[Consideration on implementation of co-administration of Seasonal Influenza and COVID-19 vaccines during pandemic in China]

Influenza is an infectious respiratory disease caused by the influenza viruses. Older people, infants and people with underlying medical conditions could have a higher risk of severe influenza symptoms and complications. The co-infection of Coronavirus Diseases 2019 (COVID-19) with influenza viruses could lead to the complication of prevention, diagnosis, control, treatment, and recovery of COVID-19. Influenza vaccine and COVID-19 vaccine overlapped in target populations, vaccination time, and inoculation units. Although there was insufficient evidence on the immunogenicity and safety of co-administration of influenza vaccine and COVID-19 vaccine, World Health Organization and some countries recommended co-administration of inactivated influenza vaccine and COVID-19 vaccine. This review summarized domestic and international vaccination policies and research progress, and put forward corresponding suggestions in order to provide scientific support for the formulation of vaccination strategy on seasonal influenza vaccine and COVID-19 vaccine.

Increased cGAS/STING signaling components in patients with Mooren's ulcer

AIM

To explore the expression of cGAS/STING signaling components in Mooren's ulcer (MU).

METHODS

Samples were obtained from ten MU patients, and eight residual corneal-scleral rings of healthy donor corneas for controls. Human corneal epithelial cells (HCECs) were used to evaluate the effect of cGAS/STING signaling pathway. Immunohistochemistry (IHC) and Western blot were used to examine the expression of cGAS, STING, and phosphorylated interferon regulatory factor 3 (p-IRF3) in MU tissues. The expression of interferon-β (IFN-β) and interferon-stimulated genes (ISGs) was quantified by real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA).

RESULTS

The protein levels of cGAS and STING in MU samples were significantly elevated when compared with the healthy controls by Western blot and IHC. After stimulation with cGAMP, real-time PCR and ELISA showed a dramatic increase of IFN-β and ISGs (containing CXCL10, IFIT1, and IL-6) in HCECs. Moreover, HCECs treated with cGAMP was characterized by increased phosphorylation and more nuclear translocation of IRF3. Meanwhile, increased p-IRF3 was observed in MU samples via IHC and Western blot.

CONCLUSION

The pronounced expression of cGAS/STING signaling components in the patients with MU and probably contribute to the onset and development of MU.

Recombinant human erythropoietin for treating severe traumatic brain injury

BACKGROUND

This study aimed to explore the efficacy and safety of recombinant human erythropoietin (RHE) for the treatment of severe traumatic brain injury (STBI).

METHODS

One hundred and twenty eligible patients with STBI were randomly divided into an intervention group or a control group equally. Patients in the intervention group received RHE. The participants in the control group received 0.9% saline. The outcome measurements included the Glasgow Outcome Scale (GOS) scores, mortality, and any adverse events.

RESULTS

At the end of 10-week follow-up after treatment, RHE neither showed greater efficacy in GOS scores (1-2, P = .43; 3-4, P = .25; 5-6, P = .58; 7-8, P = .23), nor the lower mortality in the intervention group than those in the control group (P = .47). In addition, both groups had similar safety profile.

CONCLUSION

This study found that RHE did not improve the neurological outcomes in patients with STBI.

RNAi-mediated knockdown of FANCF suppresses cell proliferation, migration, invasion, and drug resistance potential of breast cancer cells

Fanconi anemia complementation group F protein (FANCF) is a key factor, which maintains the function of FA/BRCA, a DNA damage response pathway. However, the functional role of FANCF in breast cancer has not been elucidated. We performed a specific FANCF-shRNA knockdown of endogenous FANCF in vitro. Cell viability was measured with a CCK-8 assay. DNA damage was assessed with an alkaline comet assay. Apoptosis, cell cycle, and drug accumulation were measured by flow cytometry. The expression levels of protein were determined by Western blot using specific antibodies. Based on these results, we used cell migration and invasion assays to demonstrate a crucial role for FANCF in those processes. FANCF shRNA effectively inhibited expression of FANCF. We found that proliferation of FANCF knockdown breast cancer cells (MCF-7 and MDA-MB-435S) was significantly inhibited, with cell cycle arrest in the S phase, induction of apoptosis, and DNA fragmentation. Inhibition of FANCF also resulted in decreased cell migration and invasion. In addition, FANCF knockdown enhanced sensitivity to doxorubicin in breast cancer cells. These results suggest that FANCF may be a potential target for molecular, therapeutic intervention in breast cancer.

Polymorphisms in the promoter of the CD14 gene and their associations with susceptibility to pulmonary tuberculosis

Although the role of CD14 in recognizing Mycobacterium tuberculosis is well-understood, the possible role of polymorphisms in susceptibility to develop tuberculosis remains unclear. This study evaluates whether there is an association of polymorphisms within the promoter of the CD14 gene with susceptibility to pulmonary tuberculosis. In a case-control study, we genotyped the eight known single nucleotide polymorphisms SNPs within the promoter of the CD14 gene of 698 Han Chinese subjects. Statistically significant differences between tuberculosis patients and healthy controls were found for G-1619A, T-1359G, A-1145G, and C-159T. The haplotype-GGGT, composed of these four SNPs, exhibited a significant association with the disease. Furthermore, expression levels of soluble CD14 were significantly higher in tuberculosis patients with the GGGT haplotype than with other haplotypes, while IgE expression levels were significantly reduced. Our results suggest that these four SNPs within the promoter of the CD14 gene are associated with susceptibility to pulmonary tuberculosis.

The Diagnostic Value of Ultrasound Elastography in Patients with Hepatitis B Virus Infection: A Prospective Study

The aim of this prospective study was to investigate the diagnostic value of ultrasound elastography for evaluating liver stiffness measurement (LSM) in 74 patients with hepatitis B virus (HBV) infection, treated with telbivudine (22 with chronic HBV infection, 32 with compensated cirrhosis and 20 with decompensated cirrhosis). Each patient underwent ultrasound elastography measurements and serum liver marker assays before and after 6 months' treatment with 600 mg telbivudine, orally, once daily. In the 22 patients with chronic HBV infection, LSM values measured by ultrasound elastography decreased significantly following the treatment period compared with baseline. The LSM values were significantly higher in the 20 patients with decompensated cirrhosis than in the 32 patients with compensated cirrhosis after treatment. Significant decreases in serum hepatic fibrosis indices occurred in all patients following treatment. The correlation between fibrosis index, hyaluronic acid level and LSM was statistically significant in all patients, whereas the correlation between alanine aminotransferase and LSM was not. The findings suggest that liver stiffness in patients with HBV can be measured simply with ultrasound elastography and that it is reduced within 6 months by treatment with telbivudine. The main adverse events noted during the study period were that creatine kinase levels were increased in seven patients and that seven patients had influenza-like symptoms.

