Numerous treatments have been developed to promote wound healing based on current understandings of the healing process. Hemorrhaging, clotting, and associated inflammation regulate early wound healing. We investigated treatment with a virus-derived immune modulating serine protease inhibitor (SERPIN), Serp-1, which inhibits thrombolytic proteases and inflammation, in a mouse excisional wound model. Saline or recombinant Serp-1 were applied directly to wounds as single doses of 1 μg or 2 µg or as two 1 µg boluses. A chitosan-collagen hydrogel was also tested for Serp-1 delivery. Wound size was measured daily for 15 days and scarring assessed by Masson’s trichrome, Herovici’s staining, and immune cell dynamics and angiogenesis by immunohistochemistry. Serp-1 treatment significantly accelerated wound healing, but was blocked by urokinase-type plasminogen activator (uPAR) antibody. Repeated dosing at a lower concentration was more effective than single high-dose serpin. A single application of Serp-1-loaded chitosan-collagen hydrogel was as effective as repeated aqueous Serp-1 dosing. Serp-1 treatment of wounds increased arginase-1-expressing M2-polarized macrophage counts and periwound angiogenesis in the wound bed. Collagen staining also demonstrated that Serp-1 improves collagen maturation and organization at the wound site. Serp-1 has potential as a safe and effective immune modulating treatment that targets thrombolytic proteases, accelerating healing and reducing scar in deep cutaneous wounds.

Necrotic enteritis is an economically important poultry disease caused by the bacterium Clostridium perfringens . There are currently no necrotic enteritis vaccines commercially available for use in broiler birds, the most important target population. Salmonella -vectored vaccines represent a convenient and effective option for controlling this disease. We used a single attenuated Salmonella vaccine strain, engineered to lyse within the host, to deliver up to three C . perfringens antigens. Two of the antigens were toxoids, based on C . perfringens α-toxin and NetB toxin. The third antigen was fructose-1,6-bisphosphate aldolase (Fba), a metabolic enzyme with an unknown role in virulence. Oral immunization with a single Salmonella vaccine strain producing either Fba, α-toxoid and NetB toxoid, or all three antigens, was immunogenic, inducing serum, cellular and mucosal responses against Salmonella and the vectored C . perfringens antigens. All three vaccine strains were partially protective against virulent C . perfringens challenge. The strains delivering Fba only or all three antigens provided the best protection. We also demonstrate that both toxins and Fba are present on the C . perfringens cell surface. The presence of Fba on the cell surface suggests that Fba may function as an adhesin.

immunopathogenesis in systemic viral infections can induce a septic state with leaky capillary syndrome, disseminated coagulopathy, and high mortality with limited treatment options. Murine gammaherpesvirus-68 (MHV-68) intraperitoneal infection is a gammaherpesvirus model for producing severe vasculitis, colitis and lethal hemorrhagic pneumonia in interferon gamma receptor-deficient (IFNγR −/−) mice. In prior work, treatment with myxomavirus-derived Serp-1 or a derivative peptide S-7 (G 305 TTASSDTAITLIPR 319) induced immune protection, reduced disease severity and improved survival after MHV-68 infection. Here, we investigate the gut bacterial microbiome in MHV-68 infection. Antibiotic suppression markedly accelerated MHV-68 pathology causing pulmonary consolidation and hemorrhage, increased mortality and specific modification of gut microbiota. Serp-1 and S-7 reduced pulmonary pathology and detectable MHV-68 with increased CD3 and CD8 cells. Treatment efficacy was lost after antibiotic treatments with associated specific changes in the gut bacterial microbiota. In summary, transkingdom host-virus-microbiome interactions in gammaherpesvirus infection influences gammaherpesviral infection severity and reduces immune modulating therapeutic efficacy. Viral infections induce potent immune responses, an immunopathogenesis that can lead to severe complications with sepsis or leaky capillary syndromes and very high mortality and limited effective treatments, a true unmet clinical need. Sepsis has an associated risk of disseminated intravascular coagulation (DIC) with thrombosis, hemorrhage and shock 1-3. One such group of viruses with known severe complications are the gammaherpesviruses (GHV). The murine gammaherpesvirus-68 (MHV-68) is a widely used, well-controlled laboratory model of GHV host-pathogen interaction with genetic similarity to the human viruses Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) 4. Inflammatory vasculitic syndromes (IVS) are a group of rare, heterogeneous and devastating inflammatory conditions of the body's extensive system of blood vessels with increased morbidity, including sudden loss of vision, aneurysm, aortic arch syndrome, stroke, and associated increases in mortality 5-7. The etiology of many systemic vasculitides is currently unknown, with proposed mechanisms ranging from induction by fungal spores

