activated supernatants. In this way we found a fraction from activated supernatants with high LIF activity. We assayed the effect of this LIF containing fraction on a yeast endocytosis assay by polymorphonuclear (PMN) cells. We found that the LIF containing fraction increased the number of endocytic PMN in about 80%. This effect was absent from control supernatant and from other fractions from activated supernatant but without LIF activity. The LIF containing fraction did not increase the average number of endocytosed yeast per cell nor the ability to reduce NBT. The endocytosis enhancing effect was blocked by the specific LIF blocker N-acetyl-D-glucosamine. We conclude that LIF can increase the endocytic activity of PMN cells.

The supernatant fluid of axenically grown E. histolytica contains a factor (MLIF) which inhibits the locomotion of human monocytes (including chemotaxis) without affecting that of human polymorphonuclear leucocytes. Locomotion, like other cellular functions, is modulated by changes in intracellular cAMP and cGMP. The consensus--with some exceptions--is that while rises in cGMP accompany locomotion, an increase in cAMP (without a concomitant fall in -cGMP) occurs with inhibition of cellular movement. We measured by radioimmunoassay the cAMP concentration of human monocytes exposed to inhibitory concentrations of MLIF. A significant (p less than 0.005) rise in monocyte cAMP was found, comparable to that observed with the use of forskolin, a well known cAMP stimulator. The control studies using plain axenic medium, not only failed to reveal any rise in cAMP but disclosed a small, yet not significant drop in intracellular cAMP. These results suggest that MLIF (like other locomotion inhibitors, i.e. prostaglandins E1, A1 and isoproterenol) produces a significant increase in intracellular monocyte cAMP. This modification in intracellular signals may contribute to the inhibition in monocyte locomotion, an event during which an increase in pericentriolar microtubules has also been observed.

Mononuclear cells, obtained from the spleens and lungs of influenza virus-seropositive C57BL/6 mice at 2 to 4 days after re-infection with homologous virus (strain A/Bangkok/1/79), produced a low m.w. factor in vitro that prevents the biologic expression, but not production, of the lymphokine, leukocyte migration inhibition factor (LIF). The low m.w. factor inhibited LIF activity without destroying the LIF molecule inasmuch as simple dialysis restored lymphokine activity to culture supernatants. Production of the low m.w. factor was observed from 2 to 4 days after re-infection, at which time the delayed-type hypersensitivity response to viral Ag was suppressed. In contrast, LIF was produced by splenocytes and lung mononuclear cells obtained at all times tested after re-infection (from 2 to 30 days). Production of the low m.w. factor required re-infection of influenza A virus-seropositive mice with type A virus; re-infection with influenza B virus failed to induce production. Ag specificity was also required in vitro for splenocytes to produce the factor; cells from type A virus-re-infected mice required type A Ag stimulation. Cell depletion studies with mAb plus C revealed that macrophages and T cells along with Ag stimulation were required for factor production by spleen cells. However, mononuclear cells obtained within 4 days from the lungs of re-infected mice did not require in vitro Ag stimulation for production of the low m.w. factor, and factor production was dependent upon the presence of CD4+ (L3T4) cells in the culture. Fractionation of culture supernatants over a Sephadex G-50 column indicated that the factor had a molecular mass of 2 to 3 kDa, and by FPLC chromatofocusing over a Mono P column, the factor eluted at a pH of approximately 8.2. Thus, re-exposure of influenza virus-seropositive mice to homologous virus resulted in the production of a low m.w. factor that prevented the biologic expression of LIF, but not its production. Lymphokines are an important component of the delayed-type hypersensitivity response; the presence of mononuclear cells secreting a low m.w. factor and LIF concomitantly at the site of virus replication (lungs) and the capacity of the factor to block the biologic expression of LIF in vitro suggest that the factor may have a role in the regulation of a delayed-type hypersensitivity response in vivo during re-infection.

