A Chikungunya Virus Multiepitope Recombinant Protein Expressed from the Binary System Insect Cell/Recombinant Baculovirus Is Useful for Laboratorial Diagnosis of Chikungunya

Abstract

Chikungunya virus (CHIKV) is an arbovirus currently distributed worldwide, causing a disease that shares clinical signs and symptoms with other illnesses, such as dengue and Zika and leading to a challenging clinical differential diagnosis. In Brazil, CHIKV emerged in 2014 with the simultaneous introduction of both Asian and East/Central/South African (ECSA) genotypes. Laboratorial diagnosis of CHIKV is mainly performed by molecular and serological assays, with the latter more widely used. Although many commercial kits are available, their costs are still high for many underdeveloped and developing countries where the virus circulates. Here we described the development and evaluation of a multi-epitope recombinant protein-based IgG-ELISA (MULTREC IgG-ELISA) test for the specific detection of anti-CHIKV antibodies in clinical samples, as an alternative approach for laboratorial diagnosis. The MULTREC IgG-ELISA showed 86.36% of sensitivity and 100% of specificity, and no cross-reactivity with other exanthematic diseases was observed. The recombinant protein was expressed from the binary system insect cell/baculovirus using the crystal-forming baculoviral protein polyhedrin as a carrier of the target recombinant protein to facilitate recovery. The crystals were at least 10 times smaller in size and had an amorphous shape when compared to the polyhedrin wild-type crystal. The assay uses a multi-epitope antigen, representing two replicates of 18 amino acid sequences from the E2 region and a sequence of 17 amino acids from the nsP3 region of CHIKV. The recombinant protein was highly expressed, easy to purify and has demonstrated its usefulness in confirming chikungunya exposure, indeed showing a good potential tool for epidemiological surveillance.

Recombinant multiepitope proteins expressed in Escherichia coli cells and their potential for immunodiagnosis

“…coli BL21(λDE3) cells ELISA 22 rubella-positive serum samples/11 rubella-negative serum samples Sensitivity: 100% Specificity: 90.91% [ 114 ]/Brazil Human HTLV-1 and HTLV-2/human T-lymphotropic viruses 1 and 2 HTLV-1/HTLV-2 E . coli Rosetta-gami 2(DE3) cells ELISA 162 HTLV-positive serum samples/297 serum samples from healthy individuals/92 serum samples from non-HTLV disease HTLV-1 and HTLV-2 samples Sensitivity: 82.41 to 92.36% Specificity: 90.09% to 95.19% HTLV-1 samples Sensitivity: 99.19% Specificity: 92.55% HTLV-2 samples Sensitivity: 57.14% Specificity: 94.61% [ 115 ]/Brazil Human chikungunya/chikungunya virus MULTREC Binary system insect cell/baculovirus ELISA 161 chikungunya-positive serum samples/22 serum samples from healthy individuals/312 serum sample from non-chikungunya diseases Sensitivity: 86.36% Specificity: 100% [ 116 ]/Brazil “–”: information not provided by the study …”

“…Considering the values when evaluating only HTLV-2 samples, sensitivity and specificity were determined as 57.14% and 94.61%, respectively. Lastly, da Silva et al (2022) [ 116 ] developed a new RMP for diagnosing human chikungunya, caused by the chikungunya virus. This new RMP, MULTREC, was obtained through a binary system insect cell/baculovirus, after which an ELISA assay was performed to assess protein reactivity, with 86.36% sensitivity and 100% specificity.…”