PubMed Health⌕ Search

Biomedical subjects

C Van Waes

Publications and source records attributed to C Van Waes.

44 records · Page 3Linked to original sources
PubMed1991

Monoclonal antibodies to inner ear antigens: I. Antigens expressed by supporting cells of the guinea pig cochlea.

Murine monoclonal antibodies against guinea pig cochlear epithelium were generated with the goal of identifying cochlea-specific antigens and elucidating their function. To compensate for the limited amount of cochlear tissue, intrasplenic immunization was used. Hybridoma supernatants were screened by ELISA for antibody production and for binding to homogenates from cochlea, liver, lung, kidney and brain. Hybrids producing antibody to cochlea were subcloned and tested immunocytochemically against frozen sections and surface preparations of paraformaldehyde-fixed cochlear tissue. KHRI-1, a low titer IgM antibody stained only Hensen cells. KHRI-2, also an IgM antibody, stained tectorial membrane, cells of the spiral limbus, cells bordering the space of Nuel, Hensen cells and the root cells of the spiral prominence. KHRI-3, an IgG1 antibody, stained the phalangeal processes of outer pillar cells and the apical portion of phalangeal processes of Deiters' cells in a distinctive wine goblet pattern on surface preparations. KHRI-3 antibody also reacted with peripheral nerves and pia mater of brain in unfixed frozen sections but the antigenic site was not stable to fixation in contrast to the epitope detected in the cochlea. In Western blots of detergent extracts from cochlea KHRI-3 stained a broad tissue-specific band of Mr 70-75 kDa; a narrower band of Mr 68-70 kDa was identified by KHRI-3 in extracts of tongue and brain. KHRI-1 and KHRI-2 did not detect any proteins in Western blots. The monoclonal antibodies KHRI-1, -2, and -3 which define epitopes expressed by discrete populations of supporting cells in the inner ear should be useful in characterizing the nature and function of cellular structures in the cochlea.

Animals↗
PubMed1986

Identification of a unique tumor antigen as rejection antigen by molecular cloning and gene transfer.

Tumor-specific transplantation antigens are antigens that can lead to complete immunological destruction of a transplanted cancer by the syngeneic host. When such antigens are expressed on cancers induced by chemical or physical carcinogens, then they are usually unique, i.e., antigenically different for each independently induced tumor. In this study, we show that the product of a gene encoding a novel MHC class I molecule and isolated from the murine UV light-induced regressor tumor 1591 represents one such unique tumor-specific transplantation antigen that causes tumor rejection. The major evidence comes from our finding that 1591 progressor variants regularly lost the gene encoding this antigen that is expressed in the parental tumor that regresses in normal mice; furthermore, reintroduction of this gene into a 1591 progressor variant by DNA transfection caused the progressor variant to regress in normal immunocompetent mice. Thus, the progressor tumor reverted to the parental regressor phenotype following transfection. Consistent with the conclusion that the expression of the novel MHC class I gene following transfection was responsible for the regressor phenotype is also our finding that a variant of the transfected tumor that had lost expression of the transfected gene resumed its progressive growth behavior. Finally, we show that the molecule encoded by the novel class I gene is specifically recognized by a syngeneic tumor-specific cytolytic T cell clone that we have previously shown to select in vitro for progressor variants from the parental regressor tumor cell line. It remains to be determined to what extent unique tumor-specific rejection antigens of other highly immunogenic regressor tumors are encoded by novel MHC class I genes and whether these genes represent germline mutations or somatic mutations caused by the carcinogen treatment.

Animals↗
PubMed1986

Highly malignant tumor variants retain tumor-specific antigens recognized by T helper cells.

We have studied the components of a complex of tumor-specific antigens to determine if all of the components of the complex were lost during progression from a rather benign regressor tumor to a highly malignant (HM) cancer. We find that the HM tumor cells have lost antigens recognized by CTL but retained antigens recognized by Th cells. Immunization with variants expressing Th-defined antigens induced tumor-specific immunity to challenge with a parental variant that expressed a CTL-recognized target antigen, but did not induce immunity to challenge with the variant that expressed the Th-defined antigen alone. Together, these findings suggested that Th cells fail to exert direct selective pressure upon the tumor, resulting in retention of "lineage-specific," Th-recognized antigens by highly immunoselected variants. Possible advantage could be taken of this fact for the development of specific immunotherapy.

Animals↗
PubMed1985

Multiple cancers. Tumor burden permits the outgrowth of other cancers.

We demonstrate that tumor-bearing hosts permit the outgrowth of "potentially malignant" cells that are located at a different site. These second cancers continued to grow and kill their hosts even though they retain the "premalignant" phenotype, even after removal of the original malignancy. The potentially malignant cells used in these experiments were ultraviolet light- or methylcholanthrene-induced regressor tumor cells that are rejected regularly by normal mice at any testable dose, and only form progressive tumors in immunosuppressed individuals. The immunological rejection of these highly immunogenic, potentially malignant cells was suppressed by Thy-1+, Ly-2-, nonadherent, radio-sensitive suppressor cells in the tumor-bearing mice. These suppressor cells were absent in nude tumor-bearing mice. Unlike helper and cytolytic T cell-mediated responses, which are exquisitely tumor specific, the suppression caused by a progressively growing tumor was crossreactive among many syngeneic, independently derived tumors induced by different carcinogens. However, T cell-mediated immune responses to alloantigens, allogeneic tumors, certain syngeneic tumors, and humoral responses to xenogeneic red blood cells were normal in these mice. The immune suppression in the tumor-bearing animals closely simulated that induced by ultraviolet light irradiation, and both types of suppression might therefore share common mechanisms. Our findings may contribute to understanding the growth, development, and possible control of multicentric malignancies and add a precaution to the potential use of strongly immunogenic tumor variants for active immunotherapy in hosts bearing less immunogenic tumors.

