Humoral Immune Responses to Burkholderia pseudomallei Antigens in Captive and Wild Macaques in the Western Part of Java, Indonesia

Abstract

Burkholderia pseudomallei, the Gram-negative bacterium which causes melioidosis, is a threat to human and a wide range of animal species. There is an increased concern of melioidosis in Indonesian primate facilities, especially following case reports of fatal melioidosis in captive macaques and orangutans. Our preliminary serosurveillance of immunoglobulin G (IgG) to B. pseudomallei lipopolysaccharide showed that a significant number of captive and wild macaques in the western part of Java, Indonesia, have been exposed to B. pseudomallei. To better characterize the humoral immune response in those animals, a panel of assays were conducted on the same blood plasma specimens that were taken from 182 cynomolgus macaques (M. fascicularis) and 88 pig-tailed macaques (M. nemestrina) reared in captive enclosures and wild habitats in the western part of Java, Indonesia. The enzyme-linked immunosorbent assays (ELISAs) in this study were conducted to detect IgG against B. pseudomallei proteins; alkyl hydroperoxide reductase subunit C (AhpC), hemolysin-coregulated protein (Hcp1), and putative outer membrane porin protein (OmpH). The performances of those immunoassays were compared to ELISA against B. pseudomallei LPS, which has been conducted previously. Seropositivity to at least one assay was 76.4% (139/182) and 13.6% (12/88) in cynomolgus macaques and pig-tailed macaques, respectively. Analysis of demographic factors showed that species and primate facility were significant factors. Cynomolgus macaques had higher probability of exposure to B. pseudomallei. Moreover, macaques in Jonggol facility also had higher probability, compared to macaques in other facilities. There were no statistical associations between seropositivity with other demographic factors such as sex, age group, and habitat type. There were strong positive correlations between the absorbance results of AhpC, HcpI, and OmpH assays, but not with LPS assay. Our analysis suggested that Hcp1 assay would complement LPS assay in melioidosis serosurveillance in macaques.

Evaluation of two different vaccine platforms for immunization against melioidosis and glanders

“…AhpC detoxifies peroxides and is important in defending against peroxide-induced oxidative stress (O'Riordan et al, 2012 ; Reynolds et al, 2015 ; Guo et al, 2017 ). Enhanced T-cell immunity to AhpC correlates with survival in melioidosis patients (Dunachie et al, 2017 ) and it also functions as a protective immunogen against infection with various pathogens (Felgner et al, 2009 ; O'Riordan et al, 2012 ; Reynolds et al, 2015 ; Yi et al, 2016 ; Guo et al, 2017 ; Testamenti et al, 2020 ).…”

Use of Recombinant Escherichia coli Strains in Immunofluorescence Assays for Melioidosis Diagnosis

“…Five recombinant E. coli BL21 (DE3) strains, which were expressed as AhpC (BPSS2096), BimA (BPSS1492), OmpH (BPSL2150), Hcp1 (BPSS1498), and TssM (BPSS1512), were made. The cloning protocols followed, but modified, a previous study [ 32 ]. Briefly, the DNA sequences of ahpC, bimA, ompH, hcp1, and tssM were amplified from the genomic DNA of B. pseudomallei strain K96243 using primers that introduced Sal I and Nde I sites.…”

Development of Melioidosis Subunit Vaccines Using an Enzymatically Inactive Burkholderia pseudomallei AhpC

“…AhpC is a peroxiredoxin involved in protection against oxidative stress and is an immunodominant antigen that induces strong T cell-mediated responses in melioidosis patients ( 28 – 31 ). AhpC has been used as a serodiagnostic target and is considered a protective antigen and promising vaccine candidate ( 28 , 29 , 32 ). To facilitate our studies and maximize safety in animals, we purified a recombinant version of B. pseudomallei AhpC harboring an active site mutation (AhpC C57G ).…”