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Biomedical subjects

H Festenstein

Publications and source records attributed to H Festenstein.

At least 55 records · Page 3Linked to original sources

Analytical studies of the binding parameters describing the interaction of HLA-DR epitopes with a specific monomorphic monoclonal antibody.

In this paper we present an analytical study of the binding parameters related to the interactions of the HLA-DR-specific monoclonal antibody (L243) and its reacting epitope as expressed on the cell surface of seven Epstein-Barr virus-transformed B cell lines. Scatchard, Sips and Langmuir equations were used to plot and analyse the data obtained from each reaction. A single affinity constant (K) value was derived at low and high concentrations of free antibody for each antibody-cell interaction tested and was of the order of 10(7) M-1. Similar heterogeneity indices (a) (close to 1.0) and K values were obtained for most of the cells. These results suggest that the reacting HLA-DR epitopes are homogeneously distributed and equally accessible to the antibody on all the cells tested. The average number of epitopes per cell was 3.4 X 10(6), SD 0.5 X 10(6) and were similar for all the cell lines. The analytical and experimental model presented here can be useful for studying quantitative and qualitative variations in the expression of MHC epitopes in oncogenesis and disease associations.

Antibodies, Monoclonal↗

Immunological and morphological characterisation of nucleated cells other than sperm in semen of oligospermic donors.

Nucleated cells other than sperm (NCOS) were obtained from semen samples of oligospermic donors. The cells, after separation from sperm, were studied by immunological and morphological techniques including electron microscopy (EM). Using an indirect immunofluorescence (IIF) test, more than 95% of the NCOS reacted with xenoantisera specific for human sperm and germ cells but showed less than 5% reactivity with monoclonal antibodies (MoAbs) directed against surface markers of different leucocyte subsets or cytokeratin. This indicated that the majority of NCOS were germ cells in origin. These results were concordant to those obtained by EM which showed the presence of germ cells at various stages of differentiation. Our data therefore show that the application of immunological techniques could help and may replace laborious EM in the identification of the different cell types among NCOS. Also, the results emphasize that germ cells and not leucocytes appear to be the major cell type among NCOS, a concept which could have therapeutic and biological implications.

Adult↗

Molecular dissection of human testicular germ cell differentiation with monoclonal antibodies.

Monoclonal antibodies (MoAbs) were raised by immunising mice with nucleated cells other than sperm (NCOS) obtained from semen of an oligospermic donor. These MoAbs recognised different germ cell differentiation antigens (GDA) which appear at various stages of spermatogenesis and/or spermiogenesis. The GDA were found to be differentially expressed on spermatocytes, spermatids and on the various sub-regions of human spermatozoe. Some of the MoAbs also recognised changes in the antigenic structure of the sperm during their post-testicular maturation. Using solubilised sperm products, MoAb GDA-J/F1 reacted with a 92 kDa band in Western immunoblotting. The importance of these antibodies in the study of germ cell differentiation together with their potential clinical uses in the investigation of infertility, autoimmunity and immunological contraception are discussed.

Antibodies, Monoclonal↗

HLA-DR alpha, -DX alpha, and DR beta III gene association studies in DR3 individuals.

In this study we have examined the results of probing with synthetic oligomers at the DR beta III locus, together with restriction fragment length polymorphisms defined by BglII digestion and a cDNA DR alpha probe, and Taq 1 digestion and a genomic DQ alpha probe. We have demonstrated heterogeneity of the human leukocyte antigen DR3 and close association of the DR alpha, DR beta III, and DX alpha genes. Two DR3-related preferential allelic associations have been identified, which may prove useful in family analysis as well as for investigations of DR3-related diseases.

Alleles↗

Frequency and associations of HLA-DR and HLA-DQ antigens in a British Caucasoid panel.

The frequencies of the HLA-DR and -DQ antigens, including those of the new specificities "DRBr" and TA10, were established in a random panel of 286 British Caucasoids. The most frequent DR antigens were DR2, DR4 and DR7. The DR-DQ antigen associations were examined and the only heterogeneity found was with DR7 which was found to be associated predominantly with DQw2 but also with DQw3. The DR4's were subdivided into those positive and those negative for TA10 and DR4-TA10 was found to be associated with HLA-B44.

Gene Frequency↗

HLA expression on human germinal cells.

