An ever increasing number of immunocompromised patients (mainly due to secondary immune defects caused by the HIV pandemic, organ transplantation and intensified immunosuppressive treatment strategies for cancer and autoimmune diseases) remind clinicians every day that strategies to reconstitute the human immune system are highly warranted.

Even though immunologists have used mouse models successfully during the last decades to describe the cellular texture of the immune system and its failures in disease, the translation of this knowledge into human cellular therapy still lacks behind. One reason for this gap lies in the difficulties to extrapolate findings from experimental mice to human patients, which is probably best explained by the evolutionary distance of 65 million years (Davis, Immunity 2008).  

Therefore, sophisticated human immune monitoring strategies have to be envisioned and realized to close this gap of knowledge and gain all the missing information about human immune cells required for the intelligent design of cellular therapies.

 

In this context, our group´s goal is to monitor in depth human T cells in order to identify relevant features (e.g. memory T cell subsets, cytokine patterns, T cell avidity) for successful T cell therapy. In doing so, our main technological focus lies on flow cytometry and the refined usage of MHC Multimers. Complementary mouse models are established and used whenever appropriate.

Being part of a multi-institutional immune monitoring platform ( www.helmholtz-muenchen.de/immunmonitoring; Coordination “Adoptive T cell therapy” ) we are well integrated into a strong network and actively take part in immune monitoring harmonization efforts (e.g. proficiency panels MHC multimers).

 

However, even with a promising cell therapy at hand, several hurdles have to be addressed and overcome before a cellular product can be clinically tested to get final approval for use in human beings. Major critical issues are the availability of donor cells, the establishment of gentle isolation techniques under GMP conditions, the approval by an ethics committee and the subsequent authorization by the responsible authorities.

Our group is currently involved in an authorized phase I/II adoptive T cell transfer study. In this trial, highly immunocompromised patients after allogeneic hematopoietic stem cell transplantation are treated by ex vivo isolated CMV-specific CD8⁺ T cells using reversible MHC I Streptamers. Virus-specific T cells are thoroughly monitored before, during and after T cell transfer using multicolor flow cytometry analyses and molecular biological T cell tracking techniques.     

In the future, we want to use the above-mentioned experiences to install a GLP-grade Flow Cytometry and GMP Cell Processing environment for clinical cell therapy. Reversibly binding reagents, recently developed for the gentle isolation of human blood cell subsets, will be clinically tested within this platform. The resulting cell products might eventually become a corner stone for a broad range of novel immune reconstitution therapies.

 

 

 

Literature:

 

A prescription for human immunology.

Davis MM.

Immunity. 2008 Dec 19;29(6):835-8.

 

 

 

 

Publications:

  

DCs in mouse models of intracellular bacterial infection.

Neuenhahn M, Schiemann M, Busch DH.

Methods Mol Biol. 2010;595:319-29.

 

The quest for CD8+ memory stem cells.

Neuenhahn M, Busch DH.

Immunity. 2009 Nov 20;31(5):702-4.

 

Stem cell-like plasticity of naïve and distinct memory CD8+ T cell subsets.

Stemberger C, Neuenhahn M, Gebhardt FE, Schiemann M, Buchholz VR, Busch DH.

Semin Immunol. 2009 Apr;21(2):62-8.

 

5′-Triphosphate-siRNA: turning gene silencing and Rig-I activation against melanoma.

Poeck H, Besch R, Maihoefer C, Renn M, Tormo D, Morskaya SS, Kirschnek S, Gaffal E, Landsberg J, Hellmuth J, Schmidt A, Anz D, Bscheider M, Schwerd T, Berking C, Bourquin C, Kalinke U, Kremmer E, Kato H, Akira S, Meyers R, Häcker G, Neuenhahn M, Busch D, Ruland J, Rothenfusser S, Prinz M, Hornung V, Endres S, Tüting T, Hartmann G.

Nat Med. 2008 Nov;14(11):1256-63.

 

Decreased susceptibility of mice to infection with Listeria monocytogenes in the absence of interleukin-18.

Lochner M, Kastenmüller K, Neuenhahn M, Weighardt H, Busch DH, Reindl W, Förster I.

Infect Immun. 2008 Sep;76(9):3881-90.

 

Circumvention of regulatory CD4(+) T cell activity during cross-priming strongly enhances T cell-mediated immunity.

Heit A, Gebhardt F, Lahl K, Neuenhahn M, Schmitz F, Anderl F, Wagner H, Sparwasser T, Busch DH, Kastenmüller K.

Eur J Immunol. 2008 Jun;38(6):1585-97.

 

Origin of CD8+ effector and memory T cell subsets.

Stemberger C, Neuenhahn M, Buchholz VR, Busch DH.

Cell Mol Immunol. 2007 Dec;4(6):399-405.

 

Unique functions of splenic CD8alpha+ dendritic cells during infection with intracellular pathogens.

Neuenhahn M, Busch DH.

Immunol Lett. 2007 Dec 15;114(2):66-72.

 

NF-kappaB is a negative regulator of IL-1beta secretion as revealed by genetic and pharmacological inhibition of IKKbeta.

Greten FR, Arkan MC, Bollrath J, Hsu LC, Goode J, Miething C, Göktuna SI, Neuenhahn M, Fierer J, Paxian S, Van Rooijen N, Xu Y, O’Cain T, Jaffee BB, Busch DH, Duyster J, Schmid RM, Eckmann L, Karin M.

Cell. 2007 Sep 7;130(5):918-31.

 

CD8alpha+ dendritic cells are required for efficient entry of Listeria monocytogenes into the spleen.

Neuenhahn M, Kerksiek KM, Nauerth M, Suhre MH, Schiemann M, Gebhardt FE, Stemberger C, Panthel K, Schröder S, Chakraborty T, Jung S, Hochrein H, Rüssmann H, Brocker T, Busch DH.

Immunity. 2006 Oct;25(4):619-30.

 

Differential requirement of perforin and IFN-gamma in CD8 T cell-mediated immune responses against B16.F10 melanoma cells expressing a viral antigen.

Prévost-Blondel A, Neuenhahn M, Rawiel M, Pircher H.

Eur J Immunol. 2000 Sep;30(9):2507-15.