Dependence of the intensity of the immune response on the characteristics of the formation of a Salmonella typhi antigen depot on erythrocytes

Experiments on inbred mice, opposite in the capacity of their erythrocytes for the sorption of S. typhi antigens, have revealed that the intensity of immune response to the antigens depends on the functional potency of immunocompetent cells and the conditions of their priming. The optimal manifestations of the conditions for lymphocyte priming depends on the character of the antigen fixation by erythrocytes and antigen supply from the depot into the blood stream.     

Plasmodium berghei: relative immunogenicity of infected reticulocytes and infected oxyphilic red blood cells

Hyperbleeding of mice 1 day before and 1 day after infection with Plasmodium berghei resulted in a more aggravated infection. Parasitemia rose significantly faster, but the mean survival time of these mice was not significantly different from control mice. At Day 5 of infection, parasites were almost exclusively in reticulocytes in contrast to control infections in which parasites were found in oxyphilic erythrocytes at Day 5 after infection. Purified parasitized reticulocytes taken from hyperbled mice at Day 5 after infection contained more young developmental parasite stages than purified parasitized oxyphilic erythrocytes taken from normal mice at Day 5 to 7 after infection. Parasitized reticulocytes were more readily opsonized by antibodies from immune serum when compared to parasitized oxyphilic red blood cells and when used to stimulate immune spleen cells the former were better stimulator cells than the latter. Results suggest either that parasitized reticulocytes are more immunogenic then parasitized oxyphilic red blood cells or that suspensions of parasitized reticulocytes contain more immunogenic parasite stages than suspensions of parasitized oxyphilic red blood cells.     

Aggregated immunoglobulins as antigen-binding receptors of immune lymphocytes]

At the peak of the primary immune response to sheep erythrocytes there appeared in the spleen of mice rosette-forming cells (RFC) effectively inactivated with antibodies against aggregated mouse immunoglobulins and with the complex of polyadenylic-polyuridylic acids (poly-A, poly-U, respectively). These cells disappeared from the spleen on the 9th day after the primary immunization and were not revealed at the peak of the secondary immune response. When small splenic lymphocytes obtained on the 5th day after the immunization with sheep erythrocytes were incubated in vitro for 24 hours the total amount of the RFC inactivated by antibodies to the aggregated mouse immunoglobulin disappeared completely. These data can be considered as an indication of the existence at the peak of the primary immune response of rosette-forming cells having the antigen-antibody complexes in the capacity of the antigen-binding receptors.     

New aspects in the pathogenesis of infectious and tumor anaemia

From new evidence of increased adhesion of immune complexes in the plasma protein film of erythrocytes, the pathogenesis of tumor anaemia and anaemia in chronic infections is suggested to be a mechanism of the early sequestration of the erythrocytes by erythrophagocytosis following their coating with immune complexes and denaturated immunoglobulins.     

Release of suppressor factors by the lymphocytes of mice in contact with syngeneic and xenogeneic erythrocytes]

Spleen cells from immune mice incubated in vitro with syngeneic and xenogeneic red blood cells release the factor(s) which possess the immunosuppressive activity. Release of suppressive factor(s) by spleen cells from the non-immunized mice occurs only after the contact with xenogeneic erythrocytes.     

