Immunogenetic and ontogenetic studies of chickens with selective IgA deficiency and autoimmune thyroiditis

Increase in immunoglobulin G3-secreting cells in intractable Graves' disease

Isotype switching of immunoglobulin (Ig)-secreting cells is regulated by a set of cytokines. In the present study, we studied the relation between the number of peripheral blood mononuclear cells spontaneously secreting IgG, IgM, IgA, and their subclasses and the disease severities in autoimmune thyroid diseases. Ig-secreting cells were measured by enzyme-linked immunospot (ELISPOT) assay in 99 euthyroid patients with Graves' disease (GD) or Hashimoto's disease (HD) and 13 normal subjects. The number of IgG3-secreting cells was significantly higher in patients with intractable GD who had been undergoing treatment with antithyroid drugs for more than 5 years but who did not go into remission than in patients with GD in remission. This number correlated significantly with the serum level of thyrotropin receptor antibody (TRAb) in all patients with GD. These data suggest that the number of IgG3-secreting cells whose isotype switching is stimulated by interleukin (IL)-10 and IL-4 may be related to the disease severity of GD and to the level of TRAb after long-term treatment with antithyroid drugs.

Concentration of immnoglobulin G in plasma varies among 6C.7 recombinant congenic strains of chickens

Chicken Lines 63 and 72 were inbred during selection for resistance or susceptibility to viral-induced tumors. A sandwich ELISA assay was adapted to define the milligrams per milliliter of Ig-gamma (IgG) in plasma from chickens of Lines 63 and 72, as well as 19 recombinant congenic strains (RCS). Each RCS resulted from a 7(2) x 6(3) F(1) and two backcross matings using 63 as the recurrent female line. The IgG levels in the RCS were evaluated after four to seven generations of sib-matings, when each RCS was becoming inbred and fixed for a different 12.5% of the 72 genome. In three generations approximately 24-wk-old chickens of Line 72 had higher levels of plasma IgG than chickens of Line 63 (P < 0.05). None of the RCS had repeatable IgG levels comparable to Line 7(2). However, in the last two generations, two of the 18 RCS had higher IgG levels than nine with low IgG levels (P < 0.05). There was no correlation between an IgG level of a RCS and resistance to Marek's disease. It was concluded that selected RCS may be useful for identifying genes that determine differences in IgG levels, as well as for understanding the relationship between genes, IgG levels, and other traits that differ between Lines 63 and 72.

Analysis of chicken bile by gel precipitation reactions using a lectin in the place of antibody

A lectin obtained from black turtle beans (BTB) was precipitated with IgA in chicken bile samples in various forms of agarose gel systems. Ouchterlony-type double-diffusion (ODD) precipitation patterns between the lectin, bile IgA, and heavy chain-specific antibody contained spurs of the type suggestive of partial immunologic identity. The immunoelectrophoresis precipitation patterns between the same three reactants were mirror images and fused on the cathodic side of the immunoelectrophoresis origin. In addition to use in ODD-type gels, BTB could also be incorporated into agarose gels suitable for Mancini (radial immunodiffusion) or Laurell-type rocket electrophoresis. Bile samples obtained from Cornell lines OS and C, broiler breeder males, and University of California-Davis congenic lines were investigated using BTB- and antibody-based methods. The results of this study indicated that IgA was the most frequently detected isotype in bile, occurring in 139 of 156 (89%) samples. Most bile samples (128/156; 82%) also contained IgG, whereas fewer (19/156; 12%) contained IgM. Cornell lines appeared to differ from broiler breeders, having a higher frequency of IgM-positive samples. Of the total bile samples studied, 11% (17/156) of samples from broiler breeders and the Cornell lines appeared to be devoid of IgA; the bile of one broiler breeder was found to be devoid of all three isotypes. Instances were found in which bile samples shown to be negative for IgA by antibody-ODD were shown to be positive by BTB-ODD. Thus BTB appears to be a suitable adjunct to antibody for the study of IgA.

Serum immunoglobulin G and M concentrations did not appear to be associated with resistance to Pasteurella multocida in a large-bodied turkey line and a randombred control population

Serum IgG and IgM concentrations in a randombred control line (RBC2) of turkeys and its subline (F), selected long term for increased 16-wk BW were compared. Six-week-old poults were challenged with virulent Pasteurella multocida (1.2 x 10(7) bacteria per bird of serogroup A and serotype 3,4). Sera were collected prior to challenge, and concentrations of IgG and IgM in turkey sera were quantitatively estimated with a Sandwich ELISA using the cross-reactive polyclonal antibodies specific for the chicken Ig isotypes. The F-line turkeys had a higher serum IgM concentration than turkeys from the RBC2 line. There was no significant line difference in IgG concentration. The F line had higher mortality and a shorter number of days to death following challenge with P. multocida than did the RBC2 line. No significant correlation coefficient was found between immunoglobulin isotype concentration in serum and days to death following challenge with P. multocida. The present results suggested that prechallenge IgG and IgM concentrations in serum did not appear to be associated with resistance to P. multocida in a large-bodied turkey line and a randombred control population.