Antibody-dependent Cell-mediated Cytotoxicity Response Research Articles

In vitro assessment of recombinant, mutant immunoglobulin G anti‐D devoid of hemolytic activity for treatment of ongoing hemolytic disease of the fetus and newborn

A specific treatment for ongoing hemolytic disease of the fetus and newborn (HDFN) due to anti-D would be very attractive. One approach could be administration to the mother of nonhemolytic anti-D, which by crossing the placenta can block the binding of hemolytic maternal anti-D. Two anti-D immunoglobulin G3 (IgG3) heavy-chain mutants were expressed in Chinese hamster ovary cells. To investigate whether these anti-D IgG3 mutants could inhibit the red blood cell-destructive activity of recombinant human (rHu)IgG1 with identical antigen-binding region as well as polyclonal anti-D having multiple D epitope specificities, two assays were used, antibody-dependent cell-mediated cytotoxicity (ADCC) and a chemiluminescence (CL)-based method for detection of respiratory burst in peripheral blood monocytes. The two IgG3 anti-D heavy-chain mutants inhibited the ADCC and CL responses mediated by a rHuIgG1 anti-D with identical antigen-binding region as the mutant antibodies, as well as the destructive activity mediated by a polyclonal anti-D. The use of nonhemolytic anti-D may be an effective countermeasure against hemolysis in HDFN due to anti-D.

Cytokines, GM-CSF and IFNγ administered by priming and post-chemotherapy cycling in recurrent ovarian cancer patients receiving carboplatin

BackgroundMonocyte/macrophages (MO/MA), a polymorphic population of innate immune cells, have the potential to mediate antitumor effects, and may also contribute to protumor effects. A priming and post-chemotherapy schedule of the myeloid cell mobilizing and immune stimulatory growth factor, granulocyte monocyte stimulating factor (GM-CSF, Leukine®) and the MO/MA activating cytokine recombinant interferon gamma 1b (rIFN-γ1b, Actimmune®) has been developed. The pre- and post-chemotherapy design is based upon known in vivo kinetics and immune modulatory effects of these molecules. Carboplatin (Paraplatin®) was selected as the cornerstone of treatment of epithelial ovarian cancer (EOC).MethodsWe studied hematopoietic and immunologic effects of GM-CSF and rIFN-γ1b before and after carboplatin in patients with recurrent EOC. Potentially chemotherapy-sensitive patients with recurrent measurable tumors received subcutaneous GM-CSF (starting at 400 μg/day) for 7 days plus subcutaneous rIFN-γ1b (100 μg) on days 5 and 7, before and after intravenous carboplatin (area under the curve of 5). We performed standard hematologic assessment and monitored monocyte (MO), dendritic cell, major cell subset counts, and antibody-dependent cell-mediated cytotoxicity (ADCC) against a Her2neu+ tumor cell line, as well as selected plasma inflammatory cytokine, chemokine and growth factor levels.ResultsOur analysis comprised only the first 3 months of treatment in the initial 25 patients. Relative to pretreatment baseline values, white blood cell, neutrophil, MO, and eosinophil counts increased (P ≤ .001 for each); the proportion of platelets increased 9 days after the second (P ≤ .002) and third (P ≤ .04) carboplatin treatments; and the number of cells in the activated MO subsets CD14+HLA-DR+, CD14+CD64+, and CD14+CXCR3+ increased (P ≤ .04 for each); plasma levels of the proangiogenic interleukins 1α, 6, and 8 were lower (P ≤ .03 for each); M-CSF, a product of activated MO/MA, was increased on day 9 (P = .007); and GM-CSF was increased in plasma after GM-CSF administration (P ≤ .04). Quality of life measurements were reduced during the GM-CSF/IFN-γ1b cycle while recovering at pre-chemotherapy baseline for FACT-G scores only.ConclusionA novel regimen of GM-CSF plus IFN-γ1b administered to 25 EOC patients receiving carboplatin increased myeloid cells, platelets and total activated MO populations during the initial 3 months; however, ADCC responses were not consistently enhanced during this period.

Antibody-dependent cell-mediated cytotoxic responses in participants enrolled in a phase I /II ALVAC-HIV /AIDSVAX ® B/E prime-boost HIV-1 vaccine trial in Thailand

Antibody-dependent cell-mediated cytotoxicity (ADCC) was assessed in volunteers participating in an ALVAC-HIV (vCP1521)/AIDSVAX ® B/E gp120 prime-boost vaccine trial in Thailand. ADCC activity was measured using chromium release from gp120 subtype B- and CRF01_AE-coated targets in 95 vaccinees and 28 placebo recipients. There was a significant difference in the magnitude of the ADCC response to both targets between vaccinees and placebo recipients. The frequency of responders to subtype B and to CRF01_AE was 96% and 84% in the vaccine group versus 11% and 7% in the placebo group. The results demonstrate that this HIV vaccine is a potent inducer of ADCC activity and may be an additional protection of this prime-boost vaccine in preventing HIV disease.

