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PubMed2004

Effect of tick salivary gland extract on the cytokine production by mouse epidermal cells.

Previous studies have demonstrated that both tick saliva and Borrelia burgdorferi sensu lato antigens modulate the cytokine response of the host. In this paper, the effect of salivary gland extract (SGE) from Ixodes ricinus (L., 1758) ticks on cytokine production by primary cultures of mouse epidermal cells stimulated with Borrelia afzelii Canica, Nato, du Merle, Mazie, Baranton et Postic, 1993 spirochetes was analysed. Epidermal cells were derived from C3H/HeN mice, susceptible to Lyme disease, and BALB/c mice, which are resistant. In cultures from C3H/HeN mice, SGE down regulated production of tumour necrosis factor alpha (TNF-alpha) and up regulated Th2 cytokine, interleukin 4 (IL-4). Cultures from BALB/c mice produced higher basal levels of monitored cytokines, but their production was affected by SGE a different way. While Th2 cytokines IL-6 and IL-10 were down regulated, the effect on TNF-alpha and IL-4 was ambiguous. These results indicate that the effect of tick saliva on the epidermal cells of Lyme disease-susceptible C3H/HeN mice mirrors its effect on other cells of the immune system.

Animals↗
PubMedDate not supplied

Expression of major histocompatibility complex class II and costimulatory molecules in oral carcinomas in vitro.

Recognition in the 1980 s that keratinocytes can express class II molecules of the Major Histocompatibility Complex (MHC) first raised the possibility that these cells might have an immunological function, and may even act as antigen presenting cells (APC). For effective T lymphocyte activation, APC require, in addition to MHC II, appropriate costimulatory signals. The aim of this study was to determine the expression of MHC class II and the co-stimulatory molecules CD40, CD80 and CD86 in keratinocytes derived from healthy oral mucosa and oral carcinomas. Using flow cytometry, it was confirmed that oral keratinocytes, switch on, expression of MHC class II molecules after stimulation with IFNgamma in vitro. All keratinocyte lines expressed CD40 constitutively; by contrast, CD80 and CD86 were universally absent. Loss of CD80 and CD86 may be one means whereby tumours escape immunological surveillance.

Antigenic Modulation↗
PubMed2006

Minimal residual disease testing of acute leukemia by flow cytometry immunophenotyping: a retrospective comparison of detection rates with flow cytometry DNA ploidy or FISH-based methods.

The detection and quantification of minimal residual leukemia (MRD) has importance for monitoring continued disease response and detection of early relapse. We retrospectively compared MRD detection rates and percentages of residual leukemia by flow cytometry immunophenotyping (FCIP) with results obtained by either flow cytometry DNA (FCDNA) ploidy (n = 14) and/or fluorescent in situ hybridization (FISH) (n = 33) testing for cases with 1.5% or less residual leukemia. A total of 42 paired results were obtained from 20 pediatric patients, including 16 with B lineage acute lymphocytic leukemia and 4 patients with acute myeloid leukemia during the course of induction and/or relapse. Eighty-one percent of the results were concordant (20 negative and 14 positive). There was reasonable correlation coefficients for quantity of residual disease by FCIP and FCDNA ploidy, and poor correlation coefficients for levels of residual disease between FCIP- and FISH-based results. FCIP MRD sensitivity and specificity was 78% and 83%, respectively. Factors contributing to the 19% discordant rate include low sensitivity of the DNA-based methods as applied and antigenic modulation of immunophenotype during the course of treatment. There is a reasonable agreement between the FCIP and FCDNA or FISH methods for detecting and quantifying MRD. However, the methods are viewed as complementary with their own inherent limitations.

Acute Disease↗
PubMed1991

[Acetylcholine receptor antibody titer, sensitivity to curare electromyogram and disease severity in myasthenia gravis].

All of 39 rabbits immunized with acetylcholine receptors invariably formed anti-AChR Abs and some of them developed muscular weakness or flaccid paralysis. Pharmacological, physiological and ultrastructural studies indicated that the pathology of experimental autoimmune myasthenia gravis in rabbits resembled that of human myasthenia gravis. The titer of anti-AChR Abs correlated poorly with disease severity and did not simply predicted the muscular weakness. The results ruled out the possibility that antigenic modulation of AChR was sufficient to account for the induction of myasthenia gravis. There was a close relationship between the sensitivity to curare and disease severity, but only part of immunized animals appeared electromyogram change. This led us to conclude that serum anti-AChR concentration would not be the single pathological factor in myasthenia gravis and disease severity may correlate with amount of normal AChR.

