Identification of HLA-B44 subtypes associated with extended MHC haplotypes

The HLA class I antigen B44 is found in each of two different extended major histocompatibility haplotypes (allele combinations of HLA-B, HLA-DR, and complement genes BF, C2, C4A, and C4B in linkage disequilibrium). Using isoelectric focusing, two variants of HLA-B44 were identified. The basic variant was found in all cell lines with the extended haplotype HLA-B44, DR7, FC31, and the acidic variant in all cell lines with the extended haplotype HLA-B44, DR4, SC30. The occurrence of each antigen variant with a unique extended haplotype explains previous observations concerning the nonrandom association of B44 variants with DR antigens.     

Effects of pH and predation by Chaoborus larvae on the plankton of a shallow and acidic forest lake

1. Eutrophic acid lakes are not common. Delamere Lake in Cheshire, U.K. is shallow and acid (mean pH 4.5) with a very high phytoplankton crop (mean 290 μg chlorophyll a L^?1), dominated by Dictyosphaerium pulchellum. Rotifers were dominant in the pelagic waters but small cladocerans (Alona guttata, Chydorus sphaericus and Scapholeberis mucronata) were occasional in the littoral waters. Chaoborus flavicans larvae were the top predators in this fishless lake. Two mesocosm experiments were carried out in which pH and Chaoborus populations were manipulated. 2. Progressively higher concentrations of D. pulchellum were maintained in the elevated pH treatments (pH 6 and 8; P < 0.001) with increased amounts of a Chlamydomonas species at the end of the experiment. Highest species richness was seen at ambient pH. Thus the low pH of Delamere Lake alone did not control the structure of the phytoplankton community. Keratella quadrata showed significantly higher abundance at pH 6 than in other pH treatments (P < 0.001). Species richness of rotifers was unaffected by pH. 3. Most Cladocera were C. sphaericus. Although never seen in the open lake, Daphnia pulex appeared in all the pH treatments. Low pH did not control small Cladocera abundance in Delamere Lake, but probably hampered reproduction in Daphnia. Negative correlations between chlorophyll a concentrations and Daphnia in the mesocosms (r² = 0.215, P < 0.05), however, indicated the potential of large‐bodied daphniids in controlling phytoplankton. 4. Neither different combinations of Chaoborus instars (none, instars 1 and 2 and instars 3–5) nor different densities of instars 3–5 (0.15, 0.5 and 1.0 L^?1) had a negative impact on Cladocera. Daphnia pulex remained unaffected in the experiment, perhaps because of its large size, and C. sphaericus because of its high reproductive rate compensating predatory losses. 5. Very low pH in Delamere Lake might suppress Daphnia by hampering its reproduction. Consequently, Daphnia may be vulnerable to invertebrate predation even at low predator density in the lake.     

Mouse/human chimeric anti-HIV-1 gp120 antibody to the principal neutralizing determinant: Tolerability and pharmacokinetics in cynomolgus monkeys,Macaca fascicularis

In preparing for testing a pharmaceutical grade preparation of chimeric (mouse/human) antibody CGP 47 439 in HIV-1 infected individuals, it was administered toMacaca fascicularis (cynomolgus) monkeys to study tolerability, immunogenicity and pharmacokinetics. Four groups of monkeys, three males and three females per group, received respectively four infusions of 0, 1.43, 4.3, and 14.3 mg of CGP 47 4391 kg body weight at one-week intervals. The chimeric antibody induced no fever, was tolerated well throughout the 50-day observation period, elicited no tissue damage and no anti-antibody response. The pharmacokinetic profile was similar at all dose levels with a mean T_1/2 of 14.2 h (range 11.8–19.3 h) and a mean T_1/2 of 172.6h (range 137.2–220.5h). Following four successive antibody infusions serum concentrations of CGP 47 439 increased without reaching a steady state, and its measured concentrations were comparable to the simulated values. Collectively the study has provided safety and pharmacokinetic data that would allow human studies with this antibody in AIDS patients.     

