Omental and pleural milky spots: different reactivity patterns in mice infected with Schistosoma mansoni reveals coelomic compartmentalisation

In vertebrate animals, pleural and peritoneal cavities are repositories of milky spots (MS), which constitute an organised coelom-associated lymphomyeloid tissue that is intensively activated by Schistosoma mansoni infection. This study compared the reactive patterns of peritoneal MS to pleural MS and concluded from histological analysis that they represent independent responsive compartments. Whole omentum, lungs and the entire mediastinum of 54 S. mansoni-infected mice were studied morphologically. The omental MS of infected animals were highly activated, modulating from myeloid-lymphocytic (60 days of infection) to lymphomyeloid (90 days of infection) and lymphocytic or lymphoplasmacytic (160 days of infection) types. The non-lymphoid component predominated in the acute phase of infection and was expressed by monocytopoietic, eosinopoietic and neutropoietic foci, with isolated megakaryocytes and small foci of late normoblasts and mast cells. Nevertheless, pleural or thoracic MS of infected mice were monotonous, consisting of small and medium lymphocytes with few mast and plasma cells and no myeloid component. Our data indicate that compartmentalisation of the MS response is dependent on the lymphatic vascularisation of each coelomic cavity, limiting the effects or consequences of any stimulating or aggressive agents, as is the case with S. mansoni infection.

Role of MDC/CCL22-CCR4 axis in mouse milky spots with peritoneal carcinomatosis of gastric cancer / 中华普通外科杂志

Objective To study role of MDC/CCI22-CCR4 axis in mouse milky spots with peritoneal carcinomatosis of gastric cancer. Methods We examined the expression of CCR4 in 615 Mouse gastric cancer cell (MFC) lines by RT-PCR and Western-blot; Peritoneal metastasis model on the 615mouse was established by intraperitoneal injection of 0.2 ml MFC cells(1×104 cells). Dil fluorescence was used to observe the transfer process and section of MFC. Immunohistochemistry was conducted to detect the expression of CCR4 and CCL22 in omental milky spot; the structure of Milky spot was observed by scanning electron microscopy. Mice were randomly divided into 2 groups, namely, the saline control group (received saline) and MFC group. The concentration of CCL22 in ascitic fluid was measured in the 615 mice injected MFC after 6,8,10 days and in the saline group. Results MFC first metastasizes to the milky spot on the omentum, the expression of CCR4 and CCL22 were observered in the milky spot. The surface layer cells in milky spot consisted of discontinuous mesothelial cells and mainly macrophages and lymphocytes. The average value of CCL22 was 43 pg/ml and 364 pg/ml respectively in saline control group and MFC group.Conclusions MDC/CCL22-CCR4 axis plays an important role in the development of peritoneal carcinomatosis in mouse gastric cancer.

MDC/CCL22-CCR4 axis in milky spots in peritoneal carcinomatosis of gastric cancer / 中华普通外科杂志

Objective To study the role of MDC/CCL22-CCR4 axis in milky spots in peritoneal carcinomatosis of gastric cancer.Methods We examined the expression of CCR4 in 5 gastric cancer cell lines by RT-PCR and Western-blot.Cell growth rate of BGC-823 cell lines before and after incubated with CCL22 was detemined by MTT assay.The effects of CCL22 on invasion of BGC-823 cells into Matrigel were measured using Transwell test.Immunohistochemistry was conducted to detect the expression of CCR4.Results CCR4 mRNA and protein expression were detected in all 5 human gastric cancer cell lines:CCL22had a direct promotive effect on BGC-823 cell prolifetation and invasion.There was CCR4 expression in Stomach neoplasms.The expression of CCR4 in primary tumor was correlated with tumor pathological differentiation(P<0.05),but not with age of patients,gender,location of tumor,tumor size,tumor stage,lymph node metastasis(P>0.05).Conclusions The MDC/CCL22-CCR4 axis may be one of the mechanism of peritoneal metastasis in milky spot in gastric cancer.

Defense mechanism of the greater omentum / 中国病理生理杂志

AIM:To observe the distribution of 5'-nucleotidase positive of milky spot and lymphatic vessels in the greater omentum and investigate the defense mechanisms of the greater omentum in another way. METHODS:The whole mount preparations of the greater omentum was stained with enzyme histochemistrical and immunohistochemistrical methods and observed with light microscopy and confocal laser scanning microscopy. RESULTS: Positive reaction was showed in lymphocytes at deep portions of the milky spot. A lot of lymphatic capillaries which had no basement membrane were found in intercellular spaces of adipose cells at superficial portions of the milky spot. CONCLUSION: These findings indicated that the adenosine formed in the milky spot inhibited the action of immunocyte in the milky spot. The lymphatic capillaries in the superficial portions may play some roles with the defense mechanisms of the greater omentum.