Gnotobiotic (GN) animals with defined microbiota allow us to study host-microbiota and microbiota-microbiota interferences. Preterm germ-free (GF) piglets were mono-associated with probiotic Bifidobacterium animalis subsp. lactis BB-12 (BB12) to ameliorate/prevent the consequences of infection with the Salmonella Typhimurium strain LT2 (LT2). Goblet cell density; expression of Toll-like receptors (TLRs) 2, 4, and 9; high mobility group box 1 (HMGB1); interleukin (IL)-6; and IL-12/23p40 were analyzed to evaluate the possible modulatory effect of BB12. BB12 prevented an LT2-induced decrease of goblet cell density in the colon. TLRs signaling modified by LT2 was not influenced by the previous association with BB12. The expression of HMGB1, IL-6, and IL12/23p40 in the jejunum, ileum, and colon and their levels in plasma were all decreased by BB12, but these changes were not statistically significant. In the colon, differences in HMGB1 distribution between the GF and LT2 piglet groups were observed. In conclusion, the mono-association of GF piglets with BB12 prior to LT2 infection partially ameliorated the inflammatory response to LT2 infection.

• Keywords
• Bifidobacterium animalis subsp. lactis BB-12, Salmonella Typhimurium, Toll-like receptors, high mobility group box 1, immunodeficient host, inflammatory cytokines, intestinal barrier, mucin, tight junction proteins,
• MeSH
• Bifidobacterium animalis * MeSH
• Germ-Free Life MeSH
• Humans MeSH
• Infant, Premature MeSH
• Infant, Newborn MeSH
• Swine MeSH
• Probiotics * pharmacology   MeSH
• HMGB1 Protein * MeSH
• Salmonella typhimurium MeSH
• Toll-Like Receptors metabolism   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Infant, Newborn MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• HMGB1 Protein * MeSH
• Toll-Like Receptors MeSH

Cellular and humoral aspects of the immune response develop sequentially in the fetus. During the ontogeny, the pluripotent stem cells emerge and differentiate into all hematopoietic lineages. Basic questions including the identification of the first lympho-hematopoietic sites, the origin of T and B lymphocytes, the development of different subpopulations of alphabeta T, gammadelta T and B lymphocytes as well as development of innate immunity and the acquisition of full immunological capacities are discussed here for swine and compared with other species. The description of related topics such as fertilization, morphogenesis, maternal-fetal-neonatal physiology and early neonatal development are also discussed.

• MeSH
• B-Lymphocytes cytology   immunology   metabolism   MeSH
• Immunity, Cellular MeSH
• Embryo, Mammalian immunology   MeSH
• Hematopoietic Stem Cells cytology   immunology   MeSH
• Hematopoiesis immunology   MeSH
• Immune System embryology   immunology   MeSH
• Lymphopoiesis MeSH
• Maternal-Fetal Exchange immunology   MeSH
• Morphogenesis immunology   MeSH
• Placentation immunology   MeSH
• Swine embryology   immunology   virology   MeSH
• Immunity, Innate MeSH
• T-Lymphocytes cytology   immunology   metabolism   MeSH
• Pregnancy MeSH
• Animals MeSH
• Check Tag
• Pregnancy MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH

Although porcine lymphocytes have been classified into numerous subpopulations in postnatal animals, little is known about the ontogeny of these complex cell subsets. Using double- and triple-colour flow cytometry (FCM), we investigated the surface phenotype of fetal lymphoid cells in the thymus, cord blood, spleen and mesenteric lymph nodes at different stages of gestation. It was found that the major lymphocyte subpopulations started to appear at the beginning of the second third of the gestation period, with B cells being the earliest lymphocyte subpopulation to appear in the periphery. The T-cell receptor (TCR) gamma delta+ cells were the earliest detectable T-cell subset, developing first in the thymus and subsequently arriving in the periphery. Later in ontogeny, however, the number of TCRalpha beta+ lymphocytes rapidly increased, becoming the predominant T cells both in the thymus and in the periphery. Cells with the phenotype of adult natural killer cells were also identified in pig fetuses, though their nature and functional roles remain to be investigated. In addition, CD2 was expressed on most B cells whilst very few CD4+ TCRalpha beta+ cells or CD2+ TCRgamma delta+ cells expressed CD8, suggesting that the expression of CD2 and CD8 may reflect the functional status of the cells in postnatal animals. Taken together, this study has provided a systematic analysis of fetal porcine lymphocyte subpopulations and may provide the base for studies to establish the physiological roles of these lymphocyte subsets.

• MeSH
• B-Lymphocytes immunology   MeSH
• Killer Cells, Natural immunology   MeSH
• Gestational Age MeSH
• Lymph Nodes embryology   immunology   MeSH
• Swine, Miniature embryology   immunology   MeSH
• Fetus immunology   MeSH
• Lymphocyte Subsets immunology   MeSH
• Swine MeSH
• Flow Cytometry methods   MeSH
• Receptors, Antigen, T-Cell, alpha-beta MeSH
• Receptors, Antigen, T-Cell, gamma-delta MeSH
• Spleen embryology   immunology   MeSH
• T-Lymphocytes immunology   MeSH
• Thymus Gland embryology   immunology   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Receptors, Antigen, T-Cell, alpha-beta MeSH
• Receptors, Antigen, T-Cell, gamma-delta MeSH