Differential regulation of Th1/Th2 in relevant tissues for sepsis pathogenesis with a Limulus anti-LPS factor-derived peptide increases survival in Gram-positive sepsis.

Severe sepsis and septic shock are important causes of death in intensive care units. Although Gram-negative infections were predominant in the 1960s, Gram-positive infections have increased in the past two decades and now account for about half of the cases of severe sepsis. In this study, we examined the effect of a Limulus anti-LPS factor (LALF)-derived peptide on lung and liver Th1/Th2 cytokine mRNA levels during a Gram-positive sepsis. We also examined the morphopathological changes observed in these organs during the disease. Mice challenged with a high dose of Staphylococcus haemolyticus showed severe damage in lung. In contrast, the liver of challenged mice showed an accumulation of bacterial particles in the sinusoids, associated with a severe inflammatory response due to high levels of tissue mRNA proinflammatory cytokines. Treatment with the peptide LALF(32-51) ameliorated the sepsis-induced effects in the lung and liver and increased the survival of mice in a dose- and time-dependent manner. Pretreatment with the peptide LALF(32-51) differentially regulates TNF-alpha, IFN-gamma, IL-12p40, IL-2 and IL-10 mRNA levels in lung and liver of peptide-treated mice, and limits the systemic inflammatory response. These findings support for the first time the effectiveness of an LALF-derived peptide in the treatment of a Gram-positive sepsis. Modulation of the Th1/Th2 pattern in tissues relevant for sepsis correlates with an improved outcome of the disease as denoted by increased survival.

The genomic organization of the open reading frame of the red pigment concentrating hormone gene in the blue crab Callinectes sapidus.

The open reading frame (ORF) of the gene for the precursor of the octapeptide Red Pigment Concentrating Hormone (RPCH) from the blue crab Callinectes sapidus was cloned by PCR with oligonucleotides targeted to the initiation and the end of the translation coding sequences. A 272 bp intron was characterized between nucleotides 343 and 344 of the reported cDNA, present in the region coding for the last amino acids of the precursor related peptide of RPCH. The intron genomic structure here described is similar to that reported for the gene coding for the Adipokinetic Hormone (AKH) of the grasshopper Schistocerca nitans.

A Limulus antilipopolysaccharide factor-derived peptide exhibits a new immunological activity with potential applicability in infectious diseases.

Previous studies have shown that cyclic peptides corresponding to residues 35 to 52 of the Limulus antilipopolysaccharide (anti-LPS) factor (LALF) bind and neutralize LPS-mediated in vitro and in vivo activities. Therapeutic approaches based on agents which bind and neutralize LPS activities are particularly attractive because these substances directly block the primary stimulus for the entire proinflammatory cytokine cascade. Here we describe new activities of the LALF(31-52) peptide, other than its LPS binding ability. Surprisingly, supernatants from human mononuclear cells stimulated with the LALF peptide are able to induce in vitro antiviral effects on the Hep-2 cell line mediated by gamma interferon (IFN-gamma) and IFN-alpha. Analysis of the effect of LALF(31-52) on tumor necrosis factor (TNF) and nitric oxide (NO) production by LPS-stimulated peritoneal macrophages revealed that a pretreatment with the peptide decreased LPS-induced TNF production but did not affect NO generation. This indicates that the LALF peptide modifies the LPS-induced response. In a model in mice with peritoneal fulminating sepsis, LALF(31-52) protected the mice when administered prophylactically, and this effect is related to reduced systemic TNF-alpha levels. This study demonstrates, for the first time, the anti-inflammatory properties of the LALF-derived peptide. These properties widen the spectrum of the therapeutic potential for this LALF-derived peptide and the molecules derived from it. These agents may be useful in the prophylaxis and therapy of viral and bacterial infectious diseases, as well as for septic shock.

A hyperglycemic peptide hormone from the Caribbean shrimp Penaeus (litopenaeus) schmitti.

From a crude extract of the sinus glands of the shrimp Penaeus (litopenaeus) schmitti a peptide with hyperglycemic activity in a homologous bioassay was isolated and characterized by a combination of automatic Edman degradation, enzymatic digestions, TLC of dansyl-amino acids, and mass spectrometry. Its M(r) is 8359.4 Da by MS, which coincides with the deduced sequence. Its N-terminus is free and its C-terminus is amidated. It has 6 Cys residues in conserved positions compared with other known CHHs. This is the first sinus gland hormone from an Atlantic Ocean shrimp characterized to date. It has a remarkable 90% sequence similarity to the Indo-Pacific shrimp P. (marsupenaeus) japonicus Pej-VII hyperglycemic hormone.

Amino acid sequence of the minor isomorph of the crustacean hyperglycemic hormone (CHH-II) of the Mexican crayfish Procambarus bouvieri (Ortmann): presence of a D-amino acid.

The primary structure of the neurohormone crustacean hyperglycemic hormone (CHH-II) was determined by means of enzymatic digestions, manual Edman degradation, and mass spectrometry. CHH-II is a 72 residue peptide (molecular mass 8388 Da), with six cysteines forming three disulfide bridges that connect residues 7-43, 23-39, and 26-52. The peptide has blocked N- and C-termini, and lacks tryptophan, histidine, and methionine. The CHH-I and CHH-II of Procambarus bouvieri have identical sequences and elicit levels of hyperglycemia that are not distinguishable. The difference between the two isomorphs consists in a posttranslational modification of a L-Phe in CHH-I to a D-Phe in CHH-II at the third position from the N-terminus.

Primary structure of the major isomorph of the crustacean hyperglycemic hormone (CHH-I) from the sinus gland of the Mexican crayfish Procambarus bouvieri (Ortmann): interspecies comparison.

The amino acid sequence of this neuropeptide was elucidated by means of a combined approach of enzymatic digestions, manual and automatic Edman degradations, and mass spectrometry. It is a 72 residue peptide (molecular mass 8388 Da), with six cysteines forming three disulfide bridges connecting residues 7-43, 23-39, and 26-52, with blocked N- and C-termini, and lacking the amino acids histidine, methionine, and tryptophan. The CHH-I of Procambarus bouvieri is compared with the other known CHHs from Orconectes limosus (98.6% identity), Homarus americanus isomorph A (83.3% identity), Homarus americanus isomorph B (79.2% identity), and Carcinus maenas (61.1% identity).