Regulation of IL-17A production is distinct from IL-17F in a primary human cell co-culture model of T cell-mediated B cell activation.

Improper regulation of B cell responses leads to excessive production of antibodies and contributes to the development of autoimmune disease. T helper 17 (Th17) cells also drive the development of autoimmune disease, but the role of B cells in shaping Th17 cell-mediated immune responses, as well as the reciprocal regulation of B cell responses by IL-17 family cytokines, remains unclear. The aim of this study was to characterize the regulation of IL-17A and IL-17F in a model of T cell-dependent B cell activation. Stimulation of primary human B cell and peripheral blood mononuclear cell (BT) co-cultures with α-IgM and a non-mitogenic concentration of superantigens for three days promoted a Th17 cell response as evidenced by increased expression of Th17-related gene transcripts, including Il17f, Il21, Il22, and Il23r, in CD4 T cells, as well as the secretion of IL-17A and IL-17F protein. We tested the ability of 144 pharmacologic modulators representing 91 different targets or pathways to regulate IL-17A and IL-17F production in these stimulated BT co-cultures. IL-17A production was found to be preferentially sensitive to inhibition of the PI3K/mTOR pathway, while prostaglandin EP receptor agonists, including PGE2, increased IL-17A concentrations. In contrast, the production of IL-17F was inhibited by PGE2, but selectively increased by TLR2 and TLR5 agonists. These results indicate that IL-17A regulation is distinct from IL-17F in stimulated BT co-cultures and that this co-culture approach can be used to identify pathway mechanisms and novel agents that selectively inhibit production of IL-17A or IL-17F.

Neurocognitive profiles in Salla disease.

Salla disease, a free sialic acid storage disorder, is one of the 36 currently known disorders in Finland that form the Finnish disease heritage. Salla disease leads to learning disability* with a wide clinical variation. Two main categories of the disease have been classified: a conventional subtype and a severe subtype with more severe defects. We present detailed neurocognitive profiles of 41 Finnish patients with Salla disease (19 females, 22 males; age range 11mo to 63y, median 19y). The neurocognitive development of patients with Salla disease was assessed by psychological and neuropsychological testing. All patients were also examined by a paediatric neurologist and a speech therapist. The characteristic cognitive profile consisted of a lower non-verbal performance (mean developmental age 13mo) compared with linguistic skills (mean developmental age 17mo). In particular, spatial and visual-constructive impairments were typical of these patients. Tactile and visual discrimination of forms was poor. Tasks demanding hand-eye coordination, maintenance of visual attention, and those requiring short-term visual memory and executive skills were performed better. Receptive language skills were notably better compared with expressive speech. The patients' interactive and non-verbal communication skills were quite strong. Another typical pattern with Salla disease was severe motor disability. After the second decade of life, the decline in these skills was more pronounced than patients' cognitive deterioration. Our results indicate that even though there is a considerable variation in the clinical findings of patients with Salla disease, the characteristic neurocognitive profile of the disease can be outlined.

Phenotypic spectrum of Salla disease, a free sialic acid storage disorder.

Salla disease (MIM 269920) represents the mildest phenotype among recessively inherited lysosomal-free sialic acid storage disorders. Although the vast majority of Salla disease patients in Finland share the same founder mutation, R39C in the SLC17A5 gene, there still is a wide clinical variation among mentally retarded, ataxic patients. We evaluated neurologic and neurocognitive findings of Salla disease in a cross-sectional study of 41 Finnish patients who were 11 months to 63 years of age (median = 19.5 years). The phenotype of Salla disease could be classified into two main categories. The majority of patients (90%) had so-called conventional phenotype, including a subgroup of seven patients with relatively mild symptoms. All but two patients with conventional phenotype were homozygous for the Finnish founder mutation. Four severely disabled, profoundly mentally retarded patients, 15-28 years of age, clearly could be clinically delineated as a separate group, likely reflecting the underlying compound heterozygous genotype. A typical developmental pattern could be outlined in the conventional type of the disease, emphasizing a strong motor handicap in Salla disease. The cognitive profile consisted of better verbal ability, especially speech comprehension, compared with nonverbal functioning in all patients. Our results indicate a partial genotype-phenotype correlation, although factors other than the molecular background are also involved in the phenotypic manifestation of Salla disease.