The migration inhibitory activity of supernatants of Con A-Sepharose stimulated MNC cultures was tested by measuring the migration of [3H]leucine-labeled granulocytes or macrophages from agarose-containing capillary tube fragments. The migrated cells were harvested with an automated cell harvester on glass fiber filters and counted in a beta counter. Suspension of the target cells in agarose improves the accuracy of the method since migration from packed capillary tube fragments is sometimes not significantly different as between control and assay preparations. The concentration of agarose may inversely influence results, lower concentrations correlating with higher migration inhibition in the presence of assay supernatants. Different migration inhibition results are obtained when allogeneic granulocytes are used in parallel. For this reason a 10 times concentrated supernatant from a Con A-Sepharose-stimulated MNC culture, exhibiting the highest LIF activity at any mitogen concentration, was used as standard considered arbitrarily to contain 100 U. On the parallel regression lines of the dilution curves of the standard and assay preparations, reference with the standard is made at 25% migration inhibition as the comparison point.

80 persons from a city environment, aged 22 to 62, were examined (Cfr. Report I). Spontaneous blast T lymphocyte transformation was found to depend on lead concentration in the blood; the transformation was intensified as Pb 2+ ion concentration in the lymphocyte culture increased within the range of 10(-5) mg/ml. The process was of positive correlation and was statistically significant. PHA-induced blast lymphocyte transformation was found inversely proportional to serum Pb2+ ion concentration, the negative correlation of the two parameters was worked out. Thus, it was proved that mitogenic effects of the action of lead and PHA were of no additive nature, the actions of the two agents opposed each other, probably a competition for the place of specific binding to the cell membrane receptors took place. The process may be helpful in accounting for immunity changes in bodies exposed to the action of lead.

36 patients suffering from chronic spastic bronchitis were treated with acupuncture. The patient group consisted of 13 men and 23 women varying in age from 26 to 64 years, with an average age of 42.2 years. The therapy consisted of two or three months of acupuncture treatment in alternation with an equal period (2 or 3 months) of recess during which no treatment was administered. Before acupuncture, patients had taken corticosteroids either orally and/or intramuscularly for a period of 2 to 24 years. For those taking corticosteroids orally the daily dosages ranged from 10 to 40 mg Encorton (Polfa, Poland). The patients took intramuscular injections of 40 to 60 mg Kenalog (Squibb) every three or four weeks. Acupuncture sessions were twice a week. All the patients had 42 acupuncture sessions. Before the treatment all the patients, and 30 healthy volunteers, made leukocytes migration tests [(in vivo, using the Rebuck method (1) as modified by Southam (2)]. It was found that patients suffering from chronic spastic bronchitis have leukocytes migration defect. This defect increases in patients who have taken corticosteroids. We have also found that after 42 acupuncture sessions the amount of leukocytes in the tissue pool comes close to the value found in healthy persons during leukocyte migration, [(tested in vivo, using the Rebuck method as modified by Southam (2)].

Human ultrafiltrated leukocyte extracts (MW less than 5000) were fractionated by Sephadex G-10 column chromatography and the effects of these fractions on leukocyte random locomotion were investigated in vitro. Fr-4, one of these fractions, had significant leukocyte random locomotion inhibitory activity, independent of the presence of mononuclear leukocytes. This inhibitory activity was not due to cytotoxic effects on leukocytes. As seen by scanning electron microscopy, the number of cell surface pseudopods on leukocytes incubated with Fr-4 was reduced. Fr-4A, one of three fractions separated from Fr-4 by Sephadex G-25 column chromatography, significantly inhibited leukocyte random locomotion. Fr-4A contained numerous components, one of which was identified as 2-deoxyribose, on the basis of thin-layer chromatography. Biologically 2-deoxyribose showed an inhibitory effect on leukocyte locomotion and a reduction of the extrusion of pseudopods on the surface of leukocytes, at the range of assayed concentrations. This inhibitory activity is probably derived from 2-deoxyribose.