Immune response to Schistosoma mansoni infections in inbred rats. VII. Resistance is contingent on OX-8(+)-regulated high affinity IL-2 receptor-bearing W3/25+ lymphocytes but not on IL-4-dependent cells.

These studies assess the roles of subpopulations of T lymphocytes in resistance to Schistosoma mansoni. CDF rats were depleted of the T cell subpopulation bearing the high affinity IL-2R by in vivo treatment with ART18+ mAb or of soluble IL-4 by treatment with 11B11 mAb. The development of parasites, the expression of resistance after sensitization, and the intensity of delayed type hypersensitivity (DTH), Ag-mediated blast transformation (AMBT), IgG2a, passive cutaneous anaphylaxis, and IgE-mediated antibody-dependent cell-mediated cytotoxicity responses against S. mansoni or control Ag were ascertained. Isolated T cell subpopulations were assessed in vivo and in vitro for effects upon the protective Ir. Depletion with ART18 mAb suppressed the development of W3/25+ helper-inducer cells and resulted in the initial survival of more worms, decreased resistance to challenge after initial sensitization, decreased IgG2a and IgE antibody, AMBT, and DTH reactivity against schistosome Ag. Depletion with ART18 did not prevent the development of OX8+ (T suppressor) cells. Depletion with 11B11 mAb led to insignificant changes in initial parasite survival and resistance to challenge; had no effect on IgG2a antibody, AMBT, or DTH; but profoundly suppressed the IgE responses against the parasite. Protective immunity to S. mansoni in rats is dependent upon IL-2R-bearing T lymphocytes and regulated by OX8+ cells but not absolutely contingent upon IL-4 or the IgE response.

Cellular immune responses in pigs fed a vitamin E- and selenium-deficient diet.

The effects of dietary restriction of vitamin E (Vit E) and selenium (Se) on lymphocyte proliferation, natural killer (NK) cell activity, antibody-dependent cell-mediated cytotoxicity (ADCC), and on burst respiratory response of stimulated granulocytes as measured by chemiluminescence (CL) were studied in pigs. Six male weanling pigs were maintained for 25 d on a torula yeast-based diet containing no measurable amount of alpha-tocopherol and less than .02 mg of Se per kilogram of feed. Six others received the same basal diet supplemented with 33 IU of DL-alpha-tocopheryl acetate and .2 mg of Se per kilogram of feed. All pigs were inoculated with Salmonella typhisuis on d 21 of the feeding period and killed on d 25. Tests to measure cellular immune functions were performed on cells isolated from blood samples taken on d 21 and 25. After 21 d of feeding, lymphocyte blastogenesis responses to phytohemagglutinin, concanavalin A, and pokeweed mitogen in pigs fed the Vit E- and Se-deficient diet were normal compared with the response in pigs fed the supplemented diet. Moreover, the cytotoxic activity of NK cells, the ADCC response, and the CL response of granulocytes were not affected. After 25 d, a marked suppression of lymphocyte response to mitogens occurred in pigs fed the Vit E- and Se-deficient diet when the cells were cultured in the presence of autologous serum. When fetal bovine serum replaced autologous serum in the cultures, no suppression was observed. No effect on NK activity and ADCC was observed, whereas the CL peak response of granulocytes tended to be higher in pigs fed the deficient diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Possible Beneficial Effects of Neutralizing Antibodies and Antibody-Dependent, Cell-Mediated Cytotoxicity in Human Immunodeficiency Virus Infection

