Transgenic mice for HTLV-1

3. Transgenic mice for
Human T cell Lymphotropic Virus
type I (HTLV-I)

4. 4
Clinical Syndromes Reported in Association with Human T-Cell Lymphotropic Virus
Types I
Adult T-cell leukemia/lymphoma
HTLV associated myelopathy
Mycosis fungoides?
Increased susceptibility to infections
Polymyositis
Uveitis
Arthropathy
Sjogren's syndrome
Pulmonary syndrome, alveolitis
Infectious dermatitis
HTLV-I

5. 5
Associated with 2 fatal human
diseases
 Adult T cell leukemia (ATL)
 clonal malignancy of infected mature
CD4+ T cells
 Tropical spastic paraparesis/HTLV-1
associated myelopathy(HAM/TSP)
 neurodegenerative disease

6. 6
Human T cell Leukemia Virus
type I (HTLV-I)
• Endemic in parts of Japan, South America,
Africa, and the Caribbean
• With an estimated 10-20 million people infected worldwide
• Asymptomatic in majority of individuals with
approximately 2-5% of HTLV-I carriers
developing disease 20-40yrs post infection.
• The long clinical latency and low percentage of individuals
who develop leukemia suggest that T-cell transformation
occurs after a series of cellular alterations and mutations.

11. 11
 Sexual (60% male to female versus 1%
female to male transmission)
 Blood products (screening of blood supply
since 1988)
 Mother to child (breast feeding: 20%
children with seropositive mothers
acquire virus)

12.  DNA viruses: papovaviruses
hepadnaviruses
herpesviruses
adenoviruses
poxviruses
 RNA viruses: retroviruses
flaviviruses
12
HPV
SV-40
BK, JCHBV
EBV
KSHV
HTLV-1
Hepatitis C virus

18. Promoter Gene Disease ATLL-like HAM/TSP-like Reference
HTLV-1 LTR tax Neurofibroma None None Nerenberg et al. (1987)
HTLV-1 LTR tax Sjögren-like syndrome
(exocrinopathy)
None None Green et al. (1989)
HTLV-1 LTR env-pX Arthritis None None Iwakura et al. (1991)
HTLV-1LTR tax Skeletal abnormalities None None Ruddleetal.(1993)
Granzyme B tax Granular lymphocytic
leukemia
Leukemia/
lymphoma
None Grossman etal.(1995)
lck-proximal tax CD4−CD8− pre-T-cell
leukemia
Leukemia/
lymphoma
None Hasegawaetal.(2006)
lck-distal tax CD4+, CD8+,
andCD4+CD8+ T-cell
leukemia
Leukemia/
lymphoma
Symmetrical
paraparesis of
the hind limbs
Ohsugi etal.(2007)

19. The tat gene of HTLV-1 under control of its own long
terminal repeat is capable of inducing tumors in
transgenic mice.
The morphologic and biologic properties of these tumors
indicate their close resemblance to human
neurofibromatosis.

21. At 2 to 3 months of age, many of the mice developed chronic arthritis
resembling rheumatoid arthritis.
Synovial and periarticular inflammation with articular erosion caused by
invasion of granulation tissues were marked.
These observations suggest a possibility that HTLV-I is one of the
etiologic agents of chronic arthritis in humans.

22. To investigate its leukemogenic potential, Tax was targeted to the
mature T-lymphocyte compartment in transgenic mice by using
the human granzyme B promoter.
These mice developed large granular lymphocytic leukemia,
demonstrating that expression of Tax in the lymphocyte
compartment is sufficient for the development of leukemia.
Furthermore, these observations suggest that human T-cell
leukemia virus infection may be involved in the
development of large granular lymphocytic leukemia.

23. The lck gene encodes a protein tyrosine kinase that participates in lymphocyte-
specific signal transduction pathways.
Previous studies have established that kck transcription is regulated by two distinct
promoter elements termed proximal (or 3') and distal (or 5').
The proximal promoter is active almost exclusively in thymocytes and becomes
inactive later during T-cell maturation.
To dissect the mechanisms responsible for lck gene regulation, we generated
transgenic animals bearing 5' truncations in the proximal promoter element.
These results provide a basis for the biochemical dissection of transcriptional
regulators that act at defined points during T-cell development.

24. 1-amplify Tax cDNA by PCR from DNA extracted from infected
peripheral blood mononuclear cells (PBMCs)
2-subclone the HTLV-I Tax coding sequence into the BamHI site of
p1017(restrict transgene expression to developing thymocytes)
3-The pLck-Tax plasmid was linearized by digestion with NotI
4- 6.3-kb fragment containing the transgene
5-generate transgenic mice using inbred C57BL/6 mice and standard
methods
5-For detection of the transgene ,performe Southern blotting on
genomic DNA extracted from tail-tip biopsies.
6-Chromosomal mapping of the inserted transgene

28. After prolonged latency periods,
transgenic mice developed diffuse large-cell lymphomas and
leukemia with clinical, pathological and immunological features
characteristic of acute ATLL.
Transgenic mice were functionally immunocompromised and they
developed opportunistic infections.

29. To examine whether the induction of apoptosis caused by anti-Fas mAb may play a potential
role as a new therapeutic strategy for RA, we investigated the effect of anti-Fas mAb (RK-8)
on synovitis in an animal model of
RA, the human T cell leukemia virus type I (HTLV-I) tax transgenic mice.
We report here that administration of anti- Fas mAb into mice intra-articularly improved the
paw swelling and arthritis within 48 h.
Results demonstrated that administration of anti-Fas mAb in arthritic joints of the HTLV-I tax
transgenic mice produced improvement of arthritis.
These findings suggest that local administration of anti-Fas mAb may represent a useful
therapeutic strategy for proliferative synovitis such as RA

30. We examined the role of IFN-gamma in tumorigenesis, by mating Tax-
transgenic mice with a gene-specific knockout for IFN-gamma.
IFN-gamma-/- Tax-transgenic mice show accelerated tumor onset
(median, 4 versus 6 months), dissemination (median, 5 versus 7 months),
and death (median,7 versus 10 months), compared with IFN gamma +/- or
IFN gamma +/+ Tax mice.
These results provide insight into a possible mechanism by which IFN-
gamma contributes to host resistance against HTLV-induced tumors
through an angiostatic effect.

31. To elucidate the roles of interleukin-1(IL-1) in the development of 2
etiologically different rheumatoid arthritis (RA) models: the type II
collagen (CII)–induced arthritis (CIA) model and the human T
cell leukemia virus type I transgenic (HTLV-I Tg) mouse model.
For the HTLV-I Tg model, BALB/c IL-1 beta-/- or IL-1alpha/beta-/-mice
were crossed with HTLV-I Tg mice.
The development of arthritis was markedly suppressed in IL-1// mice
in both models.
These observations suggest that T ell activation by IL-1 is important
for the development of autoimmunity and arthritis in these mice.