Selective,Prolonged Alteration of Complement-Mediated Immune Clearance after Acute Exposure of Mice to Ethanol

A selective and prolonged alteration in complement-mediated immune clearance was found in mice given a single intraperitoneal injection of ethanol. Rate constants for the separate components of complement- and IgG Fcγ-mediated clearance were determined using a branched series, first-order reaction sequence model and measurements of the disappearance of radiolabeled IgG-opsonized murine erythrocytes from the circulation of BALB/c mice. The rate constant governing immune clearance mediated by IgG Fcγ receptors (k₃) decreased to 16% of control at 1 hr after ethanol injection but returned to normal in 72 hr. A >50% decrease in complement-mediated clearance occurred, with a nadir of complement-mediated sequestration (k₁) and complement-dependent phagocytosis (k₄) at 1 hr (P < 0.001). In this case, however, k₁ and k₄ rate constant values did not return to control levels until 6 weeks after the injection of ethanol. The rate constant governing C3b deactivation and release of deactivated, sensitized cells back to the circulation before they undergo phagocytosis (k₂) was initially normal, but decreased in Week 6 and remained low to the end of the observation period at 22 weeks (P < 0.0001). These changes resulted in a major reduction in overall complement-mediated immune clearance up to 4 weeks after the ethanol injection. The change to normal rates for sequestration and phagocytosis coupled with decreased deactivation and release at 6 weeks postinjection resulted in a small increase in overall complement-mediated clearance that persisted through Week 22.     

Abnormal IgG galactosylation in MRL-lpr/lpr mice: pathogenic role in the development of arthritis

MRL-lpr/lpr (MRL/lpr) mice spontaneously develop arthritis by an increase in the incidence of agalactosylated oligosaccharides in serum IgG, similar to rheumatoid arthritis patients. However, whether this association has a pathogenic significance is still unknown. In this study, we analyzed the oligosaccharide structure of serum IgG in various MRL mice with or without arthritis, to clarify the relationship between the oligosaccharide abnormality and the development of arthritis. The level of agalactosylation in serum IgG was comparable in both arthritis-free MRL/lpr and MRL-+/+ (MRL/+) mice at 6 weeks of age. In contrast, the incidence of IgG lacking galactose markedly increased in MRL/lpr mice at 6 months of age (the age at which arthritis occurred), compared with that from age-matched MRL/+ mice without arthritis. However, the proportion of agalactosylated IgG increased similarly in anti-CD4 monoclonal antibody-treated MRL/lpr mice at 6 months of age, despite the absence of the development of arthritis, because of depletion of CD4+ T cells. These results suggest that the abnormality in IgG galactosylation of MRL/lpr mice developed in an age-dependent manner, but it did so independently of CD4+ T cell-dependent B-cell activation and is not a consequence of the development of arthritis.     

Effect of Abrin on Cell-Mediated Immune Responses in Mice

Effect of abrin isolated from Abrus precatorius on the cellular immune responses was studied in normal as well as tumor-bearing animals. Administration of abrin was found to enhance the proliferation of splenocytes and thymocytes (lymphocytes in general) in responses to mitogens. Natural killer cell activity was enhanced significantly by abrin in both the normal (49.8% cell lysis on day 9) and the tumor-bearing group (51.7% cell lysis on day 9), and it was found to be earlier than the control. Antibody dependent cellular cytotoxicity was enhanced in the abrin treated tumor-bearing group on the ninth day (44% cell lysis). An early antibody dependent complement mediated cytotoxicity was observed in the abrin treated group on day 15 (27.6% cell lysis). Results of our present study suggest the immunomodulatory property of abrin.     

Effect of Biophytum sensitivum on Cell-Mediated Immune Response in Mice

Effect of Biophytum sensitivum on cell-mediated immune response was studied in normal as well as Ehrlich ascites tumor bearing BALB/c mice. Administration of Biophytum sensitivum significantly enhanced the proliferation of splenocytes, thymocytes and bone marrow cells by stimulating the mitogenic potential of various mitogens such as Lipopolysaccharide (LPS), Concanavalin A (Con A), Phytohaemagglutinin (PHA) and Poke Weed Mitogen (PWM). Natural killer (NK) cell activity was enhanced significantly by Biophytum sensitivum in both the normal (43.6% cell lysis on day 5) and the tumor bearing group (48.2% cell lysis on day 5), and it was found to be earlier than tumor bearing control animals (maximum of 13.4% cell lysis on day 9). Antibody dependent cellular cytotoxicity (ADCC) was also enhanced significantly in both Biophytum treated normal (35% cell lysis on day 7) as well as tumor bearing animals (40.2% cell lysis on day 7) compared to untreated control tumor bearing animals (maximum of 12.3% cell lysis on day 11). An early antibody dependent complement mediated cytotoxicity (ACC) was also observed in the Biophytum treated normal (22.6% cell lysis, on day 15) and tumor bearing animals (26.4% cell lysis, on day 15). Results of our present study suggest the immunomodulatory property of Biophytum sensitivum.     

