Adaptation of a bovine cell line in an optimized way for diagnosing Lentivirus capartenc

Abstract

Goat farming is a significant economic activity in the semi-arid northeastern region of Brazil, and an infectious disease that significantly affects dairy goat farming is Lentivirus capartenc, known previously as Caprine arthritis encephalitis virus (CAEV). The objective of this research was to evaluate the efficiency and specificity of an Agar Gel Immunodiffusion (AGID) test with CAEV antigens produced through untreated and detergent-treated bovine cells and compare it with the CAE-AGID -Biovetech® commercial test. Culture of primary bovine ear (CFBov) cells was propagated at a concentration of 4x104 cells/mL and incubated at 37°C. To evaluate the treatments of bovine cells, 270 samples of goat serum from herds in the state of Pernambuco were used and tested against 30 μL of each detergent for the possible diagnosis of Lentivirus capartenc. Two hundred seventy goat serum samples from herds in Pernambuco state were used, and 30 μL were tested against each detergent. For viral particle production, CFBov were inoculated with 0.5 mL of CAEV Cork viral sample with a titer of 10-4.5 for 30 min. After 30 min of adsorption, supplementation was performed with DMEM containing 2% Fetal Bovine Serum (FBS). The culture supernatant was collected and frozen, and then concentrated using PEG 6,000. Afterwards, concentrate was submitted to treatment with the following detergents: 0.1% Triton X-100, 0.1% SDS, 0.1% Tween 20. Antigens were evaluated by specific line production in Agar Gel Immunodiffusion (AGID). Positive serum from the CAE Diagnostic Kit (AGID) was used as a control. The results were evaluated at 94.7% sensitivity and 99.6% specificity for pure antigen, 97.4% sensitivity and 98.7% specificity for SDS, 97.2% sensitivity and 98.7% specificity for Triton X-100, and 97.3% sensitivity and 99.1% specificity for Tween 20. The CFBov cell line has been cultured for over 3 years, with more than 40 passages, and has shown no noticeable change in morphology or cell multiplication rate. The study shows that the use of treatment in bovine cells with SDS, Triton 100, and Tween 20 improved sensitivity and efficiency of the test for detecting Lentivirus capartenc.