Since some podiatric surgeons are using glucocorticosteroids to minimize postoperative edema and pain associated with traumatic procedures, the effects on wound healing should be understood as much as possible so that maximum results can be achieved with minimal risk to the patient. Considerable animal and human research has been done on the potential wound-healing effects of glucocorticosteroids. Current studies indicate a detrimental wound-healing effect with the use of glucocorticosteroids. Increased infection will also be discussed.

Acute hypertensive damage to arterial vessels was induced by intravenous injections of hypertension. The in vitro immunological method of the agarose migration technique was used for demonstration of delayed-type autoimmunity against arterial vessel-wall antigens following the damage of the arterial vessels. By means of this technique it was demonstrated that the migration indices from the rats with induced hypertension differed significantly from the control rats, P less than 0.005. This means that an autoimmunity of the delayed type had developed after the hypertensive damage to the arterial vessels. The autoimmunity was tissue specific.

An inhibitory factor on lymphocyte migration was detected using a capillary random migration assay in the culture supernatant of peritoneal exudate macrophages cultured at concentrations greater than 8 x 10(6) cells/ml. After examining different macrophage-like cell lines, J774A.1 cells were found to produce this inhibitory factor, which was termed lymphocyte migration inhibitory factor (LMIF). The inhibitory effect of LMIF on the migration of spleen lymphocytes, thymocytes, and bone marrow cells was determined. The migration of thymocytes was more sensitive to LMIF than was the migration of spleen lymphocytes and bone marrow cells. Interestingly, when the effect of LMIF was tested on the migration of spleen T cells and B cells, T cells were more sensitive than B cells. When the thymocytes were separated by peanut agglutinin into mature and immature thymocytes, the migration of mature thymocytes was more sensitive than that of immature thymocytes, the migration of mature thymocytes was more sensitive than that of immature thymocytes to the effect of LMIF, suggesting that the greatest effect of LMIF was on the migration of mature T cells. Partial purification of LMIF by ion-exchange and gel-filtration chromatography revealed that it is approximately 14,000 in molecular weight and could exist in either monomeric or dimeric forms. The possible role of this factor in an immune response is discussed.

The immunosuppressive drugs cyclosporin A (CyA) and methylprednisolone (MP) abolished the elaboration of the lymphokine leukocyte migration inhibitory factor (LIF) by mononuclear cells challenged by recall antigen. Suppression in both cases was reversible upon removal of the drugs, and participation of T suppressor cells of their mediators could not be demonstrated. The CyA-induced effect was exerted in the early stage of lymphocyte activation (less than 60 min), whereas MP still inhibited LIF release when added 60 min after the antigen. In contrast to earlier findings that the drugs failed to affect the release of T cell-activating factor (TAF) and lymphocyte-activating factor (LAF) from macrophages (M-phi's) stimulated by phorbol myristate acetate. MP (but not CyA) markedly reduced TAF production by M-phi's incubated with tuberculin. M-phireover, partially purified TAF and LAF both restored LIF production in the presence of CyA (but not MP), an effect not mimicked by the T cell product T cell growth factor. However, suppression by both drugs was abrogated by exogenous cGMP. Hence, CyA seems to obstruct the interaction between TAF/LAF and the immune T cell, whereas MP affects antigen-induced T cell activation at the Mo level as well as the level of lymphokine production and/or release. The effects of both drugs seem related to intracellular events involving cGMP.

Effects of glucocorticoids on human neutrophil responses to leukocyte migration inhibition factor (LIF) and neutrophil chemokinesis were examined using an agarose gel technique. The roles of endogenous monohydroxyeicosatetraenoic acids (HETE) and prostaglandins (PG) in basal neutrophil chemokinesis were also examined. Methylprednisolone sodium succinate (MPSS) in concentrations up to 200 micrograms/ml failed to inhibit the neutrophil response to LIF. MPSS enhanced neutrophil chemokinesis in a dose-related manner at concentrations from 2 micrograms/ml to 200 micrograms/ml (P less than 0.01). Since inhibition of membrane phospholipase activity by MPSS is known to decrease production of HETE and PG, the present data suggest that HETE and PG do not mediate basal neutrophil chemokinesis. This was confirmed by selectively inhibiting HETE production with the lipoxygenase inhibitor nordihydroguaiaretic acid (NDGA) or PG production with the cyclooxygenase inhibitor indomethacin. Neutrophil chemokinesis was unaffected by 10(-5) M NDGA (P less than 0.05) or 10(-5) indomethacin (P less than 0.05).

