Application of mass spectrometry to elucidate the pathophysiology of Encephalitozoon cuniculi infection in rabbits

Abstract

Encephalitozoon cuniculi is a microsporidian species which can induce subclinical to serious disease in mammals including rabbits, a definitive natural host. The pathophysiology of infection has not been comprehensively elucidated. In this exploratory study, we utilized two mass spectrometry approaches: first, the analysis of the humoral response by profiling the microsporidian antigens as revealed by Western blot screening, and second, implementing the iTRAQ®-labeling protocol to focus on the changes within the host proteome during infection. Seven E. cuniculi proteins were identified at one-dimensional gel regions where specific seropositive reaction was observed by Western blot, including polar tube protein 3, polar tube protein 2, and for the first time reported: heat shock related 70kDa protein, polysaccharide deacetylase domain-containing protein, zinc finger protein, spore wall and anchoring disk complex protein EnP1, and translation elongation factor 1 alpha. In addition, there was a significant increase of nine host proteins in blood samples from E. cuniculi-diseased rabbits in comparison with non-diseased control subjects undergoing various inflammatory processes. This included serum paraoxonase, alpha-1-antiproteinase F precursor and alpha-1-antiproteinase S-1 which have presumptive catalytic activity likely related to infection control, and cystatin fetuin-B-type, an enzyme regulator that has been poorly studied to date. Notably, 11 proteins were found to be statistically increased in rabbits with neurological versus renal clinical presentation of E. cuniculi infection. Overall, this novel analysis based on mass spectrometry has provided new insights on the inflammatory and humoral responses during E. cuniculi infection in rabbits.

<p><em>Encephalitozoon cuniculi</em> Genotype II Concentrates in Inflammation Foci</p>

“…1,2 In mammals, infections typically establish a balanced host-parasite relationship that produce minimal clinically overt disease in immunocompetent natural hosts. [3][4][5][6][7][8] A shift in the balance toward immune deficiency or hyperimmune responses, however, produces overt clinical signs of disease. In the past, human microsporidial infections were most commonly associated with immunodeficiency, so they were often diagnosed in AIDS patients, organ recipients, and children.…”

Translational proteomic study to address host protein changes during aspergillosis

“…For instance, the iTRAQ ® (isobaric tags for relative and absolute quantitation) protocol is a large-scale isobaric labeling method of unbiased profiling to identify and to determine the change in levels of proteins from different multiplexed sources within a single experimental run [ 16 ]. While generating no interference with peptide mass determination, iTRAQ ® technique uses stable isotope-tagged molecules that can be covalently bonded to the N-terminus and side chain amines of trypsin-digested peptides [ 17 ]. It requires no preliminary labor-intensive steps of protein separation, like two-dimensional gel (2D-gel) electrophoresis, that inevitably implies a risk of information loss [ 14 , 18 ], and which is less sensitive [ 18 ].…”

Effects of Homeopathic Phosphorus on Encephalitozoon cuniculi-Infected Macrophages In-Vitro

“…3,36,37 After ingestion, changes in pH and osmotic pressure cause the polar tube and sporoplasm to be ejected from the spore, with subsequent penetration of the host cell by the parasite. 36,38,39 Another means through which spores gain access to the host cell cytoplasm is endocytosis. If a spore is phagocytozed by a host cell, the polar tube can pass through the phagocytic vacuole membrane, delivering the sporoplasm into the host cell cytoplasm.…”