Animals↗
PubMed1990

In vivo selection of human tumor cells resistant to monoclonal antibody-Vinca alkaloid immunoconjugates.

UCLA-P3 human lung adenocarcinoma cells were grown in nude mice and given repetitive treatments of a monoclonal antibody-Vinca alkaloid immunoconjugate. Although this therapy resulted in a greater than 4-fold reduction in mean tumor mass of the established tumors, some animals experienced a reinitiation of tumor growth after cessation of conjugate treatment. Two such animals were treated again with high doses of monoclonal antibody-Vinca but one of the tumors was no longer regressed by the drug conjugate. The tumor was excised, enzymatically dissociated, and grown in tissue culture. Cultured cells were reimplanted in nude mice and subjected to further therapy with a monoclonal antibody-Vinca conjugate. The resulting tumors were also refractory to the immunoconjugate therapy. This cycle was repeated for a total of three times and resulted in the serial in vivo selection of three conjugate resistant variants. The mechanism responsible for the in vivo resistance of human tumor cells to the monoclonal antibody-Vinca immunoconjugate is unknown but does not appear to involve antigen modulation, altered tumor cell growth rate, or an apparent decrease in tumor targeting in vivo. The resistance was also not accompanied by any detectable elevation in multidrug resistance 1 mRNA or P-glycoprotein expression. Significantly, the resistance pattern was observed only in vivo and was not maintained by cells grown in vitro.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1990

Purging in auto- and allografts: monoclonal antibodies which use human complement and other natural effector mechanisms.

CAMPATH-1M is a rat IgM monoclonal antibody which binds to an antigen on all human lymphocytes and monocytes, but which is not present on marrow stem cells (Hale et al., 1983). Lymphocytes can be efficiently killed in bone marrow buffy coat preparations using the antibody and donor human serum as a means to avoid graft versus host disease (GVHD) (Waldmann et al., 1984). An analysis of 520 matched sibling bone marrow transplants (BMT) for leukaemia demonstrates that T-cell depletion using CAMPATH-1M markedly reduces the incidence and severity of GVHD, but there is an increased risk of graft rejection. In the case of CGL in chronic phase, there is also an associated extra risk of relapse, particularly in patients where engraftment may have been compromised (Hale et al., 1988a). A rat IgG2b antibody of the same specificity as CAMPATH-1 (CAMPATH-1G) was developed which is able to both fix human complement and opsonize lymphocytes in vivo (Dyer et al., 1989). Initial studies for the prophylaxis of bone marrow rejection in 55 mismatched and matched unrelated donor (MUD) BMTs suggest that CAMPATH-1G treatment of the recipient may reduce, but not eliminate, marrow graft rejection. The broad CAMPATH-1 specificity means that it is also ideal for purging a range of lymphoid malignancies prior to autologous BMT, or even for direct serotherapy of leukaemic patients. However, there may be limitations of monoclonal antibody purging using complement or other natural effector mechanisms either in vivo or in vitro; in particular, antigenic modulation and an antiglobulin response. Phase 1 studies of "in vivo purging" with a monovalent CD3 antibody (Clark et al., 1989), and also with a genetically engineered humanized IgG1 (CAMPATH-1H) (Hale et al., 1988b) suggest that these limitations can be overcome.

Antibodies, Monoclonal↗
PubMed1989

Immunotherapeutic approaches to the treatment of bone and soft tissue sarcomas.