Soluble membrane fractions derived from Raji cells trigger lymphocytes of Epstein-Barr virus (EBV)-seropositive, but not EBV-seronegative, individuals to release a lymphokine that inhibits leukocyte migration. The reaction can be blocked by the sera of patients with EBV-DNA-carrying tumors, Burkitt lymphoma, or nasopharyngeal carcinoma. Absorption of these sera with EBV-positive, but not EBV-negative, cells abrogates their blocking activity. These findings suggest that the antigen responsible for the leukocyte migration inhibition reaction is an EBV-encoded or an EBV-induced membrane component. The antigen is not identical with EBV-associated nuclear antigen or any other known antibody-detected EBV antigen.

This investigation examines the immunologic basis for specific antigen-induced tube leukocyte adherence inhibition (LAI) reactivity of draining lymph node cells (LNC) from dogs with canine transmissible venereal sarcoma (CTVS). CTVS regressor LNC, macrophage-depleted LNC, and enriched T lymphocyte fractions, but not enriched B lymphocyte fractions, were specifically reactive to CTVS antigen extract in direct tube LAI. In addition, regressor LNC amplified tube LAI responses by generating supernatants with leukocyte adherence inhibition factor (LAIF) activity for normal dog indicator LNC and enriched peripheral blood mononuclear cells (PBMC) in an indirect tube LAI assay. However, macrophage-depleted LNC and enriched T lymphocyte fractions failed to generate supernatants with LAIF activity, suggesting that macrophage accessory cells play a central role in the amplification of tube LAI. Interestingly, CTVS regressor peripheral blood leukocytes (PBL) and PBMC, which were specifically reactive in direct tube LAI, also failed to generate supernatants with LAIF activity. These findings demonstrate a distinction between LAIF-mediated amplification and direct tube LAI reactivity, and suggest that leukocyte populations with differing cellular proportions and from different immunologic compartments may participate in tube LAI via different mechanisms.

Although functional histamine receptors have generally been restricted to those human T lymphocytes expressing suppressor cell functions, more recent evidence suggests that histamine receptor-bearing human T lymphocytes are functionally heterogeneous and capable of other immunomodulatory activities. Lymphocyte chemoattractant factor (LCF) is a cationic sialoprotein with an apparent m.w. of 56,000, whose production is limited to histamine-type 2 receptor-bearing human T cells. LCF is selectively chemokinetic for T lymphocytes, and presumably contributes to the recruitment of unsensitized effector lymphocytes at inflammatory sites. In addition to LCF, Sephadex G-100 gel filtration of histamine-induced lymphocyte supernatants revealed two regions of migration inhibitory activity for human blood T and rat splenic lymphocytes. These regions corresponded to m.w. of 70,000 to 80,000 (LyMIF75K) and 30,000 to 40,000 (LyMIF35K). LyMIF75K had a single pI of 7.5 to 8.0, and its biologic activity was sensitive to trypsin but not to neuraminidase or heat (56 degrees C). LyMIF35K had a single pI of 8.5 to 8.8, and its biologic activity was sensitive to neuraminidase and heat but not to trypsin. These LyMIFs therefore appeared to be distinct from one another and physicochemically different from other migration inhibitory lymphokines. All three lymphokine activities appeared within 4 hr of incubation. The minimum concentration of histamine required to stimulate production of the LyMIF was 10(-6) M. Lymphocytes that did not adhere to a histamine affinity matrix were unable to produce either LyMIF upon subsequent stimulation with histamine or concanavalin A (Con A). Lymphocytes incubated with histamine and diphenhydramine produced LCF but neither LyMIF, whereas cells incubated with histamine in the presence of cimetidine produced both LyMIF but not LCF. These data suggest that a subset of lymphocytes defined by the presence of histamine-type 1 receptors are capable of producing two distinct species of lymphocyte migration inhibitory activity. These cells may contribute to the immobilization of effector T lymphocytes chemokinetically attracted to certain inflammatory sites.

