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Biomedical subjects

J C Bystryn

Publications and source records attributed to J C Bystryn.

At least 19 recordsLinked to original sources

Identification of immunogenic human melanoma antigens in a polyvalent melanoma vaccine.

An essential element in the development of effective vaccines against human malignant melanoma is the identification of antigens which are relevant for vaccine construction as evidenced by their ability to stimulate antimelanoma immune responses in humans. In this study, we identified immunogenic melanoma antigens using as probes antibodies induced in patients immunized with a vaccine which contains a broad range of potential immunogens. By immunoprecipitation/sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of detergent lysates of radioiodinated melanoma cells, we found that 17 (65%) of 26 patients sequentially immunized with a polyvalent melanoma antigen vaccine developed antibodies to one or more melanoma cell surface antigens with approximate molecular weights of 38,000-43,000, 75,000, 110,000, 150,000, and 210,000. The immunodominant antigens which most frequently stimulated antibody responses were the M(r) 110,000 antigen followed by the M(r) 210,000 and 38,000-43,000 antigens, which induced antibody responses in 62%, 27%, and 19% of patients, respectively. These three antigens were commonly expressed on different melanomas but rarely on nonmelanoma cells and are unrelated to class I or II human leukocyte antigens or to the previously described p97 or M(r) 240,000 proteoglycan melanoma-associated antigens. Thus, these three antigens are attractive candidates for the construction of melanoma vaccines, because they are immunogenic in humans and are preferentially expressed on melanomas.

Antibodies, Neoplasm

Relationship between immune response to melanoma vaccine immunization and clinical outcome in stage II malignant melanoma.

The authors investigated whether there was a relationship between the induction of a delayed-type hypersensitivity (DTH) response to melanoma vaccine immunization and disease recurrence. They studied prospectively 94 evaluable patients with surgically resected Stage II malignant melanoma who were immunized to a partially purified, polyvalent, melanoma antigen vaccine. The DTH response to skin tests to the vaccine was measured before treatment and at the fourth vaccine immunization. Vaccine treatment induced a strong DTH response in 29 (31%) patients, an intermediate response in 24 (25%), and no response in 41 (44%). The median disease-free survival (DFS) of patients with a strong, intermediate, and no DTH response to vaccine immunization was more than 72 months, 24 months, and 15 months, respectively. The relationship between an increase in the DTH response and a prolonged DFS was statistically significant (P = 0.02); clinically meaningful (the median DFS of patients with a strong DTH response was 4.7 years longer than that of nonresponders); and, by multivariate analysis, independent of disease severity or overall immune competence. These findings suggest, but do not prove, that vaccine treatment can slow the progression of melanoma in some patients.

Adult

An improved europium release assay for complement-mediated cytolysis.

An improved assay for complement-mediated cytolysis is described. The target cells are labeled with europium complexed to diethylenetriaminopentaacetate (Eu-DTPA). Cytolysis caused by antibody plus complement leads to the release of the Eu-DTPA complex which is then formed into a highly fluorescent chelate by the addition of 2-naphthoyltrifluoroacetone (2-NTA). The amount of europium chelate formed--a measurement of cell death--is then quantified with a time-resolved fluorometer. The results of the assay are reproducible. Complement-mediated cytolysis when measured by europium release was five times more sensitive than when measured by conventional 51Cr release and three times than when measured by trypan blue exclusion. Because europium does not decay, target cells can be labelled in batches and stored frozen until use, which speeds and simplifies the assay. Thus, europium release assay is a simple and quantitative method to measure complement-mediated cytolysis which is sensitive and more rapid than conventional assays.

Antibody-Dependent Cell Cytotoxicity

Induction of B16 melanoma melanogenesis by a serum-free synthetic medium.

Cultured murine B16 melanoma cells normally grow as spindle-shaped cells firmly attached to tissue culture flasks. Pellets obtained from harvested B16 melanoma cells are white to grey in color. When the same cells were grown in synthetic, serum-free AIM V medium, cellular morphology and pigmentation were radically altered. Within 3 days of subculture in AIM V, cells rounded up and grew in clusters in suspension. Melanin content increased to greater than 30 times and tyrosinase activity was found to be 10-50 times higher in cells grown in AIM V medium compared to those cultured in normal medium. A concomitant increase in the level of immunoreactive tyrosinase was also induced. The individual growth factors and hormones present in AIM V medium were examined to determine which component(s) stimulates melanogenesis. Only those cells grown in the presence of 2.5% human albumin were stimulated to synthesize melanin. These findings suggest that albumin, or a component associated with albumin, has a major effect upon the regulation of melanogenesis in these cells.

Animals

Identification of pigment cell antigens defined by vitiligo antibodies.

