Immunological relationships during primary infection with Heligmosomoides polygyrus (Nematospiroides dubius): parasite specific IgG1 antibody responses and primary response phenotype.

IgG1 antibody responses to Heligmosomoides polygyrus were measured in eight mouse strains supporting acute (< 8 weeks, SJL, SWR), intermediate (10-20 weeks, NIH, BALB/c) or chronic (> 25 weeks, C57BL/0, CBA, C3H, AKR) primary infections. Mice supporting acute or intermediate infections produced more intense antibody responses and total serum IgG1 concentrations were higher than in mice tolerating chronic infections. Positive correlations across mouse strains between the intensity of the antibody response and the percentage loss of worms in weeks 6 and 10 were established. No correlation was found between the response within mouse strains and loss of worms by individual mice. Heavy infections gave marginally higher antibody titres than low intensity infections, but few significant differences were detected and it was concluded that infection intensity did not markedly influence the magnitude of the antibody response. Male and female mice responded similarly despite the earlier loss of worms from females. No association was found between the primary response phenotype and recognition of particular antigens in Western blot analysis, nor did intensity of infection or host gender affect recognition. The possibility that immunomodulatory properties of adult worms may have had a differential influence on ability of strains of contrasting response phenotype to mount IgG1 responses was discussed.