@inproceedings{HeilmannWandHolzloehneretal.2012, author = {Heilmann, Katja and Wand, Inga and Holzl{\"o}hner, Pamela and Micheel, Burkhard}, title = {Cooperation of dendritic cells with naive lymphocyte populations to induce the generation of antigen-specific antibodies in vitro}, series = {The journal of immunology}, volume = {188}, booktitle = {The journal of immunology}, number = {6}, publisher = {American Assoc. of Immunologists}, address = {Bethesda}, issn = {0022-1767}, pages = {1}, year = {2012}, language = {en} } @article{WandHolzloehnerNeupertetal.2011, author = {Wand, Inga and Holzl{\"o}hner, Pamela and Neupert, Steffi and Micheel, Burkhard and Heilmann, Katja}, title = {Cooperation of dendritic cells with naive lymphocyte populations to induce the generation of antigen-specific antibodies in vitro}, series = {Journal of biotechnology}, volume = {156}, journal = {Journal of biotechnology}, number = {3}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0168-1656}, doi = {10.1016/j.jbiotec.2011.09.002}, pages = {173 -- 181}, year = {2011}, abstract = {The production of monoclonal antibodies by hybridoma technology is dependent on lymphocytes taken from vertebrates which have to be immunized against the corresponding antigen. We present here our first experiments which should allow the replacement of this in vivo immunization step by an in vitro immunization procedure. This work provides new possibilities for the specific activation of immune cells in order to use them for the generation of antibodies which are not of murine origin. Bone marrow-derived dendritic cells were loaded with antigen and co-cultured with naive T and B lymphocytes of non-immunized mice. The interaction and activation of the different cell types were investigated by measuring the expression of specific cell surface markers, the release of activation-dependent interleukins and the secretion of antigen-specific antibodies. We could demonstrate that dendritic cells process and present antigen fragments and activate T cells, that T cells proliferate and release activation-induced interleukins, and that B cells maturate under the influence of activated T cells and secrete antigen-specific antibodies.}, language = {en} } @article{HessBartelRothetal.2012, author = {Hess, Anne-Katrin and Bartel, Manuela and Roth, Karina and Messerschmidt, Katrin and Heilmann, Katja and Kenchington, Ellen and Micheel, Burkhard and Stuckas, Heiko}, title = {Expression of M6 and M7 lysin in Mytilus edulis is not restricted to sperm, but occurs also in oocytes and somatic tissue of males and females}, series = {Molecular reproduction and development}, volume = {79}, journal = {Molecular reproduction and development}, number = {8}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {1040-452X}, doi = {10.1002/mrd.22056}, pages = {517 -- 524}, year = {2012}, abstract = {Sperm proteins of marine sessile invertebrates have been extensively studied to understand the molecular basis of reproductive isolation. Apart from molecules such as bindin of sea urchins or lysin of abalone species, the acrosomal protein M7 lysin of Mytilus edulis has been analyzed. M7 lysin was found to be under positive selection, but mechanisms driving the evolution of this protein are not fully understood. To explore functional aspects, this study investigated the protein expression pattern of M7 and M6 lysin in gametes and somatic tissue of male and female M. edulis. The study employs a previously published monoclonal antibody (G26-AG8) to investigate M6 and M7 lysin protein expression, and explores expression of both genes. It is shown that these proteins and their encoding genes are expressed in gametes and somatic tissue of both sexes. This is in contrast to sea urchin bindin and abalone lysin, in which gene expression is strictly limited to males. Although future studies need to clarify the functional importance of both acrosomal proteins in male and female somatic tissue, new insights into the evolution of sperm proteins in marine sessile invertebrates are possible. This is because proteins with male-specific expression (bindin, lysin) might evolve differently than proteins with expression in both sexes (M6/M7 lysin), and the putative function of both proteins in females opens the possibility that the evolution of M6/M7 lysin is under sexual antagonistic selection, for example, mutations beneficial to the acrosomal function that are less beneficial the function in somatic tissue of females.Mol. Reprod. Dev. 79: 517-524, 2012.