PrimaryMycobacterium aviumComplex Infections Correlate with Lowered Cellular Immune Reactivity in Matschie's Tree Kangaroos(Dendrolagus matschiei)

Abstract

The National Zoological Park has maintained a breeding colony of Matschie's tree kangaroos (Dendrolagus matschiei) since 1975 with a documented history and continued prevalence of Mycobacterium avium complex (MAC) infections. No evidence of immunosuppressive retrovirus infections or loss of heterozygosity that may have led to an immune dysfunction in these animals was found. Isolates of MAC organisms from affected tree kangaroos and from their environment had no common restriction fragment DNA types. Cellular immune reactivity in apparently healthy tree kangaroos was 3- to 6-fold lower than in humans and other marsupial and eutherian mammals, as determined by lymphocyte proliferative assays. Thus, while MAC infections are typically opportunistic in humans and other mammals, tree kangaroos commonly develop primary progressive disease with MAC from random sources. Comparative information derived from this study should benefit both the endangered tree kangaroo and humans with immunosuppressive disorders that lead to mycobacterial infections.

The Nucleotide Sequence of Koala ( Phascolarctos cinereus ) Retrovirus: a Novel Type C Endogenous Virus Related to Gibbon Ape Leukemia Virus

“…Wombats are the closest living relatives of koalas, although still relatively distantly related. Other studies have also failed to demonstrate KoRV-like viruses in marsupials other than koalas (23,37,40). This suggests that endogenization of KoRV in koalas postdates the divergence of koalas from other marsupials.…”

Immunology of a Transmissible Cancer Spreading among Tasmanian Devils

“…A weak secondary response often follows the prolonged primary response (26). Mitogen-induced transformation (PHA, Con A, and PWM) and MLR responses (allogeneic and xenogeneic) in Matschie's tree kangaroos (Dendrolagus matschiei) were up to 6-fold lower than in placentals (27). Low Ag-specific responses for humoral and cell-mediated immunity led to the suggestion that the koala is "immunologically lazy" (28), and weak cell-mediated responses have been observed with captive marsupials (29,30).…”

Clonally transmissible cancers in dogs and Tasmanian devils

“…The lack of diversity at MHC loci, coupled with weak responses of east coast devils to allogeneic mixed lymphocyte culture, has led to the suggestion that this population may be functionally identical at MHC loci, thus permitting the spread of DFTD as an allograft ( Figure 2; Woods et al, 2007;Siddle et al, 2007a;Kreiss et al, 2008). However, as other marsupials have been reported to have weak responses to mixed lymphocyte culture, and antigens other than MHC also contribute to immunosurveillance, this model is yet to be confirmed (Montali et al, 1998;Stone et al, 1998;Janeway et al, 2001).…”