TY  - JOUR
A1  - Hof, H.
A1  - Emmerling, P.
A1  - Hacker, Jörg
A1  - Hughes, C.
T1  - The role of macrophages in primary and secondary infection of mice with Salmonella typhimurium
N2  - Elimination of macrophages with high-molecular dextran sulphate (OS) markedly impairs resistance of mice to primary infection with smooth, virulent strains of Salmonella typhimurium, whereas stimulation of this system by killed Bordetella pertussis organisms increases resistance. In infection with rough, avirulent strains of S. iyphimurium the elimination of macro phages was not followed by an essential loss of resistance, and it appears that other non-specific defence mechanisms, for example the complement system, may have compensated for the lack of macrophages. Macrophages, therefore, play an important role in defence during primary infection with virulent strains. In immunity to challenge infection with S. typhimurium, macrophages play an even more significant role. Treatment with OS completely removes immunity, and both humoral and cell-mediated immune mechanisms seem to require the participation of macrophages.
KW  - Macrophage
KW  - Salmonella typhimurium
KW  - Dextran sulphate
KW  - Mouse
KW  - 0 antigen
KW  - Bordeiella pertussis
Y1  - 1982
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40248
ER  - 
TY  - JOUR
A1  - Hacker, Jörg
A1  - Hof, H.
A1  - Hughes, C.
A1  - Goebel, W.
T1  - Salmonella typhimurium strains carrying hemolysin plasmids and cloned hemolysin. genes from Escherichia coli
N2  - Like all other Salmonella typhimurium strains examined, the smooth variants SF1397 (L T2) and 1366 and also their semi-rough and rough derivatives are non-haemolytic. Nevertheless, two haemolysin (Hly) plasmids of E. coli belonging to the inc groups incFllI,lv (pSU316) and incIz (pHly152) were able to be introduced into these strains by conjugation and stably maintained. A considerable percentage of the Hly+ transconjugants obtained had lost parts of their O-side chains, a result of selection for the better recipient capability of « semi-rough» variants rather than the direct influence of the Hly+ plasmids themselves. In contrast to the incF1lI1V plasmid pSU316, which exhibited higher conjugation rates with rough recipients, the incIz plasmid pHly152 was accepted best by smooth strains. Transformation with cloned E. coli haemolysin (hly) determinant was inefficient ( <10-8) for smooth strains, but 102-103 times higher for rough recipients, and was increased by the use of Salmonella-modified DNA. The transform ants and transconjugants were relatively stable and showed the same haemolytic activity as the E. coli donor strains. The virulence of the Hly+ smooth, semi-rough and rough S. typhimurium strains was tested in two mouse models, and neither the mortality rate nor the ability to multiply within the mouse spleen was influenced by the hly determinants.
KW  - Salmonella typhimurium
KW  - Plasmid
KW  - Haemolysin
KW  - Escherichia coli
KW  - Virulence
Y1  - 1985
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40309
ER  -