РАЗНОБРАЗИЕ ДИКСЕННЫХ ЖИЗНЕННЫХ ЦИКЛОВ ТРЕМАТОД У МОЛЛЮСКОВ СЕМЕЙСТВА Вithyniidae (Gastropoda: Prosobranchia) ПАЛЕАРКТИКИ

Trematodes from 11 families have dixenic life cycles. Primary dixenic life cycles are typical for trematodes families Notocotylidae and Psilostomidae. Secondary dixenic life cycles have 3 versions. Trematodes from families Sanguinicolidae and Schistosomatidae develop only in the 1-st version of the secondary dixenic life cycles. The 2-nd version of the secondary dixenic life cycles typical for trematodes Cyclocoelidae, Lecithodendriidae, Microphallidae and for trematodes of 4 families (Monorchidae, Cyathocotylidae; Echinostomatidae; Opecoelidae) only in bad conditions. Sometimes several trematodes of Monorchidae develop in the 3-rd version of the secondary dixenic life cycles.Для трематод 11 семейств возможна реализация жизненных циклов по диксенному типу. Развитие трематод семейств Notocotylidae и Psilostomidae проходит по типу первичной диксении; для семейств Sanguinicolidae и Schistosomatidae – первым вариантом вторичной диксении; для семейств Cyclocoelidae, Microphallidae и Lecithodendriidae – по второму варианту вторичной диксении. Диксенный тип развития представителей других четырех семейств (Monorchidae, Opecoelidae; Cyathocotylidae; Echinostomatidae) можно рассматривать как дополнительный (или запасной), поскольку наблюдается только при неблагоприятных для трематод условий среды. Отдельные представители семейства Monorchidae могут реализовать свой жизненный цикл по третьему варианту вторичной диксении

ПЕРВОЕ ОБНАРУЖЕНИЕ OPISTHORCHIS FELINEUS И METORCHIS BILIS В ПЕРВЫХ ПРОМЕЖУТОЧНЫХ ХОЗЯЕВАХ БИТИНИИДАХ ИЗ БАССЕЙНА ОЗЕРА ЧАНЫ (НОВОСИБИРСКАЯ ОБЛАСТЬ)

