Experimental infection of mice by Salmonella typhi inoculated orally: influence of immunosuppressive therapy

Various immunosuppressive treatments were used in order to induce a Salmonella typhi infection in mouse by oral route. Neither low protein diets nor administration of mucin, iron, streptomycin or silica could modify animal's sensitiveness, but, cyclophosphamide injections enhanced lethal effect of bacteria, while silica increased the number of bacteria in the blood and the spleen.     

鼻腔接种伤寒杆菌Fe-SOD对鼠伤寒杆菌攻击小鼠的免疫保护作用

为探讨鼻腔接种伤寒杆菌Fe-SOD对鼠伤寒杆菌攻击小鼠的交叉免疫保护作用,用IL－1作为佐剂,将伤寒杆菌Fe-SOD经鼻腔接种小鼠,再以不同剂鼠伤寒杆菌攻击,观察小鼠的存活情况,当用IL－1作为佐剂时,经鼻腔接种伤寒杆菌Fe-SOD的小鼠在2LD50鼠伤寒杆菌攻击后,3天和7天的存活率均明显高于对照组（P＜0．01或P＜0．05）,当以5LD50鼠直菌攻击时,小鼠7天的存活率明显高于对照组（P＜0．01）。结果说明伤寒杆菌Fe-SOD经鼻腔接种后对鼠伤寒杆菌的攻击可产生一定的免疫保护作用,也进一步说明了Fe-SOD是沙门氏菌的共同保护性抗原。     

Tumour-induced immune modulation of sentinel lymph nodes

Sentinel lymph nodes (SLNs), being the first nodes to receive lymph from a primary tumour and the preferential site of initial tumour metastases, are intensively exposed to the bioactive products of tumour cells and other associated cells. This makes them ideal for studies of the factors that determine selective tissue susceptibility to metastases. We postulate that tumour-induced immune modulation of SLNs facilitates lymph-node metastases by inhibiting the generation of tumour-specific cytotoxic T cells that are active against tumour cells of primary and metastatic melanomas. Immune modulation of the lymph nodes can be reversed by granulocyte/macrophage colony-stimulating factor (GM-CSF), a finding that has implications for the future therapy of lymph-node metastases.     

Effect of adjuvants on immune response and protective immunity elicited by recombinant Hsp60 (GroEL) of Salmonella typhi against S. typhi infection

Heat shock proteins (Hsps) have been reported to be dominant antigens for the host immune response to various pathogens and thus, have great potential for use in vaccination. In the present study, we evaluated the immunogenicity and protective efficacy of GroEL of Salmonella enterica serovar Typhi against lethal infection by S. typhi Ty2 in mice with or without adjuvants. Anti GroEL–IgG titers were significantly higher in mice immunized with either GroEL-alone or in combination with alum/Complete Freund’s adjuvant (CFA) as compared to the control. Analysis of antibody isotypes suggested predominance of Th2 type immune response in GroEL + alum immunized animals as revealed by higher IgG1/IgG2a ratio. Whereas, immunization of animals with GroEL + CFA or GroEL-alone shifted the immune response toward Th1 phenotype. Mice immunized with GroEL with or without adjuvants, showed a significant increase in lymphocyte proliferation and cytokine levels. The animals immunized with GroEL + CFA or GroEL-alone showed higher IFN-γ and IL-2 levels than alum group, indicating Th1 response whereas IL-4 levels (Th2 response) were found to be highest in alum group as compared to other two immunized groups. Immunization of mice with GroEL-alone, GroEL + alum, and GroEL + CFA provided 70, 50 and 80% protection, respectively, against lethal challenge by S. typhi in mice. The differences in the percentage protection among various groups were attributed to the differences in the immune responses generated by respective immunizations. The present study shows that GroEL forms an ideal candidate molecule to develop a recombinant protein based vaccine against human typhoid.     

The nature of the factors in immune lymph nodes that stimulate humoral and cellular immune reactions

In the early period after antigen action, cells of the lymph node draining area of antigen injection produce a factor, which after its administration to intact mice, promotes intensified migration of myelopeptide producers in the bone marrow and increases bone marrow suppressor activity. Factor administration produced 2-3-fold increase in macrophage, peritoneal and lymph node count as compared with control, and 2-4-fold increase in humoral and cellular immune response. The factor consists of three easily identifiable components: Ig, MHC class II determinants and antigen determinants, that form unique complex similar to, or identical with the complexes detected in vivo within 3-6 hours after immunization in serum by other authors.     

