Charles S., "Interleukin-1 polymorphisms associated with increased risk of gastric cancer" (2000). To evaluate dopaminergic cells of the dorsomedial cluster by tyrosine hydroxylase immunostaining, serial 4-mm sections were cut to include the entire brain. Immunopositive cells at the level of the giant interneuron commissure, posterior to the fan-shaped body, were counted in well oriented frontal sections at 1, 10, 30 and 60 days. At 1 day all control and experimental sections contained four or ®ve cells in the delineated region. At 30 and 60 days all controls showed four or ®ve cells. At 30 and 60 days all a-synucleinexpressing animals (a-synuclein, elav±GAL4 and a-synuclein, Ddc±GAL4 transheterozygotes) showed 0 or 1 tyrosine-hydroxylase-positive cell in the de®ned region. Tyrosinehydroxylase-positive cells outside the dorsomedial cluster were present, and served as internal controls for the immunostaining procedure. At least four, and usually between six and ten brains were examined for wild-type a-synuclein and each mutant a-synuclein. Controls included young and aged¯ies of the genotypes elav±GAL4/+ and Ddc±GAL4/+. We evaluated expression of a-synuclein and b-galactosidase on similar serial section preparations. Quanti®cation was simpli®ed in these experiments because no clear cellbody-associated a-synuclein or b-galactosidase immunoreactivity was observed in the aged a-synuclein transgenic¯ies at the times reported.For histological examination of retinas, heads were ®xed in glutaraldehyde and embedded in epon. Tangential retinal sections were prepared at a thickness of 1 mm and stained with toluidine blue (Fig 4).Standard electron microscopy was performed on brains from 25-day-old experimental (UAS±A30P a-synuclein/elav±GAL4) and control (elav±GAL4/+)¯ies. For immunoelectron microscopy, pre-embedding immunohistochemistry with an Hrp-congugated secondary antibody was performed on 60-day adult brains from experimental (UAS± A30P a-synuclein/elav±GAL4) and control (elav±GAL4/+)¯ies ®xed in 4% paraformaldehyde with 0.5% glutaraldehyde. Tissue was post-®xed in osmium and embedded in epon. Unstained ultrathin sections and ultrathin sections stained with uranyl acetate and lead citrate were examined. Climbing assayThe climbing assay was performed as described 19,20 . Forty¯ies were placed in a plastic vial, and gently tapped to the bottom of the vial. The number of¯ies at the top of the vial was counted after 18 s of climbing. Twenty trials were performed for each time point. The data shown represent results from a cohort of¯ies tested serially over 55 days. The experiment was repeated three times, with independently derived transgenic lines. Similar results were obtained from each experiment. The experiment was carried out under red light (Kodak Safelight Filter 1A). Control¯ies were of the genotype elav±GAL4/+. Experimental animals were of the following genotypes: (1) elav±GAL4/+; UAS±wild-type a-synuclein/+; (2) UAS±A30P a-synuclein/elav±GAL4; and (3) UAS±A53T a-synuclein/elav±GAL4.

Produced in response to a variety of pathogenic organisms, interleukin (IL)-12 and IL-23 are key immunoregulatory cytokines that coordinate innate and adaptive immune responses. These dimeric cytokines share a subunit, designated p40, and bind to a common receptor chain, IL-12R beta 1. The receptor for IL-12 is composed of IL-12R beta 1 and IL-12R beta 2, whereas IL-23 binds to a receptor composed of IL-12R beta 1 and IL-23R. Both cytokines activate the Janus kinases Tyk2 and Jak2, the transcription factor signal transducer and activator of transcription 4 (STAT4), as well as other STATs. A major action of IL-12 is to promote the differentiation of naive CD4+ T cells into T-helper (Th) 1 cells, which produce interferon (IFN)-gamma, and deficiency of IL-12, IL-12R subunits or STAT4 is similar in many respects. In contrast, IL-23 promotes end-stage inflammation. Targeting IL-12, IL-23, and their downstream signaling elements would therefore be logical strategies for the treatment of immune-mediated diseases.

Cytokines that use the common gamma chain ␥c are critical for lymphoid development and function. Mutations of the IL-7 receptor, ␥c, or its associated kinase, Jak3, are the major cause of human severe combined immunodeficiency. Although activated by IL-7, Stat5a͞b (Stat, signal transducer and activator of transcription) have been thought to play limited roles in lymphoid development. However, we now show that mice completely deficient in Stat5a͞b have severely impaired lymphoid development and differentiation. Absence of Stat5 also abrogates T cell receptor ␥ rearrangement and survival of peripheral CD8 ؉ T cells. Thus, deficiency of Stat5 results in severe combined immunodeficiency, similar in many respects to deficiency of IL-7R, ␥c, and Jak3.cytokine ͉ jak ͉ lymphocyte ͉ severe combined immunodeficiency ͉ interleukin T he development and homeostasis of lymphoid cells are tightly regulated by cytokines such as interleukin (IL)-7 (1). Its receptor comprises a ligand-specific subunit (IL-7R) associated with a shared receptor subunit designated the cytokine common gamma chain (␥c), which binds the Janus kinase 3 (Jak3). Importantly, mutations of IL-7R, ␥c, or Jak3 underlie the majority of cases of human severe combined immunodeficiency and mouse models in which these genes are deleted also have severe combined immunodeficiency phenotypes (2-8).Activated Jaks phosphorylate cytokine receptors, providing docking sites that recruit Signal transducers and activators of transcription (Stats), which are also phosphorylated. Stats then dimerize, bind DNA, and regulate gene transcription (9, 10). The predominant Stat activated by IL-7 and other ␥c cytokines is Stat5 (11-13). Encoded by two separate genes, the two isoforms of this transcription factor, Stat5a and Stat5b, have distinct physiological functions (14). Deficiency of Stat5a results in impaired prolactindependent mammary cell differentiation (15), whereas deficiency of Stat5b results in impaired growth (16).With respect to T and B cell development, deficiency of Stat5a or Stat5b individually does not have severe consequences (13,(17)(18)(19). Furthermore, analysis of mice in which both genes were targeted also led to the conclusion that Stat5 was not essential for T or B cell development (20,21). Peripheral B cells and bone marrow precursors were reduced but not eliminated and it was suggested that Stat5 is differentially required for T and B cell development (22-26). More recently, a 5-to 10-fold reduction in thymocytes was demonstrated in this model during fetal development, but after birth, the number of thymocytes normalized (21,27,28).Thus, the differences in phenotypes between Stat5a͞b knockout mice and mice lacking IL-7R, Jak3, or ␥c were striking, suggesting that ␥c cytokines like IL-7 must employ Stat5-independent mechanisms to direct lymphocyte development. However, the gene targeting strategy used in the original Stat5 knockout mice encodes a N-terminally truncated and partially functional Stat5 protein (Stat5 ⌬N ) (ref. 29; see also Fig. 7, which is p...