Universität zu Köln

Kleipaß, Franziska Marisa (2025). Facilitating Humanized Mouse Models to Study Novel HIV-1 Prevention Compounds. PhD thesis, Universität zu Köln.

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Abstract

The ongoing HIV-1 pandemic still remains without an effective vaccine, implying the need for novel prevention strategies. Given the predominance of mucosal transmission, recent approaches include targeting HIV-1 at the site of infection with small molecules such as nanobodies. Nanobodies formed by Camelidae spp. are the smallest natural functional antibody fragments, exhibiting favourable features as anti-HIV-1 agents including long CDR3 loops, small size, acid stability and bacterial expression capability. Animal models and humanized mice (huMice) in particular, are essential and currently irreplaceable in preclinical HIV-1 research. HuMice consist of an immunodeficient mouse strain harbouring a human immunograft with the human reconstitution varying significantly between different models. However, a reliable mucosal HIV-1 susceptibility currently requires the use of human foetal tissue, raising legal, ethical and technical obstacles. This work addresses the unmet need for a foetal-tissue-independent model by presenting and characterizing the novel CD34T+ mouse model. Furthermore the new model is employed to test the preventive potential of an HIV-1 specific nanobody in an in vivo setting. The CD34T+ model is a modification of an existing model based on an NOD.Cg-Rag1tm1Mom Il2rgtm1Wjl/SzJ (NRG) background engrafted with human hematopoietic cord blood stem cells. We enhanced human reconstitution by administrating of donor-matched mononuclear cells and human IL-7. Peripheral blood as well as distinct organ tissue flow cytometry confirmed consistently enhanced human T cell reconstitution, which led to significantly higher rectal HIV-1 susceptibility. We employed the model to assess the in vivo HIV-1 prevention potential of the broadly neutralizing nanobody VHH A6. CD34T+ mice were challenged intrarectally with HIV-1 alongside either VHH A6 or an non-specific nanobody. Sequential blood viral load measurements for 6 weeks showed a significant protective potential of VHH A6. The novel CD34T+ mouse model offers a foetal tissue-independent in vivo platform with reliable mucosal susceptibility. This first in vivo investigation further supports nanobody-mediated passive immunity as a promising strategy, warranting further exploration.

Item Type:	Thesis (PhD thesis)
Translated title:	Title Language Opitimierung humanisierter Mausmodelle zur Untersuchung neuartiger Wirkstoffe in der HIV-1-Prävention German
Creators:	Creators Email ORCID ORCID Put Code Kleipaß, Franziska Marisa f.kleipass@outlook.de UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-752807
Date:	2025
Language:	English
Faculty:	Faculty of Medicine
Divisions:	Faculty of Medicine > Virologie > Institut für Virologie
Subjects:	Natural sciences and mathematics Medical sciences Medicine
Uncontrolled Keywords:	Keywords Language HIV-1 UNSPECIFIED humanized mouse UNSPECIFIED nanobody UNSPECIFIED HIV-1 prevention UNSPECIFIED flow cytometry UNSPECIFIED animal model UNSPECIFIED broadly neutralizing nanobody UNSPECIFIED VHH A6 UNSPECIFIED CD34T+ model UNSPECIFIED foetal-tissue independent mouse model UNSPECIFIED in vivo HIV-1 study UNSPECIFIED
Date of oral exam:	6 November 2024
Referee:	Name Academic Title Klein, Florian Universitätsprofessor Dr. med. Rybniker, Jan Universitätsprofessor Dr. med. Dr. nat. med.
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/75280