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Biomedical subjects

D R Burger

Publications and source records attributed to D R Burger.

At least 19 recordsLinked to original sources
PubMed1987

Recombinant murine and human IL 1 alpha bind to human endothelial cells with an equal affinity, but have an unequal ability to induce endothelial cell adherence of lymphocytes.

Consistent with the reports of others, we have demonstrated that human peripheral blood lymphocytes adhere to cultured human umbilical vein-derived endothelial cells (EC) in vitro. In our studies adherence was increased twofold to threefold by a 6-hr preincubation of the EC with IL 1. Recombinant human IL 1 alpha induced a maximal adherence response at less than 1 U per 2 X 10(4) EC. In contrast, recombinant murine IL 1 alpha was found to be 250- to 1250-fold less active in the adherence assay, based on units of IL 1 activity defined by the murine thymocyte proliferation assay. Moreover, when EC were preincubated with excess murine IL 1, no inhibition of the adherence-inducing effect of human IL 1 was noted. To characterize further this dichotomy of biological potency of murine and human IL 1 on the adherence assay, IL 1 binding studies were initiated. Recombinant human and murine IL 1 alpha were equally effective in inhibiting the binding of 125I-labeled human and murine IL 1, based on both micrograms of protein and units of IL 1 activity. The results of this study demonstrate that although human and murine IL 1 bind with equal affinity to receptors on human EC, human IL 1 is significantly more potent at inducing the increased EC adhesiveness for lymphocytes. The implications of these results for endothelial cell IL 1 receptor function are discussed.

Animals↗
PubMed1987

Characterization of a T-cell determinant defined by a monoclonal antibody (TH5.2) which is involved in the interleukin-2-producing and proliferative capabilities of T cells.

Utilizing an OKT-4-positive human T-cell lymphoma cell line as immunogen, we have produced a monoclonal antibody (MAb), designated TH5.2, which is capable of augmenting the interleukin-2 (IL-2) production and proliferation of antigen-activated T cells. TH5.2 MAb by itself is not mitogenic for T cells; the enhanced IL-2 production and proliferation requires costimulation with either antigen or mitogen. TH.2 MAb recognizes all peripheral blood T cells at varying intensities, but does not react with monocytes. Using dual-color fluorescence analysis, it was determined that TH5.2 MAb reacts at a higher intensity on Leu-3a-positive T cells compared to Leu-2a-positive cells. Sorting T cells on the basis of fluorescent intensity with TH5.2 MAb demonstrated that the T cells reacting at high TH5.2 intensity were able to respond to mitogen at a higher rate (5-10X), as well as produce higher concentrations of IL-2 in response to mitogen as compared to the low IL-2 intensity cells. Cytotoxically treating peripheral blood mononuclear cells (PBMC) with TH5.2 MAb plus complement, which resulted in an approximate 8% decrease in the total population, significantly reduced the ability of the cells to proliferate to both mitogen and antigen. Addition of recombinant IL-2 to the cultures was able to restore the proliferative capability of the cells. In further analyzing the ability of TH5.2 MAb to augment the proliferative capability of PBMC to antigen and mitogen stimulation in vitro, it was determined that TH5.2 MAb was capable of acting synergistically with antigen or mitogen in increasing the Il-2-producing capability of T cells. Taken together the data suggest that the TH5.2 determinants is involved in the proliferative capability of T cells and is functioning at the level of IL-2 synthesis and/or secretion.

Animals↗
PubMed1987

Accessory cell function of the endothelial cell: its role in the cellular immune response.

We have proposed a hypothesis in which vascular endothelial cells, rather than or in addition to bone-marrow-derived cells, play an integral part in the antigen presentation event of cell-mediated immune phenomena including delayed-type hypersensitivity (DTH). Previously we have shown that a DTH ear-swelling response can be adoptively transferred in rats, using as few as 2 x 10(7) in vitro conditioned immune spleen cells. The transfer is antigen-specific, requiring the same sensitizing antigen in both the in vitro conditioning step and in the ear-test challenge. Adoptive transfer is also genetically restricted by alleles of the RT-1 region of the rat, requiring histocompatibility between immune donor cells and the naive recipient. In additional experiments, F1 to parental bone-marrow chimaeras were constructed such that the bone-marrow-derived cells and the non-bone-marrow-derived cells were of different RT-1 allotypes. When these chimaeras were used as adoptive transfer recipients, the transfer of DTH was possible only if the immune donor cells and the recipient non-bone-marrow-derived cells shared a common RT-1 haplotype, regardless of a shared haplotype with the bone-marrow-derived cells. These results point to a critical role for non-bone-marrow-derived cells (endothelial cells) in the DTH inflammatory response.