Listeria infection inhibits IgE production in regional lymph nodes by suppressing chemotaxis of basophils to lymph nodes

Infection with Listeria induces a dominant shift to the Th1 immune response and inhibits the Th2 response. Papain is frequently utilized in animal models of allergies. Papain administration induces chemotaxis of basophils to regional lymph nodes (LNs) and production of interleukin (IL)‐4 by basophils, resulting in a Th2‐dominant status and increased IgE production in LNs. In this model, production of immunoglobulin (Ig) E by LN cells is primarily controlled by IL‐4 produced by basophils. Based on this model, it was postulated that Listeria monocytogenes (Lm) infection suppresses IgE production by LN cells. Therefore, the effects of Lm infection on a papain‐induced mouse model of allergies were investigated. Following s.c. injection of papain, basophils transiently migrated to draining LNs because of the effects of chemokine (C–C) motif ligand (CCL) 24 and secreted IL‐4, inducing a Th2 response. Lm infection blocked recruitment of basophils into the popliteal LNs by inhibiting CCL24 production. Papain‐induced class switch recombination (CSR) to IgE is inhibited by Lm infection, whereas CSR to IgG1 is not affected by the same treatment. Therefore, the CSR of IgG1 to IgE is basophil‐dependent, whereas the CSR of IgM to IgG1 is basophil‐independent. Hence, Lm infection suppresses CSR to IgE without affecting CSR to IgG1.     

Spread of herpes simplex virus in lymph nodes after experimental infection of mice

Herpes simplex virus was frequently isolated from ipsilateral popliteal lymph nodes after percutaneous inoculation of the dorsal face of the footpad, and from ipsi- and contralateral submandibular lymph nodes after percutaneous inoculation of the cheek or the orofacial area of mice. Virus was detected only on very rare occasion in nondraining lymph nodes (inguinal or axillary) or in contralateral popliteal lymph nodes, but was frequently isolated in contralateral lumbar lymph nodes after footpad inoculation. The presence of virus in lymph nodes paralleled or followed the invasion of ipsilateral sensory ganglia and was associated with dissemination of virus in contralateral sensory ganglia after unilateral inoculation. In older mice virus was detected only occasionally in lymph nodes and dissemination of virus in contralateral sensory ganglia was generally not observed. The results suggest that lymphatic spread may contribute to dissemination of virus in contralateral sensory ganglia after unilateral inoculation of mice.     

Enhancement of natural resistance of mice to Rhodococcus equi infection by Dextran Sulfate 500

The effect of intraperitoneal injection of Dextran Sulfate 500 (DS-500, 500,000 Mr) on the intravenous clearance and host resistance to Rhodococcus equi in mice was studied. Contrary to the results seen with Listeria monocytogenes, DS-500 enhanced murine resistance to R. equi and altered organ distribution and clearance.     

一种基于数字免疫原理的伤寒沙门菌高灵敏度检测方法

目的 设计一种基于数字化免疫显色原理的检测方法,实现伤寒沙门菌的高灵敏度快速检测.方法 以伤寒沙门菌为检测对象,选取氨基磁珠对目标细菌进行富集,以偶联特异性抗体的量子点对目标细菌进行特异性荧光标记;设计制作反应腔室,在液相条件下完成对目标细菌的富集和特异性荧光标记;通过荧光显微成像和荧光特征自动提取,实现对目标细菌的"...     

Specific immunoglobulin response in mice immunized with porins and challenged with Salmonella typhi

Specific antiporin antibody (IgG, IgM, and IgA) response was studied in control, infected, immunized-infected, and immunized mice. The activity of specific IgG immunoglobulins was found to be the highest in immunized and immunized-infected groups in which 87.5% protection had been observed by laboratory potency test in mice; the next-highest activities were those of IgM and IgA immunoglobulins. However, in the infected group the activity of specific IgM and IgG immunoglobulins was almost similar.     

