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W Dunnick

Publications and source records attributed to W Dunnick.

27 records · Page 2Linked to original sources
PubMed1980

A mouse immunoglobulin heavy chain deletion mutant: isolation of a cDNA clone and sequence analysis of the mRNA.

The mouse cell line IF2 secretes an immunoglobulin heavy chain lacking the CH1 domain. We have isolated and characterised a recombinant plasmid containing cDNA copies of the IF2 mutant mRNA. The cloned sequence extends from the nucleotides coding for amino acid 96 in the variable region through 100 nucleotides of untranslated region at the 3' end. The sequence of the cDNA insert reveals no discontinuity at the variable-hinge region junction, the site of the CH1 deletion. Experiments employing direct priming on the poly(A) tail of the IF2 heavy chain mRNA suggest that the 3' end of the cDNA clone (sequence C-C-C-T-G-C) is also the 3' end of the mRNA.

Animals↗
PubMed1980

The role of gene deletion in the immunoglobulin heavy chain switch.

We have examined the arrangement of the genes for the mouse heavy chain subclasses gamma 2b, gamma 2a and gamma 1 by the Southern hybridisation procedure. Evidence has been found for rearrangement involving the gamma 2b and gamma 2a CH genes in the DNA of cells making IgG2b and IgG2a respectively. The DNA of an IgG2b-secreting line lacks detectable C gamma 1 gene, whilst the DNA of an IgG2a-secreting line lacks detectable C gamma 1 and C gamma 2b genes. The DNA of a cell line secreting IgA lacks detectable C gamma genes. These observations implicate deletion in the mechanism of the H-chain switch and allow a preliminary ordering of some of the CH genes in the mouse genome.

Animals↗
PubMed1979

Human transfer factors: structural properties suggested by HPRP chromatography and enzymatic sensitivities.

Leukocyte extracts containing human transfer factor (TF) were fractionated by exclusion chromatography, and the active fraction (Sephadex G25, Fraction IIIa) was subjected to high pressure, reverse phase (HPRP) chromatography and enzymatic degradation. TF activity was assessed by the systemic transfer of dermal skin test reactivity from KLH-immunized donors to naive recipients. Preparative HPRP chromatography resolved Fraction IIIa into multiple chromophoric regions, two of which demonstrated transfer of KLH reactivity. Alkaline phosphatase treatment of Fraction IIIa converted the major ultraviolet-absorbing component, 5'-inosine monophosphate, to inosine and resulted in TF activity being restricted to one region. This HPRP region (R1A) contained less than 1% of the UV254 active material in Fraction IIIa but greater than 90% of the reactivity. The sensitivity of TF to pronase, proteinase K, phosphodiesterase I, and phosphodiesterase II was evaluated by inhibition of systemic transfer of KLH reactivity. Pronase and proteinase K destroyed systemic transfer activity and the pronase destruction could be inhibited with traysylol. Phosphodiesterase I, a 3' exonuclease, destroyed activity, whereas phosphodiesterase II, a 5' exonuclease, did not. The data are consistent with a phosphodiester-containing polypeptide in the structure of human TF for KLH reactivity.

Alkaline Phosphatase↗
PubMed1975

Guinea pig transfer factor-like activity detected in vitro.

"Transfer factor" was prepared by Sephadex G-25 chromatography of lymph node cell lysates from guinea pigs immunized with ovalbumin or bovine gamma globulin. Treatment of nonimmune peritoneal exudate cells with the transfer factor and specific antigen leads to inhibition of migration of the cells, whereas cells treated with the transfer factor alone or specific antigen alone are not inhibited from migrating. An average of 24-28% inhibition is observed in the presence of transfer factor and specific antigen, but only 5-15% inhibition in the presence of transfer factor and nonspecific antigen. The guinea pig transfer factor we have tested in vitro has some physical characteristics in common with human transfer factor.

Animals↗