Three new sesquiterpene glycosides from Dendrobium nobile with immunomodulatory activity.

Dendroside A (1) and dendronobilosides A and B (2 and 3), three new sesquiterpene glycosides, have been isolated from the stems of Dendrobium nobile, a plant used in Chinese traditional medicine. Their structures and stereochemistry were determined as 10beta,12,14-trihydroxyalloaromadendrane 14-O-beta-D-glucopyranoside (1), 10,12-dihydroxypicrotoxane 10,12-di-O-beta-D-glucopyranoside (2), and 6alpha,10,12-trihydroxypicrotoxane 10-O-beta-D-glucopyranoside (3), respectively, on the basis of spectroscopic and chemical methods. Quantum chemistry calculations were used in support of the structural determination of 1. Compounds 1 and 2 were found to stimulate the proliferation of murine T and B lymphocytes in vitro, while compound 3 showed inhibitory activity in this same assay.

Identification of four novel potato (Solanum tuberosum) allergens belonging to the family of soybean trypsin inhibitors.

BACKGROUND: We have previously identified patatin (Sol t 1) of potato tubers as a major food allergen among atopic children. In addition to Sol t 1, concomitant IgE binding to other, then unidentified, potato proteins was observed. METHODS: Purification and identification of the putative allergens were done by both standard and advanced methods of protein chemistry. The patient series comprised 39 children with positive skin prick test (SPT) to raw potato. Immunoblotting and ELISA were used to examine IgE-binding ability and skin prick testing to assess in vivo reactivity of the purified potato proteins. RESULTS: Four IgE-binding potato proteins with molecular masses ranging from 16 to 20 kDa were purified and identified as cathepsin D-, cysteine-, and aspartic protease inhibitors belonging to the family of soybean trypsin inhibitors (Kunitz type). The proteins were designated Sol t 2, Sol t 3.0101, Sol t 3.0102, and Sol t 4. In ELISA, 51% of the sera of the 39 atopic children showed specific IgE to Sol t 2, 43% to Sol t 3.0101, 58% to Sol t 3.0102, and 67% to Sol t 4, respectively. All these four allergens were able to produce positive wheal-and-flare responses in SPT. CONCLUSION: In addition to Sol t 1, potato tubers contain several proteins belonging to the family of soybean trypsin inhibitors against which atopic children with positive SPT responses to raw potato have in vitro and in vivo reactive IgE antibodies.

Lymphotactin: a cytokine that represents a new class of chemokine.

In this study, the cytokine-producing profile of progenitor T cells (pro-T cells) was determined. During screening of a complementary DNA library generated from activated mouse pro-T cells, a cytokine designated lymphotactin was discovered. Lymphotactin is similar to members of both the Cys-Cys and Cys-X-Cys chemokine families but lacks two of the four cysteine residues that are characteristic of the chemokines. Lymphotactin is also expressed in activated CD8+ T cells and CD4-CD8- T cell receptor alpha beta + thymocytes. It has chemotactic activity for lymphocytes but not for monocytes or neutrophils. The gene encoding lymphotactin maps to chromosome one. Taken together, these observations suggest that lymphotactin represents a novel addition to the chemokine superfamily.

[Experimental lymphokine treatment of the wound process]. / Limfokinoterapiia ranevogo protsessa v éksperimente.

It is shown in experiment on the rabbits that the autologous supernatants of the culture of stimulating lymphocytes and the fractions of lymphokines with mol. weight 40000-20000 and 60000-70000 considerably reduced the periods of wound healing.

Detection of arthritogenic factor in adjuvant arthritis.

An evocation of arthritis by an Ag-specific lymphokine has recently been considered with the description of arthritogenic factor (AF) in rats with collagen arthritis. Because rats with CFA-induced arthritis also exhibit T cell reactivity to native type II collagen, T cell lines specific for this protein were established from CFA-injected rats. Supernatant material from these lines contained a type II collagen-binding lymphokine with functional and biochemical attributes identical with those described for AF, i.e., it was a 65-kDa species cross-reacting immunoprotein possessing the ability to incite an erosive, proliferative synovitis when injected into the knee joint of naive recipients. Similarities were also observed with HPLC and on two-dimensional gels. Lymph node cells from rats with arthritis created by injection of the synthetic adjuvant, CP-20,961 failed to produce AF, suggesting that this material is not a ubiquitous concomitant of inflammatory arthritis in the rat. Test injections into sites contiguous with the ear cartilage plate and into fibroblast-lined s.c. pouches suggested that cartilage was a requisite for the induction of inflammation by AF. These data identify a potentially shared effector pathway in the collagen and adjuvant models. The presence of AF in two frequently used models further supports the hypothesis that Ag-specific lymphokines can create autoimmune disease.

Jacalin: an IgA-binding lectin.

We previously reported that seeds of Artocarpus integrifolia (jackfruit) contain a lectin, which we call jacalin, that is both a potent T cell mitogen and an apparently T cell-independent activator of human B cells for the secretion of immunoglobulins. During the above experiments we noted a massive precipitation in cell cultures stimulated with greater than or equal to 100 micrograms of lectin. In this paper, we show that the precipitate is formed after the interaction of jacalin and the serum protein added to the culture medium. More importantly, we demonstrate that IgA is probably the major serum constituent precipitated by the lectin and that no IgG or IgM can be detected in the precipitates. In secretions such as colostrum, IgA is the only protein precipitated by jacalin. On the basis of this specificity we describe a simple and reliable affinity chromatography procedure for the purification of both human serum and colostrum IgA. Jacalin is a D-Gal binding lectin and should be a useful tool for studying of serum and secretory IgA.