The recent explosion of knowledge in the field of immunology has resulted in the development of many new and exciting forms of treatment for cancer patients. The identification of murine MoAbs with reactivity against antigens found on sarcomas has been accomplished in recent years. However, many problems exist with these reagents. As these antibodies are raised in mice, they represent foreign proteins for humans. As such, the development of immunity against the antibodies has been one of the major problems in applying this modality in the clinic. Other problems, such as specificity, antigenic modulation, tumor cell heterogeneity, and trafficking of the antibody to the tumor, remain to be resolved. Current research involving the development of chimeric or human MoAbs may overcome some of these obstacles. Cell-mediated approaches to therapy have met with enthusiasm and modest success so far. Although LAK cell therapy has not resulted in tumor regressions in the small number of sarcoma patients treated, further studies to define the true response rate are underway. It is possible that treatment with tumor-specific cells such as TIL or "educated" lymphocytes will be more effective in attaining regression in patients with metastatic bone and soft tissue sarcomas.

Bone Neoplasms↗
PubMed1985

[Present and future value of monoclonal antibodies in nephrology].

Many monoclonal antibodies directed against human T-lymphocytes have been produced in mice. Some of these, such as OKT 3, recognize all T-cells which can thus be counted in the blood; they have been used for the prevention of renal transplant rejection. Despite unexpected problems, such as antigenic modulation and anti-mouse sensitization, the first results obtained are promising. Other antibodies produced are directed against T-lymphocyte subsets, notably T-helpers (OKT4+) and T-suppressors or cytotoxic T-cells (OKT8+). Studies of the OKT4+/OKT8+ ratio have shown an imbalance in T-cell subsets in 2 types of glomerulonephritis: Berger's disease and membranous glomerulonephritis; they have also contributed to a better understanding of renal allograft rejection, where this ratio is often elevated.

Animals↗
PubMed1986

[AIDS--a further development].

It has been recently established that AIDS is a virus infectious disease. HTLV-I essentially makes T4 lymphocytes malignant and induces their abnormal proliferation. However, on the way, when HTLV-I induces a decrease in the function of T4 lymphocytes, the symptoms of ARC or AIDS take place on occasion. HTLV-III/LAV possesses a central function to destroy T4 lymphocytes, but, when this function is blocked, it increases T4 lymphocyte proliferation. Accordingly, the concept of carriers of the AIDS virus and patients with AIDS-related complex or AIDS has been clarified. Simultaneously, it has been discovered that a multiplicity of amino acids exists on the envelope of isolated AIDS viruses, resulting in a variety of viral envelope antigenicities. This may support the presence of antigenic modulation, which might make the development of a vaccine more difficult. Therapy has been approached from the following points of view; blockers of reverse transcriptase, drugs for destroying the virus itself through the viral envelope, vaccination, replacement of patient's T4 lymphocytes with healthy bone marrow, and use of immunopotentiators.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Initial experience in treating human lymphoma with a chimeric univalent derivative of monoclonal anti-idiotype antibody.

Murine monoclonal anti-idiotype antibody was raised against the surface IgM on the neoplastic cells of a patient with widespread follicular lymphoma. For therapy, a chimeric antibody derivative, FabIgG, was constructed by thioether-linking Fab'gamma, from the monoclonal antibody, to human normal IgG. FabIgG is univalent and thereby avoids rapid antigenic modulation. Its human IgG component is intended to optimize recruitment of effectors and metabolic survival while minimizing immunogenicity. Four intravenous (IV) infusions of 380 to 580 mg of anti-idiotype FabIgG were given over a period of 11 weeks. There was no significant toxicity. On each occasion, the antibody disappeared from the plasma with a half-life (t1/2) of less than 24 hours. The brief survival was evidently due to uptake by tumor, as infused control FabIgG, containing Fab'gamma from an irrelevant antibody, yielded a plasma t1/2 of greater than 10 days. With each therapeutic infusion, there was a fall in the number of circulating neoplastic cells over a 24-hour period. The numbers were largely replenished over the next week, but a net fall became discernible over the entire period of treatment. Four days after each infusion, nodal masses were swollen and tender, subsiding over approximately 8 days. At the end of the treatments, the blood lymphocyte count and nodal and splenic swellings continued to subside, so that by 6 weeks a partial remission with removal of greater than 50% of tumor was judged to have occurred. We did not detect any qualitative change in surface idiotype nor any antibody response to the infused Ig.

Animals↗
PubMed1987

Inhibition of T cell-dependent human B cell proliferation and B cell differentiation by polyspecific monomeric IgG.