硫丹对小鼠红细胞免疫功能的影响

为了探讨有机氯农药硫丹对小鼠(Mus musculus)红细胞免疫功能的影响,设计了体内、外两组实验。体内实验:将40只小鼠随机分成4组,灌胃硫丹的量依次为:0、0.4、1.6、6.4mg/(kg·d)。灌胃25d后,取血测定红细胞的免疫功能。体外实验:将9只小鼠的红细胞分别与不同浓度的硫丹在体外培养,实验设空白对照组、溶剂丙酮组和4个不同浓度硫丹组,其6组实验所用硫丹的量依次为:0、0、5、10、20、40μg/ml。体外培养2h后,测定红细胞免疫粘附能力。结果表明,在活体实验中,随着硫丹浓度的增加,小鼠红细胞C3b受体花环率(ratio of C3b rosetting,C3bRR)明显下降,依硫丹灌胃浓度由低到高,其C3bRR依次为7.78%、6.80%、4.96%、4.33%;而循环免疫复合物花环率(ratio of immune complexes rosetting,ICRR)随着硫丹浓度升高而升高,分别为6.69%、6.31%、7.86%、9.42%。红细胞促NK细胞活性的功能在各组间没有显著差异。硫丹6.4mg/(kg·d)组小鼠红细胞对T淋巴细胞免疫粘附促进能力较其他3组明显降低。血浆中红细胞天然免疫促进因子活性在1.6mg/(kg·d)组和6.4mg/(kg·d)组较0mg/(kg·d)组明显降低。与溶剂丙酮组相比,血浆中红细胞天然免疫抑制因子活性在0.4mg/(kg·d)组明显下降,而在6.4mg/(kg·d)组却明显升高。离体红细胞经硫丹处理后其C3bRR显著降低,4个硫丹处理组依其浓度由低到高,C3bRR依次为:6.14%、5.56%、5.06%、4.44%;而ICRR却显著升高,分别为6.69%、6.31%、7.86%、9.42%。这表明,硫丹能抑制小鼠红细胞免疫粘附能力和红细胞对T淋巴细胞的正向调节功能,降低血浆中红细胞天然免疫促进因子活性,而对抑制因子活性影响比较复杂,低剂量时起抑制作用,而高剂量时能促进其活性。     

Microparticles released by human neutrophils adhere to erythrocytes in the presence of complement

The release of cell surface-derived microparticles, or ectosomes, has now been described for many different cell types. In various diseases characterized by systemic inflammation, the numbers of ectosomes released from specific cell-types are found increased manifold in the circulation. Their pro-inflammatory and pro-coagulant functions make them potentially important actors in disease establishment and/or progression. Until now, ectosomes have been believed to be free in the circulation. Herein, we provide evidence for sequestration of ectosomes derived from human polymorphonuclear neutrophils to erythrocytes, similarly to immune complexes. We show that ectosomes activate and bind complement in vitro. In whole blood, opsonization of ectosomes by complement mediated their immune adherence to erythrocytes through complement receptor 1. Taken together, our data suggest an important role for complement and erythrocytes in the sequestration, and possibly clearance, of blood-borne ectosomes stemming from neutrophils. The immune adherence described here may modify the biological activity and function of ectosomes.     

Influenza virus-induced immune complexes suppress alveolar macrophage phagocytosis

Immune complexes in the lungs are capable of inducing adverse responses. Herein we have detailed the formation of immune complexes in the lungs of influenza virus-infected mice and examined their effect on alveolar macrophage defenses. On days 3, 7, 10, 15, and 30 after aerosol infection with influenza A/PR8/34 virus, the acellular pulmonary lavage fluid was tested for viral antigen, specific viral antibody, and immune complexes by immunoassays. Whereas peak viral antigen (day 3) diminished to undetectable levels by day 10, specific viral antibody remained at a low concentration until day 10, after which it rapidly increased. Immune complex concentrations increased through day 7, peaked at day 10, and gradually returned to the control level by day 30. These data demonstrate that immune complexes of detectable size are induced by influenza virus infection during the interface between antigen excess and antibody excess conditions. Since alveolar macrophages are the pivotal phagocytic defense cells in the lung, the ability of normal alveolar macrophages to ingest opsonized erythrocytes was quantitated in the presence of immune complexes from lavage fluid. Immune complexes from day 10 virus-infected lungs caused a dose-dependent suppression of antibody-mediated phagocytosis to 30% of control values. In contrast, although these immune complexes also markedly decreased the phagocytosis of antibody-coated yeast cells, they did not significantly impair the antibody-independent ingestion of unopsonized yeast cells by macrophages. the suppressive effects of immune complexes on alveolar macrophages may, in part, explain the phagocytic dysfunction that occurs 7 to 10 days after influenza virus pneumonia.     