Thymic (T) or bursal (B) lymphocytes from chicks sensitized to Mycobacterium tuberculosis produce an avian lymphocyte inhibitory factor (LyIF). The physiochemical properties of both T and B LyIF were established by ultrafiltration which yielded four fractions with molecular weight ranges of greater than 100,000; 50,000-100,000; 10,000-50,000; and less than 10,000; enzymatic treatment with chymotrypsin and neuraminidase; varying pH; and heat exposure. These studies demonstrated that the maximum activity for both T and B LyIF was within a molecular weight range of 10,000-50,000. Both were sensitive to chymotrypsin and neuraminidase treatment. Both were stable at 56 degrees C for 30 min and resistant to changes in pH from 5 to 9. T-Cell migration was inhibited equally by B or T LyIF, while B-cell migration was inhibited to a lesser extent by T LyIF and B LyIF. Further experiments should establish the reasons for these observed differences in cross-reactivity.

Migration inhibitory factor (MIF) was produced by lymphoid cells of Lewis rats in response to infection with Bacille Calmette Guérin (BCG), mixed lymphocyte reaction or concanavalin A stimulation. It was found that rat lymphokine-containing supernatants demonstrate a definite species specificity, in that MIF activity is observed only when rat indicator cells and not when guinea-pig indicator cells are used. A comparative study of MIF activities, using rat peritoneal exudate cells, revealed that all three methods stimulated MIF production by either spleen or lymph node cells. Only infection with BCG induced peripheral blood leukocytes to elaborate MIF. In all cases, rat MIF inhibited rat peritoneal exudate cells but not guinea-pig peritoneal exudate cells. Possible explanations for the species specificity of rat MIF including a role for receptor carbohydrate moieties and fibronectin are discussed.

The effects of the lymphokine, leukocyte inhibitory factor (LIF), on human neutrophil function were studied. This soluble mediator, which is defined by its specific inhibition of neutrophil locomotion, does not interfere with chemotactic factor binding and does not affect basal or stimulated superoxide generation by neutrophils. In contrast, phagocytosis of opsonized Staphylococcus aureus is markedly inhibited by LIF, and degranulation is stimulated by this lymphokine. The possible mechanisms of LIF action on neutrophils are discussed.

Individual lymph nodes draining tumors vary in their degree of immunological activity. Cell suspensions from tumor-free nodes located relatively near to tumors are spontaneously less reactive and respond poorly to exogenous stimulation by mitogens and lymphokines. Diminished spontaneous uptake of tritiated thymidine by lymph node cells not exposed to exogenous stimulation suggests that tumor-proximate immune suppression exists in vivo and is not purely a laboratory artefact. The present study was undertaken to explore that possibility further. Fluid in which cell suspensions from tumor-free nodes were prepared, and supernatants from short-term cultures of nodes located at different distances from tumors were compared for their capacity to inhibit the in vitro migration of the human lymphoblastoid cell line QIMR-WIL. Inhibitory activity of fluids from individual nodes was related to their position relative to the tumor and their immune competence, assessed by the responses to mitogens of cell suspensions prepared from them. Cell suspension fluids from 92/111 nodes (83%) significantly inhibited the migration of QIMR-WIL, at a level similar (44 +/- 14%) to that induced by the supernatants of mixed lymphocyte cultures (43 +/- 17%). Fluids from the nodes of melanoma patients were more inhibitory than those from breast cancer patients (49 +/- 12% and 37 +/- 13%, respectively, P = 0.003). The inhibitory activity of the different nodes of individual node groups varied significantly in 25 of 33 patients (76%), the node nearest the tumor generating least inhibitory activity (indexing the greatest immune suppression) in 20 of these 25 patients (80%). The strength of migration-inhibitory activity was concordant with the responsiveness to mitogen stimulation in up to 14 of 18 patients (78%). Studies of molecular size and heat stability indicated that the inhibitory factors had characteristics consistent with common migration-inhibitory lymphokines such as leukocyte-migration-inhibitory factor, macrophage-inhibitory factor and interleukin-2. Our findings further support the hypothesis that lymph nodes nearest to tumors are relatively immune-suppressed in vivo.