伤寒杆菌SOD抗体对小鼠腹腔吞噬细胞杀灭伤寒杆菌的影响

为了制备伤寒要直菌ＳＯＤ抗体,研究该抗体对小鼠腹腔吞噬细胞杀灭伤寒杆菌的影响,探讨ＳＯＤ与伤寒杆菌抗吞噬作用的关系。采用纯化的伤寒杆菌（Ｓｔｗｌ）Ｆｅ－ＳＯＤ免疫农兔制备兔抗Ｆｅ－ＳＯＤ抗体。利用ＥＡＬＩＳＡ法检测抗体的效价。免疫电泳、双向琼脂扩散试验和抗体对酶活性抑制试验分析抗体的特性。用不同浓度的抗体预先处理伤寒杆菌,然后进行小鼠腹腔吞噬细胞的吞噬杀菌试验。试验结果抗体的ＥＬＩＳ攻疚价为１：１     

Characterization of lymphocyte subsets in the bronchiolar lymph nodes of BALB/c mice infected with cilia-associated respiratory bacillus

Cilia-associated respiratory (CAR) bacillus is an unclassified, gram-negative, extracellular bacterium that causes chronic respiratory tract disease in rodents. Infected mice develop microscopic lesions characterized by a primary lymphocytic response followed by macrophage and neutrophilic infiltration. To characterize the lymphocytic subsets that respond to CAR bacillus infection, BALB/c mice were inoculated with 10(5) CAR bacillus bacteria. At seven weeks after inoculation, mice were euthanized and the tracheobronchiolar and hilar lymph nodes were collected and stained for cell surface markers to T cells (CD3, CD4, and CD8), B cells (B220, CD5), natural killer (NK) cells (pan-NK) and intracellular interleukin 10 (IL-10) and interferon-gamma (IFN-gamma). Flow cytometric analysis of lymph nodes from CAR bacillus-infected mice revealed 11% increase in frequency of B cells (R220+), 12% increase in the frequency of double-negative (CD4-CD8-CD3+) T cells, and slight increase in the B-1 subset of B cells (B220+CD5+). There was no change in the frequency of NK cells. The CAR bacillus-infected mice had an overall decrease in the frequency of T cells. Intracellular cytokine staining revealed distinct populations of T cells producing IL-10 and IFN-gamma, and IL-10 production from B cells; NK cells were not a substantial source of IFN-gamma. To our knowledge, this is the first characterization of lymphocytic responses and suggestion that B cells and double-negative T cells may be principally responsible for the lesions associated with CAR bacillus infection.     

B-lymphocyte responses in the large intestine and mesenteric lymph nodes of mice infected with Eimeria falciformis (Apicomplexa)

B-cell responses of 3 immunoglobulin isotypes (IgA, IgG, and IgM) were investigated in the large intestine and mesenteric lymph nodes (MLN) of naive or immune mice after inoculation of oocysts of Eimeria falciformis. Primary and anamnestic IgA and IgG lymphocyte responses to E. falciformis occurred in the large intestine of nonimmune and immune mice, respectively. IgA-containing lymphocytes (IgAc) were the largest population of responding B cells in the large intestine. In infected mice, IgAc accumulated in the apical portion of the lamina propria, whereas IgG-containing lymphocytes (IgGc) were more numerous at the base of the lamina propria. No significant increase in the number of IgM-containing lymphocytes (IgMc) was observed in the lamina propria of the large intestine. Primary but no anamnestic B-cell responses occurred in the MLN, and immune mice actually had reduced numbers of IgAc and IgGc in the MLN when compared with naive mice. IgGc were the largest population of responding B cells in the MLN. Thus, IgAc appear to accumulate preferentially at the site of parasite development, whereas IgGc are primarily localized deeper in the lamina propria of the large intestine and in the draining lymph nodes of mice infected with E. falciformis.     

Lack of age-associated immune dysfunction in mucosal-associated lymph nodes

The magnitude of the immune response in old and young mice to trinitrophenylated bovine gamma-globulin was measured in various lymphatic sites at a cellular level using the plaque-forming cell assay. As we have previously shown, the number of splenic IgM, IgG, and IgA anti-TNP PFC progressively declined in aging C57BL/6J male mice. In addition, mice receiving antigen in the 4 footpads and the base of the tail exhibited similar decline in the number of PFC in the draining peripheral lymph nodes with increasing age. In contrast, mesenteric and mediastinal lymph node IgM, IgG, and IgA anti-TNP PFC response to TNP-BGG in complete Freund's adjuvant, i.p. or via gastric intubation, in old mice remained unimpaired compared with the number in younger mice. The data support the view that the mucosal-associated lymphoid system differs from the systemic system with regard to immune competence with age. Furthermore, the findings imply a site preference for a decline in immune function with aging.