Objective of research: to perform the analysis of long-term (15 annum) dynamics of Bithyniidae snails infected by trematode parthenites from the Chany Lake, the biggest lake in the south of Western SiberiaMaterials and methods: The Bithyniidae snails examined in the lake-river systemsChanyLake in 1994-2013 (in the middle reaches and in the estuary of theKargatRiver) and in theZolotyeRossypiBay and theMalyeChanyLake. The Bithyniidae snails were collected from May to September (twice in any ten days) by hand from 4–6 plots of0.25 m2 at a depth of 0.1–0.7 m. In total, 8,316Bithynia troscheli (Paasch, 1842) and 766 В. tentaculata (L., 1758) were examined. Identification of parthenitae trematode was based on observation when mature cercariae were capable of leaving the shell of the host snail on their own.Results and discussion: In Bithyniidae snails, we found parthenites from trematodes from 12 families Cyathocotylidae Mühling, 1898 Poche, 1925; Prosthоgonimidae Luhe, 1909; Pleurogenetidae Looss, 1898; Lecithodendriidae Odhner, 1911; Microphallidae (Ward, 1901) Travassos, 1920; Plagiorchiidae Lühe, 1901 Echinostomatidae (Looss 1899) Dietz, 1909 Odhner 1910); Psilostomidae (Looss 1900) Odhner 1913; Notocotylidae Luhe, 1909; Monorchiidae Odhner, 1911; Cyclocoelidae Kossack, 1911 и Opisthorchidae (Lass, 1899) Braun, 1901. The prevalence of bithyniid snails infected by trematode parthenites varied from 1,6% to 24,1% in different years.The double infection by trematode parthenites was found in 0,96% bithyniid snails from estuary of theKargatRiver; 4,45% in theMalyeChanyLake, and 26,6%, in theZolotyeRossypiBay. The cercariae of Opisthorchidae family in four annum of the fifteen detected. The prevalence of bithyniid snails infected by trematode parthenites from Opisthorchis felineus (Rivolta, 1884) and Metorchis bilis (Braun, 1890) was observed inChanyLakesystems for the first time. Both species (O. felineus and M. bilis) of trematodes have danger to human health and causes very dangerous disease, opisthorchiasis and metorchiasis.Цель исследования. Цель настоящей работы: оценить многолетнюю динамику зараженности моллюсков семейства Вithyniidae партенитами трематод в бассейне озера Чаны, самом крупном в Западной Сибири.Материалы и методы. Моллюски семейства Вithyniidae обследованы из речных (в среднем течении и устье) и озерных (залив и озеро) участках бассейна оз. Чаны в 1994-2013гг Количественный сбор битиниид проводили вручную в летний период.. Компрессорно исследованы 9082 экз. моллюсков: 766 экз Bithynia tentaculata (L., 1758) и 8316 экз Bithynia troscheli (Paasch, 1842). Определение видовой принадлежности партенит трематод проведено основе изучения живых зрелых церкарий. Рассчитана экстенсивность инвазии разными семействами трематод.Результаты и обсуждение. У моллюсков семейства Вithyniidae из бассейна оз. Чаны найдены представители трематод 12 семейств: Cyathocotylidae Mühling, 1898 Poche, 1925; Prosthоgonimidae Luhe, 1909; Pleurogenetidae Looss, 1898; Lecithodendriidae Odhner, 1911; Microphallidae (Ward, 1901) Travassos, 1920; Plagiorchiidae Lühe, 1901 Echinostomatidae (Looss 1899) Dietz, 1909 Odhner 1910); Psilostomidae (Looss 1900) Odhner 1913; Notocotylidae Luhe, 1909; Monorchiidae Odhner, 1911; Cyclocoelidae Kossack, 1911 и Opisthorchidae (Lass, 1899) Braun, 1901.Средняя многолетняя экстенсивность инвазии битиниид партенитами трематод составила 9,32% варьируя от 1,6% до 24,1% в разные годы. Встречаемость моллюсков с двойными инвазиями составила 0,96% на устьевых участках; 4,45% в озерных и до 26,6% в заливе. Партениты сем. Opisthorchidae обнаружены в четырех из пятнадцати годовых выборках. Два вида трематод (Opisthorchis felineus (Rivolta, 1884) и Metorchis bilis (Braun, 1890)) представляют опасность для здоровья людей. Впервые локальные очаги описторхидозов обнаружены на приустьевых участках реки Каргат

ВАРИАНТЫ ТРИКСЕННЫХ ЖИЗНЕННЫХ ЦИКЛОВ ТРЕМАТОД, ПАРАЗИТИРУЮЩИХ У МОЛЛЮСКОВ РОДА BITHYNIA (GASTROPODA: PROSOBRANCHIA ВITHYNIIDAE) ПАЛЕАРКТИКИ

The data on specific structure of trematodes in mollusks from genius Bithynia are done. It is revealed, that 33 species of trematodes 19 genius of 12 families from Bithynia Palaearctic have 12 versions of trixenic life cycles.Обобщены сведения о видовом составе трематод (на стадии партенит и церкарий), обнаруженных у моллюсков рода Bithynia. Выявлено, что 33 вида трематод 19 родов 12 семейств из битиниид Палеарктики имеют триксенные жизненные циклы, представленные 12 вариантами