In Vitro Hepatic Differentiation of Mesenchymal Stem Cells from Human Fetal Bone Marrow

We examined whether human fetal mesenchymal stem cells (FMSCs) derived from fetal bone marrow were able to differentiate into functional hepatocyte-like cells in vitro The surface phenotype of FMSCs was characterized by flow cytometry. To induce hepatic differentiation of FMSCs, we added hepatocyte growth factor, basic fibroblast growth factor and oncostatin M into the cell culture medium. After 21 days of hepatocyte induction, FMSCs expressed the hepatocyte-specific markers, α-fetoprotein and cytokeratin 18, as demonstrated by immunofluorescence staining. Differentiated FMSCs also demonstrated in vitro functions characteristic of liver cells, including albumin production, urea secretion and glycogen storage. In conclusion, fetal bone marrow-derived FMSCs are able to differentiate into functional hepatocyte-like cells and may serve as a source of cells for liver disease therapy.

CD4(+)CD25(+) regulatory T cells contribute to the therapeutic effects of glatiramer acetate in experimental autoimmune encephalomyelitis

CD4(+)CD25(+) regulatory T cells (Tregs) are potent immunosuppressors that are pivotal in the maintenance of self-tolerance. The involvement of Tregs in therapies for immune-mediated diseases has been proposed, but direct supporting evidence is still lacking. While investigating mechanisms underlying the clinical benefits of glatiramer acetate (GA) in an animal model of multiple sclerosis (MS), i.e., experimental autoimmune encephalomyelitis (EAE), we recently demonstrated that GA can protect mice deficient in the Th(2) cytokines IL-4, IL-10 and IL-4/IL-10 from acquiring EAE, suggesting that mechanisms other than Th(2) cells may be responsible for the therapeutic effects of GA. Here we demonstrate that GA treatment boosts the expression of Foxp3 on Tregs during EAE. Furthermore, adoptive transfer of purified Tregs from GA-treated EAE mice is more effective in preventing EAE development than Tregs from untreated EAE controls. Thus, our current data provide evidence that Tregs may be the major contributor to GA's therapeutic action in EAE and, possibly, MS. Further mechanistic studies to reveal the molecular events linking GA with Tregs may optimize GA treatment and lead to the development of new, even more effective therapies that utilize this mechanism of action.

The clinical value of serum CEA, CA19-9, and CA242 in the diagnosis and prognosis of pancreatic cancer

AIM

Serum tumour markers carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9) and CA242 were investigated to evaluate the values of single and combined test in the diagnosis and prognosis of pancreatic cancer.

METHODS

Pre-operative serum CEA, CA19-9 and CA242 were measured in 105 pancreatic cancers, 70 non-pancreatic malignancies and 30 benign pancreatic diseases.

RESULTS

The sensitivity of CA19-9 alone was the highest in pancreatic cancer patients (80%), but the specificity was significantly lower than that of CEA and CA242 (P<0.01). The combination of CEA and CA242 could increase the specificity to 92%. In serum CA242 positive patients, the survival time was remarkably shorter than that of patients with negative result (P<0.01). The survival time in patients with more than two markers positive expression of CEA, CA19-9 and CA242 was obviously shorter than that of only one or no marker positive expression (P<0.05).

CONCLUSION

The diagnostic rate of CA19-9 in pancreatic cancer is better than that of CEA and CA242. Combined detection of CEA and CA242 can improve the diagnostic specificity obviously. High levels of serum markers are associated with advanced stage of the disease. Patients with two or three markers positive expression of CEA, CA19-9, and CA242 simultaneously had a shorter survival time.

B7H costimulates clonal expansion of, and cognate destruction of tumor cells by, CD8(+) T lymphocytes in vivo

B7H/B7RP (hereby called B7H) is a new member of the B7 family of costimulatory molecules and interacts with inducible costimulatory molecule (ICOS). Its function for CD8 T cells has not been reported. We report here that expression of B7H on the tumor cells reduced tumorigenicity and induced immunity to subsequent challenge with parental tumor cells. The immune protection correlates with an enhanced cytotoxic T lymphocyte (CTL) response against P1A, the major tumor antigen expressed in the J558 tumor. To understand the mechanism of immune protection, we adoptively transferred transgenic T cells specific for tumor antigen P1A into mice that bore P1A-expressing tumors. We found that while the transgenic T cells divided faster in mice bearing the B7H(+) tumors, optimal B7H-induced clonal expansion of P1CTL required costimulation by B7-1 and B7-2 on the endogenous host antigen-presenting cells (APCs). Interestingly, when B7H(+) and B7H(-) tumors were coinjected, P1CTL selectively eliminated the B7H(+) tumor cells. Moreover, B7H expressed on the tumor cells made them highly susceptible to destruction by CTL in vivo, even if the CTL was administrated into mice with large tumor burdens. Tumors that recurred in the P1CTL-treated mice lost transfected B7H and/or H-2L(d), the class I molecule that presents the P1A peptide. Taken together, our results reveal that B7H costimulates clonal expansion of, and cognate destruction by CD8(+) T lymphocytes in vivo.

Local costimulation reinvigorates tumor-specific cytolytic T lymphocytes for experimental therapy in mice with large tumor burdens

Cytotoxic T cells recognize tumor Ags and destroy cancer cells in vitro. Adoptive transfer studies with transgenic T cells specific for tumor Ags have demonstrated that CTL are effective only in mice with small tumor burdens and thus appear to have limited potential in cancer immunotherapy. Here we used transgenic mice that express the TCR specific for an unmutated tumor Ag P1A and multiple lineages of P1A-expressing tumors to address this critical issue. We found that local costimulation, either by expression of B7-1 on the tumor cells or by local administration of anti-CD28 mAb 37N, reinvigorated the function of CTL specific for the tumor Ag, as it substantially increased the efficacy of CTL therapy for mice with large tumor burdens. Our study suggests that CTL-based immunotherapy can be manipulated to deal with large tumors.

On the site and mode of antigen presentation for the initiation of clonal expansion of CD8 T cells specific for a natural tumor antigen

Because of the low frequency of antigen-specific T cells, early events in the activation of tumor-specific T cells in vivo have not been well characterized. There is still no direct documentation on where the clonal expansion begins and how tumor antigens are presented to the host CD8 T cells to initiate it. Here we used transgenic T cells specific for a natural tumor antigen P1A to evaluate the kinetics, location, and modes of antigen presentation for initiating CTL response in vivo. Our results demonstrate that the initial activation of P1A-specific T cells takes place in the lymphoid organs. The activated T cells then migrate into tumors, where they undergo accelerated division and acquire distinct activation markers. The site of initiation cannot be altered by either local expression of costimulatory molecules or by intratumor injection of naïve T cells. Moreover, using genetic models that allow only one mode of antigen presentation, we show here that both cross-presentation of P1A by the host antigen-presenting cells, and direct antigen presentation and costimulation by the tumor cells are sufficient to initiate rapid T cell-clonal expansion in the lymphoid organ. These results provide direct evidence for two fundamental assumptions on the mechanisms of T-cell activation in vivo.

