Out of three genotypes of Encephalitozoon cuniculi (I-III) available for experimental studies, E. cuniculi genotype I remains the less characterized. This study describes for the first time individual phases of microsporidiosis caused by E. cuniculi genotype I and efficacy of albendazole treatment in immunocompetent BALB/c and C57Bl/6 mice and immunodeficient SCID, CD4-/- and CD8-/- mice using molecular detection and quantification methods. We demonstrate asymptomatic infection despite an intense dissemination of microsporidia into most organs within the first weeks post infection, followed by a chronic infection characterized by significant microsporidia persistence in immunocompetent, CD4-/- and CD8-/- mice and a lethal outcome for SCID mice. Albendazole application led to loss E. cuniculi genotype I infection in immunocompetent mouse strains, decreased spore burden by half in CD4-/- and CD8-/- mice, and prolongation of survival of SCID mice. These results showed Encephalitozoon cuniculi genotype I infection extend and albendazole sensitivity was comparable to E. cuniculi genotype II, but the infection onset speed and mortality rate was similar to E. cuniculi genotype III. These imply that differences in the course of infection and the response to treatment depend not only on immunological status of the host, but also on the genotype causing the infection.

• MeSH
• albendazol aplikace a dávkování   MeSH
• antigeny CD4 genetika   MeSH
• antigeny CD8 genetika   MeSH
• antiinfekční látky aplikace a dávkování   MeSH
• Encephalitozoon cuniculi klasifikace   genetika   MeSH
• encephalitozoonóza imunologie   parazitologie   MeSH
• genotyp MeSH
• imunokompetence MeSH
• kvantitativní polymerázová řetězová reakce MeSH
• myši inbrední BALB C MeSH
• myši inbrední C57BL MeSH
• myši knockoutované MeSH
• myši SCID MeSH
• myši MeSH
• polymerázová řetězová reakce MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Encephalitozoon cuniculi genotype III disseminated intensively into most of the organs in all strains of mice, followed by a chronic infection with massive microsporidia persistence in immunodeficient mice and a partial decrease in C57Bl/6 mice. Treatment with 0.2 mg Albendazole/mouse/day temporarily reduces the number of affected organs in immunocompetent C57Bl/6 mice, but not in CD4-/- and CD8-/- mice. The application of medication temporarily decreased the spore burden at least by one order of magnitude in all groups. These results demonstrate that the E. cuniculi genotype III infection had a progressive course and surprisingly, Albendazole treatment had only a minimal effect. The E. cuniculi genotype III spore burden in individual organs reached up to 108 or 109 in immunocompetent or immunodeficient mice, respectively; however, these mice did not demonstrate any obvious clinical signs of microsporidiosis, and the immunodeficient mice survived longer. Our findings clearly show that the survival of mice does not correspond to spore burden, which provides new insight into latent microsporidiosis from an epidemiological point of view.

• MeSH
• albendazol terapeutické užití   MeSH
• antigeny CD4 genetika   MeSH
• antigeny CD8 genetika   MeSH
• Cercopithecus aethiops MeSH
• Encephalitozoon cuniculi genetika   MeSH
• encephalitozoonóza farmakoterapie   mikrobiologie   patologie   MeSH
• genotyp * MeSH
• modely nemocí na zvířatech MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• Vero buňky MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Of four genotypes of Encephalitozoon cuniculi, E. cuniculi genotype II is considered to represent a parasite that occurs in many host species in a latent asymptomatic form, whereas E. cuniculi genotype III seems to be more aggressive, and infections caused by this strain can lead to the death of even immunocompetent hosts. Although albendazole has been considered suitable for treatment of Encephalitozoon species, its failure in control of E. cuniculi genotype III infection has been reported. This study determined the effect of a 100× recommended daily dose of albendazole on an Encephalitozoon cuniculi genotype III course of infection in immunocompetent and immunodeficient mice and compared the results with those from experiments performed with a lower dose of albendazole and E. cuniculi genotype II. The administration of the regular dose of abendazole during the acute phase of infection reduced the number of affected organs in all strains of mice and absolute counts of spores in screened organs. However, the effect on genotype III was minor. Surprisingly, no substantial effect was recorded after the use of a 100× dose of albendazole, with larger reductions seen only in the number of affected organs and absolute counts of spores in all strains of mice, implying variations in albendazole resistance between these Encephalitozoon cuniculi genotypes. These results imply that differences in the course of infection and the response to treatment depend not only on the immunological status of the host but also on the genotype causing the infection. Understanding how microsporidia survive in hosts despite targeted antimicrosporidial treatment could significantly contribute to research related to human health.