Effect of Biophytum sensitivum on Cell-Mediated Immune Response in Mice

Effect of Biophytum sensitivum on cell-mediated immune response was studied in normal as well as Ehrlich ascites tumor bearing BALB/c mice. Administration of Biophytum sensitivum significantly enhanced the proliferation of splenocytes, thymocytes and bone marrow cells by stimulating the mitogenic potential of various mitogens such as Lipopolysaccharide (LPS), Concanavalin A (Con A), Phytohaemagglutinin (PHA) and Poke Weed Mitogen (PWM). Natural killer (NK) cell activity was enhanced significantly by Biophytum sensitivum in both the normal (43.6% cell lysis on day 5) and the tumor bearing group (48.2% cell lysis on day 5), and it was found to be earlier than tumor bearing control animals (maximum of 13.4% cell lysis on day 9). Antibody dependent cellular cytotoxicity (ADCC) was also enhanced significantly in both Biophytum treated normal (35% cell lysis on day 7) as well as tumor bearing animals (40.2% cell lysis on day 7) compared to untreated control tumor bearing animals (maximum of 12.3% cell lysis on day 11). An early antibody dependent complement mediated cytotoxicity (ACC) was also observed in the Biophytum treated normal (22.6% cell lysis, on day 15) and tumor bearing animals (26.4% cell lysis, on day 15). Results of our present study suggest the immunomodulatory property of Biophytum sensitivum.     

X射线全身照射对小鼠免疫功能的影响

目的:通过X-射线体外全身照射BALB/c小鼠建立小鼠辐射损伤模型,检测放射线对小鼠脾组织、单核巨噬细胞及T、B淋巴细胞损伤的剂量范围,探索放射线剂量与组织损伤程度之间的量效关系。方法:采用9种不同剂量的X-射线体外全身照射BALB/c小鼠,于照射后1d、60d、120d取腹腔细胞做大吞噬实验;分离脾细胞,MTT法检测T细胞增殖活性,同时取脾脏组织切片、HE染色,检测组织损伤程度;照射后120d取小鼠脾细胞用流式细胞仪检测T、B细胞数量百分比。结果:不同剂量X-射线照射的小鼠其大吞噬细胞的吞噬指数及T细胞的增殖指数之间均存在差异,且与放射剂量呈负相关性。FCM检测结果显示0.1Gy及以上剂量组与正常对照组相比较,小鼠T、B淋巴细胞数量减少(P<0.05)。0.25Gy和0.5Gy组T、B淋巴细胞数量明显高于除0.05Gy以外的其余各照射组,但是仍低于正常组(P<0.05)。脾组织切片显示,照射后1d 0.1Gy以上照射组脾脏炎性细胞浸润;60d后,4.0Gy和8.0Gy组脾脏明显萎缩、巨噬细胞增生、瘤样变,其余组损伤不明显;120d后8.0Gy组脾脏萎缩、红白髓分界不清,白髓损伤尤为严重,其余组不明显。结论:0.1Gy以上X-射线体外全身照射可引起小鼠免疫功能及组织损伤,且损伤程度与放射性强度呈剂量依赖性。     

Point Mutation of Hoxd12 in Mice

Purpose

Genes of the HoxD cluster play a major role in vertebrate limb development, and changes that modify the Hoxd12 locus affect other genes also, suggesting that HoxD function is coordinated by a control mechanism involving multiple genes during limb morphogenesis. In this study, mutant phenotypes were produced by treatment of mice with a chemical mutagen, N-ethyl-N-nitrosourea (ENU). We analyzed mutant mice exhibiting the specific microdactyly phenotype and examined the genes affected.

Materials and Methods

We focused on phenotype characteristics including size, bone formation, and digit morphology of ENU-induced microdactyly mice. The expressions of several molecules were analyzed by genome-wide screening and quantitative real-time PCR to define the affected genes.

