A pathogenic free-living amoeba, Naegleria fowleri, is a causative protozoan parasite of primary amebic meningoencephalitis in human and experimental animals. It is known that humoral and cellular immunity contribute as the defence mechanism of host against this organism. Recently splenectomy has been argued on its effect on host defence mechanisms. The present study was aimed to observe the effect of immunization in splenectomized mice. For immunization, 5-10 x 10(5) trophozoites of Naegleria fowleri o 359 were intraperitoneally inoculated once a week for two weeks to BALB/c mice, and 5-10 x 10(4) of ameba trophozoites were intranasally inoculated for infection after splenectomy and/or immunization. ELISA technique was applied for the detection of serum IgG antibody levels. Experimental animals were divided into 4 groups; I. splenectomized and immunized; II. splenectomized only; III. immunized only; IV. not splenectomized nor immunized. The results obtained were as follows: Mortality rates of splenectomized and immunized mice in group I (38.1 percent) and immurized only in group III (25.0 percent) were lower than those of not immunized mice in group II(50 percent) and control group, IV (46.4 percent). Survival times of mice in group I, II, III and IV were 20.1+/-3.6, l7.3+/-4.5, 20.4+/-7.0 and 19. 6+/-7.6 days respectively, and there were no significant differences between them. ELISA values (absorbance at 492 nm) of group I (1.10+/-0.29) and group III (1.31+/-0.28) were signficantly higher than that of group IV(0.24+/-0.37) at day 31 of infection (p<0.05). Conclusively, it is presumed that humoral immunity against N. flowleri may operate as ever, after immunization, even though the mouse was splenectomized.
parasitology-protozoa ; Naegleria fowleri ; mouse ; spleen ; immunology

Cancer immunoediting consists of three sequential phases: elimination, equilibrium, and escape. For colorectal adenoma-carcinoma sequence, the adenoma dysplastic progression may represent an equilibrium phase and the cancer stage as escape phase. Immune system eliminates transformed enterocytes by destroying them at first, sculpts them at the same time and selects the variants subsequently that are no longer recognized and insensitive to immune effectors, and finally induces immunosuppressive state within the tumor microenvironment that facilitates immune escape and tumor outgrowth. Immunosuppression and inflammation are the two crucial features of Pi (Spleen)-deficiency. Classic quotations, immune evidence and clinical observations suggest that Spleen (but not other organs) deficiency is the key pathogenesis of colorectal cancer (CRC) microenvironment. Weakness of old age, immunosuppressive cytokines from chronic inflammation, tumor-derived immunosuppressive factors and surrendered immune cells-regulatory T cells, myeloid-derived suppressor cells and tumor associated macrophages (TAMs) constitutes CRC microenvironment of Pi-deficiency. Furthermore, excess in superficiality, such as phlegm stagnation, blood stasis and toxin accumulation are induced by chronic inflammation on the basis of asthenia in origin, an immunosuppressive state. Great masters of Chinese medicine emphasize that strengthen Pi is the chief therapeutic principle for CRC which receives good therapeutic effects. So, Pi-deficiency based syndrome is the pivotal pathogenesis of tumor microenvironment. The immunosuppressive microenvironment facilitates immune escape which play an important role in the transition from adenoma to adenocarcinoma. There are some signs that strengthen Pi based treatment has potential capacity to ameliorate tumor environment. It might be a novel starting point to explore the mechanism of strengthen Pi based therapy in the prevention and treatment of CRC through regulation of tumor environment and immunoediting.
Colorectal Neoplasms ; immunology ; Humans ; Immune Evasion ; Immunosuppression ; Spleen ; immunology ; Syndrome ; Tumor Microenvironment ; immunology

To elucidate the effect of splenectomy on the development of experimental primary amoebic meningoencephalitis in mice, the death rate and survival time of mice infected intranasally with Naegleria fowleri trophozoites 5 x 10(4) cultivated in CGVS medium were compared according to the age when splenectomy was done, and post-operation until experimental infection. Immunodiffusion was undergone to detect the presence of serum antibody due to N. fowleri infection in mice. Polyacrylamide gel electrophoresis was done to compare the protein fractions of mouse serum in each experimental groups. In experiment I, splenectomy was done 3 weeks and infection 4 weeks after birth, the death rate of control, sham operated and splenectomized group were 100 percent, 85 percent and 95 percent, and the mean survival time after infection 7.3 days, 7.5 days and 7.8 days, respectively. In experiment II, splenectomy was undergone 3 weeks and infection 6 weeks after birth, the death rate of control, sham operated and splenectomized group were 95 percent, 95 percent and 95 percent , and the mean survival time after infection 12.1 days, 11.5 days and 11.5 days, respectively. In experiment III, splenectomy was done 5 weeks and infection 6 weeks after birth, the death rate of control, sham operated and splenectomized group were 95 percent, 90 percent and 95 percent, and the mean survival time after infection 8.1 days, 8.3 days and 8.5 days, respectively. By Ouchterlony immunodiffusion, anti-N. fowleri antibody in the serum of mouse with primary amoebic meningoencephalitis was detected against a N. fowleri antigen, which was prepared by ultrasonication of N. fowleri trophozoites, each reacting two lines of precipitation. The patterns of serum fractions by polyacrylamide gel electrophoresis were different between control and sham operated groups from splenectomized group in fraction II, III and V, the sera of which were collected after N. fowleri infection. This results may be summarized as that splenectomy has no effect on the development of primary amoebic meningoencephalitis in mice.
parasitology-protozoa ; Naegleria fowleri ; meningoencephalitis ; brain ; immunology ; spleen ; brain

