A synthetic standard DNA construct for use in quantification of murine cytokine mRNA molecules

gammadelta T cells promote the maturation of dendritic cells during West Nile virus infection

gammadelta T cells are important for the early control of West Nile virus (WNV) dissemination. Here, we investigated the role of gammadelta T cells in the regulation of CD4(+) T-cell response following a WNV challenge. Splenic dendritic cells (DCs) of WNV-infected gammadelta T-cell-deficient (TCRdelta(-/-)) mice displayed lower levels of CD40, CD80, CD86 and major histocompatibility complex (MHC) class II expression and interleukin-12 (IL-12) production than those of wild-type mice. Naïve DCs cocultured with WNV-infected gammadelta T cells showed enhanced levels of costimulatory molecules, MHC class II expression and IL-12 production. Further, coculture of CD4(+) T cells from OT II transgenic mice with DCs of WNV-infected TCRdelta(-/-) mice induced less interferon-gamma (IFN-gamma) and IL-2 production than with those of wild-type controls. Viral antigens were detected in WNV-infected gammadelta T cells.WNV infection or toll-like receptor (TLR) agonist treatment of gammadelta T cells induced the production of IFN-gamma, tumor necrosis factor-alpha and IL-6, which are known to promote DC maturation. Nevertheless, the levels of TLRs 2, 3, 4 and 7 expression of WNV-infected gammadelta T cells were not different from those of noninfected cells. Overall, these data suggest that WNV-induced gammadelta T-cell activation promotes DC maturation and initiates CD4(+) T-cell priming.

Cancer vaccines

This unit describes the use of retroviral vectors that can be successfully employed for gene transfer into both primary tumor cultures and established cell lines. The unit includes procedures for assaying the stability of the vaccine following gene transfer. Techniques for maintaining the retroviral producer lines and titering the retroviral vectors are also described. A protocol for frozen storage of the vaccine (transduced tumor cells) is provided. In addition, methods are described for characterizing the vaccine cells following gene transfer. Directions for testing the expression of the transferred gene in the transfected tumor line are also given. The final protocol provides suggestions for designing in vivo animal experiments and discusses what has to be observed in a clinical setting.

The clinical usefulness of the measurement of cytokines

The utilization of accurate and sensitive methods for the measurement of cytokines in body fluids is prerequisite for the proper use of these mediators in clinical practice. Many factors contribute to the complexity of cytokine quantitation. Bioassays historically preceded immunoassays, which are now very popular, but there is a need for standardization. Nevertheless, due to the local effects of cytokines, the study of their blood levels is of limited value for an understanding of the pathophysiology of these mediators. This explains the development of alternative approaches to assess the ability of cells to produce cytokines. These include the Enzyme-Linked Immuno Spot Assay (ELISPOT), the measurement of cell-associated cytokines by flow cytometry, and the study of cytokine secretion by isolated peripheral blood mononuclear cells or by whole blood test. All these techniques, associated with a local detection of cytokines by immunohistochemistry or in situ hybridization and reverse transcriptase polymerase chain reaction, appear to be complementary tools for a better understanding of the biology of cytokines. Selected examples of possible clinical applications related to infectious diseases, cancer, autoimmune diseases, allergy, transplantation and preclinical evaluation of drugs and biotechnology products are given.

Measurement of cytokines in clinical samples using immunoassays: problems and pitfalls

With the explosion in interest in cytokines and an increasing understanding of their possible involvement in the pathogenesis of many diseases, the number of studies measuring cytokines in body fluids has increased markedly over the last 5 to 10 years. However, it is readily apparent from the literature that the level of awareness of the many factors that can potentially influence the results obtained is very low. Such factors are likely to contribute considerably to the disparities seen among similar types of study. These include assay properties such as standardization and specificity, type of sample and sample handling, and many biological influences such as age, sex, ethnic background, and diurnal rhythmicity. Clearly, it is not possible to control for all these factors, but a minimum evaluation of assays should be carried out as described, including recovery and parallelity studies using relevant samples and the establishment of reproducibility and normal healthy population levels. An awareness of these factors, which is the purpose of this review, may hopefully lead to an improvement in the quality of studies incorporating the measurement of cytokines in clinical samples and should aid in the interpretation of the data.

Cytokine profiles of aqueous humor and graft in orthotopic mouse corneal transplantation

BACKGROUND

Cytokine profile is a key in understanding the mechanisms of allograft rejection. Cytokine expression in the aqueous humor and the correlation between the aqueous humor cells and corneal infiltrating cells are not fully understood in corneal transplantation.

METHODS

Orthotopic mouse corneal transplantation was performed using BALB/c (H2d) mice as recipients, and C3H/He (H2k) and BALB/c mice as donors for allografts and isografts, respectively. Immunocytochemistry was performed on aqueous humor cells. Corneal graft was studied immunohistochemically. Cytokine gene expressions of the cells infiltrating the aqueous humor and corneal grafts were determined by the semiquantitative reverse transcription and polymerase chain reaction method.

RESULTS

Interferon-gamma, interleukin (IL)-2, IL-4, and IL-10 were detected in the cells infiltrating the aqueous humor and corneal grafts at both the protein and gene expression levels. T helper 1 (Th1) cytokine expressions at the protein level, however, were consistently predominant in the rejected allografts compared to those of Th2 cytokines. The cytokine and surface marker profiles of the cells in the aqueous humor corresponded well to those of the cells infiltrating the corneal grafts. Cytokine protein and mRNA expression levels in the aqueous humor decreased rapidly.

CONCLUSIONS

Allorejection in corneal transplantation is Th1 cytokine-predominant. Infiltrating cells do not express Th2 cytokine so much in allograft rejection, as compared with Th1 cytokine. The cell infiltration patterns of the aqueous humor were well correlated with those of the cornea.

Cytokine assays in human sera and tissues

The use of accurate and sensitive methods for the measurement of cytokines in body fluids is an absolute prerequisite for the proper use of these mediators in clinical practice. Many factors contribute to the complexity of cytokines quantitation: these molecules circulate at very low levels (e.g. pg/ml) under various molecular forms, the existence of circadian rhythms has been described, and the presence of inhibitors (binding proteins, soluble receptors, autoantibodies) can potentially interfere in the assays. Blood collection for cytokines needs particular attention to prevent possible contamination by endotoxins, which can trigger cytokines cellular production after sampling. Bioassays historically preceded immunoassays; the latter techniques are now very popular, but there is an urgent need for standardisation between the different kits commercially available. Nevertheless, due to the essentially local effects of cytokines, the study of their circulating levels only represents the 'tip of the iceberg' and is of limited value for a global understanding of the pathophysiology of these mediators. This explains the development of other approaches to assess the ability of cells to produce cytokines. These include the ELISPOT assay, the measurement of cell-associated cytokines by flow cytometry, and the study of cytokine secretion by isolated peripheral blood mononuclear cells or by whole blood test. All these techniques, associated with a local detection of cytokines by immunohistochemistry or in situ hybridization and reverse transcriptase polymerase chain reaction (RT-PCR), appear to be complementary tools for a better understanding of the multiple aspects of the biology of cytokines.