Animals↗
PubMed1985

Vascular endothelial cells in cell-mediated immunity: adoptive transfer with in vitro conditioned cells is genetically restricted at the endothelial cell barrier.

Delayed-type hypersensitivity (DTH) is a cell-mediated immune response that can be adoptively transferred in rats when greater than 2 X 10(8) cells from peritoneal exudate, lymph nodes, or spleen are used. We have shown that by using an in vitro conditioning step with antigen, transfer can be subsequently carried out with as few as 2 X 10(7) spleen cells. The magnitude of DTH was reflected in ear swelling after intradermal injection of antigen [tuberculin or keyhole limpet hemocyanin (KLH)] and confirmed histologically. The transfer was antigen specific, requiring the sensitizing antigen in both the in vitro conditioning step and in the ear test challenge. Adoptive transfer with conditioned cells was genetically restricted by alleles of the RT-1 region [major histocompatibility complex (MHC) of the rat]. Brown Norway strain (n haplotype) immune cells would not transfer DTH to Lewis (1 haplotype), ACI (a haplotype), or Buffalo (b haplotype) rats, whereas each strain would transfer DTH to syngeneic recipients. Moreover, this pattern of restriction held for all strains when tested in reciprocal fashion. In additional experiments, F1 to parental bone marrow chimeras were constructed so that bone-marrow-derived cells and non-bone-marrow-derived cells were of different RT-1 haplotypes. When these chimeras were used as recipients, transfer of DTH was only observed when immune donor cells and recipient non-bone-marrow-derived cells were syngeneic. These results point to the critical role of non-bone-marrow-derived cells (endothelial cells) in the DTH reaction.

Animals↗
PubMed1985

Expression of I-region-associated antigen (Ia) and interleukin 1 by subcultured human endothelial cells.

Activation of T cells requires three signals from an antigen-presenting cell: antigen, Ia determinants (HLA-D region determinants in man), and interleukin 1 (IL-1). Recent evidence has suggested that macrophages, dendritic cells, epidermal Langerhan's cells, and endothelial cells can each function as antigen-presenting cells (APC). If these cell types can independently function as APC, they should synthesize Ia determinants and secrete IL-1. To determine if endothelial cells fulfill these requirements, we have propagated human umbilical vein endothelial cells by serial subculture for extended periods of time and assessed Ia expression and IL-1 secretion. The endothelial cells were subcultured for 8 months (approximately 20 subcultures) and were found to display classic morphology and immunofluorescent staining for the endothelial cell-specific marker Factor VIII-related antigen. In a separate paper we have shown that these subcultured endothelial cells can present antigen to T cells in a HLA-D region-restricted fashion (C. R. Wagner, R. M. Vetto, and D. R. Burger, Subcultured human endothelial cells can independently function as fully competent antigen-presenting cells, accepted for publication, Hum. Immunol.). In this paper we present evidence demonstrating that extensively subcultured endothelial cells biosynthesize both HLA-DR and HLA-DS molecules after exposure to T cells and antigen or to a supernatant from antigen-activated T cells. Evidence is also presented that when endothelial cells are cultured in the presence of lipopolysaccharide they secrete a molecule(s) with IL-1 activity as assayed by LBRM-33-IA5 cell line production of interleukin 2.

Antigen-Presenting Cells↗
PubMed1985

Subcultured human endothelial cells can function independently as fully competent antigen-presenting cells.

Recent evidence has suggested that dendritic cells, epidermal Langerhan's cells and endothelial cells (EC) as well as macrophages, fulfill the requirements of antigen-presenting cells. Despite a variety of controls, one weakness in the evidence that these latter cell types can independently serve as antigen-presenting cells is that the cell preparations may contain small numbers of contaminating macrophages or other cell types. The experiments described in this paper are directed towards providing firm evidence that human EC are independently capable of presenting antigen to T cells. EC were isolated from human umbilical veins and maintained continuously by serial subculture for periods of up to 8 months. The subcultured EC displayed classic EC morphology and uniform immunofluorescent staining for Factor VIII-related antigen. The subcultured EC (tested to the 18th subculture) presented both particulate and soluble antigens to macrophage-depleted T cells with an efficiency equivalent to freshly isolated cells. Monoclonal antibodies to HLA-DR and HLA-DS determinants inhibited antigen presentation by either autologous macrophages or EC. In addition, antigen presentation by the subcultured EC was not affected by the macrophage-specific monoclonal antibody Mac-120, which inhibited antigen presentation by autologous macrophages in the same experiments. These results are consistent with human EC being able to independently function as fully competent antigen-presenting cells.

