scholarly journals P06.07 In vivo studies of immunomodulatory a-CTLA-4 antibody in a humanized mouse model

2021 ◽  
Vol 9 (Suppl 1) ◽  
pp. A22.1-A22
Author(s):  
C Reitinger ◽  
F Nimmerjahn

BackgroundRecent findings in cancer immunotherapy have reinforced the hypothesis that the immune system is able to control most cancers. Immunomodulatory antibodies can enhance immune responses, having the potential to generate anti-cancer immunity.1–4Materials and MethodsMost current studies addressing this question are performed in murine mouse model systems or use in vitro culture systems, which do not reflect the human in vivo situation, potentially leading to results that cannot be fully translated into human cancer therapy. Therefore, it is necessary to establish a new mouse model, which allows the study of cancer immunotherapy in the context of a human immune system. We focused on the establishment of a humanized mouse model, in which different immunomodulatory antibodies can be tested in the presence of a human immune system.ResultsFirst experiments concerning the suitability to test immunomodulatory antibodies in the humanized mouse model, revealed that effects of checkpoint-control antibody a-CTLA-4 were similar to the effects seen in patients of clinical studies. To analyse the anti-tumor activities of immunomodulatory antibodies in vivo we are establishing a human melanoma-like tumor model in humanized mice.ConclusionsThis enables us to test the efficacy of immunomodulatory agonistic antibodies (such as CP-870,893) and checkpoint control antibodies (such as anti-CTLA-4) in eliminating a melanoma-like tumor. Furthermore, parameters like tumor infiltrating human cells und cytokine/chemokine production can be analysed.ReferencesSchuster M, Nechansky A, Loibner H. Cancer immunotherapy. Biotechnol J 2006;1:138–147.Mellman I, Coukos G, Dranoff G. Cancer immunotherapy comes of age. Nature rev 2011;480:480–489.Finn OJ. Immuno-oncology: understanding the function and dysfunction of the immune system in cancer. Annals of Oncology 2012;23:vii6–vii9.Langer LF, Clay TM, Morse MA. Update on anti-CTLA-4 in clinical trials. Expert Opin Biol Ther 2007;8:1245–1256.Disclosure InformationC. Reitinger: None. F. Nimmerjahn: None.

Author(s):  
Teodor-Doru Brumeanu ◽  
Pooja Vir ◽  
Ahmad Faisal Karim ◽  
Swagata Kar ◽  
Kevin K. Chung ◽  
...  

We report the first Human Immune System (HIS)-humanized mouse model (DRAGA: HLA-A2.HLA-DR4.Rag1KO.IL-2RgammacKO.NOD) for SARS-CoV-2 infection and COVID-19 research. This mouse is reconstituted with HLA-matched human hematopoietic stem cells from cord blood, thereby avoiding use of fetal tissue. It engrafts human epi/endothelial cells expressing the human ACE2 receptor for SARS-CoV-2 and the TMPRSS2 serine protease, which co-localize on lung epithelia. HIS-DRAGA mice sustained SARS-CoV-2 infection, showing abrupt weight loss, ruffed fur, hunched back and reduced mobility. Infected mice developed human-like lung immunopathology including T-cell infiltrates, microthrombi, hemorrhage, and pulmonary sequelae. Among T-cell infiltrates, lung-resident (CD103+)CD8+ T cells were sequestered in epithelial (CD326+) lung niches and secreted granzyme B and perforin, indicating cytotoxic potential. Infected mice developed antibodies against the SARS-CoV-2 S protein. Hence, HIS-DRAGA mice show unique advantages as a surrogate in vivo human model for studying SARS-CoV-2 immunopathology and for testing the safety and efficacy of candidate vaccines and therapeutics.


2012 ◽  
Vol 7 (9) ◽  
pp. 1608-1617 ◽  
Author(s):  
Moses T Bility ◽  
Liguo Zhang ◽  
Michael L Washburn ◽  
T Anthony Curtis ◽  
Grigoriy I Kovalev ◽  
...  

2021 ◽  
Author(s):  
Teodor-Doru Brumeanu ◽  
Pooja Vir ◽  
Ahmad Faisal Karim ◽  
Swagata Kar ◽  
Dalia Benetiene ◽  
...  

Abstract We report the first Human Immune System (HIS)-humanized mouse model (“DRAGA”: HLA-A2.HLA-DR4.Rag1KO.IL-2RgcKO.NOD) for COVID-19 research. This mouse is reconstituted with human cord blood-derived, HLA-matched hematopoietic stem cells. It engrafts human epi/endothelial cells expressing the human ACE2 receptor for SARS-CoV-2 and TMPRSS2 serine protease co-localized on lung epithelia. HIS-DRAGA mice sustained SARS-CoV-2 infection, showing deteriorated clinical condition, replicating virus in the lungs, and human-like lung immunopathology including T-cell infiltrates, microthrombi and pulmonary sequelae. Among T-cell infiltrates, lung-resident (CD103+) CD8+ T cells were sequestered in epithelial (CD326+) lung niches and secreted granzyme B and perforin, indicating cytotoxic potential. Infected mice also developed antibodies against the SARS-CoV-2 viral proteins. Hence, HIS-DRAGA mice showed unique advantages as a surrogate in vivo human model for studying SARS-CoV-2 immunopathology and for testing the safety and efficacy of candidate vaccines and therapeutics.