Patients with vitiligo have circulating antibodies to pigment cells. To characterize this response further and to identify the antigens defined by vitiligo antibodies, sera of 23 patients with vitiligo and 22 patients with unrelated conditions were analyzed by immunoprecipitation and SDS-PAGE analysis of 125I-labeled cell antigens on pigment and control cells. Antibodies to pigment cell antigens were present in 18 (78%) of the patients with vitiligo but in only three (14%) of the control patients (p less than 0.05). The antibodies were directed to one or more antigens with molecular weight (MW) in kilodaltons (kD) of approximately 35, 40-45, 75, 90, or 150. The responses were most commonly directed to the 40-45-kD, 75-kD, and 90-kD antigens. Antibodies to these antigens were present in 74%, 57%, and 35% of vitiligo patients versus in 14%, 9%, and 0% of control individuals. The 35-kD and 90-kD antigens were preferentially expressed on human pigment cells, whereas the 40-45-, 75-, and 150-kD antigens were expressed on both pigment and control cells. These antigens were labeled by the lactoperoxidase technique, suggesting that they are cell surface antigens. These results confirm that antibodies to pigment cells are associated with vitiligo. These antibodies are directed to several cell surface antigens, some of which are preferentially expressed on pigment cells.

Antibodies

Identification of cicatricial pemphigoid antigens.

The nature of skin antigens defined by antibodies in patients with cicatricial pemphigoid was studied with use of the 1 mol/L of sodium chloride split skin technique and Western immunoblot analysis. Antibodies in the serum samples of three of seven patients with cicatricial pemphigoid reacted to the epidermal side of 1 mol/L of sodium chloride split skin, and antibodies in the serum sample of one patient reacted to the dermal side. With Western immunoblot analysis, three patients had antibodies to antigens in the epidermal extracts of skin. The antibodies reacted in all patients to a 160-kd antigen and in one patient to an additional 230-kd antigen. These two antigens are similar in molecular weight to the 230-kd major bullous pemphigoid antigen and to the 160-kd minor bullous pemphigoid antigen. However, while the basement membrane zone antibodies present in cicatricial pemphigoid were most often directed to the 160-kd antigen, those present in 38 patients with bullous pemphigoid reacted most often (in 34 patients [89%]) to the 230-kd antigen. None of the serum samples reacted to antigens in dermal extracts that contained the epidermolysis bullosa acquisita antigen. These results indicate that the basement zone membrane antibodies present in cicatricial pemphigoid are directed in part to epidermal antigens that are similar in molecular weight to bullous pemphigoid antigens. However, the frequency of reactions to different basement membrane zone antigens differs in the two diseases, which may account for the clinical differences between the two conditions.

Autoantibodies

Immunofluorescence abnormalities in lichen planopilaris.

BACKGROUND: Lichen planopilaris is believed to be a variant of lichen planus because both diseases have similar histologic features. However, as the clinical features of the two diseases differ, we conducted immunofluorescence studies to examine the relation between the two conditions more closely. OBSERVATIONS: Direct immunofluorescence was performed on scalp lesions of seven patients with lichen planopilaris. All had abnormal linear deposits of Ig restricted to the basement membrane zone of hair follicles. The deposits consisted of only IgG or IgA in five patients (70%) and of IgG in combination with other Igs in two patients (30%). Basement membrane zone deposits of fibrin were present in only one patient (14%) and were linear in appearance. There was no staining of ovoid bodies. These immunofluorescence abnormalities differ from those associated with lichen planus where basement membrane zone deposits of fibrin are present in almost all patients, where the basement membrane zone deposits are fibrillar in appearance, and where the deposits of Ig over ovoid bodies are common. CONCLUSIONS: The different appearance and composition of abnormal deposits of immunoreactants in lichen planopilaris and lichen planus suggest that the two conditions are different diseases.

Adult

Serum levels of circulating intercellular adhesion molecule 1 in human malignant melanoma.

Current reports have suggested a role for intracellular adhesion molecule 1 (ICAM-1) in the progression of human malignant melanoma and other cancers. Stage I, II, and III patients with histologically diagnosed malignant melanoma had significantly increased serum levels of circulating ICAM-1 (cICAM-1) and a striking increase in the incidence of positive sera. In Stage II and III patients, the level of cICAM-1 was inversely correlated with survival. Patients with elevated levels of serum cICAM-1 (greater than 2 SD units above control mean) had a significantly shorter mean survival. We suggest that elevated levels of serum cICAM-1 may be of diagnostic and prognostic importance in patients with malignant cutaneous melanoma.

Adult

Effect of cell wall skeleton and monophosphoryl lipid A adjuvant on the immunogenicity of a murine B16 melanoma vaccine.

