Glycan characterization of pregnancy-specific glycoprotein 1 and its identification as a novel Galectin-1 ligand.

Pregnancy-specific beta 1 glycoprotein (PSG1) is secreted from trophoblast cells of the human placenta in increasing concentrations as pregnancy progresses, becoming one of the most abundant proteins in maternal serum in the third trimester. PSG1 has seven potential N-linked glycosylation sites across its four domains. We carried out glycomic and glycoproteomic studies to characterize the glycan composition of PSG1 purified from serum of pregnant women and identified the presence of complex N-glycans containing poly LacNAc epitopes with α2,3 sialyation at four sites. Using different techniques, we explored whether PSG1 can bind to galectin-1 (Gal-1) as these two proteins were previously shown to participate in processes required for a successful pregnancy. We confirmed that PSG1 binds to Gal-1 in a carbohydrate-dependent manner with an affinity of the interaction of 0.13 µM. In addition, we determined that out of the three N-glycosylation-carrying domains, only the N and A2 domains of recombinant PSG1 interact with Gal-1. Lastly, we observed that the interaction between PSG1 and Gal-1 protects this lectin from oxidative inactivation and that PSG1 competes the ability of Gal-1 to bind to some but not all of its glycoprotein ligands.

HLA-DR*0401 expression in the NOD mice prevents the development of autoimmune diabetes by multiple alterations in the T-cell compartment.

Several human HLA alleles have been found associated with type 1 diabetes (T1D), but their precise role is not clearly defined. Herein, we report that a human MHC class II (HLA-DR*0401) allele transgene that has been expressed into NOD (H-2(g7)I-E(null)) mice prone to T1D rendered the mice resistant to the disease. T1D resistance occurred in the context of multi-point T-cell alterations such as: (i) skewed CD4/CD8 T-cell ratio, (ii) decreased size of CD4(+)CD44(high) T memory pool, (iii) aberrant TCR Vß repertoire, (iv) increased neonatal number of Foxp3(+) and TR-1(+) regulatory cells, and (v) reduced IFN-γ inflammatory response vs. enhanced IL-10 suppressogenic response of T-cells upon polyclonal and antigen-specific stimulation. The T-cells from NOD/DR4 Tg mice were unable to induce or suppress diabetes in NOD/RAG deficient mice. This study describes a multifaceted regulatory function of the HLA-DR*0401 allele strongly associated with the lack of T1D development in NOD mice.

Heat shock stress prior to hyperbaric oxygen exposure in rats.

INTRODUCTION: Heat shock proteins (HSPs) and nuclear factor-kappa B (NF-kappaB) have been established as important mediators in lung injury; however, their role in preventing pulmonary toxicity from hyperbaric oxygen (HBO) has not been evaluated. METHODS: We aimed to study the effects of heat shock (HS) injury on hyperbaric hyperoxic lung injury (HHLI) in a rat model and identify a mechanism of protection by evaluating HSP 27 and HSP 70 mRNA and protein levels, NF-kappaB p65, lung injury and oxidative parameters. By varying the times between HS and exposure to HBO, the pathways of interaction between HSPs and NF-kappaB will be further clarified. RESULTS: Our results showed that HS exposure increases the mRNA and protein levels of HSP 27 and HSP 70; HS induced 10-fold increases of HSP 27 (9.77 +/- 0.60) and HSP 70 (10.33 +/- 2.4) within the first 10 h compared to control animals. Lesion scores were higher for the first 16 h after HS, but decreased again after 31 h (N = 7 animals; 5 lesions scores). Protein nitration showed no significant differences between groups exposed to HS or HBO; similarly there was no difference with a combination of both treatments. DISCUSSION: HBO appears to attenuate the HS response by HSP 27 and HSP 70. Histopathology results suggest that HS might mitigate pathology in animals exposed to HS and HBO. No significant effect of HS on HBO-induced HHLI was observed in animals treated with both HS and HBO.

BSL2-compliant lethal mouse model of SARS-CoV-2 and variants of concern to evaluate therapeutics targeting the Spike protein.