Elimination of immune complex deposits from the kidneys of autoimmune NZB/N mice administered a xeno-spleen perfusate

54 autoimmune NZB/N mice, 6 and 10 months of age, were intravenously injected 0.2 ml solution prepared during perfusion of the isolated sheep spleen with a buffer solution. Perfusion solution was injected 8 times with 2-3-day intervals. The control group of 43 mice received intravenously 0.2 ml of a buffer solution in the similar manner. After the treatment the levels of anti-DNA antibodies and circulating immune complexes were significantly decreased in the sera of mice which received the perfusion solution, as compared with the levels of control groups. Immunofluorescent studies showed a marked decrease in the number of glomerular immune complexes deposits in mice treated with perfusion solution. Six- and ten-month old mice exhibited a similar effect. The perfusion solution may be capable of eliminating the immune complexes from the blood and kidneys of autoimmune mice.     

Chemokinetic accumulation of human neutrophils on immune complex-coated substrata: analysis at a boundary

The locomotory behavior of human blood neutrophil leukocytes was studied at a boundary between two surfaces with different chemokinetic properties. This was achieved by time-lapse cinematography of neutrophils moving on coverslips coated with BSA, then part-coated with immune complexes by adding anti-BSA IgG with a straight-line boundary between the BSA and the immune complexes. Cell locomotion was filmed in microscopic fields bisected by the boundary, and kinetic behavior was assessed by comparing speed (orthokinesis), turning behavior (klinokinesis), and the rate of diffusion of the cells on each side of the boundary, using a recently described mathematical analysis of kinesis. In the absence of serum or complement, the proportion of motile cells and their speed and rate of diffusion were greater on BSA than on antiBSA, but there was no consistent difference in turning behavior between cells on the two surfaces. The immune complexes were therefore negatively chemokinetic in comparison with BSA, and this resulted from a negative orthokinesis with little or no contribution from klinokinesis. As would be predicted theoretically, this resulted in gradual accumulation of cells on the immune complexes even in the absence of a chemotactic factor. In further studies, a parallel plate flow chamber was used to show that, under conditions of flow, neutrophils accumulated much more rapidly on a surface coated with BSA- anti-BSA than on BSA alone. Moreover, neutrophils on immune complex- coated surfaces lost their ability to form rosettes with IgG-coated erythrocytes. This suggests that neutrophils on immune complex-coated surfaces redistribute their Fc receptors (RFc gamma) to the under surface, and that the lowered speed of locomotion is due to tethering of neutrophils by substratum-bound IgG-Fc.     

In vivo and in vitro studies of the binding of antibody/dsDNA immune complexes to rabbit and guinea pig platelets

The in vivo and in vitro binding of prepared antibody/dsDNA immune complexes to rabbit and guinea pig cellular blood components was examined. The in vitro binding in these two nonprimates was almost entirely due to platelets, and required homologous, intact complement; furthermore, no appreciable binding was observed for neutrophils, mononuclear cells, or erythrocytes at normal blood concentrations. The in vivo binding reaction occurred quite rapidly (less than 1 min for maximal binding) and the majority of the injected counts were cleared from the circulation in 3 to 5 min. Over this time period, however, a large fraction of the counts remaining in the circulation also remained bound to the animals' cells (presumably platelets), and this result was most pronounced for complement-fixing immune complexes prepared with high m.w. dsDNA. In vitro studies confirmed that immune complexes prepared with such dsDNA are rather slowly released from the animal platelets in the presence of homologous serum, and this result is in marked contrast to the considerably greater lability of bovine serum albumin/anti-bovine serum albumin immune complexes that are bound to complement receptors on animal and human cells. These observations suggest that the fate of immune-complexed dsDNA in the circulation may be very different from that of free dsDNA, and in the case of nonprimates may involve a platelet-mediated immune complex clearance mechanism analogous to the erythrocyte-mediated immune complex clearance mechanism which is believed to be operative in primates.     

Effect of centimeter microwaves on the antibody production in mice

The effect of low-intensity microwaves (8.15-18 GHz, 0.3 or 1 microW/cm2, 1.5 h daily for 30 days) on antibody production in healthy male NMRI mice after immunization with affinity-purified carboanhydrase isolated from bovine erythrocytes with and without Freund's adjuvant was studied. It was found that exposure to microwaves leads to an increase in the concentration of antibodies in blood plasma, the stimulating effect being more pronounced in the primary immune response. It is assumed that the effect of enhancement of the immune response by the action of centimeter microwaves can be used in the adjuvant therapy.     

