Lymphocyte homing in xenotransplanted human thyroid tissue can be inhibited by LFA-1 and ICAM-1 antibodies

Changes in serum adhesion molecules, chemokines, cytokines, and tissue remodeling factors in euthyroid women without thyroid antibodies who are at risk for autoimmune thyroid disease: a hypothesis on the early phases of the endocrine autoimmune reaction

BACKGROUND

The target glands in spontaneous animal models of endocrine autoimmune disease show, prior to the autoimmune reaction, growth and connective tissue abnormalities, whereas the autoimmune reaction is initiated by an early accumulation of macrophages and dendritic cells in the target glands.

AIM

The aim of the study was to test the hypothesis that serum factors related to these growth and connective tissue abnormalities and the early accumulation of immune cells, ie, tissue growth/remodeling factors, adhesion molecules, chemokines, and pro- and anti-inflammatory cytokines, are related to thyroid peroxidase autoantibodies (TPO-Abs) seroconversion in subjects at risk to develop autoimmune thyroid disease (AITD).

DESIGN

A controlled study on 64 TPO-Ab-negative euthyroid female relatives with at least 1 first- or second-degree relative with documented autoimmune hyper- or hypothyroidism, 32 of whom did and 32 who did not seroconvert to TPO-Ab positivity in 5-year follow-up. The relatives were compared with 32 healthy controls. In all subjects we measured serum levels of chemokine (C-C motif) ligand (CCL)-2, CCL3, CCL4, soluble vascular cell adhesion molecule, soluble intercellular adhesion molecule-1, thrombospondin-1, vascular endothelial growth factor-A, angiopoietin 1 receptor-2, metalloproteinase-13, platelet-derived growth factor-BB, fibronectin, IL-1β, IL-6, TNF-α, IL-10, and growth differentiation factor-15 by multiplex (cytometric bead array) or a single commercial ELISA.

RESULTS

Both seroconverting and nonseroconverting family members showed an up-regulation of fibronectin and a down-regulation of platelet-derived growth factor-BB and the adhesion and migration factors CCL2, CCL4, soluble vascular cell adhesion molecule-1, angiopoietin 1 receptor-2, and metalloproteinase-13. The seroconverters differed from the nonseroconverters by an up-regulation of the proinflammatory compounds Il-1β, IL-6, and CCL3.

CONCLUSION

This study shows that euthyroid females within AITD families show a characteristic pattern of abnormalities in serum levels of tissue remodeling factors, growth factors, chemokines, (vascular) adhesion molecules, and cytokines prior to the occurrence of TPO-Abs in serum. The results provide proof of principle that preseroconversion stages and seroconversion to AITD might be predicted using serum analytes related to growth/connective tissue abnormalities and migration/accumulation abnormalities of macrophages and dendritic cells.

Lymphocytes in peripheral blood and thyroid tissue in children with Graves' disease

BACKGROUND

This study was undertaken to analyze subsets of lymphocytes in peripheral blood in the early phase and in the thyroid tissue in the late phase of Graves' disease (GD) in children.

METHODS

The study included 30 children with GD and 30 healthy children. Monoclonal antibodies were used to define peripheral blood lymphocyte subsets and they were analyzed using the flow cytometer Ortho Diagnostic System. After thyroidectomy, T cells were detected by CD3, CD4, CD8 antibodies, B cells by CD79alpha antibodies, and the antigen presenting dendritic cells (APCs) by CD1alpha antibodies (DakoCytomation) in the thyroid tissue.

RESULTS

Before the treatment, an increased percentage of CD4+ T helper cells and B cells and decreased CD8+ T suppressor/cytotoxic cells were observed in peripheral blood in all the GD children. The number of lymphocytes and dendritic cells in the thyroid tissue increased in the children with GD in comparison to the control group, especially T cells subsets CD4+ and CD8+ and CD79alpha+ B cells. The percentage of T cells in the thyroid tissue was lower and that of B cells was higher than in peripheral blood. In their structure, thyrocytes can have components similar to alpha-chains connected with beta-microglobulins, which were characteristic for APCs.

CONCLUSIONS

The primary defect of immunoregulation in children with GD is probably dependent on a large number and the activity of T helper cells and on a small number and hypofunction of T suppressor cells. The amount of lymphocytes decreased proportionally to the duration of methimazole treatment. The thyrocytes probably can present antigens.

Replication and clearance of Venezuelan equine encephalitis virus from the brains of animals vaccinated with chimeric SIN/VEE viruses

Venezuelan equine encephalitis virus (VEEV) is an important, naturally emerging zoonotic pathogen. Recent outbreaks in Venezuela and Colombia in 1995, involving an estimated 100,000 human cases, indicate that VEEV still poses a serious public health threat. To develop a safe, efficient vaccine that protects against disease resulting from VEEV infection, we generated chimeric Sindbis (SIN) viruses expressing structural proteins of different strains of VEEV and analyzed their replication in vitro and in vivo, as well as the characteristics of the induced immune responses. None of the chimeric SIN/VEE viruses caused any detectable disease in adult mice after either intracerebral (i.c.) or subcutaneous (s.c.) inoculation, and all chimeras were more attenuated than the vaccine strain, VEEV TC83, in 6-day-old mice after i.c. infection. All vaccinated mice were protected against lethal encephalitis following i.c., s.c., or intranasal (i.n.) challenge with the virulent VEEV ZPC738 strain (ZPC738). In spite of the absence of clinical encephalitis in vaccinated mice challenged with ZPC738 via i.n. or i.c. route, we regularly detected high levels of infectious challenge virus in the central nervous system (CNS). However, infectious virus was undetectable in the brains of all immunized animals at 28 days after challenge. Hamsters vaccinated with chimeric SIN/VEE viruses were also protected against s.c. challenge with ZPC738. Taken together, our findings suggest that these chimeric SIN/VEE viruses are safe and efficacious in adult mice and hamsters and are potentially useful as VEEV vaccines. In addition, immunized animals provide a useful model for studying the mechanisms of the anti-VEEV neuroinflammatory response, leading to the reduction of viral titers in the CNS and survival of animals.