Effect of Polyinosinic-polycytidylic Acid on Humoral and Cellular Immunity

Experiments have been performed to investigate the effects of polyinosinic-polycytidylic acid (Poly I:C) on humoral and cellular immunity in RFM/Un mice. Poly I:C, 0.1 mg i.p., administered 48 and 24 hours before 4 x 108 SRBC produced a marked reduction in direct PFC/106 cells and /spleen, and in the hemoagglutinin titre on the 3rd, 4th and 5th days after antigen inoculation. On the other hand, an increase in PFC and hemoagglutinin titre was observed on the 7th and 8th days. Histological examination revealed absence of germinal centers in the spleen on the 4th day. Poly I:C administered 24 and 48 hours after antigen produced an increase in direct PFC and hemoagglutinin titre on the 4th, 5th and 6th day. Histological examination disclosed evident germinal centers in the spleen on the 4th day after antigen. Poly I:C administered 5 to 1 days before antigen produced a markedly depressed direct PFC response in the groups injected 1 and 2 days before antigen. Recovery of the immune response was progressive and complete in groups injected 4 days before antigen. To study the effect of Poly I:C on secondary response to SRBC, two groups of animals injected with Poly I:C before or after antigen were reinjected with 2 x 108 SRBC. Secondary response evaluated by hemoagglutinin titre at varying intervals after the immunization disclosed in both groups a much higher antibody titre than that seen in controls receiving SRBC only. Mice injected with Poly I:C 48 or 24 hours before reimmunization with 2 x 108 SRBC were no different from controls on 3rd and 4th days in regard to number of indirect PFC as well as hemoagglutinin titre. Finally, mice immunized with two SRBC injections and then treated with Poly I:C on alternating days for 30 days had a much higher titre of hemoagglutinins than controls. In order to study the effect of Poly I:C on the cellular immune response, spleen cells from animals receiving Poly I:C 6–5 days before sacrifice were cultured in vitro with phytohemoagglutinin. DNA synthesis subsequent to PHA stimulation was evaluated by increase in 3HTdR incorporation. Cells from animals which had received Poly I:C demonstrated a remarkably higher 3HTdR uptake than cells from control animals. On the other hand, 5 x 106 spleen cells obtained from RFM/Un mice injected with Poly I:C as above were inoculated in 1–4 day old (RFM/Un x CBA/H)F1 hybrids. These were then sacrificed on day 8 and spleen indices calculated. Experimental animals disclosed GVH activity similar to that of controls (spleen index 2.3). From the results it is clear that if Poly I:C is injected before antigen the primary immune response is deppressed, whereas it is enhanced when Poly I:C is administered after antigen. On the other hand, the secondary response is generally enhanced regardless of the time of Poly I:C administration. Moreover, in Poly I:C –- treated animals there is an enhancement of PHA –- responsive cells while the GVH reactions is unchanged. As Poly I:C is capable of enhancing immune reactivity, the possibility of its use in antineoplastic chemotherapeutic protocols is suggested.

Developmental immunotoxicity is not associated with the consumption of transgenic Bt rice TT51 in rats

TT51 is a transgenic strain of Bt rice generated by fusing a synthetic CryAb/Ac gene into MingHui rice. In this study, rats from F0, F1, and F2 generations were fed a diet with 60% TT51 rice, MingHui rice, or nominal-origin rice. The study focused on developmental immunotoxicity in F1 and F2 offspring after long-term consumption of TT51. A wide range of immunological parameters was monitored in this two-generation study on reproductive toxicity. The experiments were performed on F1 and F2 offspring at postnatal days 21 and 42. No adverse clinical effects were observed in any of the experimental groups. In addition, histopathology observations and immunotoxicity tests, including hematological indicators, spleen lymphocyte subsets, natural killer cell activity, lymphoproliferative response, and plaque-forming cell assay, revealed no significant difference between the groups. These results indicated that developmental immunotoxicity was not associated with a diet of transgenic Bt rice TT51, compared to the parental MingHui rice.

