TY - JOUR
T1 - Cytokine expression by attenuated intracellular bacteria regulates the immune response to infection
T2 - The Salmonella model
AU - Al-Ramadi, Basel K.
AU - Adeghate, Ernest
AU - Mustafa, Nada
AU - Ponery, Abdul Samad
AU - Fernandez-Cabezudo, Maria J.
PY - 2002
Y1 - 2002
N2 - Attenuated Salmonella strains have shown excellent efficacy as mucosal vaccine delivery systems. In the present report, several recombinant strains of Salmonella enterica serovar Typhimurium, engineered to express defined murine cytokines, were used to study their potential immunoregulatory capacity in the mouse model of typhoid fever. Specifically, recombinant strains expressing IL-2 (known as GIDIL2) or TNF-α (GIDTNF) were compared with the parental, non-cytokine-secreting, strain (BRD509) for their ability to induce a variety of immune responses in susceptible BALB/c mice. Our findings indicate that bacterially-expressed cytokines are functional in vivo and do induce a unique pattern of responses, quite distinct from that induced by BRD509 organisms. Both the type and magnitude of specific immune parameters were affected. These included the capacity to induce an inflammatory response resulting in a state of profound splenomegaly and hepatomegaly, activation of individual immune cells (particularly macrophages and other myeloid lineage cells), and the induction of nitric oxide (NO) secretion. Furthermore, a structural analysis using light as well as electron microscopy was undertaken to examine the host cellular response to infection with the different bacterial strains. The results indicate that cytokine expression by the invading pathogen can dramatically influence host immunity from a very early stage following infection. These findings may well have important consequences for the potential utilization of bacterial vector-encoded cytokines in immunoregulation in different disease settings.
AB - Attenuated Salmonella strains have shown excellent efficacy as mucosal vaccine delivery systems. In the present report, several recombinant strains of Salmonella enterica serovar Typhimurium, engineered to express defined murine cytokines, were used to study their potential immunoregulatory capacity in the mouse model of typhoid fever. Specifically, recombinant strains expressing IL-2 (known as GIDIL2) or TNF-α (GIDTNF) were compared with the parental, non-cytokine-secreting, strain (BRD509) for their ability to induce a variety of immune responses in susceptible BALB/c mice. Our findings indicate that bacterially-expressed cytokines are functional in vivo and do induce a unique pattern of responses, quite distinct from that induced by BRD509 organisms. Both the type and magnitude of specific immune parameters were affected. These included the capacity to induce an inflammatory response resulting in a state of profound splenomegaly and hepatomegaly, activation of individual immune cells (particularly macrophages and other myeloid lineage cells), and the induction of nitric oxide (NO) secretion. Furthermore, a structural analysis using light as well as electron microscopy was undertaken to examine the host cellular response to infection with the different bacterial strains. The results indicate that cytokine expression by the invading pathogen can dramatically influence host immunity from a very early stage following infection. These findings may well have important consequences for the potential utilization of bacterial vector-encoded cytokines in immunoregulation in different disease settings.
KW - Cytokine expression
KW - Immune response
KW - Salmonella model
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U2 - 10.1016/S0161-5890(02)00020-2
DO - 10.1016/S0161-5890(02)00020-2
M3 - Article
C2 - 12009571
AN - SCOPUS:0036253114
SN - 0161-5890
VL - 38
SP - 931
EP - 940
JO - Molecular Immunology
JF - Molecular Immunology
IS - 12-13
ER -