CD47 is an antiphagocytic signal that cancer cells employ to inhibit macrophage-mediated destruction. Here, we modified the binding domain of human SIRPα, the receptor for CD47, for use as a CD47 antagonist. We engineered high-affinity SIRPα variants with about a 50,000-fold increased affinity for human CD47 relative to wild-type SIRPα. As high-affinity SIRPα monomers, they potently antagonized...

Human leukemia cell gangliosides were found to inhibit in vitro activation of human lymphocytes by lectins and the soluble antigen Candida albicans at concentrations as low as 2 micrograms/2 X 10(5) lymphocytes/0.2-ml cultures. The inhibition was not due to a reduction in the number of viable cells, but to an inhibition of blast formation. Three gangliosides were purified from the original mixt...

INTRODUCTION The basophil activation test showing CD63 up regulation could be a specific and sensitive in vitro complementary text to the in vivo autologous serum skin test for the activity assessment of the patients suffering autoimmune chronic spontaneous urticaria. The aim of this study is to define the basophil activation test as a useful tool in clinical practice in order to identify those...

Background Cytotoxic mechanisms are involved in most forms of drug-induced skin diseases, but till now only a small number of studies has been addressed the question whether in vitro detection of cytotoxic drug-specific response could be helpful in drug hypersensitivity diagnosis. The aim of this study was to assess and compare different cytotoxic tests as an alternative nonradioactive approach...

Benastatin C, a new member of the benastatins, has been isolated from the culture broth of Streptomyces sp. MI384-DF12. The structure of benastatin C was elucidated as 2-decarboxy-benastatin A by NMR studies. Benastatin D, 2-decarboxybenastatin B, was derived from benastatin B. Benastatins C and D showed inhibitory activities against human pi class glutathione S-transferase (GST pi) and excelle...

In Siberian hamsters (Phodopus sungorus), short days suppress reproductive function and lymphocyte proliferation. To determine whether melatonin influences cell-mediated immunity through a direct action on lymphocyte proliferation, in vitro responsiveness to mitogens and melatonin was assessed in systemic and splenic lymphocytes from adult female Siberian hamsters housed in either long or short...

Toll/IL-1R (TIR) domain-containing adapter-inducing IFN-β (TRIF)-related adapter molecule (TRAM) serves as a bridging adapter that enables recruitment of TRIF to activated TLR4 and thereby mediates the induction of TRIF-dependent cytokines. A library of cell-permeating decoy peptides derived from TRAM TIR domain has been screened for the ability of individual peptides to inhibit TLR4 signaling ...

Evaluation of allergic reactions to drugs is difficult because of the poor sensitivity of in vivo tests, which makes controlled administration of the drug necessary to confirm the diagnosis. In vitro tests are important in order to avoid the risks of in vivo testing. In the present review, we describe the different methods for detecting immunoglobulin (Ig) E antibodies that are specific to drug...

Classical macrophage activation is inhibited by the CD200 receptor (CD200R). Here, we show that CD200R expression was specifically induced on human in vitro polarized macrophages of the alternatively activated M2a subtype, generated by incubation with IL-4 or IL-13. In mice, peritoneal M2 macrophages, elicited during infection with the parasites Taenia crassiceps or Trypanosoma brucei brucei, e...

It is now well established that the cytokine environment influences the activation, differentiation, proliferation and death of T lymphocytes during the primary response to antigen. Using an in vitro model, we investigated the influence of IL-4, added at the onset of TCR stimulation, on phenotypic and functional markers of naive CD8+ T cell activation including the up-regulation of activation m...