Sickle cell disease

Sickle cell disease is a common and life-threatening haematological disorder that affects millions of people worldwide. Abnormal sickle-shaped erythrocytes disrupt blood flow in small vessels, and this vaso-occlusion leads to distal tissue ischaemia and inflammation, with symptoms defining the acute painful sickle-cell crisis. Repeated sickling and ongoing haemolytic anaemia, even when subclinical, lead to parenchymal injury and chronic organ damage, causing substantial morbidity and early mortality. Currently available treatments are limited to transfusions and hydroxycarbamide, although stem cell transplantation might be a potentially curative therapy. Several new therapeutic options are in development, including gene therapy and gene editing. Recent advances include systematic universal screening for stroke risk, improved management of iron overload using oral chelators and non-invasive MRI measurements, and point-of-care diagnostic devices. Controversies include the role of haemolysis in sickle cell disease pathophysiology, optimal management of pregnancy, and strategies to prevent cerebrovascular disease.

The effect of ethephon on immune system in male offspring of mice

Ethephon can liberate ethylene which could interfere the plant growth process. The aim of the present study was to determine the effect of ethephon on developing immune system of male offspring. Ethephon could enhance NK cell activity in male mice. For 4-week-old male mice, lymphocytes of peripheral blood increased while the hemolytic plaque number decreased. Delayed type hypersensitivity(DTH) was inhibited in all groups. The expression of protein Bcl11b and p-p38 in thymus of treatment groups were lower than control group. Our results indicated that cellular immunity of male offspring is more sensitive to ethephon when exposed in pregnancy and lactation period. It should be emphasized that exposure to ethephon during the in utero stage and lactation stage still could damage the immune function of animal in the period before fully mature even in the dosage that could not influence the immune function of adult animal.

Immunotoxic Effects of MPT-IP Containing 60% Methylparathion in Mice

The effects of a single large and repeated small doses of MPT-IP (the industrial product used to produce Wofatox EC 50) containing 60% methylparathion, on the humoral and cellular immunoreactivity of CFLP mice were investigated.

Administration of a single LD50/2 dose 3 d prior to immunization caused a 40% increase in the number of splenic PFC on the 5th day but no significant increase in serum antibody titre on the 7th day after immunization.

Treatment for 4 weeks with an LD50/40 dose resulted in a 100% increase in splenic PFC, also not associated with a change in serum antibody titre. Under the same conditions and LD50/20 dose had no effect on these parameters.

Neither the single large nor the repeated small doses had any effect on the intensity or time course of a DTH reaction.

The results show that MPT-IP has an immunotoxic potential in mice under certain experimental conditions.

A randomised double-blind clinical trial of two yellow fever vaccines prepared with substrains 17DD and 17D-213/77 in children nine-23 months old

This randomised, double-blind, multicentre study with children nine-23 months old evaluated the immunogenicity of yellow fever (YF) vaccines prepared with substrains 17DD and 17D-213/77. YF antibodies were titered before and 30 or more days after vaccination. Seropositivity and seroconversion were analysed according to the maternal serological status and the collaborating centre. A total of 1,966 children were randomised in the municipalities of the states of Mato Grosso do Sul, Minas Gerais and São Paulo and blood samples were collected from 1,714 mothers. Seropositivity was observed in 78.6% of mothers and 8.9% of children before vaccination. After vaccination, seropositivity rates of 81.9% and 83.2%, seroconversion rates of 84.8% and 85.8% and rates of a four-fold increase over the pre-vaccination titre of 77.6% and 81.8% were observed in the 17D-213/77 and 17DD subgroups, respectively. There was no association with maternal immunity. Among children aged 12 months or older, the seroconversion rates of 69% were associated with concomitant vaccination against measles, mumps and rubella. The data were not conclusive regarding the interference of maternal immunity in the immune response to the YF vaccine, but they suggest interference from other vaccines. The failures in seroconversion after vaccination support the recommendation of a booster dose in children within 10 years of the first dose.

Immunomodulatory effects of crude phenylethanoid glycosides from Ligustrum purpurascens

ETHNOPHARMACOLOGICAL RELEVANCE

Ligustrum purpurascens, named as "Ku ding cha", has been used as a kind of functional tea in southern China for about two thousand years, which has the effects on diuresis, anti-hypertension, weight-loss and anti-inflammation.

THE AIM OF THE STUDY

This study was aimed to investigate the immune enhancement effects of the crude phenylethanoid glycosides (CPGs) from Ligustrum. Purpurascens on mice and analyze the chemical profiles of phenylethanoid glycosides in the CPGs.