A commercially available polyspecific, monomeric IgG preparation suitable for intravenous administration (IgSRK; Sandoglobulin) can inhibit pokeweed mitogen (PWM)-induced proliferation of peripheral blood mononuclear cells (PBMC) by a small, but statistically significant, amount compared to control cultures. Such inhibition could not be demonstrated when PBMC were stimulated with the T cell mitogen phytohaemagglutinin. Surface phenotype analysis of the PWM-stimulated cells indicated that in IgSRK-containing cultures, the proportion of B cells was decreased and the proportion of T cells was increased compared to control cultures. This alteration in T:B ratio was not due to antigenic modulation of B or T cell markers from their surfaces. In addition, IgSRK inhibited the proliferation of T cell-depleted PBMC cultures stimulated by B cell proliferation factors (BCPF) but not by fixed protein A-bearing Staphylococcus aureus strain Cowan I. The capacity to inhibit B cell proliferation was independent of and distinct from its capacity to inhibit B cell differentiation, since IgSRK inhibited the differentiation of a B cell differentiation factor (BCDF)-sensitive line by BCDF (which contains no BCPF activity). IgSRK inhibited PWM-induced generation of cytoplasmic Ig+ cells but had no effect on Ig secretion from mature Ig-secreting cells. Taken together, these findings suggest that IgSRK (which contains the IgG fraction from pooled plasma from 2,000 healthy donors) can inhibit T cell-dependent or T cell factor-dependent B cell proliferation and B cell differentiation.

B-Lymphocytes↗
PubMed1985

In vivo administration of lymphocyte-specific monoclonal antibodies in nonhuman primates: I. Effects of anti-T11 antibodies on the circulating T cell pool.

The effects of in vivo administration of three monoclonal antibodies specific for T11, the E rosette receptor on T lymphocytes, were examined in the rhesus monkey (Macaca mulatta). These three monoclonal antibodies were of different isotypes and were shown in in vitro studies to have differing affinities for the monkey T11 structure. Furthermore, each antibody induced antigenic modulation of T11 from the cell membrane of the lymphocytes to varying degrees in vitro. In vivo infusion of each of these antibodies into normal rhesus monkeys caused remarkably different effects on the circulating T lymphocyte pool. Infusion of these antibodies at doses of 2 mg/kg caused the coating of circulating T lymphocytes with antibody, the modulation of T11 off the T cell surface and the transient clearance of T cells from the circulation. Yet, the variation in the extent to which these effects were seen with these different antibodies indicates that extrapolating from studies of the in vivo use of one antibody to the use of another may be quite difficult. These studies clearly indicate the strengths of this nonhuman primate system for exploring the uses of monoclonal antilymphocyte antibodies as therapeutic agents. They, however, also demonstrate that differences may exist in the affinity of a particular antibody for homologous lymphocyte surface structures in humans and in a nonhuman primate species. These differences may make it difficult to predict the precise effects that the infusion of an antibody will cause in humans on the basis of alterations it induces in nonhuman primates.

Animals↗
PubMed1985

Athymic mouse model of a human T-cell tumor.

Because of the large number of different immunoconjugates which can be produced from monoclonal antibody-directed anti-cancer therapy, it would be useful to have in vivo tumor models to compare such preparations. Although historically human leukemias-lymphomas have been difficult to establish in athymic mice we have succeeded in establishing human T-cell tumors from primary MOLT-4 cultures in 290 of 353 animals and have successfully transferred tumors in 42 of 45 animals during ten serial passages. The potential utility of this model for testing immunoconjugates of murine monoclonal antibody T101 have been confirmed by: (a) in all 148 tumors sampled including all passaged tumors the human T-cell antigen, T65, was expressed in a manner identical to that of cultured cells; (b) 111In-T101 was concentrated preferentially in the tumor; and (c) T101 injected by both the i.p. and i.v. routes bound to tumor and induced antigenic modulation to the same extent as that observed previously in vitro and in human studies.

Animals↗
PubMed1979

Degradation of acetylcholine receptor in diaphragms of rats with experimental autoimmune myasthenia gravis.

