# THYMUS INVOLUTION AND AGING IN TL TRANSGENIC MICE

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA LOS ANGELES · 1992 · $161,953

## Abstract

The thymus leukemia (TL) antigen is encoded by a mouse Major
Histocompatibility Complex (MHC) class I gene that is expressed in the
thymus, fetal liver, skin and intestinal epithelium.  The function of TL
is unknown.  We have created several lines of TL (thymus leukemia)
antigen transgenic mice that have ectopic expression of TL. All of these
transgenic mice show a delay in thymus involution up to the age of at
least 11 months, although they are otherwise normal.  Cell transfer and
organ transplant studies will be carried out to better define the cell
type likely to be responsible for the effect of TL on thymus involution.
To determine the portion of the TL molecule responsible and gain insight
into a possible mechanism of action, gene constructs that encode Ld /TL
chimeric class I molecules will be microinjected into mouse eggs to
create new lines of transgenic mice.  These will be analyzed for thymus
size as a function of age.  The output of cells from the thymus of older
TL transgenic mice will be measured and compared to that in younger
mice.  Longitudinal studies of serum thymic hormone levels will be
performed.  The transgenic mice will be evaluated to determine if they
exhibit a delay in the senescence of T-cell immune responses that occurs
normally in older animals.  Reproductive senescence and the lifespan of
the transgenic mice will be studied to determine if the delayed
involution leads to increased longevity.

These TL transgenic mice provide an unparalleled opportunity to study
the mechanism of thymus involution, the influence of thymus involution
on the senescence of peripheral immune responses, and the relationship
between thymus involution and the aging process.

## Key facts

- **NIH application ID:** 3122120
- **Project number:** 1R01AG010152-01
- **Recipient organization:** UNIVERSITY OF CALIFORNIA LOS ANGELES
- **SAM.gov UEI:** RN64EPNH8JC6
- **Principal Investigator:** MITCHELL KRONENBERG
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1992
- **Award amount:** $161,953
- **Award type:** 1
- **Project period:** 1992-01-15 → 1994-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3122120

## Citation

> US National Institutes of Health, RePORTER application 3122120, THYMUS INVOLUTION AND AGING IN TL TRANSGENIC MICE (1R01AG010152-01). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3122120. Licensed CC0.

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