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PubMed1979

Cell-mediated reactivity to antigens shared by Moloney-virus-induced lymphomas (LSTRA) and certain 3-methylcholanthrene-induced mouse sarcomas.

Spleen cells (SC) both from BALB/c mice whose primary Moloney sarcoma virus (MSV)-induced sarcomas had spontaneously regressed and from normal, untreated BALB/c mice, were co-cultivated for 5 days with mitomycin-C-treated LSTRA cells; LSTRA is a BALB/c Moloney lymphoma which shares cell surface antigens with MSV-indiced sarcomas. These SC, referred to as CMR and CU cells, respectively, were shown to be cytotoxic to LSTRA cells in 3 h 51Cr-release assays; CMR cells showed, in most cases, the greatest lytic activity against LSTRA targets. The same SC were also reactive, in 20-h microcytotoxicity and 51Crassays, against target cells from a variety of transplanted sarcomas indiced by 3-methylcholanthrene (MCA) in Balb/c mice. The highest reactivity was seen when CMR or CU cells were tested against target cells from sarcoma lines that expressed an NB-ecotropic MuLV cross-reacting serologically with Moloney virus. Reactivity against isotope-labelled tumor cells expressing MuLV-associated cell surface antigens could be competititively inhibited by adding unlabelled tumor cells expressing such antigens. Finally, Winn assays were performed in which CMR cells strongly inhibited the outgrowth of cells from three sarcoma lines that express the NB-ecotropic MuLV. There was less but significant inhibition of cells from some other MCA sarcomas, either negative for the expression of MuLV-associated antigens or expressing the N-ecotropic endogenous BALB/c MuLV. CU cells enhanced tumor outgrowth in Winn assays at least as often as they inhibited it.

Animals↗
PubMed1978

[Effector function of acute leukemias in "spontaneous" (SCMC) and antibody dependent cellular cytotoxicity-tests (ADCC) (author's transl)].

Blood lymphocytes from 13 untreated acute leukemia patients, 3 pre-leukemias 3 immunoblastic lymphadenopathias and one infectious mononucleosis showed significantly lower spontaneous (SCMC) and antibody-dependent cellular cytotoxicity (ADCC) against 51Cr-labeled allogeneic melanoma cells of the IGR3 cell line than effector lymphocytes from 20 age- and sex matched control persons. While control lymphocytes exhibited the highest cytotoxic activity after depletion of mononuclear phagocytes (Fraction FFF), followed by the "Ficoll" purified Fraction F and defibrinated whole blood, the reverse was true for acute leukemias: here, the highest cytotoxicity was found in whole blood followed by the lymphocyte fractions F and FFF. Comparatively high cytotoxicity was found with two leukemia patients who had received blood transfusions the day before testing. During the course of an acute erythroleukemia chemotherapy drastically reduced SCMC and ADCC activities. A therapeutical splenectomy, on the other hand, did not affect cellular cytotoxicity in the case of a hairy cell leukemia. The angioimmunoblastic lymphadenopathies showed strikingly high percentages of EA- and EAC-rosettes forming cells and showed a marked increase of SCMC and ADCC activities after elimination of mononuclear phagocytes from the effector cell population.

Acute Disease↗
PubMed1978

Some requirements for a linear cell dose response in vitro assay for the T-cell progenitors of cytotoxic lymphocytes.

To develop a precise assay for the T-cells progenitors of cytotoxic lymphocytes (CL-progenitors), lymphoid were cultured under optimal conditions in Marbrook vessels with mitomycin-treated allogeneic stimulator cells, and the total level of CL produced 5 days later estimated by a modified 51Cr release assay. Conditions were adjusted so an arithmetically linear cell dose response relationship was obtained. Three aspects of the cell dose response curve required attention. (1) At low responding cell inputs a macrophage-like cell became limiting (despite the presence of allogeneic macrophages in the stimulating cell population), leading to a lag in the response. This limitation was overcome by adding a low level of irradiated syngeneic macrophages, or by using irradiated syngeneic spleen 'filler' cells. (2) The slope of the resultant linear dose response region could be reduced if desired by changing from cellophane dialysis membranes to 0.1 mu pore size nuclepore membranes, suggesting a stimulatory role for some higher molecular weight soluble factor produced in the cultures. (3) At higher responding cell inputs a marked and extensive plateau was obtained. CL developing early in the response appeared to be destroying the allogeneic stimulator cells causing the response to be self-limiting. This problem was overcome by using a responding cell concentration lower than commonly employed. Assays using mixed leukocyte cultures in the lag or plateau regions could give misleading vlaues for CL-progenitor activity. It is suggested that some examples of apparent synergism in CL generation may have resulted from these effects, rather than T-cell helper T-cell progenitor interactions.

Animals↗
PubMed1979

Removal of myelotoxicity from antilymphocytic sera.

