Cells involved in the immune response. VI. The immune response to red blood cells in irradiated rabbits after administration of normal, primed, or immune allogeneic rabbit bone marrow cells

The effect of earthworm extract on mice S180 tumor growth and apoptosis

Great efforts have been made to explore the potential treatment for cancers, and the most common therapies include surgery, chemotherapy and radiotherapy. As an alternative medication, earthworms have drawn increased attention considering its abundance in resource, easy access and minor side effects compared to traditional therapies. However, few studies had focused on the antitumor effect of earthworm-derived components. The purpose of this study is to investigate whether earthworm extract has an effect on tumor cell apoptosis and growth. Earthworm extract (EE) was purified through multiple steps of centrifugation and chromatography. Mice were inoculated with ascitic fluid derived from mice inoculated with S180 sarcoma tumor cells and fed orally with different amounts of EE for 25 days. Tumor samples were analyzed for size and cell apoptosis. And we found that the weight and sizes of tumor decreased gradually as the amount of EE administered increased. More apoptotic cells and lowered level of lactate dehydrogenase (LDH), a biomarker of tumor invasiveness, was detected in EE-treated group than the untreated group. Our results suggested that EE could dramatically promote tumor apoptosis and reduce tumor size in vivo, suggesting a novel alternative therapy for cancer patients.

Effect of Fluosol DA 20% on antibody response to type 3 pneumococcal polysaccharide in rats

Exchange transfusion with the oxygen-carrying resuscitation fluid, Fluosol DA 20% (FDA), interferes with the efficacy of penicillin therapy of pneumococcal infection in rats. Because this effect could not be attributed to an interaction between FDA and penicillin, the effect of FDA on the ability of rats to mount an antibody response to type 3 pneumococcal polysaccharide was tested. FDA (25 ml) was administered by isovolumetric exchange transfusion. Rats were immunized intravenously with 0.2 microgram of type 3 pneumococcal polysaccharide 3 days before, 1 day before, 1 day after, or 3 days after transfusion with FDA. IgM and IgG antibody responses were determined by ELISA 0, 3, 7, 10, 14, 21, and 28 days after immunization. When rats were immunized 3 days before or 1 day before transfusion with FDA, antibody levels were increased above control levels and remained relatively high through Day 28. When the animals were immunized 1 day after transfusion, antibody levels were approximately the same as in the control group. When the rats were immunized 3 days after transfusion, antibody levels were suppressed. These data suggest that FDA does not inhibit the humoral immune response when administered after or within 1 day before immunization, but does inhibit the response when immunization is given 3 days after transfusion.

The antibody-dependent cell-mediated cytotoxic reaction. I. The morphological and functional heterogeneity of the rabbit cytotoxic cells

The circulating WBC and cells of the various rabbit lymphoid organs (thymus, bone marrow, lymph nodes, appendix, sacculus rotundus and Peyer's patches) were systematically investigated for their capacity to mediate antibody-dependent cell-mediated cytotoxicity (ADCC). The target cells used were antibody-sensitized ⁵¹Cr-labelled chicken erythrocytes. Phagocytic cells and lymphocytes were capable of inducing lysis of these sensitized target cells and they might act rapidly or show a delay in the onset of activity depending upon the organ sources of these cells. Among the circulating cells, both mononuclear cells and heterophils showed ADCC activity. The cytotoxic cells in the different lymphoid organs could be distinguished from each other on the basis of the following criteria. (i) Rabbit WBC, spleen and bone marrow cells consistently exhibited cytotoxic activity early in culture with the target cells (6–8 h), with activity levelling off by 24–48 h. In contradistinction, the cells of the gut-associated lymphoid tissues (appendix, sacculus rotundus and Peyer's patches), thymus and lymph nodes did not display significant cytotoxic activity until 48–72 h of culture. (ii) Removal of phagocytic cells from the WBC, spleen and lymph node cells resulted in almost total loss of ADCC activity. On the other hand, the ADCC cytotoxic activity of the thymus and bone marrow cells was not significantly affected following removal of phagocytic cells. (iii) The cytotoxic activity of the WBC, spleen and lymph node cells was inhibited by soluble aggregates of rabbit gammaglobulin whereas that of the bone marrow and thymus cells was not.

Rabbit ADCC cytotoxic cells could therefore be classified into a number of categories on the basis of their capacity to demonstrate immediate or delayed cytotoxic activity, their phagocytic or non-phagocytic properties and the susceptibility or lack of susceptibility of their ADCC cytotoxic activity to be inhibited by aggregates of gammaglobulin. It was therefore concluded that the ADCC effector cells in the rabbit parenchymal organs were heterogeneous. The circulating effector cells (the heterophils and monocytes), however, appeared to constitute functionally homogeneous populations of cells.

