In vitro thymidine uptake and incorporation into thymic and bursal lymphocytes from young hypothyroidic chickens

Research note: T-cell activity of White Leghorn chickens selected for high and low antibody responses to sheep erythrocytes

Mitogen responses of peripheral blood lymphocytes (PBL) and the cell cycle analysis of T-cells were examined for lines of chickens selected for high (HA) and low (LA) antibody response to SRBC. At 6 wk of age, within each line, blood samples and thymic tissue were collected from chicks representing the B13B13, B13B21, B21B13, and B21B21 genotypes. Although no influence of Ea-B haplotype on T-cell activity was detected in either line, there were line differences in phytohemagglutin-M (PHA-M) and concanavalin A (Con A) mitogen responses and the percentage G0/G1 and S phase T-cells. The HA PBL had greater in vitro PHA-M and Con A responses, and the cell cycle analysis of T-cells revealed a greater percentage of cells in S phase for Line HA chicks than for LA chicks. There were significantly more resting cells in the G0/G1 phase of LA than HA chicks. Although there was no Ea-B haplotype effect observed on T-cells from either line, generalized selection for high or low antibody response did result in divergent T-cell activity.