MATERIALS AND METHODS

The immune functions enhancing potential of CPGs was determined using serum hemolysin antibody, phagocytosis, splenocyte antibody production, and NK cells activity assays. The contents of five major constituents in the crude glycosides of Ligustrum purpurascens were determined by using liquid chromatography, other five glycosides were deduced according to their UV and MS spectra compared with the literature as well.

RESULTS

In the immunizing experiment, mice treated with different doses of CPGs showed an increase (p<0.01) in the haemagglutination titre compared with the control group. The increases (p<0.05) were found to be significant at doses of 440 mg/kg and 1.32 g/kg in the experiments of antibody production of spleen cells, MΦ phagocytosis of chicken RBCs and NK cell activity. Further chemical characterization yielded 10 constituents from CPGs, five glycosides were quantified by HPLC and the structures of other five compounds were speculated according to their UV and MS spectra.

CONCLUSION

The results suggested that phenylethanoid glycosides from Ligustrum purpurascens have immunomodulatory effects on mice.

Immunotoxicity of copper alginate fibers in guinea pigs and mice

The relation between copper alginate fibers and immunotoxicity in animals was studied by dividing guinea pigs and mice into control groups and experimental groups. Varied weights of fibers were subcutaneously embedded in the experimental groups, whereas the control groups were operated on simulatively. Morphology analysis, erythrocyte osmotic fragility (EOF) test, direct plaque-forming cell (PFC) assay, quantitative hemolysis spectrophotometry (QHS) assay, macrophages phagocytosis assay, and pathology analysis were used to examine morphology, microstructure, and immunotoxicity. With increasing doses of copper alginate fibers, the EOF of experimental groups increased in contrast with the control group. Moreover, the antibody level decreased based on the results of the PFC and QHS assays, and macrophages phagocytosis descended in relation to dose. However, the immune functions were weakened without time dependence. According to pathologic photographs, the partial organs were damaged, implying bad histocompatibility. Hence, copper alginate fiber is proved to be a harmful material for medical devices.

Immunizing children aged 9 to 15 months with live attenuated SA14-14-2 Japanese encephalitis vaccine in Thailand

The authors aimed to evaluate the safety and immunogenicity of a live attenuated SA14-14-2 Japanese Encephalitis (JE) vaccine in healthy Thai infants. One hundred and fifty subjects aged 9-15 months were vaccinated with one dose of this vaccine. Regarding the vaccine safety, during the 28-day post-vaccination follow-up, no vaccine-related serious adverse events were reported. In terms of immunogenicity, the sero-conversion rate of a single dose vaccination was 95% (95% CI, 90.0-97.6%) within 90 days after vaccination and the geometric mean titer (GMT) was 66.1. Eight subjects with JE seronegative on days 28-35 post-vaccination became sero-positive on day 90. Seven subjects who remained sero-negative during days 28-35 and day 90 post-vaccination were successfully sero-converted after receiving a second dose 3 months later. Thus, two doses of this JE vaccine resulted in a 100% (95% CI, 97.3-100%) sero-conversion rate with the GMT of 260.8. Eight children with GMTs lower than protective level after a single vaccination demonstrated a booster response with GMT of 1237 after the second dose of JE vaccination. In conclusion, the live attenuated SA14-14-2 vaccine was safe, well tolerated and highly immunogenic with 95% and 100% sero-conversion rate after one and two doses, respectively. Nevertheless, its long-term immune response and possible influences from natural dengue infection requires further evaluation.

[Study on the toxic reaction induced by single dose of qingkailing injection]

OBJECTIVE

To study the toxic reaction induced by Qingkailing Injection.

METHODS

Kunming mice were injected single dose of Qingkailing Injection via tail vein and observed for 14 days to test the toxic reaction of the drug. According to Chinese Pharmacopoeia, hemolysis tests were conducted on the injections of different lots and each ingredient of the injection.