We studied the relationship between early human immunodeficiency virus type 1 (HIV-1) specific immune responses and pathogenesis of infection in participants enrolled in the multicenter AIDS cohort study (MACS). Sera collected at 6-month intervals for 2 years (visit 1-5) from 39 persons who seroconverted by enzyme-linked immunosorbent assay (ELISA) 6 months (visit 2) after enrollment were examined for isotype-specific Western blot reactivity, neutralizing antibodies (NA) against two divergent strains of HIV-1 (HIV-1IIIB and HIV-1RF), and for antibodies capable of participating in antibody-dependent, cell-mediated cytotoxicity (ADCC). These results were compared with changes in CD4+ cell number and episodes of lymphadenopathy. Twenty-five subjects had antibodies of at least one isotype reactive to at least one HIV-1 protein by Western blot at visit 1, before they became ELISA positive. NA reactive with HIV-1IIIB were detected before those reactive with HIV-1RF. NA were first observed in 11 sera at visit 2, in 22 sera at visit 3, and in 3 sera at visit 4; sera from three patients remained nonneutralizing through visit 5. In most cases, NA were detected after a decline in CD4+ cell numbers. The data are consistent with the interpretation that NA develop after about 16 to 18 months of declining CD4+ cell numbers, following which the rate of decline in CD4+ cell numbers slows. In contrast, HIV-1 envelope antigen-specific ADCC responses were first observed in 11 subjects at visit 1 when all 39 were NA and ELISA negative, in 12 subjects at visit 2, in 13 subjects at visit 3, and 1 subject at visit 4. Early ADCC responses were associated with high mean % CD4+ cell numbers and absence of lymphadenopathy throughout the 2-year observation period. Not all subjects who developed ADCC developed NA. In some subjects, ADCC and NA were detectable for the first time at the same visit, for others ADCC was detectable prior to NA, and for a few NA was detectable prior to ADCC. These findings suggest that ADCC and neutralization are mediated by different antibody populations, that they may partially inhibit the progress of HIV-1 infection, and that the late appearance of NA may relate to the failure of immunity to effect recovery from this infection.

Early Immunological Prediction of Renal Allograft Rejection

Reliable predictors of impending renal allograft rejection would be valuable for better patient management. To date, no available test has been shown to be consistently predictive and results have often been conflicting. We evaluated an effector of cell-mediated immunity, antibody-dependent cell-mediated cytotoxicity (ADCC) as well as the response of these cells to different biological response modifiers (BRM) in patients following renal allograft transplantation. The in vitro test used assayed monocytes as ADCC effector cells against antibody-sensitized chicken red blood cells. The effects of BRM were studied by preincubating the monocytes with lymphoblastoid IFN, recombinant alpha 2-interferon or gamma-interferon. A follow-up study was performed on 47 patients with end-stage renal disease treated with renal allograft transplantation. ADCC activity and its response to BRM were assayed prior to transplantation, 2, 4, and 9 weeks post transplantation. In the case of rejection, ADCC was then studied prior to initiation of antirejection therapy and for 2 months following treatment of rejection episode. We noted that in patients with stable grafts, the ADCC activity as well as its response to BRM declined gradually during the first 2 weeks post grafting and remained decreased up to 3 months after transplantation. In contrast, in recipients who experienced rejection episodes there was a sustained and significant increase in ADCC response to BRM during the first 3 weeks post grafting. By the time the diagnosis of rejection had been established the baseline ADCC activity had also increased. Following treatment and stabilization of the graft, ADCC activity and its response to BRM was decreased, similar to that in patients with stable grafts.(ABSTRACT TRUNCATED AT 250 WORDS)

Development of antibody-dependent cell-mediated cytotoxicity in the respiratory tract after natural infection with respiratory syncytial virus.

Antibody-dependent cell-mediated cytotoxicity (ADCC) was measured in nasopharyngeal secretions collected from 42 infants and young children at various intervals after primary or secondary infection with respiratory syncytial virus. ADCC was determined by specific immune release of 51Cr from respiratory syncytial virus-infected HEp-2 cell culture monolayers, with lymphocytes from adult volunteers as effector cells. Specific ADCC responses in nasopharyngeal secretions after primary infection were observed as early as 3 days after the onset of clinical symptoms, and peak activity was observed 14 to 29 days after the onset of illness. ADCC responses after reinfection were significantly greater in both the acute and convalescent phases (P less than 0.05) than were ADCC responses after primary infection. ADCC in secretions was mediated primarily by the immunoglobulin G isotype of respiratory syncytial virus antibody.

Antivirus antibody-dependent cell-mediated cytotoxicity during murine cytomegalovirus infection.

BALB/c mice infected with murine cytomegalovirus were studied to determine whether antibody-dependent cell-mediated cytotoxicity contributes to the immune control of this infection. Antibody-dependent killer cells from uninfected mice were used as effector cells to assay for antibody in sera of infected mice. Secondary immune sera were found to contain both cytomegalovirus-specific and autoreactive antibodies. After primary infection only cytomegalovirus-specific antibodies were found. These were detected by antibody-dependent cell-mediated cytotoxicity within 8 to 10 days after onset of infection, but usually not until day 21, by a neutralizing antibody assay. Antibody titers were about 10-fold higher by antibody-dependent cell-mediated cytotoxicity than by neutralization. The results indicate that cellular immunity to cytomegalovirus infection includes an antibody-dependent cell-mediated cytotoxicity response which is likely to be highly efficient and may contribute significantly to control of both acute and later stages of infection.