Optimal induction of effector but not memory antitumor cytotoxic T lymphocytes involves direct antigen presentation by the tumor cells

MHC class I-restricted tumor antigen can be presented to CD8+ T cells by two distinct mechanisms. Direct presentation involves degradation of cytosolic proteins by the proteosome into peptides, transport of the peptides across the endoplasmic reticulum membrane, and expression of the MHC-peptide complex on the tumor cell surface. Cross-presentation, on the other hand, involves uptake and intracellular processing of the tumor antigen by host antigen-presenting cells. Whereas it is clear that cross-presentation is necessary and sufficient for the induction of memory CTLs, it has not been tested whether such presentation is sufficient to induce effector CTLs. Here we analyzed the requirements of direct antigen presentation for the induction of effector and memory antitumor CTLs using a MHC class I- mutant incapable of direct antigen presentation and its parent, the MHC class I+ J558 cell line. We report that in comparison with the MHC class I+ tumor cell, the MHC class I- mutant induces equal priming for recall CTL response but poor effector CTLs. Our results demonstrate that optimal induction of effector CTLs, but not memory CTLs, requires direct antigen presentation by the tumor cells.

Adenovirus-mediated expression of antisense RNA transcripts complementary to pig alpha(1,3) galactosyltransferase mRNA inhibits expression of Gal alpha(1,3) Gal epitope

AIM

To examine the effects of the expression of antisense RNA transcripts complementary to the pig alpha(1,3) galactosyltransferase [alpha(1,3)GT]mRNA on the expression of Gal alpha(1,3) Gal structure (gal epitope) in cultured cell lines.

METHODS

Human adenoviral vectors were used to mediate the expression of antisense RNA. The expression levels of H blood group antigens and gal epitopes were analyzed by flow cytometry using FITC-UEA-I and FITC-GS-IB4 lectins, respectively.

RESULTS

Recombinant adenoviruses, Ad5anti-sGT600 and Ad5-anti-sGT1100, which express antisense RNA complementary to different regions of the pig alpha(1,3) GT mRNA, were constructed and used to infect cell line of NIH3T3. The results showed about 30% reduction in the expression level of gal epitopes on the surface of NIH3T3 cells. In addition, co-expression of human secretor type alpha(1,2) fucosyltransferase [alpha(1,2)FT]cDNA and antisense RNA complementary to the pig alpha(1,3) GT mRNA led to a further reduction in the gal epitope level.

CONCLUSION

Recombinant adenoviruses, Ad5anti-sGT600 and Ad5anti-sGT1100, are effective to down-regulate the gal epitope expression.

Adenovirus-mediated expression of human secretor type alpha(1,2) fucosyltransferase reduces level of Gal alpha(1,3)Gal epitope

AIM

To test the potential of human secretor type alpha(1, 2) fucosyltransferase [Se alpha(1,2)FT] to downregulate the expression of Gal alpha(1,3)Gal epitope (gal epitope) in cultured cell lines.

METHODS

Expression of Se alpha(1,2) FT was mediated by human adenoviral vector. Flow cytometric analysis was used to compare the expression level of H blood group antigen or gal epitope. MTT was employed to assess the susceptibility of mouse NIH3T3 cells to human natural antibody and complement mediated lysis.

RESULTS

A recombinant replication-deficient adenovirus (rAdv) containing human Se alpha(1,2)FT cDNA (Ad5hSeFT) was designed and successfully constructed. Flow cytometric analysis showed that after mock infection, Ad5null infection, and Ad5hSeFT infection, the mean fluorescence intensity (MFI) values for the binding of Ulex europaeus I (UEA-I) lectin to NIH3T3 cells were 2.3 +/- 0.6, 2.1 +/- 1.0, and 36.5 +/- 5.9, respectively; MFI values for the binding of Griffonia simplicifolia isolectin B4 (GS-IB4) lectin to NIH3T3 cells were 167 +/- 23, 170 +/- 19, and 100 +/- 14, respectively; MFI values for the binding of human natural IgG and IgM antibodies to NIH3T3 cells were 31 +/- 3, 32 +/- 4, and 22 +/- 4, respectively.

CONCLUSION

H blood group antigen was detected on NIH3T3 cells after Ad5hSeFT infection and resulted in more than 40% reduction in the level of gal epitope on the cell surface. This reduction increased the resistance of NIH3T3 cells to lysis by normal human serum.

The heat-stable antigen determines pathogenicity of self-reactive T cells in experimental autoimmune encephalomyelitis

Induction of myelin-specific CD4 T cells is a pivotal event in the development of experimental autoimmune encephalomyelitis (EAE). Other checkpoints in EAE pathogenesis have not been clearly defined, although multiple genetic loci are known to influence EAE development. We report here that targeted mutation of the heat-stable antigen (HSA) abrogates development of EAE despite a complete lack of effect on induction of autoimmune T cells. To test whether T-cell expression of HSA is sufficient, we created transgenic mice in which HSA is expressed exclusively in the T-cell lineage. We found that these mice remain resistant to EAE induction. Adoptive transfer studies demonstrate that both T cells and non-T cells must express HSA in order for the pathogenic T cells to execute their effector function. Moreover, HSAIg, a fusion protein consisting of the extracellular domain of the HSA and the Fc portion of immunoglobulin, drastically ameliorates the clinical sign of EAE even when administrated after self-reactive T cells had been expanded. Thus, identification of HSA as a novel checkpoint, even after activation and expansion of self-reactive T cells, provides a novel approach for immunotherapy of autoimmune neurologic diseases, such as multiple sclerosis.

[Eluents of non-suppressed ion exchange chromatography with conductometric detection]

A review with 64 references is presented on eluents for non-suppressed ion exchange chromatography with conductometric detection. The kinds of characteristics of eluents in non-suppressed anion exchange chromatography and non-suppressed cation exchange chromatography are described separately.

Mice with IFN-gamma receptor deficiency are less susceptible to experimental autoimmune myasthenia gravis

IFN-gamma can either adversely or beneficially affect certain experimental autoimmune diseases. To study the role of IFN-gamma in the autoantibody-mediated experimental autoimmune myasthenia gravis (EAMG), an animal model of myasthenia gravis in humans, IFN-gammaR-deficient (IFN-gammaR-/-) mutant C57BL/6 mice and congenic wild-type mice were immunized with Torpedo acetylcholine receptor (AChR) plus CFA. IFN-gammaR-/- mice exhibited significantly lower incidence and severity of muscle weakness, lower anti-AChR IgG Ab levels, and lower Ab affinity to AChR compared with wild-type mice. Passive transfer of serum from IFN-gammaR-/- mice induced less muscular weakness compared with serum from wild-type mice. In contrast, numbers of lymph node cells secreting IFN-gamma and of those expressing IFN-gamma mRNA were strongly augmented in the IFN-gammaR-/- mice, reflecting a failure of negative feedback circuits. Cytokine studies by in situ hybridization revealed lower levels of lymphoid cells expressing AChR-reactive IL-1beta and TNF-alpha mRNA in AChR + CFA-immunized IFN-gammaR-/- mice compared with wild-type mice. No differences were found for AChR-reactive cells expressing IL-4, IL-10, or TGF-beta mRNA. These results indicate that IFN-gamma promotes systemic humoral responses in EAMG by up-regulating the production and the affinity of anti-AChR autoantibodies, thereby contributing to susceptibility to EAMG in C57BL/6-type mice.

