Seeding of the mucosal leukocytes in the HALT and trachea of White Leghorn chickens.

Characterising the immune cells of the head-associated lymphoid tissues (HALT) and trachea during maturation in young birds is critical to understanding the immunological responses to avian respiratory diseases and vaccines. Selected mucosal leukocytes of the conjunctiva-associated lymphoid tissue (CALT), Harderian gland (HG), nasal-associated lymphoid tissue (NALT) and trachea from 4-, 6-, 8-, and 10-week-old chickens were enumerated and phenotyped. HG, NALT, and trachea cellularity increased as the birds aged with cell viability varying by tissue. The results showed that the T cell subset numbers, but not B cell numbers, increased in the mucosal tissues of chickens during aging.

Developmental exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin alters postnatal T cell phenotypes and T cell function and exacerbates autoimmune lupus in 24-week-old SNF1 mice.

BACKGROUND: Untreated, more than 95% of female SWR x NZB: F(1) (SNF(1)) mice spontaneously develop a fatal lupus-like glomerulonephritis by 8 months-of-age, while disease onset in males is much slower. METHODS: : Timed-pregnant SNF(1) mice (10 per treatment) were exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on gestational day (GD) 12 by oral maternal gavage with 0, 40, or 80 microg/kg TCDD. RESULTS: Offspring of the TCDD-exposed dams showed numerous alterations in T lineage cells at 24 weeks-of-age. Females but not males showed decreased CD4(+)8(+) and increased CD4(-)8(-) thymocytes. Females also showed increased autoreactive CD4(+)Vbeta17(a+) axillary and inguinal lymph node T cells. Concanavalin A-stimulated splenocytes from prenatal TCDD-treated mice produced decreased interleukin 17 (IL-17) in the females while males showed increased IL-2 and IFN-gamma, and diminished IL-4. Mitogen-stimulated pan-lymphoproliferative responses were significantly increased across sex by TCDD. Anti-IgG and anti-C3 immune complex deposition in kidneys was present in the males after TCDD, and visibly worsened in females. CONCLUSIONS: Developmental TCDD exposure can permanently alter T lymphopoiesis in autoimmune-prone SNF1 mice. The alteration profile is beyond the classic immune suppression response, to also include exacerbation and induction of a lupuslike autoimmune disease.