Inhibition of migration of mouse macrophages by tuberculin-sensitive mouse lymphocytes and by mouse migration inhibitory factor

Soluble factors in tolerance and contact sensitivity to 2,4-dinitrofluorobenzene in mice. IV. Characterization of migration inhibition factor-producing lymphocytes and genetic requirements for activation

The production of migration inhibition factor (MIF) in vitro by lymph node cells from mice with contact sensitivity to 2,4-dinitrofluorobenzene (DNFB) was investigated. MIF activity of cell-free culture supernatants was measured using a micro, indirect "hanging-drop" assay system. We found that DNFB-sensitized lymph node cells are stimulated to produce MIF by co-culture with DNP-labeled spleen cells or splenic adherent cells. The stimulation was quantitatively antigen-specific, as co-culture with TNP-spleen cells or TNP-splenic adherent cells induced only low levels of MIF activity. Pretreating the immune lymph node cells with different antisera plus complement, before addition of DNP-spleen cells, showed that MIF production is dependent on Ia- T cells. Additional experiments showed that in order for the T cells to be stimulated, homology at the I-A subregion of the major histocompatibility complex between the T cells and DNP-spleen cells is required. Collectively, these results correlate with our previous finding that transfer of contact sensitivity is mediated by Ia- T cells and indicate that both tests, i.e., transfer in vivo and MIF production in vitro, are measuring effector functions of the same T cell subset.

The effect of undernutrition on immunological responses to BCG and TAB vaccines in mice maintained on a natural diet

A study was made on the effect of undernutrition on the immunological responses of mice to TAB and BCG vaccines. The mice were fed a diet comprising chapati and germinated grams; one group was fed ad libitum while another was given half the quantity consumed by the first group. The undernourished mice showed a poor immune response to BCG: only 23% showed a positive reaction to foot pad challenge with purified protein derivative, compared with 76% of the well-fed mice. The mean increase in thickness of the foot pad was also significantly smaller in the undernourished mice. Antibody titres against the H and O antigens of TAB were essentially similar in both groups of mice. The results suggest that undernutrition depresses cell-mediated immune responses but not humoral responses.

Immunologically mediated macrophage aggregation in monolayers of peritoneal cells from BCG-sensitized mice

Aggregation of cultured macrophage monolayers derived from BCG-sensitized mice was produced if nonadherent cells and specific antigen (tuberculin) were present, particularly if the antigen was renewed in the form of tubercle bacilli. The evidence indicated that antigen-stimulated BCG-sensitized lymphocytes in these cultures produced a soluble factor, which in the presence of the renewed supply of antigen caused the aggregation. The phenomenon was irreversible and followed by death of the macrophages. The 'overlays' of aggregated monolayers would aggregate normal macrophages, provided that the recipient cultures contain-d their own (normal) lymphocytes as well as antigen; this suggested that cultures of BCG-sensitized peritoneal cells produced a factor able to effect aggregation via the activity of normal lymphocytes. Overlays from aggregated monolayers were able also to inhibit the migration of normal mouse macrophages; this and other evidence suggested a similar origin for the inhibition factor, but the latter's identity with the aggregation factor remains undecided. We conclude that the aggregation factor depends upon the presence of specific antigen both for its formation and its expression.

Effects of immune lymphocyte products and serum antibody on the multiplication of Toxoplasma in murine peritoneal macrophages

In vitro studies on cell-mediated immunity against Toxoplasma infection were carried out by estimating the ability of antigenically stimulated lymphocytes. Splenic lymphocytes from normal mice and from hyper-immunized mice were cultured in the presence or absence of Toxoplasma lysate antigen. The cell-free supernatant fluids from the lymphocyte cultures were assassed for their ability to alter the functional capacities of normal macrophages. When glycogen-induced peritoneal macrophages were incubated with the culture supernatant from immune lymphocytes reacting with specific angigen, the intracellular multiplication of the organisms was inhibited remarkably. In contrast, the addition of antitoxoplasma antibody to culture medium had no effect on the enhancement of phagocytic activity of culture macrophages. However, when extra-cellular organisms were exposed to fresh or heat-inactivated immune serum just before infection of the monolayers, the intracellular multiplication of Toxoplasmas was inhibited significantly by either activated or normal macrophages.

Macrophage migration inhibitory activity of mycobacterial growth inhibitory factor and the effect of a number of factors on mycobacterial growth inhibitory factor activity

Mycobacterial growth inhibitory factor (MycoIF), which inhibits the intracellular multiplication of virulent tubercle bacilli within normal peritoneal macrophages in vitro, was tested for its ability to inhibit the migration of normal peritoneal exudate cells. The migration of peritoneal exudate cells was not inhibited by MycoIF. It was also shown that normal peritoneal macrophages infected with virulent Mycobacterium tuberculosis, strain H37Rv, required 72 h of incubation with spleen cell culture supernatant fluids containing MycoIF in order to inhibit intracellular bacillary multiplication. Treatment of infected macrophages with trypsin before their exposure to MycoIF abolished the ability of MycoIF to inhibit intracellular mutiplication of tubercle bacilli. Incubation of infected macrophages with goat anti-mouse globulin before their exposure to MycoIF also blocked the action of MycoIF.