Cytotoxic T lymphocytes to an unmutated tumor rejection antigen P1A: normal development but restrained effector function in vivo

Unmutated tumor antigens are chosen as primary candidates for tumor vaccine because of their expression on multiple lineages of tumors. A critical issue is whether unmutated tumor antigens are expressed in normal cells, and if so, whether such expression imposes special restrictions on cytotoxic T lymphocyte (CTL) responses. In this study, we use a transgenic approach to study the development and effector function of T cells specific for P1A, a prototypical unmutated tumor antigen. We report here that although P1A is expressed at low levels in normal tissues, including lymphoid tissues, the P1A-specific transgenic T cells develop normally and remain highly responsive to the P1A antigen. The fact that transgenic expression of P1A antigen in the thymus induces T cell clonal deletion demonstrates that normal hematopoietic cells can process and present the P1A antigen and that P1A-specific T cells are susceptible to clonal deletion. By inference, P1A-specific T cells must have escaped clonal deletion due to low expression of P1A in the thymus. Interestingly, despite the fact that an overwhelming majority of T cells in the T cell receptor for antigen (TCR)-transgenic mice are specific for P1A, these mice are no more resistant to a P1A-expressing plasmocytoma than nontransgenic littermates. Moreover, when the same TCR-transgenic mice were challenged simultaneously with B7-1(+) and B7-1(-) tumors, only B7-1(+) tumors were rejected. Therefore, even though P1A can be a tumor rejection antigen, the effector function of P1A-specific CTL is restrained in vivo. These results have important implications for the strategy of tumor immunotherapy.

Linomide suppresses experimental autoimmune neuritis in Lewis rats by inhibiting myelin antigen-reactive T and B cell responses

Linomide (quinoline-3-carboxamide) is a synthetic immunomodulator that suppresses several experimental autoimmune diseases. Here we report the effects of Linomide on experimental autoimmune neuritis (EAN), a CD4+ T cell-mediated animal model of acute Guillain-Barré syndrome (GBS) in humans. EAN induced in Lewis rats by inoculation with bovine peripheral nervous system (PNS) myelin and Freund's complete adjuvant was strongly suppressed by Linomide administered daily subcutaneously from the day of inoculation. Linomide dose-dependently delayed the interval between immunization and onset of clinical EAN, as well as the severity of EAN symptoms. These clinical effects were associated with dose-dependent down-modulation of PNS antigen-induced T and B cell responses and with suppression of the proinflammatory cytokines IL-12, interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha) mRNA. In PNS sections, Linomide suppressed IL-12 and TNF-alpha, and up-regulated IL-10 mRNA expression. These findings suggest that Linomide could be useful in certain T cell-dependent autoimmune diseases.

Downregulation of the CD95 receptor and defect CD40-mediated signal transduction in B-chronic lymphocytic leukemia cells

Cross-linking of the CD40 receptors has been shown to induce protein tyrosine kinases (PTK) phosphorylation and prevent apoptosis in Bcl-2 negative germinal center B cells. The expression of CD40 on B chronic lymphocytic leukemia (B-CLL) cells was found to be similar to that of normal B cells. Activation of normal B cells with soluble anti-CD40 monoclonal antibody (mAb) induced tyrosine phosphorylation, prolonged survival and prevented apoptosis. However, activation of CD40 on B-CLL cells using soluble anti-CD40 mAb does not influence survival or apoptosis. Normal B cells entered apoptosis when cultured in the presence of soluble anti-CD95 mAb. This process was independent of PTK activity. On B-CLL cells, the CD95 molecules were downregulated and a transient PTK signal was observed when cross-linking of the receptor by soluble anti-CD95 mAb occurred. Interestingly, B-CLL cells did not enter apoptosis in the presence of anti-CD95 mAb. Our study indicates that survival signals mediated through the CD40 molecule and death signals mediated through the CD95 molecule used different intracellular pathways in control donor B cells. In contrast, B-CLL cells do not respond to these signals. The leukemic B cells showed a defective CD40-mediated signal transduction and downregulated CD95 receptor expression. As a consequence, no apoptosis could be induced in B-CLL cells by a soluble anti-CD95 mAb. The abnormalities of these receptors may contribute to the long-lived status of B-CLL cells.

Macrophage apoptosis in muscle tissue in experimental autoimmune myasthenia gravis

Combining in situ tailing and immunocytochemical staining, we demonstrated that the infiltrating macrophages in muscle tissue sections during early phase of experimental autoimmune myasthenia gravis (EAMG) in Lewis rats were eliminated by apoptosis at high frequency. These apoptotic macrophages were colocalized in the end-plate regions. Apoptosis is a major cause for elimination of infiltrating macrophages during the early phase of EAMG.

Inhibition of experimental autoimmune encephalomyelitis in Lewis rats by nasal administration of encephalitogenic MBP peptides: synergistic effects of MBP 68-86 and 87-99

Induction of mucosal tolerance by inhalation of soluble peptides with defined T cell epitopes is receiving much attention as a means of specifically down-regulating pathogenic T cell reactivities in autoimmune and allergic disorders. Experimental autoimmune encephalomyelitis (EAE) induced in the Lewis rat by immunization with myelin basic protein (MBP) and Freund's adjuvant (CFA) is mediated by CD4+ T cells specific for the MBP amino acid sequences 68-86 and 87-99. To further define the principles of nasal tolerance induction, we generated three different MBP peptides (MBP 68-86, 87-99 and the non-encephalitogenic peptide 110-128), and evaluated whether their nasal administration on day -11, -10, -9, -8 and -7 prior to immunization with guinea pig MBP (gp-MBP) + CFA confers protection to Lewis rat EAE. Protection was achieved with the encephalitogenic peptides MBP 68-86 and 87-99, MBP 68-86 being more potent, but not with MBP 110-128. Neither MBP 68-86 nor 87-99 at doses used conferred complete protection to gp-MBP-induced EAE. In contrast, nasal administration of a mixture of MBP 68-86 and 87-99 completely blocked gp-MBP-induced EAE even at lower dosage compared to that being used for individual peptides. Rats tolerized with MBP 68-86 + 87-99 nasally showed decreased T cell responses to MBP reflected by lymphocyte proliferation and IFN-gamma ELISPOT assays. Rats tolerized with MBP 68-86 + 87-99 also had abrogated MBP-reactive IFN-gamma and tumor necrosis factor-alpha mRNA expression in lymph node cells compared to rats receiving MBP 110-128 nasally, while similar low levels of MBP-reactive transforming growth factor-beta and IL-4 mRNA expressing cells were observed in the two groups. Nasal administration of MBP 68-86 + 87-99 only slightly inhibited guinea pig spinal cord homogenate-induced EAE, and passive transfer of spleen mononuclear cells from MBP 68-86 + 87-99-tolerized rats did not protect naïve rats from EAE. Finally, we show that nasal administration of MBP 68-86 + 87-99 can reverse ongoing EAE induced with gp-MBP, although higher doses are required compared to the dosage needed for prevention. In conclusion, nasal administration of encephalitogenic MBP peptides can induce antigen-specific T cell tolerance and confer incomplete protection to gp-MBP-induced EAE, and MBP 68-86 and 87-99 have synergistic effects. Non-regulatory mechanisms are proposed to be responsible for tolerance development after nasal peptide administration.

