T lymphocyte reactivity to glutamic acid-alanine-tyrosine in vitro does not reflect antibody response in vivo.
Mechanisms responsible for the differences in humoral immune response to GAT (a random linear amino acid polymer) were investigated in a line of chickens consisting of four sublines homozygous for Ea-B (B1 or B19) and high or low antibody response to GAT (Ir-GATH or Ir-GATL). Previous research provided evidence of chromosomal recombination between the serologically determined regions of the MHC (encoded by B-F and B-G genes) and the gene or genes that control immune response to GAT, but immune response to GAT did not seem to be mediated through differences in B-L gene products. In the present study, proliferation of GAT-primed T lymphocytes indicated that reactivity in vitro was not associated with antibody levels produced in the animal. Cell surface markers were identified by flow cytometry. Lymphocytes from Ea-B19 chickens that were Ir-GATL had a higher percentage of suppressor T (CD8)-positive cells than did lymphocytes from Ir-GATH chickens. The Ea-B1 chickens that were Ir-GATL had a higher percentage of CD4-positive lymphocytes than did chickens that were Ir-GATH. This may indicate that low response to GAT in the Ea-B19 chickens, but not in Ea-B1 chickens, is mediated by CD8-positive cells. The ability of antigen-presenting cells (APC) to process and present GAT to antigen-primed T lymphocytes was tested in vitro. Measurements of lymphocyte proliferation indicated that, within the Ea-B1 blood type, APC from Ir-GATL chickens produced higher (P < .05) stimulation of both GAT low- and GAT high-responder lymphocytes.(ABSTRACT TRUNCATED AT 250 WORDS)
Steadham
E M
EM
Department of Animal Science, Iowa State University, Ames 50011.
Lamont
S J
SJ
D000595:Amino Acid Sequence; D000818:Animals; D000917:Antibody Formation / Q000276:immunology*; D000938:Antigen-Presenting Cells / Q000276:immunology; D002478:Cells, Cultured; D002645:Chickens / Q000276:immunology*; D004396:Coloring Agents; D008213:Lymphocyte Activation / Q000276:immunology; D008969:Molecular Sequence Data; D010455:Peptides / Q000276:immunology*; D011108:Polymers; D013601:T-Lymphocytes / Q000276:immunology*; D013778:Tetrazolium Salts; D013844:Thiazoles
D004396:Coloring Agents; D010455:Peptides; D011108:Polymers; D013778:Tetrazolium Salts; D013844:Thiazoles; C020749:GAT; C022616:thiazolyl blue