To investigate the development of the reticular network of the thymus with aging and under pathologic conditions, we performed reticulin stains on the following samples; 5 fetal thymi (22 to 33 weeks of gestational age) and 35 postnatal thymi (less than 1 month to 33 years of age). The latter included 1 hyperplastic thymus, 4 pathologically involuted thymi and 1 physiologically involuted thymus as well as 29 normal thymi. Reticulin fibers were invariably seen along the capsule and interlobular septae of all the thymi. In fetal thymi, reticulin fibers circumscribed only cortical blood vessels and Hassall's corpuscles. Postnatal thymi from the children aged less than 1 month showed discontinuous reticulin fibers along the blood vessels of the corticomedullary junction. With aging, the amount of reticulin fibers increased and formed a "fibroreticular network(FRN)" from the branching point of the interlobular septae along the corticomedullary junction. It completely circumscribed the outer medulla in fully developed thymi. In the hyperplastic thymus, the reticular network retained its original structure. Both pathologically and physiologically involuted thymi revealed irregularly collapsed reticulin fibers. These findings suggest that the reticular network of the thymus consists of FRNs as well as capsule and interlobular septae and matures with aging before involution.
Adult ; Aging/*pathology ; Child ; Child, Preschool ; Female ; Humans ; Hyperplasia ; Infant ; Infant, Newborn ; Pregnancy ; Thymus Gland/cytology/*pathology

OBJECTIVETo investigate the influence of induced nitric oxide synthase (iNOS) expression on apoptosis of thymocyte in burn rats, and to explore the relationship between NO and pathological lesion of the thymus gland in burn rats.

METHODSFifty-six male Wistar rats were enrolled in the study and randomized into control( C, n = 8,without treatment) , burn ( B, n = 24) , and S-methylisothiourea( SMT, n = 24) groups. Equal amount of isotonic saline solution and SMT(7. 5 mg/kg) were respectively intravenously infused into the rats in B and SMT groups after being inflicted with 30% TBSA full-thickness burns. The weight of thymus gland in each group were weighed, and thymocyte apoptosis and iNOS expression were determined with TUNEL method and immunohistochemistry, respectively at 6,24,72 postburn hours( PBH) , with 8 rats at each time-point. The number of apoptotic cells and the density of iNOS positive cells in thymus was measured by stereological method.

RESULTSThe weight of thymus in B group at 24 and 72 PBH [ (153+/- 14) , (91+/-22) mg] were obviously heavier than those in C group, but much lighter than those in SMT group ( P < 0.01). A few apoptotic cells and iNOS positive cells were observed in cortex and medulla of thymus in C group, while they were observed in B group at 6 PBH, and the number of cells began to increase at 24 PBH, distributing in medulla,parenchyma, the boundary of cortex, and medulla under capsule. The iNOS positive cells in B group at 24 PBH were distributed around the interlobular septum. A large number of cortical cells with brown staining were observed in B group at 72 PBH, and the number of iNOS positive cells also increased, with scattered distribution and clear cell boundary. Fewer positive cells with uneven distribution, no iNOS positive cells, and few apoptotic foci were observed in SMT group after burns. The density of apoptotic cells in B group at 24 and 72 PBH was (2. 428 +/-0. 728) x 10(-5)/microm(3) and (5. 586 +/- 1.233) x 10(-5)/microm(3), respectively, which was obviously higher than that in C and SMT group. The density of iNOS positive cells in B group was increased in a time-dependent manner( P <0. 05).

CONCLUSIONThe apoptotic rate of thymocyte in severely burn rats increases early after burns. The up-regulation of iNOS expression in thymus can promote apoptosis of thymocytes, while SMT can partially ameliorate this phenomenon.

Animals ; Apoptosis ; Burns ; metabolism ; pathology ; Gene Expression Regulation ; Isothiuronium ; analogs & derivatives ; pharmacology ; Male ; Nitric Oxide Synthase Type II ; metabolism ; Organ Size ; Rats ; Rats, Wistar ; Thymus Gland ; cytology ; metabolism

OBJECTIVETo study the effects of liver specific antigen (LSA) on liver allotransplantation rejection.

