Previous work in this laboratory has begun to define an immunological basis for the increased susceptibility of aged mice to infection with Mycobacterium tuberculosis. Thus the long-term objective of this proposed continuation project is to conduct an in-depth analysis of the nature of this immunological basis in terms of a hypothesized age-related decline in mechanisms of acquired T cell mediated protective cellular resistance. Much of these proposed analyses will consist of low-dose aerogenic infection models, thus simulating poorly understood events in the aged lung such as recrudescence of latent disease, still relatively common in the aged community, and which thus continues to constitute an important health problem within this growing population. Accordingly, the specific Aims are designed to systematically investigate the nature of T cell response in old, tuberculosis-infected mice, from the perspectives of (a) T cells that mediate protective immunity, (b) T cells that mediate delayed sensitivity, and (c) T cells that give rise to a long- lived state of immunologic memory. In order to model events known to occur within the human population, mice will be given low-dose aerosol infections at various ages to simulate primary exogenous exposure, or initially as young animals, in order to simulate age-associated endogenous recrudescence of infection. In these latter animals, the immune status of the aged animal will be studied directly, by observing events within lung lesions, and indirectly, by measuring the response of the animal to a secondary infection with mycobacteria in the popliteal lymph node. The technology used to achieve these goals will consist of in vivo passive cell transfer, in which the capacity of T cell subsets to adoptively confer protection, DTH, or memory immunity, will be elucidated; flow cytometry, in which the accumulation of alpha/beta and gamma/delta T cells bearing markers of interest into sites of infection will be measured, immunohistochemistry, in which the patterns of cellular accumulation will be documented; and various in situ hybridization, calorimetric, ELISA, and ELISA-spot assays, in which the ability of accumulating cells to elaborate important cytokines will be assessed. Using data gathered by these diverse procedures, it is anticipated that new important knowledge will be gained regarding the precise events which occur in the aged animal exposed to virulent pulmonary tuberculosis.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Project (R01)
Project #
5R01AG006946-07
Application #
3118089
Study Section
Bacteriology and Mycology Subcommittee 2 (BM)
Project Start
1986-09-01
Project End
1996-07-31
Budget Start
1993-08-15
Budget End
1994-07-31
Support Year
7
Fiscal Year
1993
Total Cost
Indirect Cost
Name
Colorado State University-Fort Collins
Department
Type
Schools of Veterinary Medicine
DUNS #
112617480
City
Fort Collins
State
CO
Country
United States
Zip Code
80523
Turner, Joanne; Orme, Ian M (2004) The expression of early resistance to an infection with Mycobacterium tuberculosis by old mice is dependent on IFN type II (IFN-gamma) but not IFN type I. Mech Ageing Dev 125:1-9
Turner, Joanne; Turner, Oliver C; Baird, Nick et al. (2003) Influence of increased age on the development of herpes stromal keratitis. Exp Gerontol 38:1205-12
Turner, Joanne; Gonzalez-Juarrero, Mercedes; Ellis, Debi L et al. (2002) In vivo IL-10 production reactivates chronic pulmonary tuberculosis in C57BL/6 mice. J Immunol 169:6343-51
Turner, Joanne; Orme, Ian M (2002) Identification of altered integrin alpha/beta chain expression on T cells from old mice infected with Mycobacterium tuberculosis. Exp Gerontol 37:907-16
Turner, Joanne; Frank, Anthony A; Orme, Ian M (2002) Old mice express a transient early resistance to pulmonary tuberculosis that is mediated by CD8 T cells. Infect Immun 70:4628-37
Turner, J; Frank, A A; Brooks, J V et al. (2001) The progression of chronic tuberculosis in the mouse does not require the participation of B lymphocytes or interleukin-4. Exp Gerontol 36:537-45
Turner, J; D'Souza, C D; Pearl, J E et al. (2001) CD8- and CD95/95L-dependent mechanisms of resistance in mice with chronic pulmonary tuberculosis. Am J Respir Cell Mol Biol 24:203-9
Turner, J; Frank, A A; Brooks, J V et al. (2001) Pentoxifylline treatment of mice with chronic pulmonary tuberculosis accelerates the development of destructive pathology. Immunology 102:248-53
Turner, J; Gonzalez-Juarrero, M; Saunders, B M et al. (2001) Immunological basis for reactivation of tuberculosis in mice. Infect Immun 69:3264-70
Turner, J; Frank, A A; Brooks, J V et al. (2001) Tuberculosis in aged gammadelta T cell gene disrupted mice. Exp Gerontol 36:245-54

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