Adoptive transfer of immunity to oral challenge with virulent salmonellae in innately susceptible BALB/c mice requires both immune serum and T cells

Abstract

The mechanisms of immunity to salmonellae conferred by immunization with live vaccines were studied by adoptive transfer using the mouse-virulent strain Salnonella typhimurium C5 and innately susceptible BALB/c (by) mice. This organism cannot establish a sublethal infection in naive BALB/c mice. Animals immunized 2 to 3 months earlier with the S. typhimurium SL3261 aroA live vaccine were used as donors of serum, spleen cells, and mesenteric lymph node cells for naive recipients which were challenged orally with the virlent C5 strain. Simultaneous transfer of both immune serum and immune cells was necessary for protection. Simultaneously depleting the donors of CD4+ and CD8+ T cells by administration of antisera in vivo prior to cell harvesting showed that T cells were necessary for protection. The results demonstrate that both antibody and T cells are required for recall of immunity to oral challenge with virulent salmonellae in innately susceptible mice and suggest that the ability to elicit opsonizing antibody in addition to cell-mediated immunity is important for optimal protection induced by salmonella vaccines.

Human IgG isotypes and activating Fcγ receptors in the interaction of Salmonella enterica serovar Typhimurium with phagocytic cells

“…[17][18][19][20][21][22][23] Immunoglobulin G antibodies, in addition to T-cell receptor-ab + CD4 + and CD8 + T cells, are essential for resistance against enteric and septicaemic Salmonella diseases in humans and animals. 24 The requirement for systemic antibody responses against such a facultative intracellular pathogen can be explained considering that Summary Several classes and multiple subclasses of immunoglobulins are produced towards protein and polysaccharide antigens in response to Salmonella infection and play a key role in protection against systemic disease. The targeting of Salmonella to Fc receptors (FcR) on phagocytes is a key step in the antibody-mediated antibacterial functions of host cells.…”

Effect of immune serum and role of individual Fcγ receptors on the intracellular distribution and survival of Salmonella enterica serovar Typhimurium in murine macrophages

“…The crucial role of antibody in host resistance to S. enterica is supported by the observation that the expression of high levels of host resistance against these bacteria requires the presence of immune serum (IS) (anti-S. enterica immunoglobulin) in addition to T-cell-mediated immunity. 23 Antibodies specific for the lipopolysaccharide O-antigen, porins and flagellar epitopes and surface polysaccharides (Vi antigen) have been implicated in serum-mediated protection. 24 Furthermore, vaccines consisting of whole S. enterica or purified bacterial polysaccharide preparations (Vi vaccine), which elicit good anti-S. enterica immunogloblulin responses, but fail to trigger protective T-cell responses, confer a degree of protection against typhoid fever in humans.…”

Cholinergic stimulation of the immune system protects against lethal infection by Salmonella enterica serovar Typhimurium

“…Protection against S. typhimurium requires Th1-type immune responses. [22][23][24]43 Moreover, a robust antibody response is known to be required for resistance against virulent Salmonella infection. 22,44,45 Our results demonstrated that, contrary to expectations, paraoxon treatment rendered the animals more resistant to Salmonella infections.…”

“…In this animal model, control of the infection requires a robust T helper type 1 (Th1) response as well as neutralizing anti-Salmonella antibodies. [22][23][24] The essential roles of pro-inflammatory cytokines, including IL-12, interferon-c (IFN-c) and TNF-a, in resistance to Salmonella infection in mice as well as in humans is well documented. [25][26][27][28] The present data demonstrate that cholinergic activation of splenic macrophages, through the inhibition of AChE by subchronic exposure to paraoxon, confers enhanced protection against a lethal infection with a virulent strain of S. typhimurium.…”