Cystic fibrosis: Synthesis of ciliary inhibitor by amniotic cells

The presence of a ciliary inhibitor in media of cultured amniotic cells obtained from a fetus heterozygous for cystic fibrosis has been observed by the oyster gill cilia assay. The chromatographic fraction containing the inhibitor corresponded to eluted fractions chromatographed from cystic fibrosis fibroblast media and serum. An analogous chromatographic fraction from media of cultured amniotic cells from two proportedly normal fetuses did not inhibit cilia. The chromatographic fraction from media of cultured amniotic cells of a fetus at high risk for cystic fibrosis did not inhibit ciliary activity. Serum was collected from this baby seven weeks after birth and also did not inhibit ciliary action, indicating a homozygous normal genotype. These observations may lead to the development of an antenatal test for cystic fibrosis.     

C1-esterase inhibitor blocks T lymphocyte proliferation and cytotoxic T lymphocyte generation in vitro

We have previously shown that activated C1s complement and activated T cells cleave beta2-microglobulin (beta2m) in vitro leading to the formation of desLys58 beta2m. This process can specifically be inhibited by C1-esterase inhibitor (C1-inh). Furthermore we showed that exogenously added desLys58 beta2m in nanomolar amounts to a one-way allogenic mixed lymphocyte culture (MLC) increased the endogenous production of IL-2 and the generation of allo-specific cytotoxic T lymphocytes. C1-inh was purified from fresh human plasma and added to human or murine MLC and mitogen-stimulated lymphocyte cultures grown in the presence of complement-inactivated serum. Read-outs were cell proliferation, lymphokine production and development of T cell-mediated cytotoxicity. We found that addition of C1-inh to MLC and mitogen- exposed murine and human lymphocyte cultures inhibited proliferation, the development of allospecific cytotoxic activity, and changed the endogenous production of IL-2, IL-4, IL-10, IL-12 and IFN-gamma. These data clearly demonstrate a regulatory function of C1-inh on T cell- mediated immune functions.      

Watermelon mosaic virus-Morocco is a distinct potyvirus

Summary The relationship of the Morocco isolate of watermelon mosaic virus (WMV) to WMV 2, soybean mosaic virus (a virus closely related to WMV 2) and the W strain of papaya ringspot virus (PRSV-W), formerly WMV 1, was examined by comparing tryptic peptide profiles using high performance liquid chromatography. The profiles indicated that the coat protein sequence of WMV-Morocco differed substantially from those of the other potyviruses. This conclusion was supported by sequence data from five tryptic peptides from the coat protein of WMV-Morocco, which showed only 61–68% identity to equivalent sequences in PRSV-W, WMV 2 and zucchini yellow mosaic, another potyvirus infecting cucurbits. Based on the above data, and on known correlations between coat protein sequence similarities and potyvirus relationship, it is concluded that WMV-Morocco should be regarded as a distinct potyvirus.     

Coat protein of potyviruses 7. Amino acid sequence of peanut stripe virus

Summary The amino acid sequence of the 287-residue coat protein of peanut stripe virus (PStV) was determined from the sequences of overlapping peptide fragments. Results indicated that the amino terminus was blocked by an acetyl group, as has previously been found for the coat protein of Johnsongrass mosaic potyvirus. Comparison of the PStV sequence with coat proteins of 20 distinct potyviruses gave sequence identities of 47–57%, except for zucchini yellow mosaic virus (ZYMV), passionfruit woodiness virus (PWV), and the related strains watermelon mosaic virus 2 (WMV 2) and soybean mosaic virus-N, which showed sequence identities of 70–76%. Several amino acid residues which were common to the core sequences of these coat proteins were at positions previously found to be invariant among potyvirus coat proteins. The degree of these similarities suggests that although PStV, WMV 2, ZYMV, and PWV are distinct potyviruses, they share a common ancestor in their evolutionary development.     

The nucleotide sequence of two new DP alleles, DPA1*02015 and DPB1*8401, identified in a Chinese subject

The HLA-DP genes (HLA-DPA1 and -DPB1) are encoded by the major histocompatibility complex (MHC) on human chromosome 6. They are involved in the presentation of antigen to CD4+ T cells as part of the class II antigen-presentation pathway. During a small study of Oriental subjects (11 Chinese and 26 Japanese subjects), one Chinese subject was identified as having numerous heterozygous sites within the second exon of both DPA1 and DPB1. These were further analysed using novel codon-specific primers. Sequencing analysis using these primers determined the subject to have DPA1*0103/*02015 and DPB1*0501/*8401; these new alleles have been submitted to GenBank and assigned the accession numbers AF098794 and AF077015, respectively.     

