IgE antibodies are conspicuous in the response to helminths [15] and other parasites [16, 17], but we are unaware of any study that has examined IgE cDNA transcripts from parasitized individuals. In the light of the accumulating evidence of the unique mutational features of the IgE response in some conditions, we undertook immunogenetic studies of IgE selleck antibodies in a community from the highlands of Papua New Guinea (PNG), where helminth infections are endemic, malaria is increasingly common, but allergic disease is almost unknown [18]. Here, we describe an analysis of sequences derived from 14

rural PNG villagers. To provide suitable data sets for comparison, we also amplified IgG sequences from both PNG and Australian individuals, and because of the possibility that different IgG subclasses could display varying patterns of mutation, selleck chemicals we generated IgG sequences using subclass-specific PCR primers. The

average number of mutations in the IgE sequences of Papua New Guineans was very high and was broadly similar to the number of mutations seen in IgG sequences from the same individuals. Although the extent of IgE mutations was significantly higher than has been reported from studies of allergic individuals, the mean level of IgG mutations reported here is little different to previous reports of IgG sequences from the developed world. The distribution of replacement and silent mutations between framework regions (FRs) and CDRs suggest the involvement of antigen selection in the development of responses of each

IgG subclass, but there was little evidence of selection in the IgE response. Sample processing.  After informed consent, and with the PAK6 approval of both the UNSW Human Research Ethics Committee and the Papua New Guinea Medical Advisory Council, peripheral blood was collected from 14 life-long residents of Masilakaiufa village, Eastern Highlands Province. The donors had no clinical symptoms or history of allergic disease and were aged between 22 and 53 years. Peripheral blood was also collected from 14 residents of Sydney, Australia. Serum was prepared from peripheral blood samples and frozen at −70 °C for later testing. Mononuclear cells were also prepared by density gradient centrifugation and frozen at −70 °C. Serum Ig determination.  Total IgE concentrations were determined for each PNG serum sample by enzyme immunoassay on a UniCAP® 100 system (Pharmacia, Uppsala, Sweden). On initial testing, one IgE sample was out of range (>5000 kU/l). It was re-measured after 1:5 dilution in an Australian serum sample known to have very low IgE (<5 kU/l). Total IgG and IgG subclasses were determined using a BN ProSpec® (Dade Behring, Sydney, Australia) nephelometer. Reference ranges were based on data from healthy adult residents of Sydney, Australia. Sequence amplification.