The microorganisms Escherichia coli DH5␣ and Bacillus thuringiensis HD-1 show an increased tolerance to freeze-drying when dried in the presence of the disaccharides trehalose and sucrose. When the bacteria were dried with 100 mM trehalose, 70% of the E. coli and 57% of the B. thuringiensis organisms survived, compared with 56 and 44%, respectively, when they were dried with sucrose. Only 8% of the E. coli and 14% of the B. thuringiensis organisms survived drying without the sugars. Fourier transform infrared spectroscopy was used to investigate the role of membrane phase transitions in the survival of the organisms during drying and rehydration. Both E. coli and B. thuringiensis showed an increase of 30 to 40؇C in the temperature of their phospholipid phase transition when dried without the sugars, while phase transition temperatures of those dried with the sugars remained near those of the hydrated cells. A Fourier transform infrared spectroscopy microscope made it possible to investigate the effects of drying on the protein structure in the intact cells. The amide II peak shifts from 1,543 cm ؊1 in the hydrated cells to about 1,533 cm ؊1 in the cells dried without sugar. There is no shift in the amide II peak when the cells are dried with trehalose or sucrose. We attribute the increased survival to the sugars' ability to lower the membrane phase transition temperature and to protect protein structure in the dry state. In addition to increasing the immediate survival of both species, the addition of trehalose protected the cells from the adverse effects of exposure to light and air while dry. E. coli dried with trehalose and exposed to light and air for 4 h had an increase in CFU of between 2,000 and 4,000 times the number obtained with E. coli dried without trehalose. B. thuringiensis showed an increase in CFU of 150% in samples dried with trehalose compared with samples dried without trehalose. The cells dried with sucrose did not show an increased tolerance to exposure following drying.

Some adjuvants may exert adverse effects upon injection or, on the other hand, may not trigger a full immunological reaction. The mechanisms underlying adjuvant adverse effects are under renewed scrutiny because of the enormous implications for vaccine development. In the search for new and safer adjuvants, several new adjuvants were developed by pharmaceutical companies utilizing new immunological and chemical innovations. The ability of the immune system to recognize molecules that are broadly shared by pathogens is, in part, due to the presence of special immune receptors called toll-like receptors (TLRs) that are expressed on leukocyte membranes. The very fact that TLR activation leads to adaptive immune responses to foreign entities explains why so many adjuvants used today in vaccinations are developed to mimic TLR ligands. Alongside their supportive role, adjuvants were found to inflict by themselves an illness of autoimmune nature, defined as 'the adjuvant diseases'. The debatable question of silicone as an adjuvant and connective tissue diseases, as well as the Gulf War syndrome and macrophagic myofaciitis which followed multiple injections of aluminium-based vaccines, are presented here. Owing to the adverse effects exerted by adjuvants, there is no doubt that safer adjuvants need to be developed and incorporated into future vaccines. Other needs in light of new vaccine technologies are adjuvants suitable for use with mucosally delivered vaccines, DNA vaccines, cancer and autoimmunity vaccines. In particular, there is demand for safe and non-toxic adjuvants able to stimulate cellular (Th1) immunity. More adjuvants were approved to date besides alum for human vaccines, including MF59 in some viral vaccines, MPL, AS04, AS01B and AS02A against viral and parasitic infections, virosomes for HBV, HPV and HAV, and cholera toxin for cholera. Perhaps future adjuvants occupying other putative receptors will be employed to bypass the TLR signaling pathway completely in order to circumvent common side effects of adjuvant-activated TLRs such as local inflammation and the general malaise felt because of the costly whole-body immune response to antigen.

Giant axonal neuropathy (GAN) is an early-onset neurological disorder caused by mutations in the GAN

Vaccines have been used for over 200 years and are the most effective way of preventing the morbidity and mortality associated with infections. Like other drugs, vaccines can cause adverse events, but unlike conventional medicines, which are prescribed to people who are ill, vaccines are administered to healthy individuals, thus increasing the concern over adverse reactions. Most side effects attributed to vaccines are mild, acute and transient; however, rare reactions such as hypersensitivity, induction of infection, and autoimmunity do occur and can be severe and even fatal. The rarity and subacute presentation of post-vaccination autoimmune phenomena means that ascertaining causality between these events can be difficult. Moreover, the latency period between vaccination and autoimmunity ranges from days to years. In this article, on the basis of published evidence and our own experience, we discuss the various aspects of the causal and temporal interactions between vaccines and autoimmune phenomena, as well as the possible mechanisms by which different components of vaccines might induce autoimmunity.

a-Synuclein (aS) is an abundant neuronal cytoplasmic protein implicated in Parkinson's disease (PD), but its physiological function remains unknown. Consistent with its having structural motifs shared with class A1 apolipoproteins, aS can reversibly associate with membranes and help regulate membrane fatty acid composition. We previously observed that variations in aS expression level in dopaminergic cultured cells or brains are associated with changes in polyunsaturated fatty acid (PUFA) levels and altered membrane fluidity. We now report that aS acts with PUFAs to enhance the internalization of the membrane-binding dye, FM 1-43. Specifically, aS expression coupled with exposure to physiological levels of certain PUFAs enhanced clathrinmediated endocytosis in neuronal and non-neuronal cultured cells. Moreover, aS expression and PUFAenhanced basal and -evoked synaptic vesicle (SV) endocytosis in primary hippocampal cultures of wild type (wt) and genetically depleted aS mouse brains. We suggest that aS and PUFAs normally function in endocytic mechanisms and are specifically involved in SV recycling upon neuronal stimulation. The neuronal protein, a-synuclein (aS), has been implicated in the pathogenesis of Parkinson's disease (PD) at both the genetic and the cytopathological levels (1-7). Despite the involvement of this abundant neuronal protein in sporadic and familial forms of PD and related a-synucleinopathies, both its normal function and the mechanism by which it gradually accumulates in dopaminergic and other neurons in disease remain unclear.A portion of aS associates with membranes in vitro (8-16) and in vivo (17-22). These observations are consistent with its primary structure, which contains six imperfect apolipoprotein A1-like repeats in its N-terminal region that may mediate lipid binding (23,24). We obtained evidence that aS can associate with polyunsaturated fatty acids (PUFAs) in vitro and in neuronal cells and brain tissue (18). Importantly, we found that changes in aS expression can affect membrane and cytosolic PUFA composition and alter membrane fluidity. Specifically, we observed higher levels of certain long-chain PUFAs and higher fluidity in membranes of MES 23.5 dopaminergic cells overexpressing aS than in those of parental cells and lower levels of such PUFAs and lower fluidity in membranes of aSÀ/À than normal mouse brains (25). More recently, it was reported that aS can affect brain lipid metabolism and specifically PUFA metabolism (26-30). In agreement with our initial observation that aS expression affects membrane fatty acid (FA) composition (25), these studies in aS null mouse brains documented reduced incorporation of certain FAs into membrane phospholipids as well as decreases in FA uptake and turnover (26,27,29,30).During endocytosis, a small region of the plasma membrane invaginates to form a new intracellular vesicle containing various cargo molecules. Clathrin-mediated endocytosis (CME) is the major entry route for extracellular molecules such as nutrients, hormones and signali...