• MeSH
• albendazol aplikace a dávkování   farmakologie   MeSH
• antifungální látky aplikace a dávkování   farmakologie   MeSH
• antigeny CD4 genetika   MeSH
• antigeny CD8 genetika   MeSH
• buněčné linie MeSH
• Cercopithecus aethiops MeSH
• Encephalitozoon cuniculi účinky léků   genetika   izolace a purifikace   MeSH
• encephalitozoonóza farmakoterapie   MeSH
• genotyp MeSH
• imunokompromitovaný pacient imunologie   MeSH
• mikrobiální testy citlivosti MeSH
• modely nemocí na zvířatech MeSH
• myši inbrední BALB C MeSH
• myši inbrední C57BL MeSH
• myši knockoutované MeSH
• myši SCID MeSH
• myši MeSH
• počet mikrobiálních kolonií MeSH
• Vero buňky MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The coreceptor CD8αβ can greatly promote activation of T cells by strengthening T-cell receptor (TCR) binding to cognate peptide-MHC complexes (pMHC) on antigen presenting cells and by bringing p56Lck to TCR/CD3. Here, we demonstrate that CD8 can also bind to pMHC on the T cell (in cis) and that this inhibits their activation. Using molecular modeling, fluorescence resonance energy transfer experiments on living cells, biochemical and mutational analysis, we show that CD8 binding to pMHC in cis involves a different docking mode and is regulated by posttranslational modifications including a membrane-distal interchain disulfide bond and negatively charged O-linked glycans near positively charged sequences on the CD8β stalk. These modifications distort the stalk, thus favoring CD8 binding to pMHC in cis. Differential binding of CD8 to pMHC in cis or trans is a means to regulate CD8+ T-cell responses and provides new translational opportunities.

• MeSH
• aktivace lymfocytů imunologie   MeSH
• antigeny CD8 chemie   genetika   metabolismus   MeSH
• biologické modely MeSH
• CD8-pozitivní T-lymfocyty imunologie   metabolismus   MeSH
• histokompatibilní antigeny chemie   genetika   imunologie   MeSH
• interakční proteinové domény a motivy MeSH
• konformace proteinů MeSH
• molekulární modely MeSH
• multiproteinové komplexy chemie   imunologie   metabolismus   MeSH
• mutace MeSH
• myši knockoutované MeSH
• myši MeSH
• peptidy chemie   imunologie   metabolismus   MeSH
• sekvence aminokyselin MeSH
• vazba proteinů MeSH
• vztahy mezi strukturou a aktivitou MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Porcine γδ T cells have two levels of TCRγδ expression. Whereas TCRγδ(med) cells are mostly CD2(+)CD8(-) and CD2(+)CD8(+), TCRγδ(hi) cells are highly enriched for CD2(-)CD8(-). This distribution is independent of bacterial colonization and it is already established in the thymus prior to export of γδ cells to the periphery. Sorting and cultivation experiments revealed that CD2(-)CD8(-) γδ cells are unable to acquire CD2 and CD8, whereas CD2(+) subsets can gain or loose CD8. There is also differential susceptibility for proliferation between CD2(+) and CD2(-) γδ cells. Although CD2(-)CD8(-) almost do not proliferate, proliferation of CD2(+)CD8(-) and CD2(+)CD8(+) is substantial. Population of CD2(-) γδ cells is also absent in CD1(+) immature thymocytes. Additionally, subpopulations of CD2(+) and CD2(-) γδ cells in the thymus differ in expression of auxiliary surface molecules such as CD25, CD45RA/RC, and MHC class II. Moreover, TCRγδ(hi) cells can generate TCRγδ(med) cells but never the opposite. The only exception is the thymus, where a few TCRγδ(med) cells can be induced to TCRγδ(hi) but only under IL-2 influence. The repertoire of TCRδ is polyclonal in all subsets, indicating that there is the same extent of diversification and equal capability of immune responses. Results collectively indicate that CD2 expression determines two lineages of γδ cells that differ in many aspects. Because CD2(-) γδ cells are missing in the blood of humans and mice but are obvious in other members of γδ-high species such as ruminants and birds, our findings support the idea that circulating CD2(-) γδ T cells are a specific lineage.

• MeSH
• antigeny CD1 genetika   imunologie   MeSH
• antigeny CD2 genetika   imunologie   MeSH
• antigeny CD8 genetika   imunologie   MeSH
• buněčná diferenciace imunologie   MeSH
• buněčný rodokmen imunologie   MeSH
• exprese genu MeSH
• interleukin-2 imunologie   MeSH
• lidé MeSH
• myši MeSH
• prasata MeSH
• proliferace buněk MeSH
• receptory antigenů T-buněk gama-delta genetika   imunologie   MeSH
• T-lymfocyty - podskupiny cytologie   imunologie   MeSH
• T-lymfocyty cytologie   imunologie   MeSH
• thymocyty cytologie   imunologie   MeSH
• thymus cytologie   imunologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH