Proteomic Analysis and Immunogenicity of Mannheimia haemolytica Vesicles

Abstract

b Mannheimia haemolytica, a major causative agent in bovine respiratory disease, inflicts extensive losses each year on cattle producers. Commercially available vaccines are only partially efficacious. Immunity to M. haemolytica requires antibodies to secreted toxins and outer membrane proteins (OMPs) of the bacterium. Gram-negative bacteria produce membrane blebs or vesicles, the membrane components of which are primarily derived from OMPs. Accordingly, vesicles have been used as immunogens with various degrees of success. This study characterized components of M. haemolytica vesicles and determined their immunogenicity in mice and cattle. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of vesicles from this bacterium identified 226 proteins, of which 58 (25.6%) were OMPs and periplasmic and one (0.44%) was extracellular. Vesicles were used to vaccinate dairy calves and BALB/c mice. Analyses of sera from calves and mice by enzyme-linked immunosorbent assay (ELISA) showed that circulating antibodies against M. haemolytica whole cells and leukotoxin were significantly higher on days 21 and 28 (P < 0.05) than on day 0. For control calves and mice, there were no significant differences in serum anti-whole-cell and leukotoxin antibody levels from days 0 and 21 or 28, respectively. Lesion scores of lungs from vaccinated calves (15.95%) were significantly (P < 0.05) lower than those from nonvaccinated calves (42.65%). Sera from mice on day 28 and calves on day 21 showed 100% serum bactericidal activity. Sera from vesicle-vaccinated mice neutralized leukotoxin.

Membrane vesicles of Clostridium perfringens type A strains induce innate and adaptive immunity

“…4A and B). Our results correlate well with other examples of extracellular vesicles containing a variety of proteins, such as membrane proteins, cytoplasmic and intracellular proteins (Ayalew et al, 2013; Lee et al, 2007; Lee et al, 2009; Pierson et al, 2011). In contrast to previous study which indicated that vesicles secreted from another Gram-positive bacteria Staphylococcus aureus were especially enriched with extracellular proteins (Lee et al, 2009), our data demonstrated that only a small part of “extracellular region” (0.4%) proteins were identified in CP4 MVs (Fig.…”

Aggregatibacter actinomycetemcomitans Outer Membrane Vesicles Are Internalized in Human Host Cells and Trigger NOD1- and NOD2-Dependent NF-κB Activation

“…It is possible that this type of mechanism may be relevant in additional Pasteurellaceae spp., considering that OMVs capable of modulating the host's immune responses are liberated by several of the species associated with inflammatory conditions in different mammalian hosts, e.g., Actinobacillus pleuropneumoniae, H. influenzae, Mannheimia haemolytica, and Pasteurella multocida (72)(73)(74)(75). Further studies assessing their full immunogenic potential in animal models may generate a more complete picture of the roles of A. actinomycetemcomitans OMVs in periodontal inflammation and attachment loss.…”

Outer-membrane vesicles from Gram-negative bacteria: biogenesis and functions

“…1 for a comprehensive review covering aspects of OMV purification). In most cases, in addition to outer-membrane components, OMV proteomes include inner-membrane and cytoplasmic proteins 52,59–63 ; in fact, it is exceptional if no inner-membrane and cytoplasmic components are found 64 . Importantly, even in those cases in which the samples were rigorously prepared, purified and analysed, some inner-membrane and cytoplasmic components were still detected in OMVs 65,66 .…”

“…Recently, studies have advanced the utility of OMVs against the human pathogens Neisseria meningitidis, Francisella tularensis subsp. novicida, Burkholderia pseudomallei and Mannheimia haemolytica 59,134–136 . The native contextual presentation of bacterial surface antigens in complex with an adjuvant (lipopolysaccharide (LPS)) makes OMVs an effective means to generate an adaptive immune response.…”