Since first reported in 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is rapidly acquiring mutations, particularly in the spike protein, that can modulate pathogenicity, transmission and antibody evasion leading to successive waves of COVID19 infections despite an unprecedented mass vaccination necessitating continuous adaptation of therapeutics. Small animal models can facilitate understanding host-pathogen interactions, target selection for therapeutic drugs, and vaccine development, but availability and cost of studies in BSL3 facilities hinder progress. To generate a BSL2-compatible in vivo system that specifically recapitulates spike protein mediated disease we used replication competent, GFP tagged, recombinant Vesicular Stomatitis Virus where the VSV glycoprotein was replaced by the SARS-CoV-2 spike protein (rVSV-SARS2-S). We show that infection requires hACE2 and challenge of neonatal but not adult, K18-hACE2 transgenic mice (hACE2tg) leads to productive infection of the lungs and brains. Although disease progression was faster in SARS-CoV-2 infected mice, infection with both viruses resulted in neuronal infection and encephalitis with increased expression of Interferon-stimulated Irf7, Bst2, Ifi294, as well as CxCL10, CCL5, CLC2, and LILRB4, and both models were uniformly lethal. Further, prophylactic treatment targeting the Spike protein (Receptor Binding Domain) with antibodies resulted in similar levels of protection from lethal infection against rVSV-SARS2-S and SARS-CoV-2 viruses. Strikingly, challenge of neonatal hACE2tg mice with SARS-CoV-2 Variants of Concern (SARS-CoV-2-α, -ß, ϒ, or Δ) or the corresponding rVSV-SARS2-S viruses (rVSV-SARS2-Spike-α, rVSV-SARS2-Spike-ß, rVSV-SARS2-Spike-ϒ or rVSV-SARS2-Spike-Δ) resulted in increased lethality, suggesting that the Spike protein plays a key role in determining the virulence of each variant. Thus, we propose that rVSV-SARS2-S virus can be used to understand the effect of changes to SARS-CoV-2 spike protein on infection and to evaluate existing or experimental therapeutics targeting spike protein of current or future VOC of SARS-CoV-2 under BSL-2 conditions.

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.

We have engineered a Human Immune System (HIS)-reconstituted mouse strain (DRAGA mouse: HLA-A2. HLA-DR4. Rag1 KO. IL-2Rγc KO. NOD) in which the murine immune system has been replaced by a long-term, functional HIS via infusion of CD34+ hematopoietic stem cells (HSC) from cord blood. Herein, we report that the DRAGA mice can sustain inducible and transmissible H1N1 and H3N2 influenza A viral (IAV) infections. DRAGA female mice were significantly more resilient than the males to the H3N2/Aichi infection, but not to H3N2/Hong Kong, H3N2/Victoria, or H1N1/PR8 sub-lethal infections. Consistently associated with large pulmonary hemorrhagic areas, both human and murine Factor 8 mRNA transcripts were undetectable in the damaged lung tissues but not in livers of DRAGA mice advancing to severe H1N1/PR8 infection. Infected DRAGA mice mounted a neutralizing anti-viral antibody response and developed lung-resident CD103 T cells. These results indicate that the DRAGA mouse model for IAV infections can more closely approximate the human lung pathology and anti-viral immune responses compared to non-HIS mice. This mouse model may also allow further investigations into gender-based resilience to IAV infections, and may potentially be used to evaluate the efficacy of IAV vaccine regimens for humans.

Corrigendum: Repeated Low Intensity Blast Exposure Is Associated With Damaged Endothelial Glycocalyx and Downstream Behavioral Deficits.

[This corrects the article DOI: 10.3389/fnbeh.2017.00104.].

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).

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 (180WGIHHPPNSKEQ QNLY195) of hemagglutinin (HA) envelope protein of PR8/A/34 (H1N1) virus with high homology among seven influenza type A viruses. A single administration of HA180-195 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.

Repeated Low Intensity Blast Exposure Is Associated with Damaged Endothelial Glycocalyx and Downstream Behavioral Deficits.

Current clinical research into mild traumatic brain injury (mTBI) has focused on white matter changes as identified by advanced MRI based imaging techniques. However, perivascular tau accumulation in the brains of individuals diagnosed with mTBI suggests that the vasculature plays a key role in the pathology. This study used a rat model to examine whether the endothelial glycocalyx, a layer of the vasculature responsible for sensing luminal shear forces, is damaged by exposure to repeated low intensity blast, and whether this layer is associated with observed behavioral deficits. The blast exposure used consisted of 12, 40 kPa blast exposures conducted with a minimum of 24 h between blasts. We found that repeated blast exposure reduced glycocalyx length and density in various brain regions indicating damage. This blast exposure paradigm was associated with a mild performance decrement in the Morris water maze (MWM) which assesses learning and memory. Administration of hyaluronidase, an enzyme that binds to and degrades hyaluronan (a major structural component of the glycocalyx) prior to blast exposure reduced the observed behavioral deficits and induced a thickening of the glycocalyx layer. Taken together these findings demonstrate that the endothelial glycocalyx degradation following repeated blast is associated with behavioral decrements which can be prevented by treatment with hyaluronidase.

Nonobese Diabetic (NOD) Mice Lack a Protective B-Cell Response against the "Nonlethal" Plasmodium yoelii 17XNL Malaria Protozoan.

