The cellular immune response in BALB/c mice mesenteric granulomas (MG) was analysed by the means of functional ultrastructure and the assessment of the presence or absence of asynchronous plasma cells in situ.
Results from this study establish: (a) the sequential events involved in the genesis of the oil-induced granulomas, (b) the weak T-cellular immune response and the almost absence of these cells in mitosis, (c) the presence of asynchronous plasma cells of type II was found in mice Nos. 8, 9, 10 and 11 and they were considered to be plasma cell mutants of temporary type, to indicate the first step of this cell alienation in tumorigenesis, (d) the high ratio of peritoneal macrophages was found and connected with what is known about it in the literature. It was speculated that the supraoptimal presence of peritoneal macrophages could have been responsible for the appearance of plasma cell mutants and (e) four morphological types of macrophages have been found in this animal's oil-induced MG, representing different stages of the monocyte transformation in situ. 相似文献
Flavobacterium columnare is divided into three genetic groups or genomovars, genomovar II being highly virulent for channel catfish. A modified live vaccine is currently available to prevent columnaris disease under the licensed name Aquavac‐Col®. The strain of F. columnare used to generate the avirulent rifampicin‐resistant mutant used in Aquavac‐Col® belonged to genomovar I, the less virulent group towards channel catfish. In this study, we describe the generation and characterization of rifampicin‐resistant mutants from genomovar II strains. A total of 13 new mutants were obtained, and eight of them (two from each parent strain) were genetically and phenotypically characterized. Highly conserved regions within the ribosomal operons were identical between parent and mutant strains. Genetic differences between mutants and their parent strains were revealed by amplified fragment length polymorphism (AFLP). Genetic changes were distinctive among different mutants. Analysis of the lipopolysaccharide (LPS) showed that while some mutants lacked a few molecular bands of the LPS, some exhibited the same LPS profiles as their parent strains. Comparison between immunogenic proteins from mutants and parents was carried out by immunoblot analysis and further confirmed the uniqueness of individual mutants. A complete set of rifampicin‐resistant mutants with different genetic and immunogenic properties from the highly virulent genomovar II has been created. These mutants may have the potential of becoming vaccine candidates against columnaris disease. 相似文献