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Background: In this phase 1 clinical trial, healthy adult, malaria-naïve subjects were immunized with radiation-attenuated Plasmodium falciparum sporozoites (PfRAS) by mosquito bite and then underwent controlled human malaria infection (CHMI). The PfRAS model for immunization against malaria had previously induced >90 % sterile protection against homologous CHMI. This study was to further explore the safety, tolerability and protective efficacy of the PfRAS model and to provide biological specimens to characterize protective immune responses and identify protective antigens in support of malaria vaccine development., Methods: Fifty-seven subjects were screened, 41 enrolled and 30 received at least one immunization. The true-immunized subjects received PfRAS via mosquito bite and the mock-immunized subjects received mosquito bites from irradiated uninfected mosquitoes. Sera and peripheral blood mononuclear cells (PBMCs) were collected before and after PfRAS immunizations., Results: Immunization with PfRAS was generally safe and well tolerated, and repeated immunization via mosquito bite did not appear to increase the risk or severity of AEs. Local adverse events (AEs) of true-immunized and mock-immunized groups consisted of erythaema, papules, swelling, and induration and were consistent with reactions from mosquito bites seen in nature. Two subjects, one true- and one mock-immunized, developed large local reactions that completely resolved, were likely a result of mosquito salivary antigens, and were withdrawn from further participation as a safety precaution. Systemic AEs were generally rare and mild, consisting of headache, myalgia, nausea, and low-grade fevers. Two true-immunized subjects experienced fever, malaise, myalgia, nausea, and rigours approximately 16 h after immunization. These symptoms likely resulted from pre-formed antibodies interacting with mosquito salivary antigens. Ten subjects immunized with PfRAS underwent CHMI and five subjects (50 %) were sterilely protected and there was a significant delay to parasitaemia in the other five subjects. All ten subjects developed humoral immune responses to whole sporozoites and to the circumsporozoite protein prior to CHMI, although the differences between protected and non-protected subjects were not statistically significant for this small sample size., Conclusions: The protective efficacy of this clinical trial (50 %) was notably less than previously reported (>90 %). This may be related to differences in host genetics or the inherent variability in mosquito biting behavior and numbers of sporozoites injected. Differences in trial procedures, such as the use of leukapheresis prior to CHMI and of a longer interval between the final immunization and CHMI in these subjects compared to earlier trials, may also have reduced protective efficacy. This trial has been retrospectively registered at ISRCTN ID 17372582, May 31, 2016.

The autoimmune exocrinopathy, Sjögren's syndrome (SS), is associated with secretory defects in patients, including individuals with mild lymphocytic infiltration and minimal glandular damage. The mechanism(s) underlying the secretory dysfunction is not known. We have used minor salivary gland biopsies from SS patients and healthy individuals to assess acinar cell function in morphologically intact glandular areas. We report that agonist-regulated intracellular Ca(2+) release, critically required for Ca(2+) entry and fluid secretion, is defective in acini from SS patients. Importantly, these acini displayed reduction in IP3R2 and IP3R3, but not AQP5 or STIM1. Similar decreases in IP3R and carbachol (CCh)-stimulated [Ca(2+)]i elevation were detected in acinar cells from lymphotoxin-alpha (LTα) transgenic (TG) mice, a model for (SS). Treatment of salivary glands from healthy individuals with LT α, a cytokine linked to disease progression in SS and IL14α mice, reduced Ca(2+) signaling. Together, our findings reveal novel IP3R deficits in acinar cells that underlie secretory dysfunction in SS patients.

Objective: The autonomic nervous system (ANS) modulates exocrine gland function. Available data show poor correlation between the degree of function and destruction of the exocrine glands in primary Sjögren's syndrome (SS), suggesting that other mechanisms, such as autonomic dysfunction, may be important in these patients. The aim of this study was to perform a comprehensive analysis of sympathoneural and sympathetic cholinergic function in well-characterized patients with primary SS., Methods: Twenty-one patients with primary SS (mean ± SEM age 44.2 ± 2.8 years) and 13 healthy control subjects (mean ± SEM age 50.8 ± 1.9 years) were assessed during orthostasis and intravenous injection of edrophonium (10 mg). The postganglionic sympathetic cholinergic system was evaluated by assessing sweat production by means of the Quantitative Sudomotor Axon Reflex Test (QSART). Tests of gastric emptying were used to assess the gastrointestinal ANS in primary SS patients., Results: The velocity index and the acceleration index were significantly higher (P < 0.05) in patients with primary SS as compared to controls, both before and during the orthostatic and edrophonium tests. Findings of other hemodynamic and neurochemical parameters did not differ between primary SS patients and controls during the orthostasis and edrophonium test; however, the edrophonium-induced saliva increment was lower in primary SS patients (P = 0.002). Abnormally low sweat production was found in 4 primary SS patients but in none of the controls, as determined by the QSART. Gastric empting was delayed in 53% of primary SS patients., Conclusion: We observed subtle differences in several ANS domains, including the gastrointestinal and sympathocholinergic systems, suggesting the presence of a complex ANS dysfunction in primary SS. The impact was greatest on the exocrine glands, with subtle differences in the cardiac parasympathetic function that were independent of glandular inflammation and atrophy, suggesting an alternative mechanism of disease pathogenesis in primary SS., (© 2015, American College of Rheumatology.)