}, language = {en} } @article{BartelHartmannLehmannetal.2012, author = {Bartel, Manuela and Hartmann, Stefanie and Lehmann, Karola and Postel, Kai and Quesada, Humberto and Philipp, Eva E. R. and Heilmann, Katja and Micheel, Burkhard and Stuckas, Heiko}, title = {Identification of sperm proteins as candidate biomarkers for the analysis of reproductive isolation in Mytilus: a case study for the enkurin locus}, series = {Marine biology : international journal on life in oceans and coastal waters}, volume = {159}, journal = {Marine biology : international journal on life in oceans and coastal waters}, number = {10}, publisher = {Springer}, address = {New York}, issn = {0025-3162}, doi = {10.1007/s00227-012-2005-7}, pages = {2195 -- 2207}, year = {2012}, abstract = {Sperm proteins of the marine sessile mussels of the Mytilus edulis species complex are models to investigate reproductive isolation and speciation. This study aimed at identifying sperm proteins and their corresponding genes. This was aided by the use of monoclonal antibodies that preferentially bind to yet unknown sperm molecules. By identifying their target molecules, this approach identified proteins with relevance to Mytilus sperm function. This procedure identified 16 proteins, for example, enkurin, laminin, porin and heat shock proteins. The potential use of these proteins as genetic markers to study reproductive isolation is exemplified by analysing the enkurin locus. Enkurin evolution is driven by purifying selection, the locus displays high levels of intraspecific variation and species-specific alleles group in distinct phylogenetic clusters. These findings characterize enkurin as informative candidate biomarker for analyses of clinal variation and differential introgression in hybrid zones, for example, to understand determinants of reproductive isolation in Baltic Mytilus populations.}, language = {en} } @article{HeilmannGrothSchossigetal.2007, author = {Heilmann, Katja and Groth, Thomas and Schossig, Michael and Lendlein, Andreas and Micheel, Burkhard}, title = {Modulation of hybridoma cell growth and antibody production by coating cell culture material with extracellular matrix proteins}, issn = {1369-703X}, doi = {10.1016/j.bej.2007.01.035}, year = {2007}, abstract = {The influence of coating polystyrene tissue culture plates with different proteins on murine hybridoma cell growth and antibody production was investigated. Fibronectin, collagen I, bovine serum albumin and laminin were used to coat NUNC and COSTAR cell culture plates. Cell number and antibody concentration in culture fluids were quantified as indicators for cell viability, proliferation and productivity. Adhesive behaviour, morphology, expression of surface receptors of hybridoma cells and the presence of tyrosine-phosphorylated proteins in cell lysates were characterized by cell adhesion experiments, microscopy, flow cytometry and Western Blot analysis. It was shown that coatings with fibronectin (0.2 ;g/ml) lead to a substantial improvement of cell growth by 50-70\% and an increase of monoclonal antibody production by 100-120\%. Collagen I coatings showed an improvement in cell growth by 30-70\% and by 60\% for the production of monoclonal antibodies. Coatings with BSA and laminin had minor effects on these parameters. It was found that the hybridoma cell lines used in this study did not express the ;2-chain of the ;2;1-integrin, which is responsible for binding to collagen and laminin. However, the presence of ;1- integrin on the cell surface was shown, which should enable hybridoma cells to bind fibronectin. We propose, therefore, that fibronectin adsorption to cell culture materials may be a promising approach to enhance the production of monoclonal antibodies by cultivated hybridoma cells.}, language = {en} } @inproceedings{BilitewskiKabaHeilmannetal.2013, author = {Bilitewski, Ursula and Kaba, H. and Heilmann, Katja and Mayer, Yvonne and Hofmann, B. and Mueller, P. and van den Heuvel, J.