Dose-dependent mechanisms relate to nasal tolerance induction and protection against experimental autoimmune encephalomyelitis in Lewis rats

Nasal administration of soluble antigens is an exciting means of specifically down-regulating pathogenic T-cell reactivities in autoimmune diseases. The mechanisms by which nasal administration of soluble antigens suppresses autoimmunity are poorly understood. To define further the principles of nasal tolerance induction, we studied the effects of nasal administration of myelin basic protein (MBP) on experimental autoimmune encephalomyelitis (EAE) in the Lewis rat. EAE is a CD4+ T-cell-mediated animal model for human multiple sclerosis. Nasal administration of guinea-pig (gp)-MBP at a dose as low as 30 micrograms/rat can completely prevent gp-MBP-induced EAE, whereas nasal administration of bovine (b)-MBP is not effective even at a much higher dosage. Cellular immune responses, as reflected by T-cell proliferation and interferon-gamma (IFN-gamma)-ELISPOT, were suppressed in rats receiving the two different doses (30 and 600 micrograms/rat) of gp-MBP, but not after administration of b-MBP. Rats tolerized with both doses of gp-MBP had also abrogated MBP-induced IFN-gamma mRNA expression in popliteal and inguinal lymph node mononuclear cells compared with rats receiving phosphate-buffered saline nasally. However, adoptive transfer revealed that only spleen mononuclear cells from rats pretreated with a low dose, but not from those pretreated with a high dose, of gp-MBP transferred protection to actively induced EAE. Low-dose (30 micrograms/rat) gp-MBP-tolerized rats also had high numbers of interleukin-4 (IL-4) mRNA-expressing lymph node cells, while high-dose (600 micrograms/rat) gp-MBP-tolerized rats had low numbers of IL-4 mRNA-expressing lymph node cells. Our data suggest an exquisite specificity of nasal tolerance. Dose-dependent mechanisms also relate to nasal tolerance induction and protection against EAE in the Lewis rat.

Suppression of acute and protracted-relapsing experimental allergic encephalomyelitis by nasal administration of low-dose IL-10 in rats

In this study we report for the first time that nasal administration of the Th2 cell-related cytokine interleukin-10 (IL-10), at concentrations of 1.5 microg/rat and 15 microg/rat, suppressed clinical signs of acute experimental allergic encephalomyelitis (EAE) in Lewis rats and prevented the development and relapse of protracted-relapsing EAE (PR-EAE) in DA rats. In contrast, subcutaneous injection of IL-10 (15 microg/rat) did not inhibit acute EAE. The IL-10-mediated suppression of EAE was associated with decreased myelin antigen-specific T-cell proliferative responses and IFN-gamma secretion in both acute and PR-EAE. In sections of spinal cords derived from rats nasally pretreated with IL-10, there were no infiltrating CD4+ T cells or macrophages, which are considered as major encephalitogenic or inflammatory cells. Most interestingly, nasally administered IL-10 also inhibited MHC class II expression in microglia, indicating that IL-10 administration by the nasal route prevents the activation of microglia. Administration of cytokines via the nasal route offers an exciting alternative in the prevention and treatment of autoimmune diseases.

Nasal tolerance to experimental autoimmune myasthenia gravis: tolerance reversal by nasal administration of minute amounts of interferon-gamma

Tolerance to B cell-mediated experimental autoimmune myasthenia gravis (EAMG), an animal model for myasthenia gravis (MG) in humans, can be achieved by nasal administration of the autoantigen acetylcholine receptor (AChR). Nasal tolerance induction requires only 1/1000 of the amount of AChR used for oral tolerance induction, but is as effective in preventing EAMG. To investigate whether nasally induced tolerance to EAMG can be influenced by nasal administration of cytokines, recombinant rat IFN-gamma (total 5000 U/rat), a combination of AChR and IFN-gamma or AChR alone was given nasally to Lewis rats before immunization with AChR and complete Freund's adjuvant (CFA). One additional group of rats received the same amount of AChR nasally in conjunction with IFN-gamma (total 5000 U/rat) intraperitoneally. AChR given alone nasally induced effective tolerance to EAMG whereas rats receiving AChR + IFN-gamma by the nasal route exhibited a similar disease pattern, and similarly escalated T and B cell responses to AChR when compared to control EAMG rats. In contrast, administration of IFN-gamma i.p. together with AChR nasally did not affect the induction of tolerance to EAMG. IFN-gamma given alone nasally did not affect clinical EAMG. This study demonstrates that nasal tolerance can be modulated by nasal administration of minute amounts of IFN-gamma. Nasal administration of certain cytokines with beneficial effects might broaden the effectiveness of applying nasal tolerance as a potential therapeutic means of preventing autoimmune diseases.

Nasal tolerance in experimental autoimmune myasthenia gravis (EAMG): induction of protective tolerance in primed animals

Nasal administration of microg doses of acetylcholine receptor (AChR) is effective in preventing the development of B cell-mediated EAMG in the Lewis rat, a model for human MG. In order to investigate whether nasal administration of AChR modulates ongoing EAMG, Lewis rats were treated nasally with AChR 2 weeks after immunization with AChR and Freund's complete adjuvant. Ten-fold higher amounts of AChR given nasally (600 microg/rat) were required to ameliorate the manifestations of EAMG compared with the amounts necessary for prevention of EAMG. In lymph node cells from rats receiving 600 microg/rat of AChR, AChR-induced proliferation and interferon-gamma (IFN-gamma) secretion were reduced compared with control EAMG rats receiving PBS only. The anti-AChR antibodies in rats treated nasally with 600 microg/rat of AChR had lower affinity, reduced proportion of IgG2b and reduced capacity to induce AChR degradation. Numbers of AChR-reactive IFN-gamma and tumour necrosis factor-alpha (TNF-alpha) mRNA-expressing lymph node cells from rats treated nasally with 600 microg/rat of AChR were suppressed, while IL-4, IL-10 and transforming growth factor-beta (TGF-beta) mRNA-expressing cells were not affected. Collectively, these data indicate that nasal administration of AChR in ongoing EAMG induced selective suppression of Th1 functions, i.e. IFN-gamma and IgG2b production, but no influence on Th2 cell functions. The impaired Th1 functions may result in the production of less myasthenic anti-AChR antibodies and contribute to the amelioration of EAMG severity in rats treated with AChR 600 microg/rat by the nasal route.