Antibodies, Monoclonal↗
PubMed1985

Delayed type hypersensitivity to gangliosides in the Lewis rat.

Systematic study of the immunologic properties of gangliosides has been hampered by the lack of a suitable assay. In this study, significant delayed type hypersensitivity reactions to gangliosides were observed in Lewis rats immunized with whole guinea pig spinal cord (GP-SC) in complete Freund's adjuvant (CFA). The reaction was manifested by an increase in ear thickness after intradermal injection of a mixture of gangliosides and methylated bovine serum albumin (mBSA). No responses were observed to either gangliosides or mBSA alone. The reaction to gangliosides increased after immunization, persisted for 48 h, and was characterized by perivascular infiltration of mononuclear cells. Further evidence for a cellular response was demonstrated by the transfer of ganglioside-specific ear swelling by cultured spleen cells. The response to gangliosides was not due to contamination with myelin basic protein (BP) since no reaction to gangliosides was observed in GP-BP/CFA-immunized rats, and no reaction to BP was observed in ganglioside/CFA-immunized rats. In BP-immunized rats, responsiveness to BP persisted after recovery from clinical EAE for at least 60 days. However, no response to gangliosides was observed in BP-immunized animals after recovery from clinical EAE, suggesting the lack of autosensitization to gangliosides due to the disease process itself.

Animals↗
PubMed1979

Myelin basic protein binding cells in active multiple sclerosis.

A sensitive, antigen-specific rosetting technique was used to enumerate blood cells that bind myelin basic protein (BP) in MS patients and controls. Sixteen of 23 MS patients in exacerbation but only 7 of 48 in remission formed elevated numbers of rosettes. Five of the latter 7 patients had recovered from an exacerbation within four months of the laboratory evaluation. Eight of 20 patients with progressive MS, all of whom had had disease for more than four years, had BP rosette-forming cells. None of the 16 normal volunteers and 1 of 8 neurological controls had BP rosette-forming cells. These results suggest that BP-binding cells in MS are confined to patients in acute exacerbation or within four months of activity, and those who have had progressive disease for at least four years.

Antigen-Antibody Reactions↗
PubMed1979

Immune response to melanoma extracts in three melanoma-prone families.

Immune reactivity to melanoma extracts was measured by the leukocyte adherence inhibition (LAI) test in 40 members of 3 melanoma-prone families. The melanoma patients had a wide range of responsiveness to the extract, the highest responder being a 10-year survivor. As a group, family members (including spouses) without disease had significantly elevated LAI responses compared to those of unrelated controls (P less than 0.01). Within the families, members with close exposure to melanoma patients for 10 years or more had a significantly higher response to melanoma antigen than did members with 0-5 years of close exposure (P less than 0.05). Responses of spouses and members at high risk of developing melanoma (B-K mole syndrome) also correlated with length of exposure to patients, which suggests that the elevated LAI response was not genetically determined. The high frequency of positive responses to melanoma antigens in these families, particularly in spouses, suggests the presence of transmissible melanoma-associated material capable of immunizing persons in contact with melanoma patients.

Antigens, Neoplasm↗
PubMed1979

Assessment of the mechanism of the leukocyte adherence inhibition test.

This study was designed to elucidate the mechanism of the leukocyte adherence inhibition (LAI) test in man. To identify the reactive cell types, enriched leukocyte populations (dextran-separated leukocytes and Hypaque-Ficoll-isolated mononuclear cells and neutrophils, as well as rosette-isolated B- and T-lymphocytes) were tested for leukocyte adherence in the absence of serum to tumor-specific antigens. LAI reactivity was not restricted to any of the enriched populations, suggesting the involvement of multiple cell types. Attempts to demonstrate soluble lymphocyte factors in the LAI mechanism have been uniformly negative. In contrast, factors in serum of immune donors were able to arm naive cells to be specifically responsive. This suggests a role for serum factors in the mechanism of LAI reactivity and partially explains the participation of multiple cell types in the responses observed. In additional studies, we could not document a correlation between the magnitude of the dermal test (delayed cutaneous hypersensitivity) and the magnitude of the LAI response in patients with squamous cell carcinoma of the head and neck. In 34 of 54 of these patients, there was agreement between the two tests (both positive, 27 of 54; both negative, 7 of 54). In the remaining 20 patients, the dermal test was greater than 5 mm while the LAI test was negative (less than 30% inhibition).

