Treatment with a Lactococcus lactis that chromosomally express E. coli cfaI mitigates salivary flow loss in a Sjögren's syndrome-like disease

Sjögren's Syndrome (SjS) results in loss of salivary and lacrimal gland excretion due to an autoimmune attack on these secretory glands. Conventional SjS treatments address the symptoms, but not the cause of disease. Recognizing this deficit of treatments to reverse SjS disease, studies were pursued using the fimbriae from enterotoxigenic E. coli, colonization factor antigen I (CFA/I), which has anti-inflammatory properties. To determine if CFA/I fimbriae could attenuate SjS-like disease in C57BL/6.NOD-Aec1Aec2 (SjS) females, the Lactococcus lactis (LL) 301 strain was developed to chromosomally express the cfaI operon. Western blot analysis confirmed CFA/I protein expression, and this was tested in SjS females at different stages of disease. Repeated dosing with LL 301 proved effective in mitigating salivary flow loss and in reducing anti-nuclear antibodies (ANA) and inflammation in the submandibular glands (SMGs) in SjS females and in restoring salivary flow in diseased mice. LL 301 treatment reduced proinflammatory cytokine production with concomitant increases in TGF-β+ CD25+ CD4+ T cells. Moreover, LL 301 treatment reduced draining lymph and SMG follicular T helper (Tfh) cell levels and proinflammatory cytokines, IFN-γ, IL-6, IL-17, and IL-21. Such evidence points to the therapeutic capacity of CFA/I protein to suppress SjS disease and to have restorative properties in combating autoimmune disease.

Sjögren's Syndrome Treatments in the Microbiome Era

Sjögren's syndrome (SS) is a chronic autoimmune disease characterized by inflammatory cell infiltration of the salivary and lacrimal glands, resulting in acinar epithelial cell atrophy, cell death, and loss of exocrine function. At least half of SS patients develop extraglandular inflammatory disease and have a wide range of systemic clinical manifestations that can affect any organ system, including connective tissues. As many as 3.1 million people in the U.S. suffer from SS, a disease that causes severe impairment. Women are nine times more likely than men to be affected by this condition. Unfortunately, there is currently no effective treatment for SS, and the available options only provide partial relief. Treatment involves using replacement therapies such as artificial saliva and eye lubricants, or immunosuppressive agents that have limited efficacy. The medical community recognizes that there is a significant need for more effective treatments for SS. Increasing evidence demonstrates the links between the dysfunction of the human microbial community and the onset and development of many human diseases, signifying the potential use of microorganisms as an alternative strategy to conquer these issues. The role of the microbiome in controlling immune function of the human host in the context of autoimmune diseases like SS is now becoming better understood and may help to enable new drug development strategies. Natural probiotics and synthetic biology applications hold promise for novel treatment approaches to solve the encryption of many complex and multifactorial immune disorders, like SS.

Lactococcus lactis Delivery of Surface Layer Protein A Protects Mice from Colitis by Re-Setting Host Immune Repertoire

Inflammatory bowel disease (IBD) is characterized by gastrointestinal inflammation comprised of Crohn's disease and ulcerative colitis. Centers for Disease Control and Prevention report that 1.3% of the population of the United States (approximately 3 million people) were affected by the disease in 2015, and the number keeps increasing over time. IBD has a multifactorial etiology, from genetic to environmental factors. Most of the IBD treatments revolve around disease management, by reducing the inflammatory signals. We previously identified the surface layer protein A (SlpA) of Lactobacillus acidophilus that possesses anti-inflammatory properties to mitigate murine colitis. Herein, we expressed SlpA in a clinically relevant, food-grade Lactococcus lactis to further investigate and characterize the protective mechanisms of the actions of SlpA. Oral administration of SlpA-expressing L. lactis (R110) mitigated the symptoms of murine colitis. Oral delivery of R110 resulted in a higher expression of IL-27 by myeloid cells, with a synchronous increase in IL-10 and cMAF in T cells. Consistent with murine studies, human dendritic cells exposed to R110 showed exquisite differential gene regulation, including IL-27 transcription, suggesting a shared mechanism between the two species, hence positioning R110 as potentially effective at treating colitis in humans.