We examined the effect of a new adjuvant consisting of purified mycobacterial cell wall skeleton (CWS) and monophosphoryl lipid A (MPL) on the immunogenicity of a murine melanoma vaccine. C57BL/6 mice were immunized to partially purified B16 melanoma vaccine given alone or together with different dose levels of adjuvant, or with saline or adjuvant alone. Humoral response, delayed-type hypersensitivity (DTH), in vitro cytotoxicity, and tumor-protective immunity to melanoma were measured following three biweekly immunizations. The adjuvant potentiated the antibody response to some, but not all, melanoma antigens in a dose-dependent fashion. The adjuvant also potentiated cellular immunity as measured by in vitro cytotoxicity assays. No potentiation of tumor-protective immunity was detected. In comparison to Freund's complete adjuvant, cell wall skeleton plus monophosphoryl lipid A (CWS:MPL) induced fewer cutaneous toxic effects and stronger antibody and DTH responses but resulted in no greater in vitro cytotoxicity or tumor-protective immunity. Thus, the adjuvant had a selective and dose-dependent effect on humoral responses to vaccine immunization but did not potentiate a tumor-protective immunity to B16 melanoma.

Adjuvants, Immunologic

Lack of effect of cyclophosphamide on the immunogenicity of a melanoma antigen vaccine.

Melanoma antigen vaccines are a conceptually attractive approach to prevent or delay disease recurrence in patients with surgically resected malignant melanoma. However, the immunogenicity of current vaccines is relatively low. Cyclophosphamide, when given in low doses prior to antigen exposure, is an immunomodulator which has been shown to enhance both humoral and cellular antitumor responses in animals and humans. We conducted a prospective, randomized, clinical trial to study whether pretreatment with cyclophosphamide augments the immunogenicity of a polyvalent, allogeneic, melanoma antigen vaccine in patients with melanoma and low tumor burden. Forty-five patients with resected stage II melanoma (regional metastases) were randomly allocated to treatment with melanoma vaccine or melanoma vaccine plus cyclophosphamide. All patients received the same dose and schedule of vaccine immunizations; those randomized to cyclophosphamide received 300 mg/m2 i.v. 3 days prior to each vaccine immunization. Cellular immune responses were evaluated by delayed-type hypersensitivity (DTH) skin reactivity to a test dose of vaccine at baseline (prior to treatment) and following the fourth immunization. Humoral immune responses were measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiographic analysis of indirect immunoprecipitates of patients' sera at the same time points. Twenty-four patients were randomized to cyclophosphamide pretreatment and 21 to vaccine alone; 22 and 18 patients were evaluable in each group, respectively. Differences were statistically nonsignificant with respect to either cellular (DTH) or humoral (antibody) responses between the two groups. DTH responses were induced in 16 of 22 (73%) and 15 of 18 (83%) patients treated with cyclophosphamide plus vaccine and vaccine alone, respectively. The mean posttreatment augmentation in DTH response in the cyclophosphamide group was 9.5 mm, compared with 9.9 mm in the vaccine-only group. Eight of 12 (66%) cyclophosphamide-pretreated patients and 9 of 12 (75%) vaccine-only patients produced increased titers of antimelanoma antibodies following treatment. No differences were observed between the groups in disease-free or overall survival. In summary, low-dose cyclophosphamide pretreatment failed to augment the immunogenicity of a polyvalent, allogeneic, melanoma vaccine in patients with completely resected early-stage melanoma.

Adult

Regional variation in the expression of pemphigus foliaceus, pemphigus erythematosus, and pemphigus vulgaris antigens in human skin.

The expression of the pemphigus foliaceus (PF), pemphigus erythematosus (PE), and pemphigus vulgaris (PV) antigens in 16 different regions of normal human skin was evaluated by indirect immunofluorescence by using sera with a high titer of PF, PE, and PV antibodies. Regional variations were observed in the expression of all these antigens. The expression of the PF and PE antigens, as measured by endpoint titer of antibody reactivity, was highest in skin specimens obtained from the upper torso, and lowest in those from the buccal mucosa, lower torso, and scalp. This distribution pattern differed from that of PV antigen, whose expression was highest in buccal mucosa and scalp. These patterns correlate with, and may provide a partial explanation for, the different distribution of skin lesions in these different forms of pemphigus.

Antigens, Surface

Identification of basement membrane zone antigens defined by antibodies that react to both the epidermal and dermal side of 1 M sodium chloride split skin.

