Identification, localization and quantification of porcine intestinal immune cell subsets during the first seven weeks of postnatal ontogeny/Identifikacija, lokalizacija i kvantifikacija subpopulacija crijevnih imunosnih stanica prasadi tijekom prvih sedam tjedana postnatalnog razvitka

By using immunohistology and digital image analysis for histomorphometry, we investigated the influence of porcine postnatal development on distribution and quantitative patterns of naive/memory lymphoid cell subsets ([CD45RA.sup.+], [CD45RC.sup.+], respectively), helper/cytotoxic T cell subsets ([CD4.sup.+], [CD8.sup.+], respectively) as well as of [IgA.sup.+] plasma cells in the gut-associated lymphoid tissues (GALT) of pigs reared under intensive conditions during the first 7 weeks of life. Current research on the postnatal ontogenesis/maturation of porcine small intestinal mucosal immune system have shown that newborn pigs are immunologically rather immature and, thus, totally dependent on passively acquired immunity. Their jejunal mucosa almost lacks immune cells, with the exception of a low number of [CD45RA.sup.+] lymphoid cells (1.25 x [10.sup.-5]) at Day 0 post partum. A very few [CD45RC.sup.+] lymphoid cells (8.79x[10.sup.-6]) appeared at Day 7, followed by a similar number of [IgA.sup.+] plasma cells (7.65x[10.sup.-6]) which were observed at Day 14. Such first signs of the postnatal development of both innate and adaptive immunity by identification/localization of tested cell subsets residing porcine GALT, i e. jejunal mucosal sites are proceeded by a lag period of three weeks until the appearance of low quantities of [CD4.sup.+] (3.62x[10.sup.-5]) and [CD8.sup.+] (3.13x[10.sup.-5]) T cells at Day 35 after birth. After that phase of early postnatal development of the crucial cell subsets participating in the antigen-specific immunity on the gut mucosal surfaces of young pigs, further progress was visible through their different distribution patterns within the jejunal mucosa compartments, and a gradual increase in their numbers, particularly between Day 35 and Day 49 of age. A significant increase was recorded within that period in the numbers of naive, memory and plasma cells, whereas the number of helper and cytotoxic T cells only slightly increased between Day 42 and Day 49 of life. Key words: postnatal development, immune cells, gut mucosa, pigs Pomocu imunohistoloskih i histomorfometrijskih analiza racunalnom obradom slike istrazivali smo utjecaj postnatalnog razvitka u svinje na distribucijske i kvantitativne pokazatelje subpopulacija djevicanskih/ memorijskih limfoidnih stanica ([CD45RA.sup.+] odnosno [CD45RC.sup.+]), pomocnickih/citotoksicnih T-stanica ([CD4.sup.+] odnosno [CD8.sup.+]), kao i za [IgA.sup.+] plazma stanice u limfatickim t