A Non-Human Primate Model for Gluten Sensitivity

Gluten sensitivity is widespread among humans. For example, in celiac disease patients, an inflammatory response to dietary gluten leads to enteropathy, malabsorption, circulating antibodies against gluten and transglutaminase 2, and clinical symptoms such as diarrhea. There is a growing need in fundamental and translational research for animal models that exhibit aspects of human gluten sensitivity.Using ELISA-based antibody assays, we screened a population of captive rhesus macaques with chronic diarrhea of non-infectious origin to estimate the incidence of gluten sensitivity. A selected animal with elevated anti-gliadin antibodies and a matched control were extensively studied through alternating periods of gluten-free diet and gluten challenge. Blinded clinical and histological evaluations were conducted to seek evidence for gluten sensitivity.When fed with a gluten-containing diet, gluten-sensitive macaques showed signs and symptoms of celiac disease including chronic diarrhea, malabsorptive steatorrhea, intestinal lesions and anti-gliadin antibodies. A gluten-free diet reversed these clinical, histological and serological features, while reintroduction of dietary gluten caused rapid relapse.Gluten-sensitive rhesus macaques may be an attractive resource for investigating both the pathogenesis and the treatment of celiac disease

Infectivity of the Highly Transformable BBE02(−) lp56(−) Mutant of Borrelia burgdorferi, the Lyme Disease Spirochete, via Ticks

Infectious Borrelia burgdorferi strains that have increased transformability with the shuttle vector pBSV2 were recently constructed by inactivating the gene encoding BBE02, a putative restriction-modification gene product expressed by the linear plasmid lp25 (Kawabata et al., Infect. Immun. 72:7147-7154, 2004). The absence of the linear plasmid lp56, which carries another putative restriction-modification gene, further enhanced transformation rates. The infectivity of these mutants was assessed previously in mice that were inoculated with needle and syringe and was found to be equivalent to that of wild-type spirochetes. Here we examined the infectivity of spirochetes to ticks after capillary inoculation of Ixodes scapularis nymphs and the subsequent spirochetal infectivity to mice via ticks by using B. burgdorferi B31 clonal isolates lacking lp56 and/or BBE02. The absence of lp56 (but not BBE02) correlated with a lower number of spirochetes in ticks after feeding on mice; this plasmid thus may play a role, albeit not an essential one, in supporting spirochetal survival in the feeding tick. Importantly, however, the absence of lp56 and BBE02 did not detectably influence infectivity to mice via ticks

Fat absorption in FH09 (gluten-sensitive) and FR26 (control) macaques

<p>Fat absorption in FH09 (gluten-sensitive) and FR26 (control) macaques</p

Anti-gliadin antibodies (AGA) in TNPRC rhesus macaques with histories of clinical diarrhea

<p>Anti-gliadin antibodies (AGA) in TNPRC rhesus macaques with histories of clinical diarrhea</p

Histopathology of the small intestine.

<p>H&E-stained tissue sections of duodenum and proximal jejunum from rhesus macaques with idiopathic diarrhea. (A) Normal control duodenum from an age-matched rhesus macaque illustrating characteristic morphology of the villi. 100× magnification. (B) Enteropathy of duodenum. Diffuse enteritis characterized by shortening of villi, severe lymphocytic and plasmacytic infiltration of the lamina propria, and vacuolar degeneration of the epithelium. 100× magnification. (C) Normal control jejunum from an age-matched rhesus macaque. 100× magnification. (D) Enteropathy of jejunum. The mucosa appears flat with marked blunting of villi and dense infiltration of lamina propria by mononuclear cells. 100× magnification.</p

Gluten dependence of histological lesions in gluten-sensitive rhesus macaque FH09.

<p>(A) Morphometric analysis of villus height:crypt depth ratios from at least 4 different areas of distal duodenum in gluten-sensitive FH09 and control FR26 following dietary changes. Administration of a gluten-free diet increased the V:C ratio in FH09 at week 27 to a level that is statistically equivalent to that in FR26 (constant at all time points). Reintroduction of dietary gluten resulted in a drop in V:C ratio in FH09 (week 37) relative to that in FH09 on a gluten-free diet (week 27) and to that in FR26. *P<0.05. (B–C) H&E-stained duodenum at week 37 following 10 weeks of a gluten-containing diet. 100× magnification. (B) Control macaque FR26 exhibits normal villus architecture. (C) Gluten-sensitive macaque FH09 exhibits villus blunting. (D–E) Highlighted sections in B–C were examined by immunohistochemistry. 400× magnification. (D) Anti-CD3 staining in FR26 shows few CD3+ IELs (dark brown dots in epithelium). (E) Anti-CD3 staining in FH09 shows intraepithelial lymphocytosis.</p

Morbidity for rhesus macaques (<i>Macaca mulatta</i>) at TNPRC

<p>Morbidity for rhesus macaques (<i>Macaca mulatta</i>) at TNPRC</p

Comparison of celiac disease with proposed animal models for gluten sensitivity

A<p>March 2003;</p>B<p>Batt 1984, Batt 1987, Hall 1992;</p>C<p>Hall 1992;</p>D<p>Not tested for anti-TG2, but negative for anti-reticulin antibodies, unpublished data cited in Polvi 1998;</p>E<p>Polvi 1997, Polvi 1998;</p>F<p>Marietta 2004;</p>G<p>Not observed in majority of clinically ill macaques, but anti-TG2 IgG antibodies were observed in gluten-sensitive macaque FH45 during gluten challenge with EP-B2 treatment (Bethune et al., in press);</p>H<p>testing underway at TNPRC.</p