ДИНАМИКА ОЧАГОВ НОТОКОТИЛЕЗОВ ПТИЦ В ЭКОСИСТЕМЕ ОЗЕРА ЧАНЫ (ЗАПАДНАЯ СИБИРЬ) ЗА ПОСЛЕДНИЕ 80 ЛЕТ

Objective  of research:    to  perform the analysis  of  dynamics  of bird notocotylidosis  foci in the ecosystem of Lake Chany in Western Siberia in the last 80 years.  Materials and methods: Helminthological examinations of snails of the family Bithyniidae and birds were conducted in the basin of Lake Chany in 1996–2013. The intestines of 172 birds belonging to 17 species were examined using the method of incomplete helminthological autopsy. The collection of snails of the family Bithyniidae was carried out manually in the summer season. All together 9 000 examples of snails belonging to Bithynia tentaculata and B. troscheli were collected. The infestation rate for cercariae in the snails was detected by the compressor method with the following calculation of extensity and intensity of infection and the index of abundance.  Results and discussion:    Marites of trematodes of the family Notocotylidae were registered in 7 of 17 species.  Different  rate of  infestation  by the  family Notocotylidae  of  various bird species was determined. The extensity of infection was in baldicoot  - 70,5 %, mallard  - 57,1, garganey  - 42,8, red headed duck - 54,5 % by the intensity of infection 35,6; 8,0; 19,3 and 5,5 examples, respectively.  During scientific  investigation about birds in the area of Lake Chany  in 1934–1938 notocotylides were found in 15 of 90 bird species. The analysis of dynamics of bird notocotylidosis in the ecosystem of Lake Chany (Western Siberia) in the last 80 years revealed that the bird infestation had increased from 23 % in the 30s of the last century up to 31 % in the 70s, and up to  60 % in our today's research. In the last 80 years 22 bird species served as primary hosts. The detection of marites  of the  family Notocotylidae  by different scientists  in all  the  years of research and the annual presence of parthenitas in snails of the  family Bithyniidae  indicates on the constant  focus of notocotylidosis  in the ecosystem of  Lake Chany. The infestation of semi-aquatic birds has been increased more than twice in the last years.  Цель исследования  –  анализ динамики очагов нотокотилезов у птиц в экосистеме озера Чаны в Западной Сибири за последние 80 лет. Материалы и  методы.  Гельминтологические исследования моллюсков-битиниид и птиц проводили в бассейне оз. Чаны в 1996–2013 гг. Методом неполного гельминтологического вскрытия исследовали кишечники 172 птиц, относящихся к 17 видам. Сбор моллюсков-битиниид проводили вручную в летний период. Всего собрано свыше 9 000 экз. моллюсков, относящихся к видам  Bithynia  tentaculata  и  B.  troscheli.  Компрессорным методом определяли  зараженность моллюсков церкариями трематод с последующим расчетом экстенсивности и интенсивности инвазии, индекса обилия. Результаты и обсуждение.  Из 17 видов птиц мариты нотокотилид зарегистрированы у 7 видов. Установлена различная степень зараженности разных видов птиц нотокотилидами. Экстенсивность инвазии составила лысухи 70,5 %, кряквы 57,1, чирка-трескунка 42,8, красноголовой чернети 54,5 % при интенсивности инвазии соответственно 35,6; 8,0; 19,3 и 5,5 экз. При исследовании птиц в районе оз. Чаны в 1934–1938 гг. нотокотилиды обнаружены у 15 из 90 видов птиц. Анализ динамики нотокотилидозов птиц в экосистеме оз. Чаны за последние 80 лет показал, что зараженность птиц увеличилась с 23 % в 30-е годы прошлого века до 31 % в 70-е годы и до 60 % в наших исследованиях. За последние 80 лет 22 вида птиц исполняли роль окончательных хозяев. Обнаружение марит трематод сем. Notocotylidae разными исследователями во все годы обследований и ежегодное наличие партенит у моллюсков сем. Bithyniidae указывает на наличие стабильного очага нотокотилидоза в экосистеме оз. Чаны. Зараженность околоводных птиц в регионе за последние годы увеличилась более чем в два раза. 

Differential roles of CCL2 and CCR2 in host defense to coronavirus infection.

The CC chemokine ligand 2 (CCL2, monocyte chemoattractant protein-1) is important in coordinating the immune response following microbial infection by regulating T cell polarization as well as leukocyte migration and accumulation within infected tissues. The present study examines the consequences of mouse hepatitis virus (MHV) infection in mice lacking CCL2 (CCL2(-/-)) in order to determine if signaling by this chemokine is relevant in host defense. Intracerebral infection of CCL2(-/-) mice with MHV did not result in increased morbidity or mortality as compared to either wild type or CCR2(-/-) mice and CCL2(-/-) mice cleared replicating virus from the brain. In contrast, CCR2(-/-) mice displayed an impaired ability to clear virus from the brain that was accompanied by a reduction in the numbers of antigen-specific T cells as compared to both CCL2(-/-) and wild-type mice. The paucity in T cell accumulation within the central nervous system (CNS) of MHV-infected CCR2(-/-) mice was not the result of either a deficiency in antigen-presenting cell (APC) accumulation within draining cervical lymph nodes (CLN) or the generation of virus-specific T cells within this compartment. A similar reduction in macrophage infiltration into the CNS was observed in both CCL2(-/-) and CCR2(-/-) mice when compared to wild-type mice, indicating that both CCL2 and CC chemokine receptor 2 (CCR2) contribute to macrophage migration and accumulation within the CNS following MHV infection. Together, these data demonstrate that CCR2, but not CCL2, is important in host defense following viral infection of the CNS, and CCR2 ligand(s), other than CCL2, participates in generating a protective response

