ROLE OF B LYMPHOCYTES IN THE IMMUNE RESPONSE TO SHIGA TOXIN- PRODUCING ESCHERICHIA COLI INFECTION

ALAN MAURO BERNA; FERNANDO NICOLÁS SOSA; MARÍA FLORENCIA TODERO; MARÍA VICTORIA RAMOS; ROMINA JIMENA FERNÁNDEZ-BRANDO; MARTÍN RUMBO; MARINA SANDRA PALERMO

Conferencia; Reunión Anual de Sociedades de Biociencias; 2021

SAI/SAIC

We previously demonstrated a better outcome in weaned BALB/cmice (BALB) compared to C57BL/6 (C57) after Shiga toxin (Stx)-producing E. coli (STEC) infection. The main difference found wasthe early appearance of specific anti-STEC (aSTEC) and anti-Stxantibodies (aStx) in BALB. The aStx developed by infected BALBnot only protected them against an intravenous (i.v.) Stx challenge,but also passive immunization with their sera protected C57 afterSTEC infection. The aim of this work is to determine if B cell-dependent response triggered after infection is necessary to guarantee thesurvival of infected BALB.We administered a single i.v. dose of anti-B220 antibody (aB220; 4mg/mouse) to BALB to deplete B cells. We analyzed the percentageof CD19 positive cells (%CD19+) in mesenteric lymph node (MLN)and spleen at different times (4, 24 and 48 h) by flow cytometry. Thistreatment induced a significant B cell depletion in MLN at 4, 24 and48 h vs controls (control vs B-depleted: 4, 24 and 48 h, p