Background. Plasmodium yoelii 17XNL is a nonlethal malaria strain in mice of different genetic backgrounds including the C57BL/6 mice (I-Ab/I-Enull) used in this study as a control strain. We have compared the trends of blood stage infection with the nonlethal murine strain of P. yoelii 17XNL malaria protozoan in immunocompetent Nonobese Diabetic (NOD) mice prone to type 1 diabetes (T1D) and C57BL/6 mice (control mice) that are not prone to T1D and self-cure the P. yoelii 17XNL infection. Prediabetic NOD mice could not mount a protective antibody response to the P. yoelii 17XNL-infected red blood cells (iRBCs), and they all succumbed shortly after infection. Our data suggest that the lack of anti-P. yoelii 17XNL-iRBCs protective antibodies in NOD mice is a result of parasite-induced, Foxp3+ T regulatory (Treg) cells able to suppress the parasite-specific antibody secretion. Conclusions. The NOD mouse model may help in identifying new mechanisms of B-cell evasion by malaria parasites. It may also serve as a more accurate tool for testing antimalaria therapeutics due to the lack of interference with a preexistent self-curing mechanism present in other mouse strains.

Gonadotropin-releasing hormone (GnRH) agonist leuprolide acetate and GnRH antagonist cetrorelix acetate directly inhibit leiomyoma extracellular matrix production.

OBJECTIVE: To determine the direct effect that GnRH analogues leuprolide acetate and cetrorelix acetate have on extracellular matrix in human leiomyoma and patient-matched myometrial cells. DESIGN: Laboratory study. SETTING: University hospital. PATIENT(S): None. INTERVENTION(S): Cell culture, proliferation studies, and messenger RNA and protein analysis. MAIN OUTCOME MEASURE(S): Expression of GnRHR1, COL1A1, fibronectin, and versican variant V0 in treated leiomyoma cells and patient-matched myometrial cells. RESULT(S): Leiomyoma cells were treated with GnRH analogues for 6, 24, and 120 hours. Leuprolide treatment for 6 hours resulted in an increase in expression of GnRHR1 (4.02 ± 0.12-fold), COL1A1 (6.41 ± 0.29-fold), fibronectin (9.69 ± 0.18-fold), and versican variant V0 (7.58 ± 0.43-fold). Leiomyoma cells treated with cetrorelix for 6 hours showed a decreased expression of GnRHR1 (0.5 ± 0.15-fold), COL1A1 (3.79 ± 0.7-fold), fibronectin (0.92 ± 0.09-fold), and versican variant V0 (0.14 ± 0.07-fold). Leuprolide treatment of leiomyoma cells at high concentrations (10(-5) M) did not result in an increase in protein production. Cetrorelix treatment of leiomyoma cells for 6 hours showed an increase in fibronectin protein production (3.14 ± 0.09-fold). Protein production of leiomyoma cells treated with cetrorelix for 120 hours demonstrated a decrease in GnRHR1 (0.51 ± 0.07-fold), COL1A1 (0.35 ± 0.07-fold), fibronectin (1.94 ± 0.08-fold), and versican variant V0 (0.77 ± 0.19-fold). CONCLUSION(S): Our findings demonstrate that GnRH analogue treatment directly regulated COL1A1, fibronectin, and matrix proteoglycan production. The reduction in versican variant V0 gene expression caused by cetrorelix treatment, and its association with the osmotic regulation of leiomyomas, presents a new and innovative approach to therapy for this disease.

Curcumin, a nutritional supplement with antineoplastic activity, enhances leiomyoma cell apoptosis and decreases fibronectin expression.

OBJECTIVE: To determine if curcumin has an antiproliferative effect on leiomyoma cells via apoptosis induction and whether curcumin impacts extracellular matrix (ECM) production by assessing the fibronectin expression in leiomyoma cells treated with curcumin. DESIGN: Tissue culture study of immortalized human leiomyoma and patient-matched myometrial cells treated with curcumin. SETTING: University hospital. PATIENT(S): Immortalized leiomyoma and myometrial cells from patients with symptomatic leiomyomata. INTERVENTION(S): Tissue culture, followed by proliferation studies, RNA, and protein analysis. MAIN OUTCOME MEASURE(S): Cell proliferation, alteration in apoptotic signaling pathways. RESULT(S): Curcumin demonstrated an antiproliferative effect on leiomyoma cell lines (IC50 = 20 muM). Importantly, no statistically significant inhibition of growth was observed when patient-matched myometrial cells were exposed to equivalent concentrations of curcumin. Curcumin stimulated caspase-3 and caspase-9 expression while inhibiting extracellular signal-regulated kinase 1 (ERK 1), ERK 2, and nuclear factor kappa B (NF-kappaB), suggesting regulation of leiomyocyte apoptosis. Finally, curcumin inhibited expression of fibronectin in leiomyoma cells. CONCLUSION(S): Our findings demonstrate that curcumin inhibited uterine leiomyoma cell proliferation via regulation of the apoptotic pathway, and inhibited production of the ECM component fibronectin. Curcumin provides a novel direction for leiomyoma therapies.