Maternal treatment with oral intestinal alkaline phosphatase mitigates high fat diet-induced cognitive disorders in offspring mice

Intestinal alkaline phosphatase (IAP) is an endogenous enzyme that promotes gastrointestinal homeostasis by detoxifying inflammatory mediators, tightening the gut barrier and promoting a healthy microbiome. Oral IAP administration was efficacious in ameliorating diabetes in a high fat diet (HFD)-induced murine model. In humans, maternal obesity and diabetes during pregnancy have been associated with an increased risk of autism spectrum disorders (ASD). In mice, HFD-induced maternal obesity leads to offspring with cognitive deficiency. Here we investigated whether IAP administration to obese dams could ameliorate autism-like disorders in mice. Using a HFD murine model, we recapitulated that maternal obesity leads to male offspring with social deficits as shown by the three chamber test and reciprocal social interaction analyses. Notably, oral delivery of IAP to dams improved those deficiencies. In addition, a jumping behavior was noted in pups from obese dams, which was rescued by maternal IAP treatment. Our findings suggest that maternal treatment with IAP can relieve some ASD-like symptoms in offspring mice.

Factor V Leiden improves in vivo hemostasis in murine hemophilia models

The role of factor V Leiden (FVL) as a modifier of the severe hemophilia phenotype is still unclear. We used mice with hemophilia A or B crossed with FVL to elucidate in vivo parameters of hemostasis. Real-time thrombus formation in the microcirculation was monitored by deposition of labeled platelets upon laser-induced endothelial injury using widefield microscopy in living animals. No thrombi formed in hemophilic A or B mice following vascular injuries. However, hemophilic mice, either heterozygous or homozygous for FVL, formed clots at all injured sites. Injection of purified activated FV into hemophilic A or B mice could mimic the in vivo effect of FVL. In contrast to these responses to a laser injury in a microvascular bed, FVL did not provide sustained hemostasis following damage of large vessels in a ferric chloride carotid artery injury model, despite of the improvement of clotting times and high circulating thrombin levels. Together these data provide evidence that FVL has the ability to improve the hemophilia A or B phenotype, but this effect is principally evident at the microcirculation level following a particular vascular injury. Our observations may partly explain the heterogeneous clinical evidence of the beneficial role of FVL in hemophilia.

Characterization of mild coagulation factor VII deficiency: activity and clearance of the Arg315Trp and Arg315Lys variants in the Cys310-Cys329 loop (c170s)

BACKGROUND AND OBJECTIVES

Arginine 315 in factor VII (FVII) belongs to a solvent-exposed loop involved in direct interaction with the co-factor (tissue factor, TF), in transmission of TF-induced effects and potentially in FVIIa inactivation. Natural FVII variants at position 315 provide peculiar models for structure-function studies.

DESIGN AND METHODS

We characterized a mild coagulation FVII deficiency associated with reduced FVII activity (26%) and antigen (67%). Mutations were searched by FVII gene sequencing. FVII variants were created by mutagenesis of FVII cDNA and characterized through expression in HEK293 cells followed by functional studies. FVII antigen in media was estimated by immunoassay while FVII activity was assessed by prothrombin-time based and FXa generation assays. FVII variants were injected into mice to investigate their recovery and half-life. One-way ANOVA was used to test statistical significance.

RESULTS

The patient was double heterozygous for a novel R315W mutation and for the R304Q substitution (FVII Padua) previously demonstrated to impair TF binding. The recombinant 315W-FVII was normally expressed in medium but showed a markedly reduced coagulant function (52%) and activity towards factor X (FX) in plasma (34%). Moreover, the 315W-FVII showed significantly decreased recovery of the protein (20%) and a slightly shorter half-life (8.6 min) as compared to wt-FVII (50% and 10.7 min). We also studied the conservative R315K change that was responsible for low recovery (20%) and a decreased half-life (7 min) of a FVII variant with virtually normal FVII antigen and activity levels.

INTERPRETATION AND CONCLUSIONS

These findings suggest a dual role of R315 for FVII function and clearance, and indicate that substitutions at this position have appreciable effects on human FVII biology, compatible with residual FVII function and thus with mild FVII deficiency.