RESULTS

Toxic reaction induced by single dose of injection--with dose increasing,mice quickly showed different responses such as hypodynamia, convulsion, syncope and even death after injection. In the high dose group, blood routine detection showed that mice have lower counts of RBC, WBC and lower content of hemoglobin; The pulmonary pathological sections of dead mice showed significant hyperemia. And there were no significant difference in the contents of serum electrolyte (K+, Na+, Ca2+) between normal saline control group and Qingkailing injection group. Hemolysis test in vitro--Honeysuckle extraction (significantly) and gardenia extraction which were components of Qing-kailing injection caused hemolysis in certain dose; While gardenia, pearl shell and isatis root extraction caused RBC agglutination. With higher concentration, the Qingkailing injections of different lot caused different degree of hemolysis. There was no significant difference in the hemolysis test in vitro between the group of Balb/C mice which were sensitized by Qingkailing injection or not.

CONCLUSION

In clinical practice some adverse reactions induced by Qingkailing injection occurred concomitantly with acute hemolysis within vessels, which might be caused by honeysuckle and gardenia. And the hemolysis was independent of allergy.

Glycaemic status influences the nature and severity of coronary artery disease

AIMS/HYPOTHESIS

We sought to understand the relationships between glycaemic status and both severity and progression of coronary artery disease (CAD), the leading cause of death in diabetes.

METHODS

Baseline fasting blood glucose (FBG) and HbA1c (%)were measured in 426 patients with known or suspected stable CAD, who underwent coronary artery intravascular ultrasound(IVUS) at baseline and after a mean follow-up period of 664 days (range 257 to 961). The patients were categorised as normoglycaemic (n=226, 53%), or as having impaired fasting glucose (n=118, 28%) or diabetes (n=82, 19%).

RESULTS

The maximum percentage coronary atheroma area at baseline was greater in diabetic patients (73.33+/-8.86%) than in those with normoglycaemia (69.08+/-10.43%; p=0.001) and impaired fasting glucose (69.32+/-9.59%; p=0.0031). In averaged IVUS measurements of the 30-mm target segment(n=332 participants), change in percentage atheroma area during follow-up was also greater in the diabetes (1.86+/-3.90%) than in other groups (0.28+/-3.32% and 0.56+/-2.96%,p=0.0047 global). FBG correlated with maximum percentage atheroma area at baseline (r=0.17; p=0.0003). HbA1c also correlated with maximum percentage atheroma area at baseline (r=0.26; p=0.0001) and with change in maximum plaque area (r=0.16; p=0.016). A similar pattern of results occurred with plaque volume. The relationships between diabetes or HbA1c and both IVUS measurements of plaque burden and remodelling persisted after adjustment.

CONCLUSIONS/INTERPRETATION

Fasting blood glucose, HbA1c and the presence of diabetes are associated with the severity and progression of coronary atherosclerosis. These observations support the hypothesis that better glycaemic control may favourably influence CAD in patients with abnormal glucose tolerance or diabetes.

The connection between C-reactive protein (CRP) and diabetic vasculopathy. Focus on preclinical findings

Current evidence supports a central role of inflammation in the pathogenesis of atherosclerosis and diabetes. Type 2 diabetes is an inflammatory atherothrombotic condition associated with a high prevalence of cardiovascular disease. In patients with type 2 diabetes, low grade inflammation is reflected by increased plasma levels of several biomarkers of inflammation such as C-reactive protein (CRP). Small increases in CRP predict the likelihood of developing cardiovascular events both in diabetic and nondiabetic populations. In addition, in apparently healthy subjects, increased levels of CRP predict the risk of developing type 2 diabetes. There is some evidence that CRP, besides its predictive role in determining cardiovascular risk, may represent an active participant in atherogenesis. CRP is expressed in human atherosclerotic plaques and both vascular cells and monocytes/macrophages appear to represent a significant source of CRP in the inflammatory vessel wall. By activating the main cell types present in the atherosclerotic lesions, CRP generated within the coronary plaques may contribute to the development and progression of atherosclerosis. Data on vascular CRP regulation are scarce. Current evidence suggests that inflammatory and metabolic factors associated with diabetes, such as high glucose, adipokines, modified lipoproteins and free fatty acids may trigger CRP production by endothelial cells, smooth muscle cells and monocytes/macrophages. These data suggest that local CRP concentration in diabetic atherosclerotic plaques could be higher than in nondiabetic ones. Given the possible correlation between local CRP production and the degree of severity of coronary artery disease or the nature of the lesion, such alteration may contribute to the accelerated development of vascular disease in patients with type 2 diabetes.