OBJECTIVETo investigate the changes in function of splenic macrophages of hypersplenism due to portal hypertension (PH), and to provide experimental evidence for exploring the immune function of spleen in PH.

METHODSTwelve patients with hypersplenism due to PH and four patients with traumatic rupture of spleen, from September 2005 to March 2006, were enrolled into PH group and control group, respectively. Splenic M phi were isolated and purified by anchoring cultivation from all the patients, and were resuspended by RPMI-1640. Phagocytosis, cytokine secretion and antigen processing and presenting of splenic M phi were detected by Vybrant Phagocytosis Assay, the human TNF-alpha Elispot kits and DQ ovalbumin.

RESULTSCompare to the normal splenic M phi, the phagocytosis rate, antigen presentation positive cells and secretion positive cells, were all significantly increased in PH splenic M phi (86.4 +/- 7.1 vs. 61.8 +/- 4.1, 26.3 +/- 1.6 vs. 15.6 +/- 1.8, 387.0 +/- 24.3 vs. 240.3 +/- 13.0, P<0.01).

CONCLUSIONSThe phagocytosis, cytokine secretion and antigen processing and presenting of splenic M phi in PH spleen were all significantly increased, and the M phi retained at activated state. It means that the PH spleen still possessed the immune function, but these functions might be in disorder. It still needs more research to get the precious evaluation for immune function in the PH spleen.

Adult ; Antigen Presentation ; immunology ; Female ; Humans ; Hypersplenism ; etiology ; immunology ; Hypertension, Portal ; complications ; immunology ; Macrophages ; immunology ; Male ; Middle Aged ; Phagocytosis ; immunology ; Spleen ; immunology ; Tumor Necrosis Factor-alpha ; immunology

OBJECTIVETo investigate effects of the variation of immune function in high humidity environment in different time, and lay a foundation for further study of the related mechanism.

METHODThirty SD rats were divided into 3 groups (n = 10): 20 day group, 40 day group in 90% relative humidity chamber and control group in normal relative humidity. Peripheral blood and spleens were collected to detect the levels of T lymphocyte subsets by Flow Cytometery.

RESULTSIn peripheral blood of the 20 day group rats, the CD3+ %, CD4+ %, CD8+ % and CD4+/CD8+ were 52.91 +/- 6.27, 37.80 +/- 4.11, 14.85 +/- 3.73 and 2.72 +/- 0.82 separately. Expect CD3+ %, they all had significant differences (P < 0.05). In addition, the data of the 40 day group rats showed no diversity in statistics. In spleen, CD8+ % of the 20 day group rats was 6.23 +/- 2.87 with significant differences (P < 0.05) and IgG, IgA and IgM did not change a lot in blood serum of the high humidity groups except C3 of the 20 days group (P < 0.05).

CONCLUSIONIn high humidity environment, the immune function of the rats increased in the initial stage. As time went on, the immune function gradually went to normal level through the self adjustment.

Acclimatization ; Animals ; Humidity ; Rats ; Rats, Sprague-Dawley ; Spleen ; immunology ; T-Lymphocyte Subsets ; immunology

Female ; Humans ; Hypertension, Portal ; etiology ; immunology ; Male ; Proliferating Cell Nuclear Antigen ; metabolism ; Spleen ; immunology ; metabolism ; pathology

AIMTo investigate intermittent hypoxia effects on splenocyte mitogen-induced proliferation.

METHODSRats were exposured to intermittent hypoxia in a hypobaric chamber 4 h/d for 1 d, 2 d, 5 d and 15 d.

RESULTS5 km (10.8% O2) hypoxia for 1 d significantly inhibited ConA-induced splenocytes proliferation by--74.57% +/- 7.33% (P < 0.05). Hypoxia (5 km) for 2 d, 5 d and 15 d did not markedly affect splenocyte proliferation (97.03 +/- 7.18%, 104.5% +/- 8.38%, 99.55% +/- 3.8% respectively). Hypoxia 2 km (16.0% O2) for 1 d, 2 d, 5 d and 15 d had no influence on splenocytes proliferation (93.19% +/- 11.88%, 96.43% +/- 7.9%, 99.03% +/- 10.97%, 100.54% +/- 9.54% respectively). We also demonstrated that acute hypoxia exposure (5 km) 4 h significantly suppressed DNA contents of rat splenocytes by 76.22% +/- 7.06% (P < 0.05). The suppressed DNA synthesis were returned to control level after the hypoxia for 5 d and 15 d.

