T-Cell Response

The field of DNA vaccination started when eukaryotic expression vectors were injected into the muscle of laboratory animals [2]. The authors observed protein expression for more than 2 months after injection and noted that no special delivery system was required to obtain this expression. Subsequently, it was demonstrated that antibodies can be induced simply by injecting plasmid DNA into the muscle of mice [3]. Subsequent studies found that the injection of expression plasmids also leads to the induction of a cytotoxic T-cell response. After injection, the DNA enters cells of the vaccinated host and the encoded gene becomes expressed. This eventually leads to the induction of a cellular cytotoxic T-cell, T-helper, and/or humoral (antibody) immune response. 

A broad and vigorons T cell response generally accompanies elimination of HBV as well as HCV infection. By contrast, patients with chronic hepatitis B or C tend to have late, transient, or narrow T cell responses. In a long-term follow-up of HBV-infected patients receiving HPC transplants from HBV-immune individuals, 20 of 31 recipients cleared their HBV infection (Hui et al. 2005). In principle, these results encourage the development of adoptive T cell transfer strategies for the treatment of chronic viral hepatitis. However, it is still controversial whether induction of an efficient T cell response is the cause or the consequence of viral clearance. Furthermore, T cell responses do not only contribute to virus control but also to disease pathology (Rehermann and Nascimbeni 2005). 

Romagnani S Regulation of the T cell response. Clin Exp Allergy 2006 36 1357-1366. 

Francis JN, Till SJ, Durham SR Induction of 1L-10+CD4+CD25+ T cells by grass pollen immunotherapy. J Allergy Clin Immunol 2003 111 1255-1261. Jutel M, Akdis M, Budak F, Aebischer-Casaulta C. Wrzyszcz M, Blaser K, Akdis CA lL-10 and TGF-P cooperate in the regulatory T cell response to mucosal allergens in normal immunity and specific immunotherapy. Eur J Immunol 2003 33 1205-1214. 

Capobianco F. Butteroni C. Barletta B. Corinti S, Afferni C. Tinghino R. Boirivant M, Di Felice G Oral sensitization with shrimp tropomyosin induces in mice allergen-specific IgE. T-cell response and systemic anaphylactic reactions. Int Immunol 2008 20 1077-1086. 

HIV produces profound CD4 depletion, possibly through initial massive depletion of gut-associated memory T-cells, followed by chronic immune activation, leading to fatigue of homeostatic T-cell responses and progressive immunodeficiency (McArthur et al. 2005). 

T cells responsible for delayed-type hypersensitivity seerete lymphokines whieh recruit and activate non-specific cells like maerophages into the area of the reaetion. Examples of some of these lymphokines are listed below. 

F (1999) Glutenin is involved in the gluten-driven mucosal T cell response. Eur J Immunol. 29 3133-9. 

Oligoclonal CD4+ T-cell response Spleen, thymus Balb/c mouse No Increased in splenic, not in thymic Heo et al. (1997)... 

Heo Y, Lee WT, Lawrence DA. 1997. In vivo the environmental pollutants lead and mercury induce oligoclonal T cell responses skewed toward type-2 reactivities. Cell Immunol 179 185-195. 

Once activated, T cells undergo clonal expansion (they multiply) under the influence of cytokines, specifically IL-2. These steps elicit an anti-donor T cell response that results in graft destruction. 

Chemokines, Dendritic Cells, and Maturation of the Allogeneic T-Cell Response... 

Liu L, Graham G, Hu T, et al. The silent chemokine receptor D6 is required for generating T cell responses that mediate experimental autoimmune encephalomyelitis. J Immunol 2006 177(1) 17-21. 

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