Immune Response to Brugia malayi Asparaginyl-tRNA Synthetase in Balb/c Mice and Human Clinical Samples of Lymphatic Filariasis
LYMPHATIC RESEARCH AND BIOLOGY
Authors: Hameed, Afaq; Natarajan, Mahalakshmi; Jabbar, Salih; Dhanasekaran, Jeeva Jothi; Kumar, Krishna; Sivanesan, Sanjana; Kron, Michael; Dhanasekaran, Anuradha
Abstract
Background: Lymphatic filariasis (LF) is a global health problem, with a peculiar nature of parasite-specific immunosuppression that promotes long-term pathology and disability. Immune modulation in the host by parasitic antigens is an integral part of this disease. The current study attempts to dissect the immune responses of aminoacyl-tRNA synthetases (AARS) with emphasis on Brugia malayi asparaginyl-tRNA synthetase (BmAsnRS), since it is one among the highly expressed excretory/secretory proteins expressed in all stages of the parasite life cycle, whereas its role in filarial pathology has not been elaborately studied. Methods and Results: In this study, recombinant BmAsnRS (rBmAsnRS) immunological effects were studied in semipermissive filarial animal model Balb/c mice and on clinically defined human samples for LF. In mice study, humoral responses showed considerable titer levels with IgG2a isotype followed by IgG2b and IgG1. Immunoreactivity studies with clinical samples showed significant humoral responses especially in endemic normal with marked levels of IgG1 and IgG2 followed by IgG3. The cell-mediated immune response, evaluated by splenocytes and peripheral blood mononuclear cells proliferation, did not yield significant difference when compared with control groups. Cytokine profiling and qRT-PCR analysis of mice samples immunized with rBmAsnRS showed elevated levels of IFN-gamma, IL-10, inhibitory factor-cytotoxic T lymphocyte-associated protein-A (CTLA-4) and Treg cell marker-Forkhead Box P3 (FoxP3). Conclusions: These observations suggest that rBmAsnRS has immunomodulatory effects with modified Th2 response along with suppressed cellular proliferation indicating the essence of this molecule for immune evasion by the parasite.
Kai 1 and Kai 2: Characterization of these dog erythrocyte antigens by monoclonal antibodies
PLOS ONE
Authors: Lee, Jae Ho; Giger, Urs; Kim, Hee Young
Abstract
Dog Erythrocyte Antigens (DEA) have thus far been found by sensitizing dogs with canine allogeneic blood and are clinically important regarding blood transfusion incompatibilities, but remain poorly defined. The goals of this study were to discover and characterize two DEAs, named as Kai 1 and Kai 2. The monoclonal antibodies were produced by mouse hybridoma techniques and examined by ELISA isotyping, immunoblotting, and affinity chromatography. Canine blood samples were typed and the development of alloantibodies was examined in transfused dogs. The monoclonal Kai 1 and Kai 2 antibodies were isotyped as IgM kappa and IgG3 lamda, respectively, and identified two different erythrocyte membrane proteins of 200 kDa and 80 kDa in molecular weights, respectively. Either Kai 1 or Kai 2 can be expressed but not both in an individual dog. There were no naturally occurring anti-Kai 1 or Kai 2 alloantibodies. In addition, Kai 1-and/or Kai 2- dogs developed Kai 1 and Kai 2 alloantibodies, respectively, when transfused with mismatched blood. This is the first discovery of canine blood types by screening monoclonal antibodies. Kai 1 and Kai 2 are novel blood types which can induce anti-Kai 1 or anti-Kai 2 alloantibodies when Kai 1-and/or Kai 2- dogs are transfused with Kai 1+ or Kai 2+ blood. These canine blood types may explain some of the blood incompatibilities and transfusion reactions observed in dogs in clinical practice.