Protein Microarray-Guided Development of a Highly Sensitive and Specific Dipstick Assay for Glanders Serodiagnostics

Abstract

Burkholderia mallei , the causative agent of glanders, is a clonal descendant of Burkholderia pseudomallei , the causative agent of melioidosis, which has lost its environmental reservoir and has a restricted host range. Despite limitations in terms of sensitivity and specificity, complement fixation is still the official diagnostic test for glanders.

Deciphering the human antibody response against Burkholderia pseudomallei during melioidosis using a comprehensive immunoproteome approach

“…Here, the multiplex detection of complementary antibodies can further increase both sensitivity and specificity, and contribute to the reliability of the test, as we could show in our recent studies ( 13 , 19 ). However, the known cross-reactivity of antibodies to B. pseudomallei and other Burkholderia species in both melioidosis patients and controls ( 6 , 32 , 59 ) and the potential use of serodiagnostic antigens in vaccines ( 60 ) require the detection of further biomarkers with a high specificity and sensitivity for an optimal serological diagnostic of melioidosis in endemic regions. Furthermore, even (multiplex-) assays with the best serodiagnostic antigens give false negative results ( 15 , 16 , 20 ) as there are still individuals who showed no response against any of the antigens ( 13 ).…”

“…It will be very interesting to analyze whether there are certain profiles associated with, for example, acute and chronic disease, reactivation, latent infection and protective immunity. Furthermore, there are known cross-reactivities between the antibody response to B. pseudomallei and other Burkholderia species of lower pathogenicity ( 31 , 32 ) that might also be resolved based on the associated profiles. Since there is no vaccine available, such analyses and the detailed insights into the (protective) immune response of melioidosis patients may also lead to the identification of additional antigenic candidates for subunit vaccines.…”

Burkholderia pseudomallei Complex Subunit and Glycoconjugate Vaccines and Their Potential to Elicit Cross-Protection to Burkholderia cepacia Complex

“…As a result, natural exposure to such intracellular bacteria is often associated with robust immune responses to these proteins, making them popular candidate antigens for a variety of pathogenic bacteria [225][226][227]. This trend is also observed with B. pseudomallei AhpC, which acts as a highly serodiagnostic antigen in human melioidosis [75,141,228] and horse glanders [140]. PBMCs from human melioidosis seropositive donors also respond strongly to AhpC-derived peptides or full-length protein and the strength of this response appears to correlate with improved disease outcomes [141,202,228,229].…”

“…Multiple studies have demonstrated that Hcp1 is highly immunogenic, reacting particularly strongly to human melioidosis sera [ 136 , 139 ] and glanders sera from mice, horses, and one human [ 132 , 140 ]. PBMCs from melioidosis seropositive donors also respond to stimulation with Hcp1, correlating with patient survival [ 141 ].…”

“…vaccination/challenge murine models [ 192 ]. Despite this, only Omp7 received further attention as a potential candidate vaccine antigen while Omp3 has only seen use as a serodiagnostic marker, with numerous studies identifying it as highly reactive to human melioidosis serum [ 75 , 76 , 77 , 192 , 217 , 218 ] and horse glanders serum [ 140 ]. In addition to these B cell antigenic properties, PBMCs derived from healthy melioidosis seropositive donors and recovered melioidosis donors react strongly to Omp3-derived peptides, suggesting that robust T cell immunity is also mounted to this protein during natural exposure to B. pseudomallei [ 202 ].…”