Antilymphocyte sera (ALS) were prepared by different methods and examined for their myelotoxicity by bone marrow colony-forming assay, both before and after absorption with B cell antigens. The results show that myelotoxicity can readily be removed from some, but not all, ALS. The source of antigen and the immunisation protocol used determine the degree of myelotoxicity and hence the number of absorptions required. Non-myelotoxic ALS may be suitable for the prevention of graft-versus-host disease (GVHD) by in vitro treatment of bone marrow before transplantation.

Animals↗
PubMed1979

Specific and nonspecific cytotoxicity of leukocytes from human renal allograft recipients against donor fibroblasts.

A microcytotoxicity assay was used to search for cell-mediated cytotoxicity, serum-blocking factors, and antibody-dependent cell-mediated cytotoxicity (ADCC) against fibroblasts of donor origin in 19 human renal allograft recipients. Peripheral mononuclear cells (PMC) were frequently cytotoxic when they were obtained within 6 days prior to rejection, following sustained rejections, and within 1 month after removal of rejected grafts, but the toxicity was usually nonspecific. Recipient PMC were noncytotoxic when they were obtained within 6 days after the onset of an acute reversed rejection and during quiescent intervals when there was no evidence of rejection within 6 days before or after the assay. These data suggest that, regardless of its lack of specificity, there is some relationship between cytotoxicity of recipient PMC and allograft rejection. In none of 69 post-transplant serum samples was ADCC against donor target cells detected with the microcytotoxicity assay.

Cytotoxicity Tests, Immunologic↗
PubMed1979

Natural cytotoxicity of human Fc gamma-receptor-positive T lymphocytes after surface modulation with immune complexes.

In humans T cells with surface receptors for the Fc fragment of IgG (Fc gamma receptors) (TG cells) are effector cells in antibody-dependent cellular cytotoxicity (ADCC) and in natural cytotoxicity. While Fc gamma receptors are required to mediate ADCC, their role in natural cytotoxicity is unknown. To investigate this question, Fc gamma receptors on effector cells were modulated by interaction with IgG immune complexes. As a consequence of this modulation, TG cells lost most of their ADCC activity but retained a significant part of their natural killer activity. Thus, these experiments demonstrate that the cytotoxic mechanisms exerted by the same cell population can be dissociated experimentally. Furthermore, they suggest that the net natural cytotoxicity of normal human lymphocytes in certain effector cell-target cell combinations is the result of distinct types of reaction.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1978

Immune effector cell activity in canines: failure to demonstrate genetic restriction in direct antiviral cytotoxicity.

Experiments were undertaken to establish whether the cytotoxic activity of canine immune effector cells against viral antigens was affected by the genotype of the target cell (genetic restriction). Puppies from three different breeds were infected with vaccinia virus, and the peripheral blood leukocytes were collected at various times for measurement of their cytotoxicity against autologous and heterologous vaccinia virus-infected and uninfected skin fibroblasts. In all cases cytotoxicity only occurred against virus-infected targets, and there was no consistent evidence of preferential killing of autologous targets. Several indirect approaches were used to demonstrate that direct, presumably T cell, cytotoxicity was being measured rather than antibody-dependent cell cytotoxicity. On the basis of the evidence from cross mixed-lymphocyte assays and cell-mediated lympholysis assays, the dogs were shown not be be identical with respect to their histocompatibility antigens. The significance of our findings to the phenomenon of genetic restriction as observed for mouse-derived immune effector cells is briefly discussed.

Animals↗
PubMed1979

Effect of cell-mediated immune factors on the replication of an attenuated temperature-sensitive mutant of vaccinia virus.

Studies of the in vivo multiplication of an attenuated temperature-sensitive strain of vaccinia virus (ts2) indicated that temperature sensitivity alone could not account for the attenuation. Immunodepressive treatment of intracerebrally inoculated mice had a dramatic stimulatory effect on the multiplication of the attenuated strain and suggested that establishment of ts2 infection in the mice was hindered by host defense mechanisms mediated by cellular elements. Experiments carried out in vitro with the 51Cr release assay showed that cells infected with the ts2 mutant represented more susceptible targets to the cytotoxic action of immune spleen cells than cells infected with the parent vaccinia strain. Moreover, it appeared that ts2 replication, compared with wild-type replication in vitro, was more inhibited by the immune spleen cells. Although this work did not evaluate the role of specifically sensitized lymphocytes within the lesions, indirect evidence suggests that lymphocytes could cause a more effective halt in ts2 virus multiplication than in wild-type multiplication.

Animals↗
PubMed1979

Cytotoxic antibody to cells infected with measles virus in serum and cerebrospinal fluid of multiple sclerosis and control patients.