Results

We report on limb phenotypes of an ENU-induced A-to-C mutation in the Hoxd12 gene, resulting in alanine-to-serine conversion. Microdactyly mice exhibited growth defects in the zeugopod and autopod, shortening of digits, a missing tip of digit I, limb growth affected, and dramatic increases in the expressions of Fgf4 and Lmx1b. However, the expression level of Shh was not changed in Hoxd12 point mutated mice.

Conclusion

These results suggest that point mutation rather than the entire deletion of Hoxd12, such as in knockout and transgenic mice, causes the abnormal limb phenotype in microdactyly mice. The precise nature of the spectrum of differences requires further investigation.     

Effect of Boar Seminal Immunosuppressive Component on Humoral Immune Response in Mice

PROBLEM: The effect of seminal immunosuppressive component (ISF) on the primary and secondary antibody response, induced by soluble and/or corpuscular antigens, was evaluated in the sera obtained at different intervals before and after immunizations. The duration of the immune suppression induced by ISF treatment within the primary and secondary immunizations was also determined. METHOD OF STUDY: The ability of the seminal immunosuppressive component to suppress the primary and secondary antibody response was evaluated by enzyme-linked immunoadsorbent assay (ELISA) in the sera of mice treated in vivo with the immunosuppressor before and after immunization with antigens. Likewise, the duration of the immune suppression induced by the seminal immunosuppressor administered before the primary and secondary immunizations was tested by ELISA with antisera to keyhole limpets hemocyanin. RESULTS: Intravenous and rectal deposition of ISF led to a suppression of the primary and secondary antibody response to soluble and corpuscular antigens. The most effective suppression of the immune response was achieved in mice treated with immunosuppressor 3 days before the immunization with antigens. Also the secondary antibody response to the challenging antigen was significantly suppressed by ISF. The production of immunoglobulin G (IgG), IgM, and IgA to keyhole limpets hemocyanin was depressed for a relatively long period in mice treated with the immunosuppressor. The results indicated that the preexposure is needed for maximal immunosuppression of the primary antibody production. The treatment with ISF led to a prolonged immunosuppression but not to permanent tolerance to the challenging antigen. CONCLUSIONS: The in vivo deposition of semen may compromise some aspects of the immune system and may be an important factor in the development of viral and bacterial infections. The suppression of humoral immune response suggests potential uses of seminal immunosuppressor for the animal model study in the therapy of antibody-mediated diseases.     

有丝分裂原对小鼠的免疫抑瘤作用

用刀豆蛋白Ａ（ＣｏｎＡ）治疗移植有ＭＡ７３的小鼠可在一定程度上抑制肿瘤，并延长了小鼠生存期。电镜下治疗了小鼠的肿瘤细胞可见程序性死亡倾向，与对照相比，有更多淋巴细胞浸润。     

Effect of Thyroxine on the Immune Response of Mice in Vivo and in Vitro

The effect of thyroxine on the immune response of BALB/c mice to sheep erythrocytes was investigated. In mice rendered hypertiyroid by subcutaneous injections of T4 the primary immune response to an injection of SRBC in vivo did not show a consistent increase in splenic anti-SRBC plaque-forming cells. However, the total number of splenic cells in T4-treated mice was generally decreased, and thus, the number of PFC per 10⁶ splenic cells in T4-treated mice was higher than those of saline and buffer controls. In in-vitro primary response to SRBC PFC per culture (3×10⁷ splenic cells) increased significantly in T₄-injected animals as compared with controls. The calculated PFC per spleen also increased significantly. The addition of T₄ to normal splenic cell cultures enhanced the primary immune response to SRBC in vitro. The optimum concentration of T₄ was found to be 10^-8 M. These results indicate a direct enhancing effect of T₄ on the immune response of lymphoid cells. This enhancing effect, however, may be attenuated in vivo by the alteration of the number and/or composition of lymphoid cells brought about directly or indirectly by injections of exogenous thyroxine.     

Immune Response to Mycobacterium leprae: Plaque-Forming Cells in Mice

Intravenous immunization with a cell extract of Mycobacterium leprae produced a primary immune response of considerable magnitude, followed by an equally large response after secondary stimulation, as measured by assay of plaque-forming cells (PFC). Infection with M. leprae or immunization with cell extract by the footpad route produced a lower level of response than that seen in the intravenous group. Identical patterns of response, although not of the same magnitude, were observed after both primary and secondary challenges in the two footpad groups, one infected with viable M. leprae and the other immunized with M. leprae cell extract. The secondary response after a booster dose to all these groups appeared to be an enhanced immunoglobulin M response. Control studies confirmed that the immune response was a direct result of the host-parasite interaction and that the PFC observed resulted from stimulation of antibody-forming cells by antigens of M. leprae. The similarity in time of appearance of peak PFC levels in the two footpad groups may be attributed to the live challenge passing through a latent phase. Alternatively, the challenge is known to contain a large proportion on nonviable cells, and it may also contain soluble M. leprae antigens. Studies of the cross-reactivity of the antigens have extended previous observations on antigens shared between M. leprae and other mycobacterial species. Use of the two antigen-containing fractions of the M. leprae cell extract has suggested that one of the fractions contains some shared antigens, whereas the other has an antigen specific to M. leprae.     