Some individuals have basement membrane zone (BMZ) antibodies that react to both the epidermal and dermal side of skin split with 1 M NaCl. To examine the significance of this combined staining pattern, we tested sera from 185 different, sequential, patients with BMZ antibodies for reactivity to normal human skin split with 1 M NaCl. Six sera (3.2%) stained both the epidermal and dermal sides of split skin, 173 (93.5%) stained only the epidermal side, and 6 (3.2%) only the dermal side. All six sera with a combined staining pattern yielded the same pattern when tested with three different specimens of skin, indicating that this pattern is reproducible. By immunoblot analysis, five (83%) of the six combined staining sera reacted to a 160-kD antigen present only in epidermal extracts of normal skin, one reacted in addition to a 230-kD epidermal antigen, and one did not react to either epidermal or dermal extracts. In contrast, five (83%) of the six sera with dermal staining reacted to a 290-kD antigen present only in dermal extracts. Eighteen (90%) of twenty representative epidermal staining sera reacted to a 230-kD epidermal antigen and seven (35%) sera (five with the 230-kD antibody and two without) also reacted to the 160-kD epidermal antigen. Affinity purified antibody to the 160-kD antigen defined by combined staining sera reacted to the BMZ of normal human skin. These results indicate that the combined staining pattern on 1 M NaCl split skin is due to the presence of a distinctive antibody response directed predominantly to a 160-kD BMZ antigen located on the epidermal side of the split skin and to an as yet unidentified BMZ antigen located on the dermal side.

Aged

Relation between the incidence and level of pigment cell antibodies and disease activity in vitiligo.

Patients with vitiligo often have antibodies to pigment cells. To examine whether there is a relation between the presence of such antibodies and disease activity, sera of 24 patients with vitiligo (10 with active and 14 with inactive disease) and 19 normal individuals were tested for antibodies to pigment cell surface antigens using a live cell enzyme-linked immunoabsorbent assay. IgG pigment cell antibodies were present in 80% (eight of 10) of patients with active vitiligo but in none of those with inactive disease or in normal individuals. The antibody level of patients with active vitiligo (mean binding index [BI] 3.3 +/- 0.59) was significantly higher than in patients with inactive disease (BI 0.96 +/- 0.04) or normal individuals (BI 1.0 +/- 0.04, p less than 0.001). Antibodies present in eight patients with high titers of pigment cell antibodies reacted to three of four pigment cells but to only one of six unrelated cells. These findings indicate that a correlation exists between the incidence and level of pigment cell antibodies and the activity of vitiligo, and support the hypothesis that vitiligo is an autoimmune disease mediated by an immune reaction to pigment cells.

Antibodies

Immunotherapy of malignant melanoma.

The growth of melanoma in humans depends not only on the malignant potential of the tumor but also on the patient's immune response to the melanoma. As a result, a variety of strategies have evolved to treat melanoma by stimulating antitumor immune responses to melanoma. This article reviews the different approaches being taken and the results obtained to date.

Antibodies, Monoclonal

Epidermolysis bullosa acquisita. Incidence in patients with basement membrane zone antibodies.

We examined the incidence of epidermolysis bullosa acquisita in patients with circulating basement membrane zone antibodies. Serum samples from 100 sequential patients with basement membrane zone antibodies were tested by indirect immunofluorescence against 1 mol/L sodium chloride split skin and by Western immunoblot against epidermal and dermal extracts of skin. Ninety-two (92%) serum samples stained only the epidermal side of split skin, 5 (5%) stained only the dermal side, and 3 (3%) stained both sides. Four of the 5 serum samples with dermal staining but none of the serum samples with epidermal or combined staining reacted with the 290-kd epidermolysis bullosa acquisita antigen by Western immunoblot. These results indicate that approximately 5% of unselected patients with basement membrane zone antibodies have epidermolysis bullosa acquisita or bullous lupus erythematosus rather than bullous pemphigoid.

Adolescent

Tumor vaccines.

Melanoma vaccines are an exciting and increasingly attractive immunotherapeutic approach for malignant melanoma. Vaccines can be used for patients with high risk primary melanoma and regional disease, stages in the progression of melanoma for which there is presently no treatment. They are unique in their potential to prevent cancer in high risk individuals. Multiple approaches are being followed to develop effective vaccines. It is too early to judge whether any of them effectively slow the progression of melanoma. However, it is clear that vaccines are safe to use, and that they can stimulate immune responses to melanoma in some patients. The specificity of these responses needs to be clarified, and multiple challenges remain to be overcome before effective vaccines to melanoma become available. We must first identify the antigens on melanoma that stimulate immune responses, define the immune effector mechanisms that are stimulated by vaccine immunization and identify those responsible for increasing resistance to tumor growth, devise appropriate ways of constructing vaccines that will induce such responses, and find adjuvants and/or immunodulators that will potentiate desirable immune responses.

Animals