Phagocytosis and intracellular killing of Staphylococcus aureus by normal mouse peritoneal macrophages

Although Staphylococcus aureus is incapable of intracellular multiplication in cultured mouse peritoneal macrophages, it is killed at a much slower rate than the avirulent Staphylococcus epidermidis. In addition to the presence of capsular material which inhibits phagocytosis of specific strains of S. aureus, the data show that a number of cellular and environmental factors affect the functional capacities of mononuclear phagocytic cells. The data obtained by varying the initial level of infection indicate that the number of ingested bacteria may subsequently alter the kinetics of intracellular killing. In vitro maturation of macrophages in culture was also found to exert a pronounced effect on the kinetics of bacterial death.

The immune response to infection with vaccinia virus in mice. II. Appearance of hypersensitivity, production of macrophage migration inhibitory factor and transformation of spleen cells in response to virus antigens

The appearance of specific hypersensitivity to virus antigens was examined in mice infected intravenously with vaccinia virus. Both immediate hypersensitivity, transferable by serum, and delayed-type hypersensitivity, transferable only by cells, were apparent 8 days after infection and demonstrable for at least a further 130 days. Production of macrophage migration inhibitory factor by lymphocytes from infected mice was measured directly in terms of inhibition of migration by antigen or indirectly by determining the effect of soluble factors elaborated by the stimulated lymphocytes. The irregular results may have been the resultants of antigen-mediated macrophage stimulation, toxicity and induction of migration inhibitory factor. Transformation of spleen cells - presumably lymphocytes - from infected mice could be induced in vitro by virus antigens for at least 139 days after infection. Virus/lymphocyte interaction appears to be a particularly fruitful area for further study.

Cell-mediated immune phenomena induced by lymphokines from splenic lymphocytes of mice with chronic staphylococcal infection

Splenic lymphocytes from normal mice and from mice displaying delayed hypersensitivity to Staphylococcus aureus were cultured in the presence or absence of specific staphylococcal antigens. The cell-free supernatant fluids from these lymphocyte cultures were assessed for their ability to alter the functional capacities of normal macrophages. It was found that supernatants from staphylococcus-immune cells cultured in vitro with antigen possessed migration inhibitory factor activity and also were capable of stimulating the incorporation of [14C]glucosamine into macrophage membrane glycoproteins. In addition, the lymphokine-containing supernatants were capable of inducing activation of normal macrophages so that they inhibited the multiplication of intracellular Listeria monocytogenes. Although it was not possible to snow any significant enhancement of intracellular killing of S. aureus by the activated macrophages, evidence is presented that suggests that cell-mediated immune responses to S. aureus may significantly enhance pahgocytosis of staphylococci and, thereby, may provide for their rapid clearance from extracellular fluids.

Isolation of substances responsible for lymphokine activity from sensitized mouse spleen cells

Cultures of brucella-sensitized mouse spleen cells exposed to Brucella abortus antigens in vitro release macrophage migration inhibition factor (MIF) and macrophage spreading factor. Subjecting the supernatants from such cultures to preparative scale electrophoresis in acrylamide gel yields several fractions, one of which contains both MIF and macrophage spreading factor. This material has properties attributable to guinea pig MIF: it is nondialyzable, heat stable, nontoxic to macrophages from heterologous murine donors, and has a greater anodal electrophoretic mobility than guinea pig serum albumin. Another fraction from the gel column inhibits macrophage spreading; its electrophoretic mobility is similar to that of guinea pig gamma globulin. Neither brucella antigen nor skin reactive substances were detectable in any acrylamide gel column fraction when tested by the mouse footpad induration assay technique.

Relationship between tuberculin hypersensitivity and cellular immunity to infection in mice vaccinated with viable attenuated Mycobacterial cells or with Mycobacterial ribonucleic acid preparations

The migration inhibition technique has been used to study delayed hypersensitivity in vitro by using peritoneal exudate cells and splenic lymphocytes from mice vaccinated with viable cells of the attenuated H37Ra strain of Mycobacterium tuberculosis and from mice vaccinated with ribonucleic acid (myc RNA) preparations obtained from viable mycobacterial cells of the same strain. Inhibition of macrophage migration was noted when purified protein derivative (PPD) or viable H37Ra cells were added to peritoneal exudate cells obtained from mice immunized with viable H37Ra cells and not from mice immunized with myc RNA. Splenic lymphocyte cultures were exposed to the same antigens in vitro. Filtered supernatant fluids from these lymphocyte cultures, when added to peritoneal exudate cells obtained from nonimmunized mice, inhibited migration only when they were obtained from lymphocytes which came from mice immunized with viable H37Ra cells. Injection of PPD intravenously into vaccinated mice resulted in inhibitory supernatant fluids from splenic lymphocyte cultures only when the lymphocytes came from mice immunized with viable H37Ra cells. However, intravenous injection of either viable H37Ra cells or of myc RNA preparations into mice vaccinated with myc RNA occasionally produced inhibitory supernatant fluids when lymphocytes were obtained from these mice. On the other hand, mice vaccinated with myc RNA or viable H37Ra cell preparations were consistently and equally protected against intravenous challenge with the virulent H37Rv strain. Thus, although some evidence was obtained for a delayed type hypersensitivity in mice vaccinated with H37Ra cells or with myc RNA to ribosomal proteins or other proteins associated with the RNA preparation, no evidence of tuberculin hypersensitivity could be detected in any mice vaccinated with the myc RNA. These results argue against a role for tuberculin hypersensitivity in immunity to tuberculous infection.