Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have developed an animal model for congenital syphilis. Treponema pallidum is injected intravenously into pregnant rabbits and fetuses are infected in utero. As a prelude to characterizing the immunologic consequences of fetal infection, it was necessary to expand on the baseline information about newborn rabbit immune capabilities. Studies were undertaken to determine splenic macrophage and T lymphocyte functions with emphasis on newer immunologic parameters. Newborns aged 2 weeks were compared to adults. Macrophage capabilities in newborn rabbits differed from those of their adult counterparts. These cells produced similar basal levels of interleukin 1 (IL-1) but failed to respond to the IL-1 stimulants of lipopolysaccharide (LPS) or T. pallidum. Macrophages also exhibited diminished levels of la expression and increased levels of prostaglandin E2 (PGE2) secretion. T lymphocyte functions were altered in newborn spleen preparations. Following concanavalin A (Con A) stimulation, interferon gamma production was half that of adults; in direct contrast, IL-2 production was twice that of adults. Con A-induced lymphocyte proliferation was markedly decreased in newborn preparations. This diminished response resulted from down-regulation rather than immaturity. When newborn splenic cells were stimulated with Con A in the presence of indomethacin, anti-transforming growth factor (anti-TGF), or exogenous IL-1/IL-2, better proliferation resulted. PGE2, which is well established as a down-regulator of newborn immune functions in human and mouse systems, also appears to play a role in suppressing newborn rabbit functions. TGF is a potent suppressor of a number of adult immunologic reactions. This is the first documentation of the potential role of this factor in down-regulating newborn immune capabilities. These findings provide a framework for future investigations of our congenital syphilis model.
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PMID:Macrophage and lymphocyte functions are down-regulated in newborn rabbits. 143 51

Spleens from 1-20-wk-old guinea pigs infected in utero with Treponema pallidum and age-matched controls, born to normal and heat-killed (56 degrees C, 2 h.) T. pallidum-injected mothers, were examined for their in vitro lymphoproliferative response to phytohemagglutinin, concanavalin A, and lipopolysaccharide. Additionally, T cell surface markers (mu-chain, pan T, CD4, and CD8) were determined in spleen, lymph node, and peripheral blood from 10-wk infected and normal pups by single and dual parameter fluorescence-activated cell sorter analysis. Compared with control animals, congenitally infected animals showed a remarkable prolonged naive-type of immune response as reflected by the higher (p < 0.01) proliferative responses to both T cell mitogens (up to 20 wk of age), and the weaker response to the B cell mitogen, significantly different (p < 0.01) at 10 wk of age. As opposed to controls, in all organs examined the level of CD8+ (cytotoxic/suppressor) T cells was significantly diminished (p < 0.01); consequently, the CD4/CD8 ratio was significantly elevated (p < 0.05). The role of C4 complement component and the nature and potential role of the immature T and B lymphocyte responses in asymptomatic congenital syphilis is discussed.
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PMID:Immune abnormalities in guinea pigs with asymptomatic congenital syphilis. 939 60