The mononuclear cell in human blood which mediates antibody-dependent cellular cytotoxicity to virus-infected target cells. II. Identification as a K cell.

Studies were carried out to determine whether the mononuclear cell in human blood which mediates antibody-dependent cellular cytotoxicity (ADCC) to herpes simplex virus (HSV)-infected target cells has surface Fc receptors which participate in the reaction. The F (ab')2 fragment of human IgG antibody was inactive both in ADCC and in complement-mediated cytolysis, but retained the capacity to neutralize infectious virus, to agglutinate erythrocytes coated with viral antigens, and to bind to the surface of virus-infected cells. Treatment of sensitized virus-infected target cells with staphylococcus protein A, which has affinity for the Fc epitope of IgG, strongly reduced their susceptibility to lysis by ADCC in a dose-dependent relationship. These findings indicate that the Fc portion of IgG antibody to the virus is necessary for cytotoxicity. Treatment of blood mononuclear cells with either heat-aggregated gamma-globulin or HSV immune complexes inhibited effector cell activity. The presence of "third party" cellular immune complexes also strongly inhibited ADCC. Adsorption of mononuclear cells to plastic surfaces coated with soluble third party immune complexes resulted in a significant reduction in effector cell activity. These findings demonstrate that the ADCC effector cell possesses surface Fc receptors which are utilized in the ADCC reaction. The presence of Fc receptors on the surface of the effector cell indicates that it is a K cell rather than a null cell.     

Use of the passive hemagglutination test for the purpose of determining antibody levels following animal immunization with Cl. perfringens toxoid]

Data are presented on the study of possibilities of the application of the passive hemagglutination test for titration of the blood sera of mice, guinea pigs and rabbits immunized with Cl. perfringens toxoid. A diagnostic agent obtained by the sensitization of formalin- and tannin-treated sheep erythrocytes with the serologically pure toxoid, and homologous sera (as standard) were used in this test. A high immune response of BALB/c and C3H mice to the Cl. perfringens toxoid permits to suggest inbred mice as a model for the immunological and immunogenetic studies connected with this toxoid.     

Changes in the sorption of the antigens of the causative agent of typhoid on erythrocytes in the dynamic immune response

The study of the adsorption capacity of erythrocytes in 4 strains of mice was made. According to the results of the determination of the background capacity of erythrocytes, the strains of mice, opposite with respect to the sorption of S. typhi Vi- and O-antigens, were selected. After the immunization of these mice with the killed culture of S. typhi, the process of the sorption of the antigen on erythrocytes showed a characteristic kinetics. The course of immune response was characterized by specific changes in the adsorption capacity of erythrocytes in all strains of mice: the increase of this capacity on week 1 was followed by its sharp drop on weeks 3-4 and its subsequent restoration to the initial level by weeks 7-8. The non-specific stimulation of the host had no essential influence on the kinetics of the fixation of S. typhi antigens on erythrocytes. Experiments with the passive immunization of the animals revealed that different receptors take part in the process of the sorption of Vi-antigen on erythrocytes, some of these receptors being related to antibodies.     

Monoclonal antibody characterization of Plasmodium falciparum antigens in immune complexes formed when schizonts rupture in the presence of immune serum

When Plasmodium falciparum parasites are cultured with some immune sera, merozoites are agglutinated by antibodies to form immune clusters of merozoites and prevent their invasion into erythrocytes. Within these immune clusters of merozoites, several antigens that are normally found in the soluble fraction after detergent extraction accumulate in relatively insoluble immune complexes. From mice immunized with these immune complexes, we obtained hybridomas secreting monoclonal antibodies (mAb) that react with various immune clusters of merozoites antigens, including mAb 3D5, which recognizes a 101-kDa antigen (p101) and mAb, 5E3, which recognizes a 113-kDa antigen (p113). Both mAb reacted with antigens at the surface of schizonts, in the vacuolar space, and at the surface of merozoites before their release from schizont-infected cells. Both p101 and p113 were synthesized by mature trophozoites and young schizonts. In pulse-chase experiments, p113 was processed to 100-, 70-, 55-, and 50-kDa products. Both p101 and p113 appeared in the culture medium when schizont rupture occurred in normal culture medium but were found in immune complexes when schizont rupture occurred in the presence of immune serum. Antibodies in immune complexes, when dissociated with acid and used to probe immunoblots, reacted with affinity-purified p101 and p113. Antigens such as these, which are accessible at the parasite surface and react with antibodies present in immune serum that inhibits parasite invasion, are logical candidates to study in the search for a vaccine against the erythrocytic stages of malaria.     