Antibodies, Neoplasm↗
PubMed1979

Human transfer factors: structural properties suggested by HPRP chromatography and enzymatic sensitivities.

Leukocyte extracts containing human transfer factor (TF) were fractionated by exclusion chromatography, and the active fraction (Sephadex G25, Fraction IIIa) was subjected to high pressure, reverse phase (HPRP) chromatography and enzymatic degradation. TF activity was assessed by the systemic transfer of dermal skin test reactivity from KLH-immunized donors to naive recipients. Preparative HPRP chromatography resolved Fraction IIIa into multiple chromophoric regions, two of which demonstrated transfer of KLH reactivity. Alkaline phosphatase treatment of Fraction IIIa converted the major ultraviolet-absorbing component, 5'-inosine monophosphate, to inosine and resulted in TF activity being restricted to one region. This HPRP region (R1A) contained less than 1% of the UV254 active material in Fraction IIIa but greater than 90% of the reactivity. The sensitivity of TF to pronase, proteinase K, phosphodiesterase I, and phosphodiesterase II was evaluated by inhibition of systemic transfer of KLH reactivity. Pronase and proteinase K destroyed systemic transfer activity and the pronase destruction could be inhibited with traysylol. Phosphodiesterase I, a 3' exonuclease, destroyed activity, whereas phosphodiesterase II, a 5' exonuclease, did not. The data are consistent with a phosphodiester-containing polypeptide in the structure of human TF for KLH reactivity.

Alkaline Phosphatase↗
PubMed1979

Association of melanoma tumor antigen activity with beta2-microglobulin.

The majority of melanoma tumor antigen activity present in melanoma extracts derived from fresh tumor tissue binds to a Sepharose-anti-beta2-microglobulin adsorbent. Removal of HLA antigens from the extracts of melanoma tissue by using a KBr flotation technique did not reduce either the tumor antigen activity of the extracts or the binding of melanoma tumor antigen (MTA) activity to the Sepharose-anti-beta2-microglobulin adsorbent. The complete blocking of MTA activity by pretreating the anti-beta2-microglobulin adsorbent with beta2-microglobulin and the lack of detectable MTA binding to a Sepharose anti-normal human serum adsorbent demonstrated the specificity of the binding of MTA to the anti-beta2-microglobulin adsorbent.

Antigens, Neoplasm↗
PubMed1978

Changes in tumor immunity during therapy determined by leukocyte adherence inhibition and dermal testing.

Leukocyte adherence inhibition (LAI) is an easily carried out in vitro test for tumor reactivity which is based on the prevention of adherence of leukocytes incubated with antigen to which the donor is immune. In this study a comparison is made with dermal response to tumor antigen. A total of 234 patients were tested, 74 of whom had melanoma, 111 of whom had squamous cell carcinoma of the head and neck, 18 of whom had neuroblastoma and 31 of whom had other tumors. Forty-two persons without tumors acted as controls for the LAI test. A high degree of correlation was found between LAI and dermal response. Furthermore, LAI exhibited marked tumor specificity and showed a ten-fold greater sensitivity than dermal response. LAI may be used to monitor serial changes in tumor reactivity in cancer patients.

Adolescent↗
PubMed1978

Transference of cell mediated immunity in patients with head and neck cancer.

A group of 67 patients with head and neck cancer has been studied of which 40 have received immunologic transfer factor from a normal donor pool. Examination of these patients revealed that lymphocyte reactivity to nonspecific mitogrens is depressed in patients who have head and neck cancer to a much greater extent than is seen in patients with other types of tumors. Furthermore, the depression is more prevalent among patients who have been treated with radiation. Patients in the head and neck group who have received transfer factor show an initial decreased response to PHA stimulation in culture. This is not seen in a control group of head and neck cancer patients or in patients with nonsquamous cander. Thymus-derived lymphocytes are depressed in patients with head and neck cancer, irrespective of whether they have received radiation. Th T-lymphocyte levels increased in eight of 38 patients who received nonimmune transfer factor, but 7 of these were in the group who had not received radiation. The leukocyte adherence inhibition (LAI) test has been used to determine tumor immunity in the patient test group. Changes in tumor immunity did not occur in those patients who received normal nonimmune transfer factor. Studies are presently in progress which provide for treatment of patients with head and neck cancer with specific squamous carcinoma immune transfer factor.

Antibody Specificity↗