Animals↗
PubMed1985

Dissection of tumour-specific antigenicity.

Unique tumour-specific antigens have been detected on many tumours induced by physical or chemical carcinogens. Although a seemingly endless diversity of such antigens has been identified, very little is currently known about the nature and complexity of the antigenicity of any single tumour. We describe the characterization of the complex unique antigenicity expressed on an ultraviolet-light-induced tumour. Such tumours are highly immunogenic and are clearly subject to immunosurveillance in the normal host. The antigenicity of an ultraviolet-light-induced regressor tumour was dissected with the aid of monoclonal T-cell probes and with antigen-loss tumour variants that were selected in vitro or in vivo. It was demonstrated that the total antigenicity of this tumour consisted of multiple antigens, all of which were independent, tumour-specific and expressed simultaneously on the same tumour cell. Additional experiments determined which antigens were critical for tumour rejection by studying the in vivo growth behaviour of antigen-loss variants selected in vitro. Evaluation of the complexity of the host anti-tumour response revealed that a hierarchy existed in the host recognition of these antigens, a finding that should have important implications on the effectiveness of tumour rejection and immune escape. Finally, using tumour-specific monoclonal antibodies against the syngeneic tumour, investigation into the molecular nature of these tumour antigens indicated that some of these antigens represent novel class I major-histocompatibility-complex molecules. Thus we describe the complexity of a unique tumour-specific antigen and discuss the implications of this complexity on tumour immunity and tumour escape.

Animals↗
PubMed1984

Pecking order among tumor-specific antigens.

The ultraviolet light-induced fibrosarcoma 1591 is regularly rejected upon transplantation into young syngeneic mice; in rare instances, however, this tumor grows progressively and the tumors that develop are then heritably stable variant progressor tumors (1591-PRO tumors). In this study, we have induced transplantation resistance to 1591-PRO tumors and determined which antigens were recognized by mice that rejected these progressor tumors. We found that cytolytic T cells of such mice recognized a 1591-specific antigen that was present not only on all the independently derived 1591-PRO tumors but also on the parental regressor tumor (1591-RE). However, the cytolytic immune response of mice that rejected 1591-RE lysed 1591-RE tumor cells but not 1591-PRO tumor cells. Thus, the 1591-RE tumor seemed to express two antigens that were specific for tumors of the 1591 lineage, one that was lost and a second that was retained by 1591-PRO tumor cells. Mice challenged with 1591-R# tumor cells mounted a response to only one of the tumor-specific antigens which was therefore "immunodominant" over the other "immunorecessive" antigen. This immunorecessive antigen became the target of the immune response once the immunodominant antigen was lost. This "pecking order" interfered with the simultaneous recognition of two tumor-specific antigens and this mechanism may favor immune escape.

Animals↗
PubMedDate not supplied

Cell adhesion and regulatory molecules involved in tumor formation, hemostasis, and wound healing.

BACKGROUND: Dynamic changes in cell adhesion and migration are fundamental properties of the cells that are important in hemostasis, vascularization, and wound repair. Changes in cell adhesion and migration are very important in the formation of tumors, and invasion and metastasis by neoplasms. METHODS: Using immunolocalization and immunopurification techniques, expression of integrin molecules involved in cell adhesion has been characterized during tumor development and wound healing. The ability of cytokines to regulate expression and antibody and peptide inhibitors to inhibit function of integrins has been explored to better understand the role of integrins in pathogenesis. RESULTS: Increased suprabasilar expression of the integrins alpha 6 beta 4, alpha 2 beta 1, and alpha 3 beta 1 accompanies development of squamous cell neoplasms of the head and neck. Integrin alpha II beta 3 is an integrin receptor which is important in platelet aggregation in hemostasis and formation of tumor metastases. Increased expression of integrin alpha v beta 3 has been identified in angiogenesis in response to growth factors and tumor angiogenic factors. Cytokine TGF-beta and arachadonic acid metabolite 12(S)-HETE are important signals in regulation of integrins and affect cell aggregation and migration in these processes. Ligands and inhibitors for some of these receptors have been identified which will be useful in determining their role during tumor development and progression. CONCLUSION: Recent advances in understanding the functions of the integrin cell adhesion molecules may soon add new diagnostic methods and therapies to the armamentarium of the head and neck oncologic, microvascular, plastic, and reconstructive surgeon. Therapies directed at controlling integrin cell-adhesion molecule expression and function are being explored to improve scar formation, bone synthesis, inhibition of vascular occlusion, and inhibition of tumor invasion and metastasis.

Antigens, Surface↗