Candida albicans Induces Selective Development of Macrophages and Monocyte Derived Dendritic Cells by a TLR2 Dependent Signalling

As TLRs are expressed by haematopoietic stem and progenitor cells (HSPCs), these receptors may play a role in haematopoiesis in response to pathogens during infection. We have previously demonstrated that in in vitro defined conditions inactivated yeasts and hyphae of Candida albicans induce HSPCs proliferation and differentiation towards the myeloid lineage by a TLR2/MyD88 dependent pathway. In this work, we showed that C. albicans invasive infection with a low virulence strain results in a rapid expansion of HSPCs (identified as LKS cells: Lin− c-Kit+ Sca-1+ IL-7Rα−), that reach the maximum at day 3 post-infection. This in vivo expansion of LKS cells in TLR2−/− mice was delayed until day 7 post- infection. Candidiasis was, as expected, accompanied by an increase in granulopoiesis and decreased lymphopoiesis in the bone marrow. These changes were more pronounced in TLR2−/− mice correlating with their higher fungal burden. Accordingly, emigration of Ly6Chigh monocytes and neutrophils to spleen was increased in TLR2−/− mice, although the increase in macrophages and inflammatory macrophages was completely dependent on TLR2. Similarly, we detected for the first time, in the spleen of C. albicans infected control mice, a newly generated population of dendritic cells that have the phenotype of monocyte derived dendritic cells (moDCs) that were not generated in TLR2−/− infected mice. In addition, C. albicans signalling through TLR2/MyD88 and Dectin-1 promotes in vitro the differentiation of Lin− cells towards moDCs that secrete TNF-α and are able to kill the microorganism. Therefore, our results indicate that during infection C. albicans can directly stimulate progenitor cells through TLR2 and Dectin-1 to generate newly formed inflammatory macrophages and moDCs that may fulfill an essential role in defense mechanisms against the pathogen

Impaired Functions of Peripheral Blood Monocyte Subpopulations in Aged Humans

Aging is associated with increased susceptibility to microbial infections, and monocytes play an important role in microbial defense. In this study, we have identified and compared four subpopulations of monocytes (CD14++(high)CD16−, CD14+(low)CD16−, CD14++(high)CD16+, and CD14+(low)CD16+) in the peripheral blood of young and aged subjects with regard to their numbers, cytokine production, TLR expression, and phosphorylation of ERK1/2 in response to pam3Cys a TLR-1/2 ligand. Proportions and numbers of CD14++(high)CD16+ and CD14+(low)CD16+ monocytes were significantly increased, whereas proportions of CD14+(low)CD16− monocytes were decreased in aged subjects as compared to young subjects. In aged subjects, IL-6 production by all four subsets of monocytes was significantly decreased, whereas TNF-α production was decreased in monocyte subsets, except the CD14+(low)CD16− subset. A significantly reduced expression of TLR1 was observed in CD14++(high)CD16+ and CD14+(low)CD16+ monocyte subsets in aged subjects. Furthermore, following pam3Cys stimulation, ERK1/2 phosphorylation was significantly lower in CD14+(low)CD16+, CD14++(high)CD16+, and CD14+(low)CD16− subsets of monocytes from aged subjects. This is the first study of four subpopulations of monocytes in aging, which demonstrates that their functions are differentially impaired with regard to the production of cytokines, expression of TLR, and signaling via the ERK–MAPK pathway. Finally, changes in the number of monocyte subsets, and impairment of TLR1 expression, TNF-α production, and EK1/2 phosphorylation was more consistent in CD16+ monocyte subsets regardless of expression of CD14high or CD14+low, therefore highlighting the significance of further subdivision of monocytes into four subpopulations

Visualizing early splenic memory CD8+ T cells reactivation against intracellular bacteria in the mouse