Effect of Dexamethasone on Immune Response of Mice with Different Behavioral Types

Experiments on a model of paired sensory contact showed that dexamethasone effectively suppressing the response to ACTH not only prevented immunosuppression in male C57Bl/6J mice with submissive behavior formed during different periods of confrontation testing (days 10 and 20), but also stimulated the immune response in comparison with the control. Immune response in aggressive animals after 20-day confrontations was higher than in controls and submissive mice and did not change after dexamethasone injection. The authors conclude that the immunosuppressive effect in submissive animals is realized through ACTH, which little contributes into immunomodulation in aggressive mice.__________Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 139, No. 5, pp. 550–552, May, 2005     

Modulatory Effect of the Pesticide Captan on the Immune Response in Rats and Mice

The effect of short-term oral administration of captan, [N-(trirnethylthio)-4-cyclohexene-1,2-carboximidel on the immune response was studied in rats and mice. Animals were fed a diet with or without 0.3 % (w/w) of captan for 7, 14, 21 and 42 days. The SRBC-antibody formation was depressed by about 70 % in both species after 14 days of treatment. A release of inhibition occurred in mice at day 42. In a parallel manner, the lymphoblastic stimulation of splenic cells by PHA and by LPS was studied in captan-treated mice and their controls. The stimulation by PHA of splenic cells that were mainly T cells was clearly inhibited (45 %) by day 14 of captan ingestion. Thereafter, the inhibition was only partially released until day 42. B cells, stimulated by LPS, presented a decrease in stimulation in captan-treated mice, during the first week of diet (20 %). Then an important increase in the stimulation of these cells occurred at day 21 (85 %) followed by a return to the normal value at day 42. These results pointed out a clear depressive effect of captan-diet on the immune response of the animals. The inhibition of SRBC-antibody formation during the first stage of the treatment may be correlated to the inhibitory effect of captan on T cells, which were cooperative with B cells for the expression of SRBC-antibody synthesis. These effects were obtained at a level of captan which was considerably lower than the toxic dose.     

Modulatory Effect of the Pesticide Captan on the Immune Response in Rats and Mice

Abstract

The effect of short-term oral administration of captan, [N-(trirnethylthio)-4-cyclohexene-1,2-carboximidel on the immune response was studied in rats and mice. Animals were fed a diet with or without 0.3 % (w/w) of captan for 7, 14, 21 and 42 days. The SRBC-antibody formation was depressed by about 70 % in both species after 14 days of treatment. A release of inhibition occurred in mice at day 42. In a parallel manner, the lymphoblastic stimulation of splenic cells by PHA and by LPS was studied in captan-treated mice and their controls. The stimulation by PHA of splenic cells that were mainly T cells was clearly inhibited (45 %) by day 14 of captan ingestion. Thereafter, the inhibition was only partially released until day 42. B cells, stimulated by LPS, presented a decrease in stimulation in captan-treated mice, during the first week of diet (20 %). Then an important increase in the stimulation of these cells occurred at day 21 (85 %) followed by a return to the normal value at day 42. These results pointed out a clear depressive effect of captan-diet on the immune response of the animals. The inhibition of SRBC-antibody formation during the first stage of the treatment may be correlated to the inhibitory effect of captan on T cells, which were cooperative with B cells for the expression of SRBC-antibody synthesis. These effects were obtained at a level of captan which was considerably lower than the toxic dose.     

Effect of Paris Saponin on Antitumor and Immune Function in U14 Tumor-Bearing Mice

We evaluated the effect of Paris saponin on inhibition of cervical cancer in mice and on immune regulation in tumor-bearing mice. MTT assay was used to examine the effect of Paris saponin on U14 cell proliferatiosn in vitro; the ascites tumor model of U14 cervical cancer was established to observe the effect of Paris saponin on inhibition of the tumor and on survival time of mice; and serum IL-4 and IFN-γ levels in tumor-bearing mice were detected. The Paris saponin showed significant inhibitory effect on growth of cervical cancer U14 cells both in vitro and in vivo, prolonged the survival time of mice, increased the serum IFN-γ level of tumor-bearing mice, and reduced the serum IL-4 level. The Paris saponin can inhibit U14 cell growth and prolong survival time of mice; it is speculated that the Paris saponin may express its anti-tumor activity by improving the body''s immune system.     

