# POSTNATAL HEMATOGENOUS & INTRATHYMIC T CELL PROGENITORS

> **NIH NIH R01** · UNIVERSITY OF WASHINGTON · 1993 · $181,170

## Abstract

Although the generation of T cells in the fetal thymus and the
reestablishment of thymocytopoiesis in the irradiated or grafted
thymus is dependent on bone marrow-derived hematogenous immigrants
(prothymocytes), the thymus also contains intrinsic T cell
progenitors.  The relative roles of hematogenous vs. intrinsic
progenitors has defied investigation in the steady-state postnatal
thymus.  Although this question has been of long-standing interest,
our preliminary studies have established that congenic parabiotic
mice and part body BM chimeras are ideal for exploring this
problem:  in the steady-state thymus, only 10% of cells are of
hematogenous and 90% of intrinsic thymic origin; hematogenous and
intrinsic progenitor pools are independent of one another.  The
proposed studies will characterize the progeny of hematogenous and
intrinsic T cell progenitors in the steady-state, post-natal thymus
and will provide evidence for the derivation of phenotypically and
functionally defined subsets of thymocytes and peripheral T cells
from one or the other of the progenitor pools.  We will investigate
the contribution of these two progenitor pools to the recovery of
the thymus following its depletion by hydrocortisone- or tumor-
induced atrophy, and by selective irradiation under conditions
which do not deplete the animal's own prothymocytes.  The in vivo
studies will combine multi-parameter flow cytometry and sorting in
conjunction with selective lysis of defined T cell populations with
their selective labeling for migration studies and with functional
assays.  The significance of the proposed work is that it will
clarify the developmental lineages of T cell subclasses under
steady-state conditions and will provide information about the
response of different T cell progenitors when T cell production
has been compromised by conditions comparable to those that may be
clinically encountered in humans.

## Key facts

- **NIH application ID:** 2199379
- **Project number:** 5R01HD025069-05
- **Recipient organization:** UNIVERSITY OF WASHINGTON
- **SAM.gov UEI:** HD1WMN6945W6
- **Principal Investigator:** CORNELIUS M ROSSE
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1993
- **Award amount:** $181,170
- **Award type:** 5
- **Project period:** 1988-12-01 → 1994-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/2199379

## Citation

> US National Institutes of Health, RePORTER application 2199379, POSTNATAL HEMATOGENOUS & INTRATHYMIC T CELL PROGENITORS (5R01HD025069-05). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/2199379. Licensed CC0.

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