Role of B lymphocytes in the immune response to Shiga toxin-producing Escherichia coli infection

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

Congreso; Reunión Anual de Sociedades de Biociencias (SAIC-SAI-AAFE-NANOMED.AR) 2021; 2021

We previously demonstrated a better outcome in weaned BALB/c mice (BALB) compared to C57BL/6 (C57) after Shiga toxin (Stx)- producing E. coli (STEC) infection. The main difference found was the early appearance of specific anti-STEC (aSTEC) and anti-Stx antibodies (aStx) in BALB. The aStx developed by infected BALB not only protected them against an intravenous (i.v.) Stx challenge, but also passive immunization with their sera protected C57 after STEC infection. The aim of this work is to determine if B cell-dependent response triggered after infection is necessary to guarantee the survival of infected BALB. We administered a single i.v. dose of anti-B220 antibody (aB220; 4 mg/mouse) to BALB to deplete B cells. We analyzed the percentage of CD19 positive cells (%CD19+) in mesenteric lymph node (MLN) and spleen at different times (4, 24 and 48 h) by flow cytometry. This treatment induced a significant B cell depletion in MLN at 4, 24 and 48 h vs controls (control vs B-depleted: 4, 24 and 48 h, p