Cells involved in the immune response. XXVIII. the cellular composition of the lymphoid organs in the normal outbred rabbit

Horse anti-rabbit spleen cell antiserum was obtained by the intravenous immunization of horses with rabbit spleen cells. The antisera obtained were analysed for their lymphocytotoxic activity with respect to the lymphoid cells of the different lymphoid organs prior to and following absorption with the different lymphoid cells. The results have been integrated with those obtained in previous investigations and an all-embracing concept of the interrelationship of the lymphoid cells in the different lymphoid organs in the rabbit has emerged. The distinction between the heretofore considered central lymphoid organs (bone marrow and thymus) and peripheral lymphoid organs (spleen, lymph node and appendix) has been blurred by the finding that, at least in the rabbit, appendix cells possess specific antigen markers and participate in cell-mediated immune reactions in vitro and the observation that the spleen also has a central lymphoid function in the generation of cells in vivo capable of carrying out a cell-mediated immune reaction in vitro. It is concluded that the distinction of central and peripheral lymphoid function may be an artificial one in that it may reflect a function of the particular organ in only one of the many different types of immune reactions and that it should not influence the investigator in the elucidation of the cellular mechanisms participating in the mediation of the different immune responses.

Cells involved in the immune response. XXVI. The demonstration of bone marrow-specific antigens in the rabbit

Horse anti-rabbit bone marrow cell antiserum was tested for its cytotoxic activity with respect to the lymphocytes of the various lymphoid organs. The unabsorbed antiserum was highly cytotoxic with respect to the circulating WBC and cells of the bone marrow and thymus but demonstrated low cytotoxic activity with respect to spleen, lymph node and SAPP cells (sacculus rotundus, appendix and Peyer's patches). However, following absorption with thymocytes, lymph node cells or SAPP cells, cytotoxic activity directed toward any of these cell types disappeared without affecting the cytotoxic activity with respect to bone marrow and circulating lymphocytes. On the other hand, bone marrow and spleen cells and circulating white blood cells were capable of absorbing out completely the cytotoxic activity directed toward these cells. On the basis of a comparison of efficiency of absorption of anti-bone marrow cell activity by cells of the different lymphoid organs and cytotoxicity assays of the absorbed antiserum, it is concluded that approximately 15–25 per cent of the spleen lymphocytes and 20–40 per cent of the circulating lymphocytes in the rabbit are bone marrow-derived cells. The other lymphoid organs do not normally appear to possess these cells.

Dual regulatory role of the thymus in the maturation of immune response in the rabbit

Rabbits thymectomized in early adulthood produced more antihapten antibody than sham-thymectomized controls after hyperimmunization with 2,4-dinitrophenyl bovine gamma globulin (DNP-BGG). The average associated constant of anti-DNP antibody produced by thymectomized animals was more than 10 times higher than that of the controls. Similar effects were obtained by extensive treatment of rabbits with antithymocyte serum (ATS) before and during the immunization with DNP-BGG. The results indicated that relative diminution of thymus-derived lymphocytes (T cells) resulted in a stimulation of antibody-forming cells with a higher affinity. On the other hand, preimmunization of rabbits with different doses of BGG caused either enhancement or suppression of the hapten-specific antibody response, depending on the priming dose of BGG. The suppressed antibody response was always associated with a marked decrease in the antibody affinity. If rabbits were partially tolerized with a large dose of soluble BGG, some of the animals produced little antibody against hapten (DNP) coupled to this carrier, and the affinity of produced antibody was low. However, other rabbits tolerized with BGG produced large amounts of anti-DNP antibody upon hyperimmunization with DNP-BGG, whose affinity was only slightly lower than that of the control. These results can be harmonized if it is assumed that the thymus plays an important role in the maturation of the immune response. It is postulated that T cells, in numbers ordinarily available, would first assist in the proliferation of antihapten antibody-forming cell precursors already selected by antigen, thus accounting for the rapid increase of antibody affinity in the early stage of immunization. However, after a larger number of carrier-specific T cells are made in response to continued immunization, these would suppress antibody-forming cells. The suppression would be greater for cells with higher affinity for antigen, resulting in a decrease in antibody affinity. This postulate explains preferential stimulation and suppression of cells having higher affinity receptors under circumstances in which T cell are relatively depleted or overstimulated, and further permits an explanation for the decrease of antibody affinity after long-term immunization.

Immunoglobulin receptors on human leucocytes. 3. Comparative study of human bone marrow and blood B cells: role of IgM receptors

A comparative study of B cells present in human bone marrow and blood was performed. In both compartments the cells carrying the Ig receptors were found to be small mononuclear cells. Predominance of IgM receptors was found on bone marrow cells whereas Ig receptors present on peripheral blood cells were predominantly of the IgG class. Bone marrow lymphoid cells of non-sensitized donors were capable of binding a primary antigen, keyhole limpet haemocyanin (KLH) and could be retained on glass bead columns coated with either KLH or with goat anti-human IgM antiserum but not with anti-IgG. Whereas bone marrow cells of donors immunized with KLH 16–27 days earlier lacked KLH reactive cells, the latter cells could be demonstrated in the blood. It is concluded that human bone marrow B cells carrying IgM receptors are essential for the early antigen recognition step following which recruitment of these cells into the circulation takes place.