Sera and cerebrospinal fluids (CSFs) from 66 patients selected from a larger sample of multiple sclerosis (MS) and control patients were studied for presence of complement-dependent cytotoxic (CT) antibody against baby hamster kidney cells infected with measles virus, strain Lec. The MS group contained 26 patients with clinically definite disease and 7 with probable MS. Seventeen of the 33 patients selected from the MS group had hemagglutination-inhibiting (HI) antibody to measles virus in their CSFs. Specimens from 33 control patients with other identifiable neurological disorders were matched according to the time of specimen sampling and with the age of the donors. Seven of the controls had HI CSF antibody. The serum CT geometric mean antibody titer of the MS group was approximately twofold higher than that of the control group. Forty-two percent of the MS group and 18% of the control group had CT antibody in the CSF. With the exception of the ratio of one control patient, the serum/CSF ratios of CT antibody from all patients were 128 or less. Nine CSFs (six MS and three control specimens) had CT antibody but no detectable HI antibody. Conversely, 12 CSFs (eight MS and four control specimens) had HI antibody but no detectable CT antibody. Five patients in the MS group with both kinds of CSF antibodies had reduced CT ratios but normal HI ratios. The results suggest that the two tests detect CSF antibodies reactive with different antigens. In this study, where less than half of the MS patients displayed CSF CT antibody, it is unlikely that such antibodies play an active role in the pathogenetic mechanism operative in the disease.

Antibodies, Viral↗
PubMed1979

Pulmonary cell-mediated cytotoxicity in hamsters with parainfluenza virus type 3 pneumonia.

A 51Cr-release cytotoxic assay in vitro was developed to permit definition of the role of local pulmonary cell-mediated immunity in the recovery phase of experimental parainfluenza virus type 3 pneumonia in the Syrian hamster. Cytotoxic effector cells were obtained by bronchalveolar lavage; virus-infected targets were syngeneic secondary hamster kidney cells. Maximal target-cell killing was mediated by lung lavage cells obtained one week after infection; the response waned rapidly thereafter. There was a close temporal correlation between the cytotoxic response and termination of virus replication in the lung. Cytotoxicity was virus specific and was restricted by a requirement for species identity between effector and target cells. Immune spleen cells mediated one-fourth the amount of 51Cr release effected by lung lavage cells, which suggests that cytotoxic effectors were concentrated in the lung. Although the identity of the cytotoxic effector cell was not established conclusively, the characteristics of the response suggested strongly that thymus-derived lymphocytes mediated lysis of target cells. Further work is required to determine the relative importance of this aspect of the host response during recovery from respiratory viral infection.

Animals↗
PubMed1977

In vitro cell-mediated cytotoxicity in primary biliary cirrhosis and chronic hepatitis. Dysfunction of spontaneous cell-mediated cytotoxicity in primary biliary cirrhosis.

The in vitro cytotoxic function and target cell specificity of peripheral blood lymphocytes from selected patients with primary biliary cirrhosis and hepatitis B surface antigen-negative chronic hepatitis were investigated using 51Cr-labeled human Chang and EL-4 mouse sarcoma cell targets in assays of spontaneous cell-mediated cytotoxicity (SCMC) and mitogen-induced cellular cytotoxicity (MICC). In addition, antibody-dependent cellular cytotoxicity (ADCC) against Chang cells was assessed. At an effector-to-target cell ration of 100:1, the mean SCMC against Chang cells was much less in patients with primary biliary cirrhosis than that in either the controls (P less than 0.001) or the patients with chronic hepatitis (P less than 0.005) whereas the value for patients with chronic hepatitis did not differ significantly from that of the controls. The mean SCMC against EL-4 mouse sarcoma cells was also less in patients with primary biliary cirrhosis than in controls (P less than 0.005) whereas the value for chronic hepatitis was not significantly different from that of the controls or patients with primary biliary cirrhosis. In contrast, MICC against both targets and ADCC against Chang cells were similar for each group. Comparison of SCMC and MICC against both target cells, measured simultaneously, showed similar cytotoxic potenital against both target cells for each group. Effector cells capable of mediating cytotoxicity in each assay were defined by testing the cytotoxic function of lymphocyte subpopulations isolated from two representative patients with each disease using techniques of immunoabsorbent affinity chromatography and Fc receptor binding to antigen-antibody complexes. In both primary biliary cirrhosis and chronic hepatitis SCMC and ADCC were mediated by a subpopulation of lymphocytes which lack surface immunoglobulin (sIg-) and bear Fc receptors (Fc+). In contrast, MICC was mediated by sIg- cells which lack Fc receptors. Lymphocytes bearing sIg- were not cytotoxic in any assay. These results establish a difference in cytotoxic function in primary biliary cirrhosis and chronic hepatitis by defining the presence of a defect in spontaneous cytotoxic function of sIg-, Fc+ lymphocytes against Chang cells in primary biliary cirrhosis.

Adult↗
PubMed1977

Immunobiology of primary intracranial tumors. Part 3: Microcytotoxicity assays of specific immune responses of brain tumor patients.

Fifty-six in vitro microcytotoxicity assays were conducted on 30 patients with intracranial tumors at various times during the postoperative course. Significant specific cellular cytotoxic responses were found in nine of 56 assays, humoral cytotoxic responses in nine of 54 assays, and host effector cell-dependent, antibody-dependent cytotoxic responses in four of 28 assays. Variables that might influence the occurrence of cytotoxicity were studied, and the relationship of these findings to other immune parameters was discussed.

Adolescent↗