Neutrophils Are Essential for Rapid Clearance of Enterococcus faecium in Mice

A progressive increase in infections with multiresistant Enterococcus faecium has been reported, especially in cancer patients and neutropenic patients. Despite its increasing importance as a nosocomial pathogen, knowledge of the pathogenesis of E. faecium infections is highly limited. In this study, we investigated the role of neutrophils during peritonitis with subsequent bacteremia caused by E. faecium. Therefore, we depleted neutrophils by intraperitoneal injections of monoclonal antibody RB6-8C5. Mice were followed for 5 days, and the enterococcal outgrowth and inflammatory response were compared between neutropenic mice and immunoglobulin G-injected control mice. Neutropenic mice demonstrated a severe delay in enterococcal clearance from all cultured organs (peritoneal fluid, blood, and lung and liver tissue). In particular, neutropenic mice remained bacteremic for up to 3 days, whereas all nonneutropenic mice had cleared the bacteria from circulation by 2 days. Furthermore, neutropenic mice displayed elevated peritoneal cytokine and chemokine levels 1 day after the infection and attracted fewer macrophages into the peritoneal cavity. In the circulation, a prolonged elevation of tumor necrosis factor alpha, interleukin-6, and the acute-phase proteins serum amyloid A and complement 3 were measured in neutropenic mice. In conclusion, attraction of neutrophils to the primary site of E. faecium infection is important for a rapid clearance of this bacterium, thereby attenuating a systemic inflammatory response.Enterococci are part of the normal bacterial flora of human and animal gastrointestinal tracts. Although enterococci were once not regarded as virulent, they are now recognized as a major cause of nosocomial infections worldwide (13). They are the third most common cause of nosocomial bacteremia in the United States and the fourth most common in Europe (http://www.earss.rivm.nl/). Although enterococci rarely cause diseases in healthy individuals, they can become pathogenic in patients in intensive care units, in hospitalized patients with severe underlying diseases or an impaired immune system, and in elderly people (23). Severely ill patients with hematologic malignancies and deep neutropenia are especially at an increased risk of developing enterococcal bacteremia (6, 7, 18, 29, 43).The emergence of infections with enterococci can largely be attributed to their multiresistant nature to various classes of antibiotics. Especially Enterococcus faecium has acquired resistance to high-dose aminoglycosides, beta-lactam antibiotics, and vancomycin (5, 20, 37). Hospital-acquired E. faecium isolates belong predominantly to a distinct genetic subpopulation currently known as clonal complex 17 (CC17), which has adapted extremely well to the hospital environment and has spread worldwide (39). CC17 is characterized by the acquisition of multiple adaptive mechanisms, including ampicillin and quinolone resistance, a putative pathogenicity island harboring the esp virulence gene, and other cell surface protein genes (16, 19-21).Despite the clinical importance of enterococci, little is known about defense mechanisms that protect the normal host against invasive enterococcal infections. The innate immune system represents the first line of defense against bacterial infections (27, 46). In previous studies, we described the normal immune response during primary E. faecium peritonitis (22). In a nonlethal model, we found a fast and brisk peritoneal neutrophil influx and a consecutive, rapid decline in peritoneal and systemic enterococcal load. In Toll-like receptor 2 (TLR2) and myeloid differentiation protein 88 knockout mice, a significantly reduced amount of neutrophils was attracted to the peritoneal cavity, which was accompanied by a delay in enterococcal clearance (22). These data, together with the fact that neutropenic patients are more vulnerable to acquiring E. faecium infections, prompted us to investigate the role of neutrophils during nonlethal E. faecium peritonitis with subsequent bacteremia.     

四氧嘧啶糖尿病小鼠的细胞免疫状态的研究

以四氧嘧啶糖尿病小鼠为模型探讨了细胞免疫状态的变化。结果显示,四氧嘧啶糖尿病小鼠脾淋巴细胞DNA合成减少,IL-2产生降低。自然杀伤活性细胞功能减弱,表现为体内YAC-1细胞清除速率延缓。将糖尿病鼠脾淋巴细胞悬浮于含一定量胰岛素的培养液内,其细胞增殖应答活性明显升高,IL-2产生显著增多。提示胰岛素可能是一种重要的免疫调节激素。