Targeting to the HIV-1 RRE of the influenza virus NS1 protein effector domain as a potent, specific anti-HIV agent

The Rev axis of HIV autoregulation is one of two critical viral regulatory pathways required for expression of viral genomic and mRNA and for replication. Consequently it is an attractive therapeutic target. Previous studies have investigated the anti-HIV efficacy of targeting to the RRE (the viral RNA target sequence of the Rev axis) a trans-dominant negative inhibitor mutant Rev, M10. In this study we have fused a portion of the influenza virus NS1 protein (which normally inhibits polyA(+) mRNA transport and splicing) to the Rev M10 gene while deleting the NS1 poly(A) binding region. The resulting chimera demonstrates specific and enhanced inhibition of viral-RRE-containing RNA expression.     

Coexistence of multiple peptides in small intensely fluorescent (SIF) cells of inferior mesenteric ganglion of the guinea pig

Summary Coexistence of peptides in the small intensely fluorescent cells was demonstrated by immunocytochemistry for met-enkephalin-Arg-Gly-Leu, vasoactive intestinal polypeptide, somatostatin, neuropeptide Y and dynorphin. In the extreme example, a single cell was immunoreactive to all 5 peptides examined. Four peptides coexisted in 8% and three peptides in 13% of SIF cells. In 10% of SIF cells no peptide immunoreactivity could be detected. The most prevalent peptide was met-enkephalin (in 46% of cells), then vasoactive intestinal polypeptide (45%), somatostatin (39%), neuropeptide Y (31%) and dynorphin (24%). Met-enkephalin and vasoactive intestinal polypeptide coexisted most commonly (25%).     

CNIH4 Interacts with Newly Synthesized GPCR and Controls Their Export from the Endoplasmic Reticulum

The molecular mechanisms regulating G protein‐coupled receptors (GPCRs) trafficking from their site of synthesis in the endoplasmic reticulum (ER) to their site of function (the cell surface) remain poorly characterized. Using a bioluminescence resonance energy transfer‐based proteomic screen, we identified a novel GPCR‐interacting protein; the human cornichon homologue 4 (CNIH4). This previously uncharacterized protein is localized in the early secretory pathway where it interacts with members of the 3 family of GPCRs. Both overexpression and knockdown expression of CNIH4 caused the intracellular retention of GPCRs, indicating that this ER‐resident protein plays an important role in GPCR export. Overexpression of CNIH4 at low levels rescued the maturation and cell surface expression of an intracellularly retained mutant form of the β2‐adrenergic receptor, further demonstrating a positive role of CNIH4 in GPCR trafficking. Taken with the co‐immunoprecipitation of CNIH4 with Sec23 and Sec24, components of the COPII coat complex responsible for ER export, these data suggest that CNIH4 acts as a cargo‐sorting receptor, recruiting GPCRs into COPII vesicles .      

Reduction of myocardial infarct size by doxycycline: A role for plasmin inhibition

Myocardial ischemia-reperfusion (I/R) is associated with the activation of matrix metalloproteinases (MMPs) and serine proteases. We hypothesized that activation of MMPs and the serine protease plasmin contribute to early cardiac myocyte death following I/R and that broad-spectrum protease inhibition with doxycycline (DOX) preserves myocyte viability. Rats treated daily with or without DOX beginning 48 h prior to experimentation were subjected to 30 min of coronary occlusion and 2 days of reperfusion. DOX pre-treatment reduced infarct size by 37%. DOX attenuated increases in MMP-9 and plasmin levels as determined by gelatin zymography and immunoblot, respectively. Neutrophil extravasation was unaltered by DOX as assessed by myeloperoxidase (MPO) activity. To examine the contribution of MMP-9 and plasmin to myocyte injury, cultures of neonatal rat ventricular myocytes (NRVMs) were treated for 48 h with 83 kDa MMP-9 or plasminogen in the presence or absence of DOX. MMP-9 treatment did not affect myocyte viability. Plasminogen treatment led to increased plasmin activity, resulting in loss of ₁-integrin, NRVM detachment and apoptosis. DOX co-treatment inhibited plasmin activity and preserved NRVM attachment, whereas co-treatment with the broad-spectrum MMP inhibitor GM6001 had no effect. These results indicate that plasmin causes disruption of myocyte attachment and viability independently of MMP activation in vitro and that inhibition of plasmin by DOX may reduce I/R-induced myocyte death in vivo through the inhibition of plasmin. (Mol Cell Biochem 270: 1–11, 2005)