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.

The chemokine receptor 5 (CKR5) protein serves as a secondary receptor on CD4(+) T lymphocytes for certain strains of human immunodeficiency virus-type 1 (HIV-1). The CKR5 structural gene was mapped to human chromosome 3p21, and a 32-base pair deletion allele (CKR5Delta32) was identified that is present at a frequency of approximately0.10 in the Caucasian population of the United States. An examination of 1955 patients included among six well-characterized acquired immunodeficiency syndrome (AIDS) cohort studies revealed that 17 deletion homozygotes occurred exclusively among 612 exposed HIV-1 antibody-negative individuals (2.8 percent) and not at all in 1343 HIV-1-infected individuals. The frequency of CKR5 deletion heterozygotes was significantly elevated in groups of individuals that had survived HIV-1 infection for more than 10 years, and, in some risk groups, twice as frequent as their occurrence in rapid progressors to AIDS. Survival analysis clearly shows that disease progression is slower in CKR5 deletion heterozygotes than in individuals homozygous for the normal CKR5 gene. The CKR5Delta32 deletion may act as a recessive restriction gene against HIV-1 infection and may exert a dominant phenotype of delaying progression to AIDS among infected individuals.

Natural killer (NK) cells provide a central defense against viral infection by using inhibitory and activation receptors for major histocompatibility complex class I molecules as a means of controlling their activity. We show that genes encoding the inhibitory NK cell receptor KIR2DL3 and its human leukocyte antigen C group 1 (HLA-C1) ligand directly influence resolution of hepatitis C virus (HCV) infection. This effect was observed in Caucasians and African Americans with expected low infectious doses of HCV but not in those with high-dose exposure, in whom the innate immune response is likely overwhelmed. The data strongly suggest that inhibitory NK cell interactions are important in determining antiviral immunity and that diminished inhibitory responses confer protection against HCV.