METHODSOrthotopic liver transplantation was performed in this study. Group I: syngeneic control (Wistar-to-Wistar); Group II: acute rejection (SD-to-Wistar). Group III: thymic inoculation of SD rat LSA day 7 before transplantation. The observation of general condition and survival time, rejection grades and the NF-kappaB activity of splenocytes were used to analyze severity of acute rejection and immune state of animals in different groups.

RESULTSThe general condition of group I was fair post transplantation with no sign of rejection. All recipients of group II died within days 9 to 13 post transplantation with median survival time of 10.7 +/- 1.37 days. As for group III, 5 out of 6 recipients survived for a long period with remarkably better general condition than that of group II. Its rejection grades were significantly lower than group II (P<0.05). NF-kappaB activity was only detected in group I between days 5 and 7 after transplantation, whereas high activity of NF-kappaB was detected at all points in group II and low NF-kappaB activity was detected in group III which was significantly lower than that of group II (P<0.05).

CONCLUSIONSLSA is an important transplantation antigen directly involved in the immunorejection of liver transplantation. Intrathymic inoculation of LSA can alleviate the rejection of liver allotransplantation, grafts survive for a period of time thereby, allowing a novel way to liver transplantation immunotolerance.

Animals ; Cell Separation ; Graft Rejection ; metabolism ; pathology ; Isoantigens ; administration & dosage ; pharmacology ; Liver ; pathology ; Liver Transplantation ; Male ; NF-kappa B ; metabolism ; Rats ; Rats, Sprague-Dawley ; Rats, Wistar ; Spleen ; cytology ; metabolism ; Thymus Gland ; physiology

The study was purposed to investigate the effect of alloreactive natural killer (alloNK) cells on immune reconstitution in murine haploidentical bone marrow transplantation (BMT). The murine model of haploidentical BMT was established by using (C57BL/6×BALB/c)BCF(1)(H-2(d/b)) mouse as the donor, and BALB/c (H-2(d)) mouse as the recipient. Recipient mice were divided into BMT group, non-allo-reactive NK (non-alloNK) cell group and alloNK cell group according to different transfusion. The effect of adding alloNK cells to transfusion was assessed by thymus pathology, the proportion of spleen NK cells, the spleen cell proliferation, the IFN-γ and IL-4 concentrations product at 24 and 48 h of recipient spleen cell culture supernatant at 2 months after BMT. The results showed that there were no obvious difference in thymus tissue among 3 groups under the optical microscope. The proportion of recipient spleen NK cells in non-alloNK group was significantly lower than that in BMT group (P < 0.05). There was no significant difference in proliferation of the recipient spleen cells among 3 groups at 2 months after BMT. The IFN-γ concentration product at 24 and 48 h of recipient spleen cell culture supernatant in alloNK group was significantly lower than that in other 2 groups at 2 months after BMT (P < 0.05). The IL-4 concentration in each group was not significantly different (P > 0.05). It is concluded that alloNK cells do not damage the thymus structure and may induce Th2 immune response in murine haploidentical BMT.
Animals ; Bone Marrow Transplantation ; Interferon-gamma ; immunology ; Interleukin-4 ; immunology ; Killer Cells, Natural ; immunology ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Spleen ; cytology ; Thymus Gland ; pathology ; Transplantation, Homologous

OBJECTIVETo study the effect of spleen lymphocytes on the splenomegaly by hepatocellular carcinoma-bearing mouse model.

METHODSCell counts, cell cycle distribution, the percentage of lymphocytes subsets and the levels of IL-2 were measured, and two-dimensional gel electrophoresis (2-DE) was used to investigate the relationship between spleen lymphocytes and splenomegaly in hepatocellular carcinoma-bearing mice.