When sheep were infected with Cytoecetes phagocytophila the in vitro migration of peripheral leucocytes was reduced even when antigen was not added. The inhibition of migration coincided with parasitaemia and was due to soluble factors which inhibited the migration of leucocytes from normal sheep. After the cessation of parasitaemia addition of antigen was necessary for migration inhibition to occur.

Supernatants of human blood mononuclear cells stimulated with PHA, contained factors inhibitory for in vitro migration of human lymphocytes and granulocytes. After ultrafiltration of supernatants through Amicon PM-10 some stimulatory activity appeared in the bottom fraction. Sephadex G-100 gel filtration chromatography of supernatants showed three zones of lymphocyte migration inhibitory activity: In the range of molecules of m.w. 35 000-90 000, heat-stable; Factors of m.w. from several to from ten to twenty thousand daltons, heat unstable; Low molecular weight substances, resistant to heat. The possible relationship of these factors to lymphotoxins, soluble lymphocyte T receptors for SRBC, lymphocyte chemotactic factor and prostaglandins is discussed. Ampicillin in doses of 10, 20 and 50 micrograms/ml potentiated both the development of lymphocyte migration inhibitory factors and the production of factors with an opposing effect (stimulating lymphocyte migration).

Leukocyte migration inhibitory factor (LIF) is produced by lymphocytes with receptors specific to sensitizing antigens. This principle was used to detect possible antigenic differences between sperm of autoimmune and nonautoimmune men. Sixteen fertile and 91 infertile couples were screened for cytotoxic and hemagglutinating antibodies to sperm from their husbands and controls. Their lymphocytes were tested for the production of LIF to sperm extracts and seminal plasma from the husbands and controls by a direct leukocyte migration inhibition assay. Twenty-nine of 35 men producing LIF to sperm and/or seminal plasma were positive for sperm antibodies (p = 0.0004, vs sperm antibody-negative controls). Twenty-three of 29 wives with LIF production had sperm-autoimmune husbands (p = 0.04). Leukocyte migration was significantly inhibited in sperm-autoimmune men by autologous sperm extracts and seminal plasma in contrast to control sperm extracts and seminal plasma (p = 0.0006 and 0.001, respectively). The wives of autoimmune men had significantly higher LIF responses to their husbands' sperm extracts than to other antigens (p = 0.02). Men with cytotoxic antibodies in their seminal plasma produced LIF to autologous sperm (p = 0.001). It is suggested that certain sperm and seminal plasma antigens of autoimmune men may lead to specific humoral and cell-mediated immune responses in both partners.

The effect of the leukotrienes LTB4, LTC4 and LTD4 on the production of the lymphokine leukocyte migration inhibitory factor (LIF) from human peripheral blood mononuclear cells was tested. LTC4 and LTD4 failed to influence LIF production by cells stimulated by antigen or the polyclonal T cell activator, phytohemagglutinin (PHA). LTB4, at concentrations 10(-7) to 10(-6) M, showed significant inhibition of antigen-induced LIF production but was without effect when cells were stimulated by PHA. The cell levels of cyclic adenosine monophosphate (cAMP) were unaffected by 2.5 X 10(-7) M LTB4 in the absence or presence of theophylline. These results indicate that LTB4 acts on the early effector stage of the immune response without affecting the cellular cAMP content.