Cells involved in the immune response. XXII. The demonstration of thymus-specific antigens in the rabbit

Horse anti-rabbit thymus cell serum (HARTS) was obtained by immunizing a horse with rabbit thymocytes intravenously at weekly intervals for 3 weeks. The horse was bled 2 weeks later and the antiserum was analysed for its cytotoxic activity with respect to the lymphocytes of the various lymphoid organs. It was demonstrated that the cytotoxic activity of the antiserum was several orders of magnitude greater for thymus cells than for cells of the other organs tested. Only thymus and lymph node cells were capable of absorbing the thymocytotoxic activity of the antiserum; however, ten to fifteen times as many lymph node cells as thymus cells were required to neutralize the thymocytotoxic activity of the serum. Absorption of the antiserum with the cells of the other lymphoid organs (spleen, bone marrow, appendix, sacculus rotundus, Peyer's patches and circulating leucocytes) resulted in a slight but significant decrease in the thymocytotoxic activity. At no time was the thymocytotoxic activity completely absorbed with cells of these organs. The cytotoxic activity of the antiserum with respect to the cells of the different lymphoid organs other than the thymus could be abolished following absorption of the antiserum with the cells of any of the lymphoid organs. On the basis of our data, it is concluded that (a) the thymocytes possess two groups of antigens—one thymocyte specific and one common to all rabbit lymphocytes and (b) only the lymph nodes of all the lymphoid organs other than the thymus possess significant numbers of thymus-derived or T-cells. However, the proportion of these cells in the lymph node does not exceed 7–10 per cent, a figure much lower than that found in the lymph nodes of the mouse. Less than 1 per cent of the circulating lymphocytes in the rabbit are T-cells.

Early antibody-forming cells of double specificity

Simultaneous immunization of mice with sheep and pigeon erythrocytes results in multiplication not only of spleen cells capable of specifically agglutinating on their surface one or other of these antigens, but of spleen cells agglutinating both kinds of erythrocytes. These latter cells only appear on the 3rd day following immunization and tend to disappear after the 10th day. Their peak number is reached on the 5th day, when more than 10 per cent of the specific cells show double specificity.

When sheep erythrocytes are given 1 or 3 days before pigeon erythrocytes, the cells showing double specificity appear and disappear earlier after injection of the second antigen. These kinetics and those of the corresponding haemagglutinins suggest that such cells simultaneously synthesize antibodies of two different specificities.

Cells involved in cell-mediated and transplantation immunity. II. A consideration of the functional identity of the cells involved in both humoral and cell-mediated immunity: a phylogenetic approach

The literature concerned with the types of cells that participate in the humoral and cell-mediated immune response has been reviewed. It is postulated that the initial cells that are involved in mediating both types of immunity are functionally identical in that both are antigen-reactive cells. In the case of the humoral immune response, the interaction of the antigen-reactive cells with the antigen leads to the release or transfer of "information" to the antibody-forming cell, resulting in the synthesis and secretion of antibody molecules. In the case of cell-mediated immunity, it is considered that the primitive antigen-reactive cell itself transforms into the sensitized cell which infiltrates the site of antigen administration.

Cells involved in cell-mediated and transplantation immunity in the rabbit. I. The noninvolvement of the bone marrow antigen reactive cell in the transplant rejection reaction

Rabbits were subjected to 800 r total body irradiation to render them immunoincopetent with respect to the humoral immune response. These rabbits were, however, only slightly less capable of rejecting skin allografts than nonirradiated rabbits. Furthermore, the administration of normal or specifically "primed" bone marrow cells (bone marrow obtained from a rabbit injected one to two days previously with the spleen cells obtained from the prospective skin donor) did not enhance or inhibit the graft rejection reaction. It is concluded that the cells mediating the humoral immune response are different from those mediating the cellular immune response.

Cells involved in the immune response. 8. The relationship between the loss and reappearance of antigen-reactive cells and immune responsiveness after irradiation of normal adult rabbits

By appropriate irradiation and cell transfer experiments, a direct correlation was observed between the presence of viable and immunologically active antigen-reactive cells and the capacity of the rabbits to respond following immunization. Rabbits given 800 R total body irradiation were unable to elicit a humoral immune response nor did they possess significant numbers of antigen-reactive cells. The ability to respond with humoral antibody formation did not reappear until antigen-reactive cells could be detected. These results strongly indicate that the presence of competent antigen-reactive cells are necessary for the successful induction of the humoral immune response in the rabbit.

