Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0153470 (Spleen)
 4,015 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Natural suppressor (NS) cell activity is the ability of apparently unprimed "null" cells to nonspecifically suppress immune responses. Previously we have shown that NS cell activity from the spleens of mice undergoing chronic graft-vs-host disease (GVHD) is enhanced in vitro by activated T cell signals (e.g., Con A supernatant [CAS]). Here we asked if the naturally occurring suppressor activity found in the neonatal mouse spleen is caused by NS cells, and if so whether this NS activity is also responsive to T cell signals. Finally, we wanted to identify the material in the CAS to which the NS cells respond. Spleen cells from (BALB/c X B10.D2)F1 neonates contain potent, genetically unrestricted suppressor activity toward normal mitogen responses. The cells responsible for this suppression are nonadherent, Thy-, Ig- and are thus by definition NS cells. Neonatal spleen NS cells suppress the indicator Con A response of all mouse strains tested, but their behavior with regard to LPS responses is different. They significantly inhibit the indicator LPS response of allogeneic strains, but are less inhibitory of LPS-stimulated syngeneic (BALB/c X B10.D2)F1 and parental strains. However, the addition of CAS to these latter cultures enhances the NS inhibition of the LPS response to the level of suppression seen with a Con A response. Two lymphokines were able to replace the CAS. Recombinant interferon-gamma (rIFN-gamma) closely mimics the activity found with whole CAS, with low concentrations (1 U/well) being capable of enhancing the neonatal NS activity to near-maximal levels. Recombinant interleukin 2 (rIL 2) is also capable of stimulating the neonatal NS activity to near maximum. However, the rIL 2 must be added at much higher concentrations, taking greater than 50 U/well to get maximum activation of NS suppression. The addition of anti-IFN-gamma antiserum to these LPS suppression assays removes the ability of CAS to activate the neonatal NS cells. Anti-IFN-gamma antiserum also removes the ability of rIL 2 as well as rIFN-gamma to activate the NS cells. It thus appears that the rIL 2 is working by its ability to stimulate IFN-gamma production. Anti-IFN-gamma also removes the ability of the neonatal NS cells to suppress a Con A response. Therefore, it appears that neonatal splenic NS cells respond to, and are activated by, IFN-gamma to carry out their suppressive activity.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Natural suppressor (NS) activity from murine neonatal spleen is responsive to IFN-gamma. 295 98

New Zealand Black ( NBR ) rats that are innately immune to challenge with a syngeneic 3-methylcholanthrene [(MCA) CAS: 56-49-5]-induced fibrosarcoma have spleen cells that produce helper effects for in vitro lymphoproliferative responses in the presence of individual MCA-induced fibrosarcoma cells. Spleen cells from MCA-induced fibrosarcoma progressor rats (which lack innate tumor immunity) do not produce demonstrable helper activity. Supernatants from 48-hour cocultures of spleen cells from tumor-immune (TI) rats and syngeneic MCA-induced fibrosarcoma cells replaced the spleen cell helper activity. Comparable spleen cell supernatants from tumor progressor rats or unchallenged rats (controls) as well as supernatants from MCA-induced fibrosarcoma cells cultured alone did not produce any helper factor activity. Supernatants from TI rat spleen cells following inoculation with MCA-induced fibrosarcoma cells did not affect lymphoproliferative responses of NBR spleen cells induced by concanavalin A or alloantigens. The supernatants also did not contain detectable interleukin 2 activity as determined with the use of the thymocyte costimulator assay. These data indicate that the production of soluble helper factors by TI rat spleen cells may be involved in the augmentation of a protective host antitumor response.
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PMID:Helper factor(s) generated by tumor-immune rats for lymphoproliferative responses to syngeneic tumor cells. 623 43