Nasal administration of multiple antigens suppresses experimental autoimmune myasthenia gravis, encephalomyelitis and neuritis

Oral tolerization with acetylcholine receptor (AChR) and myelin basic protein (MBP) prior to immunization with AChR+MBP+ complete Freund's adjuvant (CFA) alleviated clinical signs of experimental autoimmune myasthenia gravis (EAMG)+experimental allergic encephalomyelitis (EAE) and AChR- or MBP-specific T and B cell responses. Tolerance induced via the nasal route needs much less tolerogen and may still be as effective as oral tolerance induction. We now immunized Lewis rats with AChR+MBP+bovine peripheral nerve myelin (BPM)+CFA, which resulted in a multiphasic clinical picture with a combination of clinical signs of the EAMG+EAE+experimental allergic neuritis (EAN), accompanied by massive macrophage infiltrations in sections of muscle, spinal cord and sciatic nerve, and strong T and B cell responses to AChR, MBP and BPM in lymphoid organs. Nasal administration of microg doses of AChR+MBP+BPM prior to immunization with a mixture of these antigens+CFA effectively suppressed the incidence and severity of clinical disease, reduced macrophage infiltrations in sections of muscle, spinal cord and sciatic nerve, and down-regulated autoreactive T cell responses to the three antigens in lymphoid organs. Numbers of AChR-, MBP-, BPM-reactive Th1 type of cytokine interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha mRNA expression in lymph node cells were markedly suppressed, while transforming growth factor-beta (TGF-beta) mRNA expression was upregulated from nasally tolerized rats, suggesting an active suppression mechanism may act partly in the induction of tolerance. The results implicate the possibility to establish multiple autoantigen-based vaccination for the prevention of autoimmune diseases in humans.

Complexities of applying nasal tolerance induction as a therapy for ongoing relapsing experimental autoimmune encephalomyelitis (EAE) in DA rats

EAE is an autoimmune disease of the central nervous system (CNS) that serves as an experimental model for the human inflammatory demyelinating disease multiple sclerosis (MS). Antigen-based immunotherapy including soluble antigen administration via feeding has been shown to be successful in treating EAE in rodents. In the present study, we explore nasal administration of small amounts of myelin basic protein (MBP) as a potential means of treatment of protracted, relapsing EAE (PR-EAE) in a novel DA rat system. We found that nasal administration of MBP prevented EAE induced with whole spinal cord homogenate + Freund's incomplete adjuvant (FIA), and strongly down-regulated levels of MBP-reactive interferon-gamma (IFN-gamma)-secreting Th1-like cells. However, in rats with ongoing PR-EAE receiving the same regimen of MBP, a trend of aggravated disease was recorded, in conjunction with augmented levels of MBP-reactive IFN-gamma-secreting Th1-like splenocytes during the acute phase of EAE. These data have implications for the clinical application of nasal tolerance to autoimmune diseases.

Nasal administration of myelin basic protein prevents relapsing experimental autoimmune encephalomyelitis in DA rats by activating regulatory cells expressing IL-4 and TGF-beta mRNA

This study explores nasal administration of myelin basic protein (MBP) as a potential means of inducing tolerance to relapsing experimental autoimmune encephalomyelitis (PR-EAE), an experimental multiple sclerosis (MS) model that was induced in DA rats by immunization with rat spinal cord homogenate and incomplete Freund's adjuvant. DA rats received a total dosage of 0, 6, 60, 600 micrograms/rat of bovine MBP on ten consecutive days prior to immunization. EAE with typical course was observed in control rats receiving only PBS nasally, and in rats receiving 6 micrograms/rat of MBP. Rats receiving 60 micrograms/rat of MBP developed acute EAE but no relapse during 60 days of observation post immunization (p.i.). Only one of eight rats receiving 600 micrograms/rat of MBP developed slight, transient EAE. This protection was confirmed at the histology level and was associated with decreased levels of MBP-reactive IFN-gamma secreting Th1-like spleen cells on day 13 and 60 p.i. Rats receiving 60 and 600 micrograms/rat of MBP showed decreased serum anti-MBP IgG2b antibody levels on day 60 p.i., and rats receiving 600 micrograms/rat of MBP had marginally increased anti-MBP IgG1 antibody levels in serum compared to control EAE rats. Cytokine mRNA profiles in central nervous system (CNS) and spleen mononuclear cells were evaluated. Dose-dependent reduction of TNF-alpha mRNA expression were observed both in CNS and in splenocytes. Increased IL-4 and TGF-beta mRNA expression were observed in CNS of low (6 micrograms/rat) and median (60 micrograms/rat) dose of MBP tolerized rats and in splenocytes of rats tolerized with 600 micrograms/rat of MBP. We conclude that nasal administration of MBP in DA rat prevents EAE induced by immunization with whole rat spinal cord homogenate that, besides MBP, contains multiple antigenic myelin proteins. A mechanism involving MBP-reactive regulatory cells expressing IL-4 and TGF-beta mRNA acts as part in the induction of this tolerance.

Experimental allergic neuritis: cytolysin mRNA expression is upregulated in lymph node cells during convalescence

Experimental allergic neuritis (EAN) is a T cell mediated animal model of Guillain-Barré syndrome, characterized by inflammation and demyelination of the peripheral nervous system (PNS). To study the involvement of immunoregulatory cytokines, we induced EAN in Lewis rats by immunizing with bovine PNS myelin (BPM) and Freund's complete adjuvant. mRNA expression of the cytokines IL-1beta, IL-6, IL-10, IL-12, TNF-alpha and TNF-beta, and the cytolytic effector molecule cytolysin was examined in lymph node mononuclear cells (MNC) over the course of EAN by in situ hybridization after culture without antigen and in the presence of BPM, the myelin P2 protein, the control antigen acetylcholine receptor, or the mitogen PHA. Three patterns of cytokine mRNA expressing MNC in relation to clinical EAN could be distinguished: (i) IL-1beta mRNA expressing cells peaked already on day 3 post immunization (p.i.), and BPM- and P2-reactive TNF-alpha, and BPM-reactive IL-6 mRNA expressing cells were also detected already on day 7 p.i., i.e., before onset of clinical EAN; (ii) BPM- and P2-reactive TNF-alpha peaked together with P2-reactive TNF-beta, IL-6 and IL-12 mRNA expressing cells at height of clinical EAN, consistent with a disease-promoting role for these four cytokines; (iii) high levels of BPM- and P2-reactive IL-10 and cytolysin mRNA expressing cells were observed only during recovery (day 28 p.i.), consistent with a disease down-regulating role of IL-10 and cytolysin. The results suggest a major proinflammatory role for IL-1beta, TNF-alpha, TNF-beta, IL-6 and IL-12 and a disease down-regulating function of IL-10 as well as cytolysin in EAN.

