High immunological response against a Trypanosoma equiperdum protein that exhibits homology with the regulatory subunits of mammalian cAMP-dependent protein kinases

• Published in: Journal of immunoassay & immunochemistry 2018-07, Vol.39 (4), p.451-469
• Main Authors: Mendoza, Emiliana, Bubis, José, Pérez-Rojas, Yenis, Montilla, Alejandro J., Spencer, Lilian M., Bustamante, Floritza, Martínez, Juan C.
• Format: Article
• Language: English
• Subjects: Animals; Antibodies; Cell proliferation; Concanavalin A; Cross-reaction; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases - chemistry; Cyclic AMP-Dependent Protein Kinases - metabolism; dourine; Enzyme-linked immunosorbent assay; Female; Homogeneity; Homology; Horses; humoral immune response; Immune response; Immune response (humoral); Immune system; Immunization; Immunology; Kinases; Lymphocytes B; Mammals; Mice; Mice, Inbred BALB C; Polyclonal antibodies; Protein kinase A; Proteins; Protozoan Proteins - chemistry; Protozoan Proteins - immunology; Regulatory subunits; regulatory subunits of the cAMP-dependent protein kinase; serodiagnosis; Spleen; Trypanosoma - chemistry; Trypanosoma - immunology; Trypanosoma equiperdum; Trypanosome; Western blotting
• ISSN: 1532-1819; 1532-4230
• DOI: 10.1080/15321819.2018.1506930

Previously, we have identified a protein in Trypanosoma equiperdum that possesses homology with the regulatory (R) subunits of the mammalian cAMP-dependent protein kinase (PKA). The recombinant T. equiperdum PKA R-like protein was expressed in bacteria and purified to homogeneity. Mice polyclonal antibodies were raised against the recombinant R-like protein to serologically evaluate its humoral immune response. High titers of specific sera antibodies were obtained against the parasite R-like protein by indirect enzyme-linked immunosorbent assay (ELISA), and immunoblots revealed that this protein was specifically recognized by the hyperimmune mice sera. Cellular proliferation assays using splenic B cells from the immunized mice showed higher values when the recombinant T. equiperdum R-like protein was employed than when concanavalin A was utilized as an unspecific mitogen. Two healthy horses that were experimentally infected using either T. equiperdum or Trypanosoma evansi showed a curve response characterized by the appearance of anti-T. equiperdum PKA R-like protein antibody production in sera using indirect ELISA. The recombinant parasite PKA R-like protein was also recognized by sera from naturally trypanosome-infected horses using western blotting. These findings demonstrated that the T. equiperdum PKA R-like protein is an antigen that exhibits cross-reaction with T. equiperdum and T. evansi.