Previous Article | Next Article ![]()
Infect Immun, May 1998, p. 2135-2142, Vol. 66, No. 5
Medical Service,
Received 20 November 1997/Returned for modification 11 January
1998/Accepted 12 February 1998
The Syrian golden hamster (Mesocricetus auratus) is
uniquely susceptible to a variety of intracellular pathogens and is an excellent model for a number of human infectious diseases. The molecular basis for this high level of susceptibility is unknown, and
immunological studies related to this model have been limited by the
lack of available reagents. In this report we describe the cloning and
sequence analysis of portions of the Syrian hamster interleukin 2 (IL-2), IL-4, gamma interferon (IFN-
0019-9567/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.
Cloning of Syrian Hamster (Mesocricetus
auratus) Cytokine cDNAs and Analysis of Cytokine mRNA Expression
in Experimental Visceral Leishmaniasis
), tumor necrosis factor alpha,
IL-10, IL-12p40, and transforming growth factor
cDNAs. In addition,
we examined the cytokine response to infection with the intracellular
protozoan Leishmania donovani in this animal model.
Sequence analysis of the hamster cytokines revealed 69 to 93% homology
with the corresponding mouse, rat, and human nucleotide sequences and
48 to 100% homology with the deduced amino acid sequences. The hamster
IFN-
, compared with the mouse and rat homologs, had an additional 17 amino acids at the C terminus that could decrease the biological
activity of this molecule and thus contribute to the extreme
susceptibility of this animal to intracellular pathogens. The splenic
expression of these genes in response to infection with L. donovani, the cause of visceral leishmaniasis (VL), was
determined by Northern blotting. VL in the hamster is a progressive,
lethal disease which very closely mimics active human disease. In this
model there was pronounced expression of the Th1 cytokine mRNAs, with
transcripts being detected as early as 1 week postinfection. Basal
expression of IL-4 in uninfected hamsters was prominent but did not
increase in response to infection with L. donovani. IL-12
transcript expression was detected at low levels in infected animals
and paralleled the expression of IFN-
. Expression of IL-10, a potent
macrophage deactivator, increased throughout the course of infection
and could contribute to the progressive nature of this infection. These
initial studies are the first to examine the molecular
immunopathogenesis of a hamster model of VL infection and indicate that
progressive disease in this model of VL is not associated with early
polarization of the splenic cellular immune response toward a Th2
phenotype and away from a Th1 phenotype.
*
Corresponding author. Mailing address: Department of
Medicine, Division of Infectious Diseases, The University of Texas
Health Science Center, 7703 Floyd Curl Drive, San Antonio, TX
78284-7881. Phone: (210) 567-4823. Fax: (210) 567-4670. E-mail:
melby{at}uthscsa.edu.
Infect Immun, May 1998, p. 2135-2142, Vol. 66, No. 5
0019-9567/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.
This article has been cited by other articles:
| J. Bacteriol. | J. Virol. | Eukaryot. Cell |
|---|
| Microbiol. Mol. Biol. Rev. | Clin. Vaccine Immunol. | All ASM Journals |
|---|