CONCLUSIONThese results suggest that the acute hypoxia (5 km, 4 h) induces a transient suppression on splenic lymphocyte proliferation, and the intermittent hypoxia may induce an adaptation response of the splenocytes proliferation.

Animals ; Cell Proliferation ; Hypoxia ; immunology ; Lymphocyte Activation ; Lymphocytes ; cytology ; immunology ; Male ; Rats ; Rats, Sprague-Dawley ; Spleen ; immunology

The immune function of spleen after partial splenectomy (PSM) of rabbits was stuided using microwave tissue coagulation (MTC). Streptococcus pneumoniae suspension was injected into the ear veins of rabbits 4 weeks after they were subjected to partial splenectomy using microwave tissue coagulation (PSM) group and to sham operation (SO groups), respectively. India ink was given via portal vein. Residual spleen were resected and microscopic examinations were performed on spleen slices stained using HE to compare phagocytic functions of macrophage. Gradings of phagocytic function in macrophage were of no significant difference between PSM and SO groups (P > 0.05). Weights of spleens showed no significant difference between the two groups (P > 0.05). The phagocytic function of macrophage after PSM can be preserved well. The result of this experiment implies that splenic salvage using MTC is a clinically applicable method.
Animals ; Female ; Macrophages ; immunology ; Male ; Microwaves ; therapeutic use ; Phagocytes ; immunology ; Rabbits ; Regeneration ; immunology ; Spleen ; physiology ; Splenectomy ; methods

To investigate the differential expression of various types of leukocyte common antigen (LCA) isoforms during development, we analyzed human fetal lymphoid organs, including the thymus, liver, spleen, and bone marrow from 14 weeks to 29 weeks of gestational age by immunohistochemical and flow cytometric methods. In fetal thymus, over 90% of thymocytes throughout the entire fetal life expressed CD45RO and CD45RB, while CD45RA was expressed only in less than 5% of thymocytes. This expression pattern of LCA isoforms was established by a gestational age of 14 weeks or earlier, and persisted throughout the fetal period. The tissue distribution was different from each isoform; CD45RO-positive thymocytes were found in both the cortex and medulla at the 14th week with low intensity, but was localized in the cortex with increasing fetal age. CD45RB-positive thymocytes distributed mainly in the medulla from early gestational age. Among extrathymic lymphoid organs, a small portion of lymphoid cells expressing leukocyte common antigens appeared first in the liver at 10-12 weeks of gestational age and was followed by a small number in the spleen and bone marrow by 13-15 weeks. All lymphoid cells in these extrathymic lymphoid organs at this stage were CD19+ B cells. The number of these CD19+ cells increased abruptly during the early period of mid-gestational age. The pattern of tissue distribution of each LCA isoform in the fetal liver and spleen correlated well with the patterns of quantitative analysis by flow cytometry. In summary we found that different LCA isoforms expressed in cell-type-specific pattern and showed different tissue distribution during the period of fetal development, and that LCA was the earliest antigen expressed by lymphocytes in the thymus and extrathymic lymphoid organs in our series.
Antigens, CD45/*analysis ; Bone Marrow/immunology ; Female ; Fetus/*immunology ; Flow Cytometry ; Human ; Immunoenzyme Techniques ; Liver/immunology ; Lymphoid Tissue/*immunology ; Pregnancy ; Spleen/immunology

OBJECTIVESTo study the cellular immune response to HSP70-HBcAg(18-27) complex in HBV transgenic mice.

METHODHSP70-HBcAg(18-27) complex was reconstituted in vitro, then it was injected into HBV transgenic mice to observe the cellular immune response. At the same time, we investigated whether HSP70-HBcAg(18-27) complex could generate antigen specific cytotoxic T lymphocyte responses in spleen cells.

RESULTSOur results demonstrated that HSP70-HBcAg(18-27) complex increased levels of CD4+ and CD8+ T cells in the spleens and peripheral blood of HBV transgenic mice, and the complex also activated dendritic and natural killer cells.

CONCLUSIONHSP70-HBcAg(18-27) complex has an immunological antigenicity in raising the immunoresponse to chronic HBV infection in HBV transgenic mice. HSP70-HBcAg(18-27) complex might be considered as a candidate for further studies on its role as a therapeutic vaccine against chronic HBV infection in humans.

Animals ; Female ; HSP70 Heat-Shock Proteins ; immunology ; Hepatitis B Core Antigens ; immunology ; Hepatitis B virus ; genetics ; immunology ; Male ; Mice ; Mice, Transgenic ; Spleen ; immunology ; T-Lymphocytes, Cytotoxic ; immunology