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.     

Effects on Plant Growth Produced by Azotobacter paspali Related to Synthesis of Plant Growth Regulating Substances

S ummary . Treating seedling roots of several plant species with cultures of Azotobacter paspali changed plant growth and development and significantly increased weight of leaves and roots; effects were probably caused by plant growth regulators. Culture supernatant fluids contained indolyl-3-acetic acid, at least 3 gibberellins and 2 cytokinins. The added inoculum of A. paspali survived in plant rhizospheres for only a few weeks and no nitrogen was fixed in the root zone of young Paspalum notatum , the grass with which A. paspali is associated.     

Molecular cloning and expression of human trophoblast antigen FDO161G and its identification as 3 beta-hydroxy-5-ene steroid dehydrogenase

The monoclonal antibody FDO161G reacts with a 43-kDa protein found in human extravillous trophoblast, syncytiotrophoblast, adrenal cortex, interstitial cells of the testis and ovarian follicle cumulus cells. cDNAs for this protein have been isolated from the lambda gt11 library, sequenced, and expressed in COS-7 cells. The protein was identified as 3 beta-hydroxy-5-ene steroid dehydrogenase (HSD). The sequence of the HSD protein raises questions about its association with cell membrane systems. The lack of reactivity of FDO161G with other tissues suggests that HSD has a limited tissue distribution and that other enzymes may exist in peripheral tissues, which can convert delta 5 3-hydroxysteroids to delta 4 3-ketosteroids.