Generation and testing anti-influenza human monoclonal antibodies in a new humanized mouse model (DRAGA: HLA-A2. HLA-DR4. Rag1 KO. IL-2Rγc KO. NOD)

Abstract

Pandemic outbreaks of influenza type A viruses have resulted in numerous fatalities around the globe. Since the conventional influenza vaccines (CIV) provide less than 20% protection for individuals with weak immune system, it has been considered that broadly cross-neutralizing antibodies may provide a better protection. Herein, we showed that a recently generated humanized mouse (DRAGA mouse; HLA-A2. HLA-DR4. Rag1KO. IL-2Rgc KO. NOD) that lacks the murine immune system and expresses a functional human immune system can be used to generate cross-reactive, human anti-influenza monoclonal antibodies (hu-mAb). DRAGA mouse was also found to be suitable for influenza virus infection, as it can clear a sub-lethal infection and sustain a lethal infection with PR8/A/34 influenza virus. The hu-mAbs were designed for targeting a human B-cell epitope (WGIHHPPNSKEQ QNLY) of hemagglutinin (HA) envelope protein of PR8/A/34 (H1N1) virus with high homology among seven influenza type A viruses. A single administration of HA specific hu-mAb in PR8-infected DRAGA mice significantly delayed the lethality by reducing the lung damage. The results demonstrated that DRAGA mouse is a suitable tool to (i) generate heterotype cross-reactive, anti-influenza human monoclonal antibodies, (ii) serve as a humanized mouse model for influenza infection, and (iii) assess the efficacy of anti-influenza antibody-based therapeutics for human use.

The humanized DRAGA mouse (HLA-A2. HLA-DR4. RAG1 KO. IL-2R g c KO. NOD) establishes inducible and transmissible models for influenza type A infections

“…This sequence is highly conserved among seven different IAV heterosubtypes. 24 Both DRAG and DRAGA mouse strains were shown to respond to several pathogens with specific human IgM and IgG antibodies. [24][25][26][27][28] Our data indicate that the DRAGA mouse is a viable model for studies of human-like lung physiopathology, and of humoral and cellular immune responses to infections with IAVs such as A/H1N1/PR8 and A/H3N2 subtypes of Aichi, Victoria and Hong Kong viruses.…”

“…NOD) knocked out for the murine immune system whilst expressing a long-lived functional human immune system (HIS) upon engraftment with human CD34 + hematopoietic stem cells (HSC) from cord blood. 22,23 Both DRAG and DRAGA mice responded by specific antibodies to infection or immunization with malaria protozoans, HIV, ZIKA, malaria protozoan, influenza A/ H1N1 PR8 virus, 24 and scrub typhus. [25][26][27][28] Although various wild-type and humanized mouse models have been described for a number of viral infections (i.e., HIV, EBV, HCV, HBV, HCMV, DENV, HTL-1, HSV-2, HuNoV, JVC, Scrub typhus, ZIKA virus) and bacterial or parasitic infections (i.e., Plasmodium falciparum, Leishmania, Neisseria meningitides, Salmonella Typhi, Borrelia herrmesii, Streptococcus agalactiae group B sepsis, and Scrub Typhus), 18 HIS-humanized animal models for infections with influenza type A infections (IAV) of groups 1 and 2 have not been established yet.…”

A Human-Immune-System (HIS) humanized mouse model (DRAGA: HLA-A2. HLA-DR4. Rag1 KO.IL-2Rγc KO. NOD) for COVID-19

“…DRAGA mice express HLA-A2.1 and HLA-DR0401 molecules on a Rag1KO.IL2RγcKO.NOD (NRG) background, and they have been described previously [52][53][54][55] . HLA-A2.…”

Glycan repositioning of influenza hemagglutinin stem facilitates the elicitation of protective cross-group antibody responses

“…While several murine and other animal species have been engineered to carry partial or entire human immunoglobulin loci to produce humanized antibodies, recapitulating the V H genedependent immune responses in these animal models is still challenging [55][56][57][58][59] . Moreover, cross-group bNAbs often have human-specific immunogenetic constraints that could be even more difficult to recapitulate in animal models 22,35,49,60 .…”