On 30th of June the three price winners got awarded for their project “„A three-dimensional coculture of enterocytes, monocytes and dendritic cells to model inflamed intestinal mucosa in vitro”. It deal with the development of an in vitro-coculture system consists of an enterocyte cell line¹ (CaCo-2) and the generation of a process of intestinal inflammation for the study of alterations of the cell barriere properties after addition of for instance pharmaceuticals. The ceremony's orator was Dr. Christiane Baumgartl-Simons, chairwoman of People for Animal Rights Rhineland-Palatine and vice chairwomen of the federal association of People for Animal Rights.

The director of the research group, Prof. Dr. Claus-Michael Lehr, gave an short interview to InVitroJobs in the run-up of the price-giving at the 30th of June.




Award-winner of the current animal protection research award Rhineland-Palatine (from left to right): Dr. Eva-Maria Collnot, Fransisca Leonard and Prof. Dr. Claus-Michael Lehr.
Photo: Xavier LeGuevel.


InVitroJobs: Are you glad to receive the animal protection research award? You are awarded several times especially in the field of pharmacy: What importance does the price has?

Prof. Claus-Michael Lehr: As a matter of fact, there are not too many awards either. With 20.000 Euro it is the Highest Prize Money which we have recieved.

InVitrojobs: What are the current results from the examinations with the co-culture system  with the enterocyte cell line?

Prof. Claus-Michael Lehr: By addition of suitable substances we can initiate inflammatory processes, which are reproducible. Based on especially biomarkers² we can follow-up and quantify the course of disease as well as investigate the effect of anti-inflammatory pharmaceuticals concerning their efficacy and period of action.

InVitroJobs: What kind of animals and how many animals are normally used for such studies?

Prof. Claus-Michael Lehr: Primarily rats and mice are used. Beneath so-called „acute“ inflammation model³, which are used for chemical tests, there are also chronical models⁴, which are based on genetic modifications.

InVitroJobs: How long are the enterocytes durable in your co-cultures? Do it influence your research work?

Prof. Claus-Michael Lehr: Normally, CaCo-2 cells need 21 days before they are fully differenciated. Thereafter they can used several days. This was our starting point for the development of the co-culture system. Optimising the culture conditions for yielding comparable data in a short time and over a longer period should be topic of further validation studies for this test system.

InVitroJobs: You research on cell barriers and nanoparticles: What are the current knowledge of transport through cell barriers?

Prof. Claus-Michael Lehr: Nanoparticles of certain size seem to store themselve in inflammated regions of the intestinal epithelium preferentially without, however, penetrating the epithelium and  without coming to the blood stream in a significant amount. The observation gives the perspective to locate anti-inflammatory substances by „delivery systems“ at the site where the effect is desired and reduce the unwanted effects at other sites (for instance by systemic absorption in blood stream). This so-called „drug targeting“⁵ principle have been applied for some tine relating to cytostatic drugs⁶ and tumor deseases.

InVitroJobs: What are the urgent problems which occure during the research on cell barriers?

Prof. Claus-Michael Lehr: After the feasibility  of such kind of system could be proved basically, now a very careful validation has to follow. - Here the conditions and tolerance limits have to point out in which the system works reliable. This includes comparative studies („round-robin studies“) in other laboratories. Not before the long-running process is finished, then a statistical solid comparison with animal models can be done for so-called „vitro-vivo-correlation“. This pre-supposes that the in the comparison used animal models  has been also validated accordingly.

Thank you for this interview.

Literature:
Leonhard, F., Collnot, E. M. & Lehr, C. M. (2010): A three-dimensional coculture of enterocytes, monocytes and dendritic cells to model inflamed intestinal mucosa in vitro. MolPharm.2010 Dec 6;7(6):2103-19. Epub 2010 Nov 1.

Glossary:
¹ Enterocyte cell line (CaCo-2)
Enterocytes are the most often cells of the small intestine epithelium. They are responsible for the resorption of different substances from nutrient (Wikipedia).

The CaCo-2 cell line is a well differentiated cell line which rerived from a human colon adenocarcinoma (ROUSSET et al. 1980 see Möhring 2003). The cell line is well suitable as model for studies of the intestine cell proliferation and cell differentiation (PAGEOT et al. 2000 see Möhring 2003). The cell culture forms a closed monolayer similar to intestinal mucosa  and shows typical characteristics of human intestinal mucosa (DELIE u. RUBAS 1997, GAUTHIER et al. 2001 see Möhring 2003).

² Biomarkers
are properties, for instance a mutation or a particular enzyme or ion concentration) which can be measured and evaluated objectively and can serve as indicator for normal or pathogenic biological processes or for measure of pharmacological reactions to therapeuticval interventions (Bracht 2009).

³ Acute inflammatory model
During an acute inflammatory forms, a change of the microcirculation occures reseasing of inflammation mediators (body-own substances, which initiate or sustain the inflammation reaction of the body), which are produced from the endothelia cells and the surrounding cells in a first step. In the later stage these transmitters are produced by the immigrant leucocytes, primarily nezutrophiles and macrophages. They serve for eliminating the destructive substance / the initiator of desease and bring the inflammation to healing (Walther 2010).
In an animal experiment, in an originate „healthy“ animal a artificial inflammation is induced, for instance  by an injection in the ear or a paw, which is a precondition for following investigations.

⁴ Chronic (inflammatory) model
When it is not possible to eliminate the inflammation stimulus a chronicity may developes. In this case, growing and rampant conversion processes occures with vessel sprouting and separation of dead and healthy connective-tissue  (Walther 2010). In most of the cases the animal „model“ has a permanent inflammatory process by gene modification in the purpose to perform animal experiments.

⁵ drug targeting
target-orientied and selective enrichment or release of pharmaceutical substances at the desirable site ( Cogito et al. 2006-2011).

⁶ cytostatic drugs
cell groweth inhibiting substances; cancer drug, drug against auto-immune deseases, drug for inhibiting of cell division (http://medikamente.onmeda.de/Wirkstoffgruppe/Zytostatika.html)

Sources:
Möhring, M. (2003): Die Caco-2 Zellkultur, ein geeignetes In-vitro-System zum Studium anti-gen-abhängiger Effekte auf Enterozyten. Inaugural-Dissertation , Universität Leipzig. http://www.qucosa.de/fileadmin/data/qucosa/documents/3384/Die_Caco-2_Zellkultur,_ein_geeignetes_In-vitro-System_zum_St.pdf
Wikipedia, div. Bearbeiter (2006-2011): Enterozyt. http://de.wikipedia.org/wiki/Enterozyt.
Bracht, K. (2009): Pharmazeutische Zeitung online. http://www.pharmazeutische-zeitung.de/index.php?id=29346
Walther, S.(2010): Etablierung eines Entzündungsmodells an der isoliert profundiert humanen Placenta. Dissertation an der Medzinischen Fakultät der Ludwig Maximilians Universität München.
Cogito et al. (2006-2011): Drug targeting. Wikipedia. http://de.wikipedia.org/wiki/Drug_Targeting