When introduced in the 1990s, immunization with DNA plasmids was considered potentially revolutionary for vaccine development, particularly for vaccines intended to induce protective CD8 T cell responses against multiple antigens. We conducted, in 1997-1998, the first clinical trial in healthy humans of a DNA vaccine, a single plasmid encoding Plasmodium falciparum circumsporozoite protein (PfCSP), as an initial step toward developing a multi-antigen malaria vaccine targeting the liver stages of the parasite. As the next step, we conducted in 2000-2001 a clinical trial of a five-plasmid mixture called MuStDO5 encoding pre-erythrocytic antigens PfCSP, PfSSP2/TRAP, PfEXP1, PfLSA1 and PfLSA3. Thirty-two, malaria-naïve, adult volunteers were enrolled sequentially into four cohorts receiving a mixture of 500 μg of each plasmid plus escalating doses (0, 20, 100 or 500 μg) of a sixth plasmid encoding human granulocyte macrophage-colony stimulating factor (hGM-CSF). Three doses of each formulation were administered intramuscularly by needle-less jet injection at 0, 4 and 8 weeks, and each cohort had controlled human malaria infection administered by five mosquito bites 18 d later. The vaccine was safe and well-tolerated, inducing moderate antigen-specific, MHC-restricted T cell interferon-γ responses but no antibodies. Although no volunteers were protected, T cell responses were boosted post malaria challenge. This trial demonstrated the MuStDO5 DNA and hGM-CSF plasmids to be safe and modestly immunogenic for T cell responses. It also laid the foundation for priming with DNA plasmids and boosting with recombinant viruses, an approach known for nearly 15 y to enhance the immunogenicity and protective efficacy of DNA vaccines.

Several studies showed signs of autonomic dysfunction in patients with primary Sjögren's syndrome (pSS). Adrenomedullary function might be of importance for pSS pathogenesis by affecting salivary gland functions and modulating immune responses. The aim of the study was to evaluate the adrenomedullary hormonal system in patients with pSS. The glucagon test (1 mg i.v.) was performed in 18 pSS patients and 13 control subjects. During the test each patient had electrocardiographic and impedance cardiographic monitoring. Plasma epinephrine and norepinephrine were assayed by liquid chromatography with electrochemical detection after batch alumina extraction. Baseline concentrations of epinephrine and norepinephrine were comparable between pSS and controls. Glucagon administration induced a significant increase in systolic blood pressure, diastolic blood pressure, heart rate, cardiac output (P < 0.01), and stroke volume; however, the changes were comparable between pSS and controls. Epinephrine levels increased (P < 0.01) in response to glucagon administration while norepinephrine concentration did not change. There was no significant difference in neurochemical responses to glucagon between pSS and controls. In conclusion, the present results suggest normal adrenomedullary function in pSS.

Although adoptive transfer of regulatory T cells (Foxp3(+) Tregs) has proven to be efficacious in the prevention and treatment of autoimmune diseases and graft-versus-host disease in rodents, a major obstacle for the use of Treg immunotherapy in humans is the difficulty of obtaining a highly purified preparation after ex vivo expansion. We have identified latency-associated peptide (LAP) and IL-1 receptor type I and II (CD121a/CD121b) as unique cell-surface markers that distinguish activated Tregs from activated FOXP3(-) and FOXP3(+) non-Tregs. We show that it is feasible to sort expanded FOXP3(+) Tregs from non-Tregs with the use of techniques for magnetic bead cell separation based on expression of these 3 markers. After separation, the final product contains greater than 90% fully functional FOXP3(+) Tregs. This novel protocol should facilitate the purification of Tregs for both cell-based therapies as well as detailed studies of human Treg function in health and disease.

The recent explosion in genomic sequencing has made available a wealth of data that can now be analyzed to identify protein antigens, potential targets for vaccine development. Here we present, in the context of Plasmodium falciparum, a strategy that rapidly identifies target antigens from large and complex genomes. Sixteen antigenic proteins recognized by volunteers immunized with radiation-attenuated P. falciparum sporozoites, but not by mock immunized controls, were identified. Several of these were more antigenic than previously identified and well characterized P. falciparum-derived protein antigens. The data suggest that immune responses to Plasmodium are dispersed on a relatively large number of parasite antigens. These studies have implications for our understanding of immunodominance and breadth of responses to complex pathogens.