PRIMED B LYMPHOCYTE DEPLETION BY POPLITEAL LYMPH NODE RESECTION SURGERY IN A MURINE MODEL OF DENGUE VIRUS INFECTION

TOLEDO,FA; BYRNE, ALANA B.; BRAHAMIAN JM,,; TALARICO, LAURA B.

Mar del Plata

Congreso; LXIV Reunión Annual de la Sociedad Argentina de Investigación clínica VI Reunión Regional de la Asociación Argentina de Ciencias del Animale de Laboratorio; 2019

SAIC AACYTAL

Strategies designed to study B cell responses to viral infections in mice comprise passive transfer of antigen-specific antibodies, adoptive transfer of primed B lymphocytes or use of B-cell-deficient mice, among others. The objective of the present work is to describe ipsilateral popliteal lymph node resection surgery as a strategy to abrogate B cell responses in a mouse model of dengue virus (DENV) infection. C57BL/6 mice were inoculated with UV-inactivated DENV-1 or DENV-2 (equivalent of 5x105 PFU) via footpad (f.p.). On day four, the ipsilateral popliteal lymph nodes in the hind legs corresponding to the inoculation site were removed. Control mice were inoculated with UV-inactivated DENV-1 via f.p. and underwent mock surgery or were inoculated with C6/36 cell supernatant (placebo) f.p. Briefly, C57BL/6 mice were anesthetized using an intraperitoneal injection of a mixture of ketamine and xylazine (100 mg/kg and 10 mg/kg of body weight, respectively, via i.p. injection). After depilation and skin antisepsis, the ipsilateral popliteal lymph nodes were removed. After surgery enrofloxacin (0.1 mg/ml, diluted in drinking water) was administered for 3 days as prophylaxis and tramadol (200 l of a solution 100 mg/ml, diluted in 1 liter of drinking water) was administered for 4 days as an analgesic. Post-surgical wound healing and behavior was monitored. All the animals being operated survived the surgery and did not show mobility impairments in the operated member or disturbances in normal behavior. The efficacy of B cell depletion was tested at 40 days post-inoculation by DENV-specific IgG immunoassay. DENV-1 and DENV-2 IgG endpoint titers were significantly reduced 13- and 36- times, respectively, in lymph node resected mice, compared to animals that received mock surgery. The results demonstrate that popliteal lymph node resection was a successful strategy to deplete B cell response to DENV inoculation in mice