Ejaculated human seminal plasma cells obtained from 46 healthy men and 48 infertile patients were tested for expression of HLA class I and II antigens by complement-mediated cytotoxicity, cell-binding radioimmunoassay (CB-RIA), and an ELISA involving monoclonal antibodies (mAbs). In a group of healthy men tested for HLA expression on human spermatozoa, 4 of 46 were positive for class I and II HLA antigens. However, the results were negative in a second examination of the same donors, possibly on account of alterations with time in the expression of various subpopulations of cells which are antigen positive or antigen negative. In a group of infertile patients, we found positive expression of HLA class I and II antigens in 7 of 48 men. The samples contained immature and mature sperm but no contaminating leucocytes or epithelial cells.

Antibodies, Monoclonal↗

Human cytotoxic T-cells against measles virus-infected and myelin basic protein-coated targets are cross-reactive.

Cytotoxic T lymphocytes (CTL) which recognized measles virus antigens were generated by in vitro sensitization of peripheral blood lymphocytes from normal volunteers against autologous measles virus-infected lymphocytes. Cytotoxicity of measles virus-infected targets by these effectors was considerably enhanced when the effector-target cell mixtures were incubated in presence of 10 or 100 ng myelin basic protein (MBP) for the 3-hour duration of the 51Cr release assay. In most experiments, specific release of radioisotope was doubled or tripled. Bovine serum albumin caused only slight increases in cytotoxicity. The killing of allogeneic target cells by alloimmune CTL was not affected by either of these reagents. Measles-specific CTL were also able to kill target cells that were cultured overnight in presence of MBP but washed prior to the assay. Conversely, CTL generated by culturing lymphocytes in presence of MBP for 6 days were able to kill MBP-coated and measles virus-infected target cells. The implications of these findings in the pathogenesis of multiple sclerosis are discussed.

Antigens, Viral↗

HLA class II alpha chain gene polymorphisms in patients with insulin-dependent diabetes mellitus, dermatitis herpetiformis, and celiac disease.

We have investigated DNA polymorphism of the class II alpha chain genes in HLA typed patients with insulin dependent diabetes mellitus (IDDM; n = 79), celiac disease (CD; n = 46), dermatitis herpetiformis (DH; n = 53), and controls (n = 86). Preferential allelic associations of HLA genes and gene products have thus been constructed for susceptibility to these diseases. DR alpha and DQ alpha gene polymorphisms indicated heterogeneity of HLA DR3, DRw6, and DR7, and HLA DR2 and DRw6, respectively. In DR7 positive CD patients a 3.8-kilobase (kb) DR alpha fragment, which correlated with DQw3, was found in only 11% of patients compared with 45% of corresponding controls (P less than 0.05). An increased frequency of a DX alpha genotype UU in all three diseases was found (IDDM 59%, DH 45%, CD 48%, compared to 21% in controls, P less than 0.001), which is not explained solely by the increased frequencies of DR3-DX alpha U. We therefore conclude part of the genetic susceptibility for these three conditions is encoded by genes within the DQ-DX subregion.

Celiac Disease↗

Genetic markers in late paraphrenia: a study of HLA antigens.

Patients with late paraphrenia were typed for HLA-A, -B and -C. Increased frequencies of BW55 (P = 0.036), B37 (P = 0.008) and CW6 (P = 0.056) were found relative to controls. Unlike findings in paranoid schizophrenia, there was no HLA-A9 association, suggesting that paraphrenics may be genetically distinct from schizophrenics. The primary association seems to be with B37, which has the lowest corrected P value and highest relative risk; if this were replicated, it would make possession of this antigen a strong risk factor for developing the disorder.

Aged↗

DQ beta restriction fragment length polymorphism and its relationship to insulin dependent diabetes mellitus.

HLA Class II serological and DQ beta restriction fragment length polymorphisms (RFLPs) were compared in 69 patients with insulin-dependent diabetes mellitus (IDDM) and 81 healthy British Caucasoid controls. The backbone of the analysis was formed by two Taq 1 RFLPs of the DQ beta region designated T2 omega and T6. The two are not allelic and can be inherited individually, together on one, or separately on both, parental haplotypes, the latter almost invariably in association with DR4. In our study the frequency in IDDM patients of both T2 omega and T6 together (relative risk for IDDM = 6.4) is similar to that of DR3/DR4 (relative risk for IDDM = 5.4) with an even higher relative risk for IDDM when they are combined, (relative risk = 18 with 95 per cent confidence limits between 14 and 22). We have thus defined DQ beta RFLPs which tightly associate with IDDM individuals with DR4.

DNA Probes, HLA↗