Cytokine dichotomy in peripheral nervous system influences the outcome of experimental allergic neuritis: dynamics of mRNA expression for IL-1 beta, IL-6, IL-10, IL-12, TNF-alpha, TNF-beta, and cytolysin

Experimental autoimmune neuritis (EAN) is a T-cell-mediated autoimmune disease of the peripheral nervous system (PNS) that can be actively induced in Lewis rats by immunization with bovine PNS myelin and Freund's complete adjuvant. EAN is used as an animal model of the Guillain-Barré syndrome (GBS) in humans. To study the potential role of cytokines in EAN, we used in situ hybridization to detect mRNA expression of interleukin 1 beta (IL-1 beta), IL-6, IL-10, IL-12, tumor necrosis factor-alpha (TNF-alpha), TNF-beta, and cytolysin in sciatic nerve sections over the course of EAN. Cells expressing IL-1 beta and IL-6 mRNA appeared early and peaked on Day 7 postimmunization (p.i.), i.e., at onset of clinical signs of EAN, consistent with a role of these cytokine in an early immune response leading to autoaggressive immunity in EAN. TNF-alpha, TNF-beta, and IL-12 mRNA expression was maximally upmodulated on Day 14 p.i., i.e., at height of clinical EAN, favoring a role for these cytokines in disease development. On the contrary, transcription of cytolysin and IL-10 in sciatic nerves reached maxima during clinical improvement of EAN. The data argue for a major proinflammatory role for IL-1 beta, IL-6, TNF-alpha, TNF-beta, and IL-12 and a disease downregulating function for both cytolysin and IL-10 at the target site in EAN. These findings have relevance for future studies on pathogenesis and treatment of GBS in humans.

Cellular mRNA expression of interferon-gamma (IFN-gamma), IL-4 and IL-10 relates to resistance to experimental autoimmune myasthenia gravis (EAMG) in young Lewis rats

Age-related alterations in the immune system, including changes in lymphocyte subset composition, result in changes of cytokine patterns and might thereby influence the incidence and severity of autoimmune diseases. To investigate the age-related resistance to EAMG, an animal model for human MG, young (4-week-old) and adult (8-10-week-old) female Lewis rats were immunized with Torpedo acetylcholine receptor (AChR) and Freund's complete adjuvant (FCA). Adult Lewis rats showed severe weight loss and progressive muscular weakness after immunization, while young rats developed minor clinical signs of EAMG after a prolonged interval post-immunization. By comparison with adult rats, the young had lower AChR-specific T and B cells responses, and less muscle AChR loss. In situ hybridization performed on mononuclear cells (MNC) from lymph nodes revealed that young rats had lower levels of AChR-specific IFN-gamma, IL-4 and IL-10 mRNA-expressing cells compared with adult rats. Since IFN-gamma, IL-4 and IL-10 promote the development of EAMG, the low expression of these cytokines might contribute to EAMG resistance in young Lewis rats.

Linomide-induced suppression of experimental autoimmune neuritis is associated with down-regulated macrophage functions

Experimental autoimmune neuritis (EAN) is a T-cell mediated autoimmune disease of the peripheral nervous system, in which macrophages and T-cells feature prominently in nerve lesions. EAN represents a counterpart to Guillain-Barré syndrome in humans. In the present study, we investigated the in vitro and in vivo effects of Linomide (LS-2616, quinoline-3-carboxamide), a synthetic immunomodulatory compound, on macrophages in relation to EAN. Linomide strongly suppressed IFN-gamma and lipopolysaccharide (LPS)-induced IL-1 beta, TNF-alpha and IL-6 mRNA expression in macrophages in vitro as demonstrated by in situ hybridisation. Linomide administered daily subcutaneously from the day of inoculation completely prevented the development of clinical symptoms of EAN. Linomide administered from day 9 post immunisation (p.i.) significantly suppressed clinical EAN. Macrophages from Linomide-treated EAN rats showed decreased IL-1 beta, TNF-alpha and IL-6 mRNA expression in response to IFN-gamma and LPS. LPS-induced nitric oxide production by macrophages was also suppressed by Linomide in vitro. Linomide, however, does not affect macrophage death and release of lactate dehydrogenase. We conclude that Linomide may exert its actions in EAN and perhaps also in other autoimmune disease models, by suppressing macrophage functions.

IL-10 suppresses experimental autoimmune neuritis and down-regulates TH1-type immune responses

Experimental autoimmune neuritis (EAN) is a CD4+ T cell-mediated monophasic inflammatory disorder of the peripheral nervous system (PNS). Cellular mechanisms, including macrophage and T cell infiltration, and cytokines like IFN-gamma and TNF-alpha are intimately involved in the pathogenesis of EAN. Interleukin 10 (IL-10) is a TH2-type cytokine that suppresses monocyte and TH1 cell functions. We examined the effect of recombinant human IL-10 (rHuIL-10) in EAN. When administered from the start of immunization with bovine peripheral myelin emulsified in Freund's complete adjuvant, IL-10 effectively suppressed and shortened clinical EAN. Even when given after Day 12 post immunization (pi) after clinical EAN had been established, IL-10 also effectively suppressed the severity of EAN. Pheripheral nerve myelin antigen-reactive IFN-gamma-secreting TH1-like cells were decreased in lymph nodes from IL-10-treated compared to control EAN rats. PNS autoantigen-induced T cell proliferation and B cell responses were not affected. P2 protein-reactive IFN-gamma, TNF-alpha, IL-1 beta, and IL-6 mRNA-expressing lymph node cells were also downregulated in IL-10-treated compared to control EAN rats at Day 14 and 26 pi, while P2-reactive IL-4 mRNA-expressing cells were upregulated throughout treatment. Also, in IL-10-treated EAN rats, upregulated anti-P2 IgG1 and downregulated IgG2a were observed. Our results clearly show that rHuIL-10 can suppress clinical EAN, and this suppression is associated with downregulation of TH1 responses and macrophage function and upregulated TH2 responses.

Transforming growth factor-beta1 induces apoptosis of rat microglia without relation to bcl-2 oncoprotein expression

Transforming growth factor-beta (TGF-beta) plays a role as an immunosuppressive cytokine within the central nervous system (CNS). The CNS cells targeted by action of TGF-beta1 have not been defined. In this study, we tested the effect of TGF-beta1 on microglia, astrocytes and oligodendrocytes from newborn rats. TGF-beta1 selectively induced apoptosis of microglia, and not of astrocytes or oligodendrocytes. To study the apoptotic mechanism, bcl-2 oncoprotein expression in microglia, astrocytes and oligodendrocytes was measured. Bcl-2 was mainly expressed in microglia, indicating that microglial bcl-2 does not prevent TGF-beta1-mediated microglial apoptosis. The relative protein expression of bcl-2 in microglia was not related to frequency of microglial apoptosis. Thus, TGF-beta1-induced microglial apoptosis was regulated by a bcl-2-independent mechanism. Expression of cytokine (IL-1beta, IL-6, IL-12, IFN-gamma and TNF-alpha) mRNA on microglia was not influenced by treatment with TGF-beta1.