Cells involved in the immune response. 13. The nature of the cellular interactions relating antibody formation and immunologic tolerance: a unified hypothesis

The various cells and cell pathways involved in the induction of the primary humoral immune response have been discussed from the point of view of the unitary, as opposed to the multiple, pathway concept. The immunocompetent cells made unresponsive in the immunologically tolerant animal and the cells capable of responding with antibody formation were considered. It is concluded that there exist multiple cellular pathways through which the humoral immune response may be expressed.

Cells involved in the immune response, IX. Depletion from the normal rabbit bone marrow of antigen-reactive cells directed toward human peripheral leukocytes

Normal adult rabbits were injected intravenously with peripheral leukocytes obtained from a normal human volunteer (donor A). The animals were sacrificed 24 hours later, and their bone marrow cells (primed bone marrow) or bone marrow cells obtained from a normal, unimmunized rabbit (normal bone marrow) were injected intravenously into irradiated (800 r) rabbits. The latter were immunized with peripheral leukocytes of donor A. The antisera obtained from the irradiated rabbits given primed bone marrow cells displayed minimal or no cytotoxic activity toward white cells of either donor A or an unrelated donor B. On the other hand, antisera obtained from irradiated rabbits given normal bone marrow cells displayed high titers of cytotoxic activity with respect to donor A cells only. It is concluded that rabbit bone marrow can be depleted of antigen-reactive cells directed toward white cell antigens following injection of the white cells intravenously and that these bone marrow cells are incapable of conferring antibody-forming capacity, in irradiated recipients, directed to this particular species of white cells. The relevance of these findings to the field of transplantation in general is discussed.

Cells involved in the immune response. XI. Identification of the antigen-reactive cell as the tolerant cell in the immunologically tolerant rabbit

Rabbits were made immunologically tolerant to either human serum albumin or bovine gamma globulin by the neonatal administration of antigen. At 10 wk of age, they were challenged with the tolerogenic antigen and found to be non-responsive. However, these tolerant rabbits could respond with humoral antibody formation directed toward the tolerogenic antigen if they were treated with normal, allogeneic bone marrow or bone marrow obtained from a rabbit made tolerant toward a different antigen. They were incapable of responding if they were given bone marrow obtained from a rabbit previously made tolerant to the tolerogenic antigen. Irradiated rabbits were unable to respond if treated with tolerant bone marrow, but could respond well if given normal bone marrow. Since it has previously been demonstrated that the antibody-forming cell, in an irradiated recipient of allogeneic bone marrow, is of recipient and not donor origin, the data presented strongly indicate that the unresponsive cell in the immunologically tolerant rabbit is the antigen-reactive cell.

Cells involved in the immune response. X. The transfer of antibody-forming capacity to irradiated rabbits by antigen-reactive cells isolated from normal allogeneic rabbit bone marrow after passage through antigen-sensitized glass bead columns

The antigen-reactive cells in normal rabbit bone marrow could be isolated from a suspension of marrow cells by passage of the cells through an antigen-sensitized glass bead column. The cells which passed through the column were deficient in antigen-reactive cells directed to the antigen used to sensitize the glass beads, whereas the cells eluted from the column could transfer antibody-forming capacity to irradiated recipients only with respect to the specific sensitizing antigen. Separation of the bone marrow antigen-reactive cells could not be achieved by passage of the cells through nonsensitized glass bead columns or in the presence of excess free antigen in the column. Cells which were retained by, and later eluted from, the antigen-sensitized glass bead columns were mostly small mononuclear cells, whereas cells which passed through the columns were morphologically similar to the original unfractionated bone marrow cell suspension. The data indicate the presence of an antibody or antibody-like structure, with defined immunological specificity, on the surface of the normal bone marrow antigen-reactive cell.

Cells involved in the immune response. VII. The demonstration, using allotypic markers, of antibody formation by irradiation-resistant cells of irradiated rabbits injected with normal allogeneic bone marrow cells and sheep erythrocytes

Bone marrow cells obtained from rabbits of one allotype were injected into irradiated rabbits of a different allotype. The recipients were also injected with sheep red blood cells, and their spleen cells were tested for plaque-forming capacity 7 days later. Spleen cells of all recipients gave large numbers of plaques as did spleen cells incubated with antiserum, directed toward donor allotype. However, incubation of the recipient spleen cells with antiserum directed toward recipient allotype completely suppressed plaque formation. These results demonstrate that antibody-formation in irradiated recipients of transferred lymphoid cells is a property of the recipient animal and that the antibody-forming cell is relatively irradiation-resistant. It was also demonstrated that only viable normal bone marrow cells are capable of transferring antibody-forming capacity to irradiated recipient rabbits. Neither sonicates nor heat-killed preparations of normal rabbit bone marrow cells possessed this capacity.