2019 ◽  
Vol 221 (2) ◽  
pp. 201-213 ◽  
Author(s):  
Jordana G A Coelho-Dos-Reis ◽  
Ryota Funakoshi ◽  
Jing Huang ◽  
Felipe Valença Pereira ◽  
Sho Iketani ◽  
...  

Abstract Background For the purpose of studying functional human dendritic cells (DCs) in a humanized mouse model that mimics the human immune system (HIS), a model referred to as HIS mice was established. Methods Human immune system mice were made by engrafting NOD/SCID/IL2Rgammanull (NSG) mice with human hematopoietic stem cells (HSCs) following the transduction of genes encoding human cytokines and human leukocyte antigen (HLA)-A2.1 by adeno-associated virus serotype 9 (AAV9) vectors. Results Our results indicate that human DC subsets, such as CD141+CD11c+ and CD1c+CD11c+ myeloid DCs, distribute throughout several organs in HIS mice including blood, bone marrow, spleen, and draining lymph nodes. The CD141+CD11c+ and CD1c+CD11c+ human DCs isolated from HIS mice immunized with adenoviruses expressing malaria/human immunodeficiency virus (HIV) epitopes were able to induce the proliferation of malaria/HIV epitopes-specific human CD8+ T cells in vitro. Upregulation of CD1c was also observed in human CD141+ DCs 1 day after immunization with the adenovirus-based vaccines. Conclusions Establishment of such a humanized mouse model that mounts functional human DCs enables preclinical assessment of the immunogenicity of human vaccines in vivo.


2021 ◽  
Author(s):  
Shivkumar Biradar ◽  
Yash Agarwal ◽  
Antu Das ◽  
Sherry T. Shu ◽  
Jasmine Samal ◽  
...  

AbstractLoss of function mutations in the human immunodeficiency virus (HIV) negative factor (Nef) gene are associated with reduced viremia, robust T cell immune responses, and delayed acquired immunodeficiency syndrome (AIDS) progression in humans. In vitro studies have shown that mutations in the Nef dimerization interface significantly attenuate viral replication and impair host defense. However, in vivo, mechanistic studies on the role of Nef dimerization in HIV infection are lacking. Humanized rodents with human immune cells are robust platforms for investigating the interactions between HIV and the human immune system. The bone marrow-liver-thymus-spleen (BLTS) humanized mouse model carries human immune cells and lymphoid tissues that facilitate anti-viral immune responses. Here, we employed the BLTS-humanized mouse model to demonstrate that preventing Nef dimerization abrogates HIV viremia and the associated immune dysregulation. This suggests that Nef dimerization may be a therapeutic target for future HIV cure strategies.


2021 ◽  
Author(s):  
Wei Zhou ◽  
Kin-hoe Chow ◽  
Rory Geyer ◽  
Paola Peshkepija ◽  
Elizabeth Fleming ◽  
...  

Human gut microbiota has co-evolved with human, and plays important roles in regulating the development and functioning of the host immune system. To study the human-specific microbiome-immunune interaction in an animal model is challenging as the animal model needs to capture both the human-specific immune functions and the human-specific microbiome composition. Here we combined two widely-used humanization procedures to generate a humanized mouse model (HMA-huCD34) with functional human leukocytes developed from engrafted huCD34+ cells and human fecal microbes introduced through fecal microbiota transplantation, and investigated how the two introduced human components interact. We found that the engrafted human leukocytes are resilient to the transplanted human microbes, while reciprocally the transplanted microbial community in the huCD34 mice was significantly different from mice without a humanized immune system. By tracking the colonization of human fecal Bacteroides strains in the mouse gut, we found that the composition of the strain population changes over time, the trajectory of which depends upon the type of mouse. On the other hand, different from Bacteroides, Akkermansia muciniphila exhibited consistent and rapid fixation of a single donor strain in all tested mice, suggesting strong purifying selection common to all mouse types. Our prospect study illustrated the complex interactions between the transplanted microbiome and different host factors, and suggested that the humanized mouse model may not faithfully reproduce the human-specific microbiome-immune interaction.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Maria M. Klicznik ◽  
Ariane Benedetti ◽  
Laura M. Gail ◽  
Suraj R. Varkhande ◽  
Raimund Holly ◽  
...  

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