Studies on the maturation of immune responsiveness in the mouse. II. Role of the spleen.

Experiments were designed to investigate the role of the spleen in the development of the murine immune system. By using mice splenectomized within 24 hr of birth, as well as mice with a hereditary, congenital absence of the spleen, the primary immune response to sheep erythrocytes was examined. The immunocompetence of lymph node cells from spleenless or control mice was assessed in vitro, in organ and in cell suspension cultures, and in vivo, by transfer into lethally irradiated syngeneic recipients followed by antigenic stimulation. The immunologic capacities of thymus and bone marrow cells were similarly tested by injection separately or in combination into irradiated syngeneic mice. Lymph node cells from spleenless animals appeared fully competent both in vitro and in transfer experiments. Neither neonatal splenectomy nor congenital absence of the spleen significantly reduced the capacity of bone marrow or thymus cells to participate in the immune response to sheep erythrocytes.     

Mechanisms of action of synthetic polyelectrolytes and polyampholytes on the immune response]

We investigated the effect of polyacrilic acid (PAA) on the immune response in mice of various strains on sheep red blood cells and also the influence of poly-2-methyl-5-vinyl-pyridine (PMVY), PAA and their statistical copolymers on antibody-forming cells (AFC) production in cultures of T- and B-lymphocytes in vivo. PAA was seen to increase accumulation of AFC in the spleen of mice depending on their genotypes. PMVP and PAA were found to intensify the cooperating interaction of T- and B-lymphocytes, whereas their copolymers exert quite an opposite effect. The injection of copolymers to the recipients of cooperating T- and B-lymphocytes practically results in the complete elimination of the cooperation effect between T- and B-lymphocytes in the immune response to sheep erythrocytes without cytostatic action of cell proliferation.     

The partial characterisation of maternal anti-trophoblast antibody responses generated during normal human pregnancy

The anti-trophoblast antibody response generated during a normal human pregnancy and detected by a recently developed enzyme-linked immunosorbent assay, was partially characterised in terms of maternal influences, nature of the antibodies and nature of the antigenic determinants present on the syncytiotrophoblast plasma membrane. The level and incidence of the response was significantly affected by maternal parity, while the maternal ABO, but not Rhesus, blood group antigens exerted a minor influence. The antibody response was predominantly mediated by IgG molecules of the IgG1,2 and 4 subclasses. The IgG molecules existed in the maternal sera either in the form of 'free' molecules or were involved in immune complexes. The antibodies interacted with determinants that were present on all the placental membranes tested and hence are possibly organ specific. The antigenic specificities were absent from erythrocytes and peripheral blood lymphocytes.     

Study of the phenomenon of specific suppression of the immune response in an adoptive transfer system]

It was revealed that the administration of the spleen cells (SC) of syngeneic animals immunized with a high dose of sheep red blood cells (SRBC) to intact mice led to a marked specific suppression of the recipients' immune response. The donors' SC obtained on the 14th day after the intraperitoneal injection of SRBC had the greatest suppressive activity. The SC of intact animals and mice given rat erythrocytes preliminarily failed to influence the immune response of the intact recipients in their SRBC immunization. Treatment of immune SC with the anti-T-serum (ATS) or the anti-B-globulin (ABG) and the complement considerably decreased or completely eliminated the suppressive activity. Administration of a mixture of two immune SC suspensions one of which was ATS- and another ABC-treated did not produce any suppression of the immune response in the intact recipients. It is supposed that the suppressor cells in the given model were T-lymphocytes expressing the antigens, common of cross-reacting with the B-cells.