International audienceMemory CD8(+) T cells represent an important effector arm of the immune response in maintaining long-lived protective immunity against viruses and some intracellular bacteria such as Listeria monocytogenes (L.m). Memory CD8(+) T cells are endowed with enhanced antimicrobial effector functions that perfectly tail them to rapidly eradicate invading pathogens. It is largely accepted that these functions are sufficient to explain how memory CD8(+) T cells can mediate rapid protection. However, it is important to point out that such improved functional features would be useless if memory cells were unable to rapidly find the pathogen loaded/infected cells within the infected organ. Growing evidences suggest that the anatomy of secondary lymphoid organs (SLOs) fosters the cellular interactions required to initiate naive adaptive immune responses. However, very little is known on how the SLOs structures regulate memory immune responses. Using Listeria monocytogenes (L.m) as a murine infection model and imaging techniques, we have investigated if and how the architecture of the spleen plays a role in the reactivation of memory CD8(+) T cells and the subsequent control of L.m growth. We observed that in the mouse, memory CD8(+) T cells start to control L.m burden 6 hours after the challenge infection. At this very early time point, L.m-specific and non-specific memory CD8(+) T cells localize in the splenic red pulp and form clusters around L.m infected cells while naïve CD8(+) T cells remain in the white pulp. Within these clusters that only last few hours, memory CD8(+) T produce inflammatory cytokines such as IFN-gamma and CCL3 nearby infected myeloid cells known to be crucial for L.m killing. Altogether, we describe how memory CD8(+) T cells trafficking properties and the splenic micro-anatomy conjugate to create a spatio-temporal window during which memory CD8(+) T cells provide a local response by secreting effector molecules around infected cells

Inflammatory Monocytes and Neutrophils Are Licensed to Kill during Memory Responses In Vivo

Immunological memory is a hallmark of B and T lymphocytes that have undergone a previous encounter with a given antigen. It is assumed that memory cells mediate better protection of the host upon re-infection because of improved effector functions such as antibody production, cytotoxic activity and cytokine secretion. In contrast to cells of the adaptive immune system, innate immune cells are believed to exhibit a comparable functional effector response each time the same pathogen is encountered. Here, using mice infected by the intracellular bacterium Listeria monocytogenes, we show that during a recall bacterial infection, the chemokine CCL3 secreted by memory CD8+ T cells drives drastic modifications of the functional properties of several populations of phagocytes. We found that inflammatory ly6C+ monocytes and neutrophils largely mediated memory CD8+ T cell bacteriocidal activity by producing increased levels of reactive oxygen species (ROS), augmenting the pH of their phagosomes and inducing antimicrobial autophagy. These events allowed an extremely rapid control of bacterial growth in vivo and accounted for protective immunity. Therefore, our results provide evidence that cytotoxic memory CD8+ T cells can license distinct antimicrobial effector mechanisms of innate cells to efficiently clear pathogens

Depletion of Dendritic Cells Enhances Innate Anti-Bacterial Host Defense through Modulation of Phagocyte Homeostasis

Dendritic cells (DCs) as professional antigen-presenting cells play an important role in the initiation and modulation of the adaptive immune response. However, their role in the innate immune response against bacterial infections is not completely defined. Here we have analyzed the role of DCs and their impact on the innate anti-bacterial host defense in an experimental infection model of Yersinia enterocolitica (Ye). We used CD11c-diphtheria toxin (DT) mice to deplete DCs prior to severe infection with Ye. DC depletion significantly increased animal survival after Ye infection. The bacterial load in the spleen of DC-depleted mice was significantly lower than that of control mice throughout the infection. DC depletion was accompanied by an increase in the serum levels of CXCL1, G-CSF, IL-1α, and CCL2 and an increase in the numbers of splenic phagocytes. Functionally, splenocytes from DC-depleted mice exhibited an increased bacterial killing capacity compared to splenocytes from control mice. Cellular studies further showed that this was due to an increased production of reactive oxygen species (ROS) by neutrophils. Adoptive transfer of neutrophils from DC-depleted mice into control mice prior to Ye infection reduced the bacterial load to the level of Ye-infected DC-depleted mice, suggesting that the increased number of phagocytes with additional ROS production account for the decreased bacterial load. Furthermore, after incubation with serum from DC-depleted mice splenocytes from control mice increased their bacterial killing capacity, most likely due to enhanced ROS production by neutrophils, indicating that serum factors from DC-depleted mice account for this effect. In summary, we could show that DC depletion triggers phagocyte accumulation in the spleen and enhances their anti-bacterial killing capacity upon bacterial infection