RESULTSCompared with the normal group, the thymus was obviously atrophied and the spleen was significantly enlarged in the tumor-bearing group. Correlation study showed that the number of whole spleen cells was positively correlated with the splenic index. The cell diameter and cell-cycle phase distribution of splenocytes in the tumor-bearing group showed no significant difference compared to the normal group. The percentage of CD3+ T lymphocytes and CD8+ T lymphocytes in spleen and peripheral blood of tumor-bearing mice were substantially higher than that in the normal mice. Meanwhile, the IL-2 level was also higher in the tumor-bearing group than in the normal group. Furthermore, two dysregulated protein, β-actin and S100-A9 were identified in spleen lymphocytes from H22-bearing mice, which were closely related to cellular motility.

CONCLUSIONIt is suggested that dysregulated β-actin and S100-A9 can result in recirculating T lymphocytes trapped in the spleen, which may explain the underlying cause of splenomegaly in H22-bearing mice.

Animals ; Carcinoma, Hepatocellular ; complications ; Cell Cycle ; Female ; Liver Neoplasms ; complications ; Lymphocytes ; physiology ; Mice ; Mice, Inbred ICR ; Neoplasms, Experimental ; therapy ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Spleen ; cytology ; pathology ; Splenomegaly ; etiology ; therapy ; Thymus Gland

OBJECTIVETo explore the characteristic of hypoxia-induced immune injury, its mechanisms and the intervention measure.

METHODSThe change of immune organ index, T lymphocyte subsets of peripheral blood and immune organ in mice during hypoxia were detected. Lymphocyte apoptosis of immune organ, pathology of lung and kidney in mice were observed. Then by way of prophylaxis we studied the effect of Chinese Traditional Medicine on hypoxia-induced immune injury in mice.

RESULTS(1) Exposure to hypoxia at 8 000 m simulated altitude for 8 h resulted in marked decrease in CD4+ CD8+ thymocytes and marked increase in CD4+ CD8-, CD4- CD8+ thymocytes (P < 0.01). After 3 days of hypoxia, the mice had a much lower percentage of CD4+ T-cell (P < 0.05). The ratio of CD4+/CD8+ decreased significantly and aforesaid changes of thymocyte were further enlarged. Also mice had a pronounced increase in rates of late apoptosis or necrosis of spleen lymphocyte and thymocyte (P < 0.05). After 6 days of hypoxia, index of spleen was significantly increased (P < 0.05), index of thymus was significantly decreased (P < 0.05) and CD3+, CD4+, CD8+ lymphocyte percentage of spleen were significantly decreased (P < 0.01). Also late apoptosis or necrosis lymphocytes of spleen and thymus were further increased (P < 0.01), viable cell rates of spleen lymphocyte and thymocytes were markedly decreased (P < 0.01), early apoptosis rates of spleen lymphocyte were markedly increased (P < 0.01). There was no significant change in the percentage of CD8+ lymphocyte in peripheral blood during the whole hypoxia period. (2) New Compound Codonopsis Pilosula (NCCP), Xiang Qi Polysaccharide (XQP) and NCCP + XQP could significantly increase the number of peripheral blood CD3+, CD4+ and spleen CD4+, but had no significant influence on the number of spleen CD8+. XQP and XQP+ NCCP could significantly decrease the number of CD4+ CD8+ (P < 0.01), increase that of CD4+ CD8- (P < 0.01), and had no significant influence on CD4- CD8+ in thymus. However, NCCP didn't influence the component of thymocytes.

CONCLUSIONAfter hypoxia at 8 000 m simulated altitude decrease of lymphocyte of periphery in mice may be related with increase of apoptosis and necrosis of lymphocyte, and with increase of distribution of lymphocyte to lung in early period of exposure. NCCP and XQP have hopeful prospect in intervention study of hypoxia-induced immune injury.

Altitude ; Animals ; Apoptosis ; drug effects ; CD4-Positive T-Lymphocytes ; CD8-Positive T-Lymphocytes ; Drugs, Chinese Herbal ; pharmacology ; Flow Cytometry ; Hypoxia ; immunology ; pathology ; prevention & control ; Lung ; cytology ; Lymphocyte Count ; Male ; Medicine, Chinese Traditional ; Mice ; Mice, Inbred BALB C ; Spleen ; cytology ; T-Lymphocyte Subsets ; cytology ; drug effects ; Thymus Gland ; cytology