CTLA4 Autoimmunity-Associated Genotype Contributes to Severe Pulmonary Tuberculosis in an African Population

The gene of Cytotoxic T Lymphocyte-associated Antigen 4 (CTLA4), a negative regulator of T lymphocytes, contains a single-nucleotide polymorphism (SNP) at position +6230A->G (ct60A->G), which has been found associated with several autoimmune diseases and appears to reduce T-cell inhibitory activity. In Ghana, West Africa, we compared the frequencies of CTLA4 +6230 A/G and 6 haplotype-tagging SNPs in 2010 smear-positive, HIV-negative patients with pulmonary tuberculosis (TB) and 2346 controls matched for age, gender and ethnicity. We found no difference in allele frequencies between cases and controls. However, +6230A and a distinct CTLA4 haplotype and a diplotype comprising the +6230A allele were significantly less frequent among cases with large opacities in chest radiographs compared to those with small ones (P_{corrected [cor]} = 0.002, P_cor = 0.00045, P = 0.0005, respectively). This finding suggests that an increased T-cell activity associated with the CTLA4 +6230G allele contributes to pathology rather than to protection in pulmonary TB.     

Genome-wide CRISPR Screens Reveal Host Factors Critical for SARS-CoV-2 Infection

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Three unique base pair changes in a family with Gaucher disease

Summary Single-stranded cDNA was prepared from RNA obtained from a patient with type 1 Gaucher disease. The cDNA was amplified in vitro and analyzed by sequencing. Three base-pair changes were identified which included a G to C transversion at nucleotide 3119 of the active gene (Asp¹⁴⁰His), an A to C transversion at nucleotide 3170 (Lys¹⁵⁷Gln) and a G to A change at nucleotide 5309 (Glu³²⁶Lys). To study the mode of inheritance of the three different base-pair changes, genomic DNA was prepared from blood or skin fibroblasts of several family members. Genomic glucocerebrosidase DNA sequences were amplified and subjected to hybridization with allele-specific oligonucleotides (ASOs). The hybridization profiles demonstrated that two of the basepair changes originated from the mother and were transmitted to her two affected sons and to a grandchild, while the third base-pair change, originating from the father, was transmitted to his two affected sons, a carrier daughter and a second grandchild. Tests of other patients with Gaucher disease failed to disclose the presence of the three base-changes. This is a unique family with three base-pair changes tightly linked to Gaucher disease.     

Segments of chromosomal DNA from Rhynchosciara americana that undergo additional rounds of DNA replication in the salivary gland DNA puffs have only weak ARS activity in yeast

We have constructed a library of recombinant phage containing DNA from salivary gland chromosomes of Rhynchosciara americana. We have isolated phage from this library that carry sequences homologous to cDNA clones that hybridize in situ to the DNA puffs at the polytene chromosome regions C3 and C8. This has enabled us to demonstrate a 16-fold amplification of the genomic DNA sequences at these regions during DNA-puffing. At the C8 site there is a sequence element that has characteristics of 'scrambled' moderately repetitive DNA. This is located within 3 kb from the gene encoding a 1.95-kb mRNA. We have assayed restriction fragments from the two DNA puffs for Ars activity in yeast. The only strong Ars activity is associated with a part of the moderately repetitive DNA element from the C8 puff which is not present at this site in all animals.     

alpha-N-acetyl-beta-endorphin1-26 from the neurointermediary lobe of the rat pituitary: isolation, purification, and characterization by high-performance liquid chromatography

The neurointermediary lobes from 190 rat pituitaries were homogenized in an acidic medium which inhibits peptidase activity and maximizes the solubilization of undamaged peptides. Octadecylsilyl-silica (ODS-silica) was used to extract the supernatant of the tissue homogenate. The ODS-silica eluate, now largely protein and salt free, was subjected to reversed-phase high-performance liquid chromatography (HPLC) employing 0.1% trifluoroacetic as counter ion. The column eluates were monitored for beta-endorphin immunoreactivity. Five immunoreactive components were observed. The most hydrophobic of these was repurified on the same HPLC column using 0.13% heptafluorobutyric acid as counter ion. Characterization of the purified peptide by gel permeation HPLC, amino acid analysis, and tryptic fragmentation indicated that it corresponded in structure to alpha-N-acetyl-beta-endorphin1-26. Amino acid analysis of the native peptide and its trypsin and carboxypeptidase fragments indicated that an alanyl residue occupies position 26. This finding is in contrast to the sequence predicted for the beta-lipotropin/corticotropin precursor by recombinant DNA techniques which suggests that the 26th residue of the beta-endorphin molecule should be valine.