Background Ischemia-reperfusion injury (IRI) is an antigen-independent, innate immune response to arterial occlusion and ischemia with subsequent paradoxical exacerbation after reperfusion. IRI remains a critical problem after vessel occlusion and infarction or during harvest and surgery in transplants. After transplant, liver IRI (LIRI) contributes to increased acute and chronic rejection and graft loss. Tissue loss during LIRI has been attributed to local macrophage activation and invasion with excessive inflammation together with hepatocyte apoptosis and necrosis. Inflammatory and apoptotic signaling are key targets for reducing post-ischemic liver injury. Myxomavirus is a rabbit-specific leporipoxvirus that encodes a suite of immune suppressing proteins, often with extensive function in other mammalian species. Serp-2 is a cross-class ser ine p rotease in hibitor ( serpin ) which inhibits the inflammasome effector protease caspase-1 as well as the apoptotic proteases granzyme B and caspases 8 and 10. In prior work, Serp-2 reduced inflammatory cell invasion after angioplasty injury and after aortic transplantation in rodents. In this report, we explore the potential for therapeutic treatment with Serp-2 in a mouse model of LIRI. Methods Wildtype (C57BL/6 J) mice were subjected to warm, partial (70%) hepatic ischemia for 90 min followed by treatment with saline or Serp-2 or M-T7, 100 ng/g/day given by intraperitoneal injection on alternate days for 5 days. M-T7 is a Myxomavirus-derived inhibitor of chemokine-GAG interactions and was used in this study for comparative analysis of an unrelated viral protein with an alternative immunomodulating mechanism of action. Survival, serum ALT levels and histopathology were assessed 24 h and 10 days post-LIRI. Results Serp-2 treatment significantly improved survival to 85.7% percent versus saline-treated wildtype mice ( p = 0.0135), while M-T7 treatment did not significantly improve survival ( p = 0.2584). Liver viability was preserved by Serp-2 treatment with a significant reduction in serum ALT levels ( p = 0.0343) and infarct scar thickness ( p = 0.0016), but with no significant improvement with M-T7 treatment. Suzuki scoring by pathologists blinded with respect to treatment group indicated that Serp-2 significantly reduced hepatocyte necrosis ( p = 0.0057) and improved overall pathology score ( p = 0.0046) compared to saline. Immunohistochemistry revealed that Serp-2 treatment reduced macrophage infiltration into the infarcted liver tissue ( p = 0.0197). Conclusions Treatment with Serp-2, a virus-derived inflammasome and apoptotic pathway inhibitor, improves sur...

Background Necrotic enteritis (NE) is caused by type A strains of the bacterium Clostridium perfringens. Total global economic losses to the poultry industry due to NE is estimated to be over two billion dollars annually. Traditionally, NE has been effectively controlled by inclusion of antibiotics in the diet of poultry. However, recent concerns regarding the impact of this practice on increasing antibiotic resistance in human pathogens have led us to consider alternative approaches, such as vaccination, for controlling this disease. NE strains of C. perfringens produce two major toxins, a-toxin and NetB. Immune responses against either toxin can provide partial protection against NE. Methods We have developed a fusion protein combining a non-toxic carboxyl-terminal domain of a-toxin (PlcC) and an attenuated, mutant form of NetB (NetB-W262A) for use as a vaccine antigen to immunize poultry against NE. We utilized a DNA sequence that was codon-optimized for Nicotiana benthamiana to enable high levels of expression. The 6-His tagged PlcC-NetB fusion protein was synthesized in N. benthamiana using a geminiviral replicon transient expression system, purified by metal affinity chromatography, and used to immunize broiler birds. Results Immunized birds produced a strong serum IgY response against both the plant produced PlcC-NetB protein and against bacterially produced His-PlcC and His-NetB. Immunized birds were significantly protected against a subsequent in-feed challenge with virulent C. perfringens when treated with the fusion protein. These results indicate that a plant-produced PlcC-NetB toxoid is a promising vaccine candidate for controlling NE in poultry.