The properties of transmembrane and soluble transplantation antigens were compared with respect to the induction of tolerance and the selection of the T-cell repertoire. For this purpose, transgenic (H-2b x H-2d)F1 mice were constructed that carry integrated copies of a modified H-2Kk gene resulting in the secretion from various cell types including thymocytes of soluble H-2Kk molecules. Despit...

The influence of time and temperature on the storage of an alkaline antigen of L. major-like and L.(V.) braziliensis promastigotes added or not of a proteases inhibitor (PMSF) was evaluated by means of an IgG-ELISA. Antibodies in assays using L. major-like antigen stored at -20 degrees C for 6 months had a statistically lower geometric mean titer (GMT) and different 95% confidence interval limi...

Dogs play an important role in transmission of Leishmania infantum, but epidemiologic and clinical studies canine tegumentary leishmaniasis (CTL) are scarce. In endemic area human American (ATL) caused by braziliensis, we determine the prevalence incidence both CTL subclinical (SC) L. braziliensis infection dogs evaluated if presence with or SC is associated occurrence ATL. healthy animals ulce...

The induction of antigen-specific primary cytotoxic T lymphocyte (CTL) responses in vitro clearly requires interactions between several cell types and soluble mediators (1-5). One essential interaction occurs between the Lyt-2 + C T L precursor (CTL-P) and an antigen-activated Lyt-1 + helper T cell (6-8). This interaction is considered to occur by way of soluble mediator such as interleukin 2 (...

background: leishmania major lmsti1 is a conserved protein among different species of leishmania, and expressed in both amastigote and promastigote forms of l. major life cycle. it has previously been expressed in bacterial systems. m aterials and methods: to express lmsti1 in the methylotrophic yeast         pichia pastoris ( p. pastoris ), the shuttle vector ppicza containing gene lmsti1 was ...

background: naltrexone, an opioid receptor antagonist shifts the immune response toward a th1 profile. in the current study, we evaluated the efficacy of the mixture of ntx and alum, as a new adjuvant, to enhance immune response and induce protection against leishmania major in a mouse model. methods : balb/c mice were immunized three times either autoclaved l. major promastigotes’ antigens alo...

We found that virulent hemolysin-producing (Hly+) Listeria monocytogenes strains inhibit antigen processing and presentation when added to macrophages in vitro. A virulent Hly- bacteria caused little or no inhibition. Live Hly+ bacteria inhibited presentation of both heat-killed L. monocytogenes and ovalbumin. Several observations indicate that hemolysin produced by intracellular bacteria was r...

Recent advances in molecular medicine have shown that soluble MHC-multimers can be valuable tools for both the stimulation of as well as the analysis of antigen-specific T cells in vitro. In this review, we describe the use of dimeric major histocompatibility complexes, HLA-Ig, to visualize antigen-specific T cells as well as their potential to stimulate immune responses as part of an artificia...

INTRODUCTION Soluble major histocompatibility complex class I chain-related antigen A (soluble MICA) has recently been considered as an inhibitory molecule which is shed from tumors and protects them against natural killers and some subgroups of T cells' cytolysis. In transplantation, soluble MICA is also a foreign antigenic molecule that can induce allospecific responses. This study aimed to c...

Vi antibody response of rabbits varied depending on whether Vi antigen was administered in particulate or soluble state. Vi antigen in particulate form induced hemagglutinins, bacterial agglutinins, and passive cutaneous anaphylaxis (PCA) antibodies, whereas soluble Vi antigen induced only hemagglutinins. Guinea pigs passively sensitized with antisera against particulate Vi antigen gave PCA rea...