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Ginsenoside Rh2 (G-Rh2) has well-established potent antitumor activity; yet, the effects of G-Rh2 on immune and metabolism regulation in cancer treatment, especially non-small cell lung cancer (NSCLC) remain unclear. We showed that G-Rh2 had a synergistic antitumor effect with cyclophosphamide (CY) on mice with NSCLC, and improved the immune deficiency caused by CY. Consistently, G-Rh2 exhibited no inhibitory effect on tumor growth of T cells-deficient nude mice. Furthermore, G-Rh2 treatment triggered the oxidative decomposition of fatty acid (FA), suppressed FA synthesis, increased ketone level, and decreased glucocorticoid (CORT) secretion. G-Rh2 significantly down-regulated the expression of fatty acid synthase (FASN). Of note, in liver-specific FASN knockout mice G-Rh2 failed to show the same immune enhancement effects. Further mechanistic exploration revealed that G-Rh2 suppressed the expression and nuclear translocation of sterol regulatory element binding protein 1 (SREBP-1), and disturbed the SREBP-1-FASN interaction in vitro., (©2019 Society for Leukocyte Biology.)

Royal jelly (RJ), the exclusive food for queen bees, is taken as a dietary supplement because it is highly rich in nutrients. However, RJ is known to induce an anaphylactic response in some individuals. We evaluated in the present study the hypoallergenicity of alkaline protease-treated RJ in vitro and in vivo. We first confirmed that this treated RJ contained the same levels of vitamins, minerals and specific fatty acid as in untreated RJ. We then showed that the IgE-binding capacity of the treated RJ was very significantly reduced by conducting in vitro assays of the blood from RJ-sensitive patients. An in vivo skin-prick test on the RJ-sensitive patients also showed that, in the majority of the patients (3 out of 4 tested), the treated RJ did not evoke any allergenic response. It is thus advantageous to prepare hypoallergenic RJ by a protease enzyme treatment for its safe consumption.

The acute motor axonal neuropathy (AMAN) variant of Guillain-Barré syndrome (GBS) is associated with anti-GD1a and anti-GM1 IgG antibodies. The basis of preferential motor nerve injury in this disease is not clear, however, because biochemical studies demonstrate that sensory and motor nerves express similar quantities of GD1a and GM1 gangliosides. To elucidate the pathophysiology of AMAN, we have developed several monoclonal antibodies (mAbs) with GD1a reactivity and reported that one mAb, GD1a-1, preferentially stained motor axons in human and rodent nerves. To understand the basis of this preferential motor axon staining, several derivatives of GD1a were generated by various chemical modifications of N-acetylneuraminic (sialic) acid residues (GD1a NeuAc 1-amide, GD1a NeuAc ethyl ester, GD1a NeuAc 1-alcohol, GD1a NeuAc 1-methyl ester, GD1a NeuAc 7-alcohol, GD1a NeuAc 7-aldehyde) on this ganglioside. Binding of anti-GD1a mAbs and AMAN sera with anti-GD1a Abs to these derivatives was examined. Our results indicate that mAbs with selective motor axon staining had a distinct pattern of reactivity with GD1a-derivatives compared to mAbs that stain both motor and sensory axons. The fine specificity of the anti-GD1a antibodies determines their motor selectivity, which was validated by cloning a new mAb (GD1a-E6) with a chemical and immunocytochemical binding pattern similar to that of GD1a-1 but with two orders of magnitude higher affinity. Control studies indicate that selective binding of mAbs to motor nerves is not due to differences in antibody affinity or ceramide structural specificity. Since GD1a-reactive mAb with preferential motor axon staining showed similar binding to sensory- and motor nerve-derived GD1a in a solid phase assay, we generated computer models of GD1a based on binding patterns of different GD1a-reactive mAbs to different GD1a-derivatives. These modelling studies suggest that critical GD1a epitopes recognized by mAbs are differentially expressed in motor and sensory nerves. The GD1a-derivative binding patterns of AMAN sera resembled those with motor-specific mAbs. On the basis of these findings we postulate that both the fine specificity and ganglioside orientation/exposure in the tissues contribute to target recognition by anti-ganglioside antibodies and this observation provides one explanation for preferential motor axon injury in AMAN.

Ceramide mono (CMH) or dihexoside (CDH) fractions from Trypanosoma cruzi (Dm28c clone) were identified as glucosyl and lactosylceramides containing non-hydroxylated fatty acids. The di-glycosylated form was much more efficiently recognized by sera from T. cruzi-immunized rabbits, indicating that glycosylation influences antigenicity. Fatty acid hydroxylation was also a determinant of serological reactivity, since an alpha-hydroxylated CMH, only present at the Y clone, was recognized by the hyperimmune sera. In summary, these data indicate that T. cruzi CMHs with non-hydroxylated fatty acids are unable to induce antibody responses in animal hosts, which is reverted by the addition of a sugar residue or an alpha-hydroxyl group.

Several reports have demonstrated that major changes occur in the fatty acid content of HIV-infected cells. In order to evaluate if these changes are recognized by the immune system, we have attempted to assay the possible presence of autoantibodies (autoAb) directed against conjugated fatty acids (CFA). Using an adapted ELISA, anti-CFA autoAb were assayed in sera of 150 HIV-1-infected patients and 116 controls (healthy donors and patients suffering from other diseases). Significantly increased anti-CFA autoAb of IgG class were found in HIV-1-infected patients (alpha < 0.001). Using our ELISA method and CFA differing in their length and their degree of unsaturation (lauric, myristic, palmitic, palmitoleic, stearic, oleic, linolenic, linoleic, lignoceric, arachidonic, eicosapentaenoic and docosahexaenoic acids), it was demonstrated that the acyl chain of CFA is the immunodominant part recognized by these autoAb. Anti-CFA autoAb were present in 15/52 asymptomatic carriers, 14/36 symptomatic carriers, 16/39 ARC patients, but only 3/23 AIDS patients. Anti-CFA activity seemed to be linked with the CD4+ T cell count, and was not related to the total IgG amounts. Anti-CFA autoAb could result from self-antigen presentation to immunological cells, and may reflect lipid membrane modifications occurring in HIV-infected cells.