Human mini-chromosomes in mouse embryonal stem cells

We have introduced human mini-chromosomes of 4 Mb and approximately 15 Mb in size into mouse embryonal stem cells. Although these human mini- chromosomes are stable in hamster and chicken cells, they re-arrange or segregate aberrantly in the embryonal stem cells and are rapidly lost in the absence of selection. However, one of the mini-chromosomes re- arranged, acquired mouse centromeric sequences and was then stably maintained for at least 60 population doublings in culture. This mini- chromosome, which is 4 Mb in size, is a candidate for a mouse germ line chromosome vector.      

Determination of the parent of origin in nine cases of prenatally detected chromosome aberrations found after intracytoplasmic sperm injection

Prenatal cytogenetic analysis of 71 fetuses conceived by intracytoplasmic sperm injection (ICSI) resulted in the detection of nine (12.7%) chromosome aberrations including two cases of 47,XXY, four cases involving a 45,X cell line and three autosomal trisomies. Molecular analysis of the parental origin of the deleted or supernumerary chromosome was performed by using polymorphic microsatellite markers. Six cases involving a sex chromosome abnormality were found to be of paternal origin while the two trisomic cases that could be analysed were of maternal origin. Two cases involved the same infertile couple who had two consecutive ICSI pregnancies terminated because of a chromosome abnormality. The replaced embryos in both cases originated from a single batch of ICSI fertilized oocytes of which part was used to initiate the first pregnancy and part was cryopreserved and used to initiate the second pregnancy.      

Allergens in the white and yolk of hen's egg. A study of IgE binding by egg proteins

The radioallergosorbent test (RAST) was used to compare the IgE binding of egg white and yolk, and allergenic proteins were detected by immunoelectrotransfer ('Western blotting'). The main allergens were found in egg white, but for a large proportion of the egg-sensitive patients, yolk contained specific IgE-binding constituents. For blood sera from 36 patients, there was a positive correlation between the results of RAST for egg white and for yolk. Lysozyme was found to be an allergen for some patients. The effect of heating on the allergenicity of egg white was examined and the allergenicity of hen egg white was compared with that of a duck egg. The allergens in yolk were associated with each of the three yolk fractions, and several of the proteins in the low-density lipoprotein fraction bound IgE.     

LPS stimulated invertebrate hemocytes: a role for immunoreactive TNF and IL-1

Mytilus edulis hemocytes have similarities with vertebrate monocyte/macrophages. We have recently shown that they respond to human TNF and IL-1. We tested the possibility that Mytilus hemocytes produce similar substances in response to LPS. We show that Mytilus hemocytes respond to LPS in a fashion similar to vertebrate monocytes and macrophages and that these responses are inhibited by antibodies to TNF and/or IL-1. These findings are demonstrated both in vitro and in vivo.     

The effects of carnosine on oxidative DNA damage levels and in vitro lifespan in human peripheral blood derived CD4+T cell clones

Carnosine (beta-alanyl-L-histidine), an abundant naturally-occurring dipeptide has been shown to exhibit anti-ageing properties towards cultured cells, possibly due in part to its antioxidant/free radical scavenging abilities. In this paper the results of an investigation on the effects of carnosine, at the physiological concentration of 20 mM, on oxidative DNA damage levels and in vitro lifespan in peripheral blood derived human CD4+ T cell clones are reported. Under the culture conditions used (20% O(2)) long term culture with carnosine resulted in a significant increase in the lifespan of a clone derived from a healthy young subject. No such extension was observed when a T cell clone from a healthy old SENIEUR donor was similarly cultured. Culture with carnosine from the midpoint of each clone's lifespan did not have any effect on longevity, independent of donor age. Oxidative DNA damage levels were measured in the clones at various points in their lifespans. Carnosine acted as a weak antioxidant, with levels of oxidative DNA damage being lower in T cells grown long term in the presence of carnosine. The possibility that carnosine might confer anti-ageing effects to T cells under physiological oxygen tensions would appear to be worthy of further investigation.