SipA, SopA, SopB, SopD and SopE2 effector proteins of Salmonella enterica serovar Typhimurium are synthesized at late stages of infection in mice.
Salmonella pathogenicity island (SPI)-1 is essential for invasion of non-phagocytic cells, whereas SPI-2 is required for intracellular survival and proliferation in phagocytes. Some SPI-1 effectors, however, are induced upon invasion of both phagocytic and non-phagocytic cells, suggesting that they may also be required post-invasion. In the present work, the presence was analysed of SipA, SopA, SopB, SopD and SopE2 effector proteins of Salmonella enterica serovar Typhimurium in vitro and in vivo during murine salmonellosis. Tagged (3xFLAG) strains of S. enterica serovar Typhimurium were inoculated intraperitoneally or intragastrically to BALB/c mice and recovered from the spleen and mesenteric lymph nodes of moribund mice. Tagged proteins were detected by SDS-PAGE and immunoblotting with anti-FLAG antibodies. In vitro experiments showed that SPI-1 effector proteins SipA, SopA, SopB, SopD and SopE2 were secreted under SPI-1 conditions. Interestingly, it was found that S. enterica serovar Typhimurium continued to synthesize SipA, SopB, SopD and SopE2 in colonized organs for several days, regardless of the route of inoculation. Together, these results indicate that SPI-1 effector proteins may participate in the late stages of Salmonella infection in mice.
Giacomodonato
M N
MN
Centro de Estudios Farmacológicos y Botánicos CEFyBO-CONICET, Universidad de Buenos Aires, Facultad de Medicina, Departamento de Microbiología, Parasitología e Immunología, Buenos Aires, Argentina.
Uzzau
S
S
Dipartimento di Scienze Biomediche, Università di Sassari, Italy.
Bacciu
D
D
Dipartimento di Scienze Biomediche, Università di Sassari, Italy.
Caccuri
R
R
Centro de Estudios Farmacológicos y Botánicos CEFyBO-CONICET, Universidad de Buenos Aires, Facultad de Medicina, Departamento de Microbiología, Parasitología e Immunología, Buenos Aires, Argentina.
Sarnacki
S H
SH
Centro de Estudios Farmacológicos y Botánicos CEFyBO-CONICET, Universidad de Buenos Aires, Facultad de Medicina, Departamento de Microbiología, Parasitología e Immunología, Buenos Aires, Argentina.
Rubino
S
S
Dipartimento di Scienze Biomediche, Università di Sassari, Italy.
Cerquetti
M C
MC
Centro de Estudios Farmacológicos y Botánicos CEFyBO-CONICET, Universidad de Buenos Aires, Facultad de Medicina, Departamento de Microbiología, Parasitología e Immunología, Buenos Aires, Argentina.
D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism*; D000939:Epitopes / Q000378:metabolism; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008840:Microfilament Proteins / Q000378:metabolism*; D009154:Mutation; D012481:Salmonella Infections, Animal / Q000382:microbiology*; D012486:Salmonella typhimurium / Q000378:metabolism*
D001426:Bacterial Proteins; D000939:Epitopes; D020662:Guanine Nucleotide Exchange Factors; D008840:Microfilament Proteins; C118287:SipA protein, Salmonella; C116105:SopD protein, Salmonella; C436324:SopE2 protein, Salmonella typhimurium; C060971:SopA protein, Bacteria; C489224:SopB protein, Salmonella