Induction of cytolysin mRNA in glial cells by IFN-gamma: a possible cytotoxic pathway in the CNS

We utilized in situ hybridization to detect expression and regulation of cytolysin mRNA in microglia, astrocytes and oligodendrocytes from newborn rat brains. Expression under natural culture conditions was undetectable or very low, even after 10 days of culture. Cytolysin mRNA expression in microglia, astrocytes and oligodendrocytes was up-regulated by IFN-gamma. This up-regulation in glial cells was slow, and characterized by a gradually increased expression until day 10 of culture. IFN-gamma-mediated up-regulation of cytolysin mRNA was markedly more prominent in oligodendrocytes than in microglia and astrocytes. Unexpectedly, a combination of LPS and IFN-gamma did not exhibit a synergistic effect in the induction of cytolysin mRNA expression in the three types of glial cells. On the contrary, LPS strongly inhibited IFN-gamma-mediated cytolysin mRNA expression in microglia, astrocytes and oligodendrocytes. These results reveal that there may exist a glial cell-dependent cytotoxic pathway within the CNS, and that inducible cytolysin may play an important role in destruction of oligodendrocytes or clearance of infiltrating cells within the CNS in inflammatory diseases such as multiple sclerosis or experimental allergic encephalomyelitis.

Shift from anti- to proinflammatory cytokine profiles in microglia through LPS- or IFN-gamma-mediated pathways

In this study, cytokine mRNA profiles in microglia from newborn rats were detected by in situ hybridization. Under natural culture conditions, microglia expressed the immunosuppressive transforming growth factor-beta 1 (TGF-beta 1) and interleukin (IL) 10 to a greater degree than the pro-inflammatory cytokines IL-1 beta, IL-6, IL-12, interferon-gamma (IFN-gamma) and TNF-alpha. High TGF-beta 1 and IL-10 levels could reflect one mechanism for immune privilege within the CNS under physiological conditions. Stimulation of microglia with LPS or IFN gamma resulted in strong up-regulation of proinflammatory cytokines, while TGF-beta 1 and IL-10 were down-regulated. These effects of LPS or IFN-gamma are anticipated to reflect immunopathogenic processes within the CNS.

Inhibition of hepatitis B viral gene expression by antisense phosphorothioate oligodeoxynucleotides

The inhibitory effect of antisense phosphorothioate oligodeoxyribonucleotides (S-oligos) on the production of hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) was studied using Hep G2 cells transfected with hepatitis B virus (HBV). Synthetic antisense oligos (15-mers) directed against the cap site of mRNA transcribed from the SP II promoter and regions of the translational initiation site of the S gene showed a sequence-specific, dose-dependent inhibitory effect on HBV gene expression between concentrations of 1.0 microM-5.0 microM. Oligos directed against the middle of the S gene had little effect on HBsAg and HBeAg expression, as did non-complementary random-sequence control. The cells remained viable throughout the experiments and no morphological abnormalities were observed with antisense S-oligos at concentrations below 20.0 microM. These results suggest a therapeutic potential for antisense oligonucleotides in the treatment of patients who are chronically infected with HBV.

Localization and changes of hemorrhagic fever with renal syndrome virus in lymphocyte subpopulation

Double-labeled immunocytochemistry was used for studying the localization and distribution of hemorrhagic fever with renal syndrome virus (HFRSV) antigen in the peripheral blood lymphocyte subpopulations in HFRS patients and the quantitative changes of these subpopulations. It was found that HFRSV might infect different subpopulations of lymphocytes. The infection rate of B cells (31.3%) was significantly higher than that of T cells (8.5%), and the infection rate of CD8+ subpopulation (10.5%) was significantly higher than that of CD4+ subpopulation (6.1%). The infection rates of HLA-DR+ cells and Tac+ cells were 2.5% and less than 0.5%, respectively. From febrile to oliguric stage, the number of CD8+ cells increased gradually, leading to a decrease and reverse of CD4/CD8 ratio, while the number of CD4+ cells remained almost unchanged. The appearance and disappearance of HFRSV in lymphocytes were closely associated with the dynamic changes of CD4/CD8 ratio and HLA-DR and Tac expressions. The results suggested that there were certain differences in HFRSV infectivity of different lymphocyte subpopulations, which might be due to the disorders of immunoregulation and immunopathology of HFRS.

The distribution and duration of hantaan virus in the body fluids of patients with hemorrhagic fever with renal syndrome

The distribution and duration of Hantaan virus (HTNV) in the body fluids of patients were studied by immunofluorescence, reverse passive hemagglutination, and cell culture assays. Virus antigen of hemorrhagic fever with renal syndrome in peripheral blood mononuclear cells (PBMCs) was usually present before day 11 of the disease, especially from days 4-7. Virus isolates were more readily recovered from plasma early in the course of the illness and less frequently after day 7. The use of PBMCs rather than plasma enabled isolates to be recovered at a rate nearly twice that permitted by plasma and allowed the isolation peak of HTNV (days 4-7 after onset of disease) to extend an additional 2 or 3 d, thus prolonging the period of detectable viremia until days 8-11. PBMCs were especially useful in isolating viruses from patients with hemorrhagic fever with renal syndrome in whom antibody titers were generally high during the acute phase of the disease. HTNV was isolated from the cerebrospinal fluid of patients, but was difficult to recover from other body fluids.

The duration of viremia patients with epidemic hemorrhagic fever

The duration of viremia in patients with epidemic hemorrhagic fever (EHF) was studied using immunofluorescence technique and cell culture assays. The duration of virus in plasma of EHF patients was about 1 week, which was concomitant with the febrile phase of the disease. Comparatively, the separation rate of viruses in peripheral blood mononuclear cells (PBMC) was greater (1.8 times) than in plasma, while the detected peak of EHF (in 4-7 days after onset of the disease) was found to be 2 or 3 days less than that of plasma, thus the detectable viremia was prolonged until the 8th to 11th day of the disease. High titre EHF antibody of IgG, TgM was unable to neutralize the virus in human blood. The results revealed that a blood-cell-associated prolonged viremia is one of the characteristics of EHF infection.

Investigation on monoclonal antibodies against two serovars of the icterohaemorrhagiae serogroup of Leptospira

By means of the cell fusion technique, two hybridoma cell lines, V-1 and H2-1 have been obtained. V-1 cells secrete monoclonal antibody against serovars icterohaemorrhagiae and dakota. The H2-1 cell line secretes serovar-specific monoclonal antibody against serovar H2. These monoclonal antibodies have been successfully used in serovar-typing of leptospires isolated in China. The results of identification of leptospires by using monoclonal antibodies showed total coincidence with that by the traditional cross agglutinin absorption test and factor antiserum method. It was confirmed by using monoclonal antibody that the serological agglutination totally paralleled with animal protection. On the basis of the study, a concept was proposed that the agglutination in vitro and the protection in vivo are different manifestations in different reaction systems from the same antibody (antibodies) stimulated by a component(s) of the surface antigen of leptospires.