The degradation of acetylcholine receptor observed in denervated and innervated normal rat diaphragms in organ culture is stimulated by exogenous antireceptor serum. In this paper we demonstrate that diaphragms from rats with experimental autoimmune myasthenia gravis contain reduced amounts of acetylcholine receptor. Acetylcholine receptor from myasthenic, but not from normal, rats has antibody bound to it and is degraded at an accelerated rate. We conclude that in the chronic phase of experimental autoimmune myasthenia gravis increased acetylcholine receptor degradation can be accounted for by a mechanism involving antigenic modulation, and that such a process can contribute to the clinical symptoms of impaired neuromuscular transmission.

Acetylcholine↗
PubMed1981

Serotherapy of acute lymphoblastic leukemia with monoclonal antibody.

We tested the efficacy of passive serotherapy in the treatment of acute lymphoblastic leukemia in four patients who had relapsed while receiving standard chemotherapeutic agents. Each patient received multiple intravenous infusions of J-5 monoclonal antibody specific for common acute lymphoblastic leukemia antigen (CALLA). In the three patients with circulating leukemic cells, there was a rapid decrease in circulating blasts that began immediately after antibody infusion, but not all leukemic cells were cleared, and remaining cells appeared to be resistant to further serotherapy. Although J-5 antibody was also demonstrable on bone marrow lymphoblasts immediately after antibody infusion in one patient, there was no change in bone marrow cellularity or differential during serotherapy. Analysis of the cell surface phenotype of leukemic cells during serotherapy and in vitro studies with patient cells suggests that resistance to serotherapy was mediated in part by antigenic modulation of CALLA in response to J-5 antibody.

Adolescent↗
PubMed1981

In vivo effects of murine hybridoma monoclonal antibody in a patient with T-cell leukemia.

A murine monoclonal antibody directed against a normal T-cell differentiation antigen was given to a patient with adult T-cell leukemia. Immunofluorescence staining showed increased amounts of this antigen on the patient's leukemia cells. Using a competition radioimmunoassay, free antigen was not detectable in the serum prior to therapy. Two courses of in vivo therapy were given using a 1-mg dose. Each produced a prompt and dramatic fall in WBC with return to pretreatment levels over the ensuing 24 hr, a pattern similar to that seen with leukopheresis. After the first dose of antibody, circulating free antigen became detectable in the serum and a transient decline in creatinine clearance was noted. A 5-mg dose of antibody given at that time was ineffective, presumably because it was blocked by free antigen. Antigenic modulation by leukemia cells was found transiently following each course of antibody. A weak and clinically insignificant host antimouse antibody response was found 5 days after the first treatment. The patient tolerated antibody therapy without difficulty. Monoclonal antibodies offer promise as an immunotherapeutic approach to cancer but problems encountered here must be addressed.

Aged↗
PubMed1981

Enzyme-enhancement immunoassay: a homogeneous assay for polyvalent ligands and antibodies.

A homogeneous enzyme immunoassay for proteins has been developed that avoids the need for a labeled antigen. The technique involves antibody labeled with beta-galactosidase (EC 3.2.1.23), succinylated antibody, and a macromolecular o-nitrophenyl-beta-galactoside substrate. The enzyme-labeled antibody and the succinylated antibody form an immune complex in the presence of sample antigen. An enzyme within this negatively charged microenvironment produces a product that forms a second light-scattering phase, whereas the product produced by free enzyme remains soluble. Thus the antigen modulates the rate of increase in light scattering. The technique has been applied to assays for human immunoglobulin G and C-reactive protein as well as for specific antibodies.

Antibodies↗
PubMed1982

[Fall in the levels of circulating lymphoblasts caused by intravenous administration of the A50 monoclonal antibody in a patient with acute T-cell lymphoblastic leukemia. A step in the demonstration of serotherapy with monoclonal antibodies].

In an 8-year-old boy with acute lymphoblastic leukaemia not previously treated intravenous administration of a single 8 mg dose of a monoclonal antibody that recognizes an epitope restricted to the surface of mature T-cells resulted, within 20 hours, in a fall in circulating lymphoblasts from 200 000 to 70 000. No adverse clinical or biological reaction was detected and no antigenic modulation occurred at lymphoblast surface. This observation constitutes a first step in the complex development of effective serotherapy for malignant diseases, using monoclonal antibodies.

Animals↗