}, title = {Monoclonal antibodies against specific peptides derived from the 1,3-beta-glucosyltransferase Bgl2p allow detection of Candida albicans cells}, series = {Mycoses : diagnosis, therapy and prophylaxis of fungal diseases}, volume = {56}, booktitle = {Mycoses : diagnosis, therapy and prophylaxis of fungal diseases}, number = {1}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0933-7407}, pages = {27 -- 27}, year = {2013}, language = {en} } @inproceedings{HolzloehnerSchliebsMaieretal.2013, author = {Holzl{\"o}hner, Pamela and Schliebs, Erik and Maier, Natalia and F{\"u}ner, Jonas and Micheel, Burkhard and Heilmann, Katja}, title = {Production of monoclonal camelid antibodies by means of hybridoma technology}, series = {The journal of immunology}, volume = {190}, booktitle = {The journal of immunology}, publisher = {American Assoc. of Immunologists}, address = {Bethesda}, issn = {0022-1767}, pages = {1}, year = {2013}, language = {en} } @article{HeilmannGrothBehrsingetal.2005, author = {Heilmann, Katja and Groth, Thomas and Behrsing, Olaf and Wagner, Albrecht and Schossig-Tiedemann, Michael and Lendlein, Andreas and Micheel, Burkhard}, title = {The influence of the chemical composition of cell culture material on the growth and antibody production of hybridoma cells}, year = {2005}, abstract = {The multiplication and antibody production of murine hybridoma cells cultured on five different polymer membranes were tested and compared with conventional tissue culture polystyrene (TCPS). Membranes were prepared from polyacrylonitrile (PAN) and acrylonitrile copolymerized with N-vinylpyrrolidone (NVP20, NVP30), Na-methallylsulfonate (NaMAS) and N-(3-amino-propyl-methacrylamide-hydrochloride) (APMA). Cell number and antibody concentration were quantified as criteria for viability and productivity. Adhesion of hybridoma cells was characterized by vital and scanning electron microscopy. The results suggest that a strong adhesion of cells, observed on APMA and TCPS, increased cell growth but reduced monoclonal antibody production. In contrast membranes with lowered adhesivity such as NVP20 provided favourable conditions for monoclonal antibody production. In addition it was shown that this membrane also possessed a minor fouling as indicated by the low decrease of water flux across the membrane after protein adsorption. It was concluded that NVP20 could be a suitable material for the development of hollow fibre membranes for bioreactors.}, language = {en} } @article{MesserschmidtHeilmann2013, author = {Messerschmidt, Katrin and Heilmann, Katja}, title = {Toxin-antigen conjugates as selection tools for antibody producing cells}, series = {Journal of immunological methods}, volume = {387}, journal = {Journal of immunological methods}, number = {1-2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0022-1759}, doi = {10.1016/j.jim.2012.10.010}, pages = {167 -- 172}, year = {2013}, abstract = {The generation of antibodies with designated specificity requires cost-intensive and time-consuming screening procedures. Here we present a new method by which hybridoma cells can be selected based on the specificity of the produced antibody by the use of antigen-toxin-conjugates thus eliminating the need of a screening procedure. Initial experiments were done with methotrexate as low molecular weight toxin and fluorescein as model antigen. Methotrexate and a methotrexate-fluorescein conjugate were characterized regarding their toxicity. Afterwards the effect of the fluorescein-specific antibody B13-DE1 on the toxicity of the methotrexate-fluorescein conjugate was determined. Finally, first results showed that hybridoma cells that produce fluorescein specific antibodies are able to grow in the presence of fluorescein-toxin-conjugates.}, language = {en} } @inproceedings{MesserschmidtNeumannSchaalHeilmann2013, author = {Messerschmidt, Katrin and Neumann-Schaal, Meina and Heilmann, Katja}, title = {Use of antibody gene library for the isolation of specific single chain antibodies by ampicillinantigen conjugates}, series = {The journal of immunology}, volume = {190}, booktitle = {The journal of immunology}, publisher = {American Assoc. of Immunologists}, address = {Bethesda}, issn = {0022-1767}, pages = {1}, year = {2013}, language = {en} }