Immunotoxicity and biodistribution analysis of arsenic trioxide in C57Bl/6 mice following a 2-week inhalation exposure

In these studies the immunotoxicity of arsenic trioxide (ATO, As(2)O(3)) was evaluated in mice following 14 days of inhalation exposures (nose only, 3 h per day) at concentrations of 50 microg/m(3) and 1 mg/m(3). A biodistribution analysis performed immediately after inhalation exposures revealed highest levels of arsenic in the kidneys, bladder, liver, and lung. Spleen cell levels were comparable to those found in the blood, with the highest concentration of arsenic detected in the spleen being 150 microg/g tissue following the 1 mg/m(3) exposures. No spleen cell cytotoxicity was observed at either of the two exposure levels. There were no changes in spleen cell surface marker expression for B cells, T cells, macrophages, and natural killer (NK) cells. There were also no changes detected in the B cell (LPS-stimulated) and T cell (Con A-stimulated) proliferative responses of spleen cells, and no changes were found in the NK-mediated lysis of Yac-1 target cells. The primary T-dependent antibody response was, however, found to be highly susceptible to ATO suppression. Both the 50 microg/m(3) and 1 mg/m(3) exposures produced greater than 70% suppression of the humoral immune response to sheep red blood cells. Thus, the primary finding of this study is that the T-dependent humoral immune response is extremely sensitive to suppression by ATO and assessment of humoral immune responses should be considered in evaluating the health effects of arsenic containing agents.

Beneficial effect of Bupleurum polysaccharides on autoimmune disease induced by Campylobacter jejuni in BALB/c mice

AIM OF THE STUDY

Radix Bupleuri, is one of the most frequently prescribed crude herbs in the prescriptions of traditional Chinese medicine for the treatment of inflammatory diseases and auto-immune diseases. This study was to determine whether the crude polysaccharides (BPs) isolated from the roots of Bupleurum smithii var. parvifolium, had beneficial effects on autoimmune disease.

MATERIALS AND METHODS

BALB/c mice were immunized with CJ-S(131) in Freund's complete adjuvant on day 0, and then boosted on day 14. BPs 15 or 30 mg kg(-1) day(-1), or prednisone 5 mg kg(-1) day(-1) was given to BALB/c mice intragastrically from day 0 to day 34.

RESULTS

Treatment with BPs 15 or 30 mg kg(-1) day(-1) for 35 days protected kidney from glomerular injury with reduced immunoglobulin deposition and lowered proteinuria. The increased production of serum autoantibodies and total immunoglobulin G (IgG) was also inhibited. BPs 30 mg kg(-1) day(-1) improved weight loss and spleen swelling when compared with vehicle-treated group.

CONCLUSIONS

These findings suggested that Bupleurum polysaccharides had a beneficial effect on systemic lupus erythematosus-like syndroma induced by CJ-S(131) in BALB/c mice.

EVIDENCE FOR A ROLE OF DOPAMINERGIC MECHANISMS IN THE IMMUNOSTIMULATING EFFECT OF µ-OPIOID RECEPTOR AGONIST DAGO

The present study demonstrates that: (1) activation of micro -opioid receptors by systemic administration of a highly selective agonist DAGO (100 microg/kg) results in a significant increase in the number of plaque- and rosette-forming cells in the spleen of CBA mice as well as Wistar rats on the 5th day following sheep red blood cells (5 x 10(8)) immunization, (2) the immunostimulatory effect of DAGO is mediated by central mechanisms including the hypothalamus-hypophysis complex; (3) the postsynaptic dopamine (DA) receptors of D2 type are involved in the DAGO-induced immunostimulation since the combined treatment of animals with haloperidol (2 mg/kg), a blocker of DA D2 receptors, and DAGO abolished this effect; (4) the nuclei caudatus and accumbens of the nigrostriatal and mesolimbic DAergic systems, respectively, are implicated in the immune response stimulation caused by DAGO.

The evaluation of the immunomodulating properties of ERA-63 a pharmaceutical with estrogenic activity

This paper describes studies performed with ERA-63 a low molecular weight pharmaceutical with intended immunomodulatory effects. Since this compound was also known to have estrogenic activity a non-conventional approach was taken in order to differentiate between estrogenic and non-estrogenic-induced immunomodulatory effects. EE was included not only for qualitative comparison (hazard identification) between immunomodulatory effects but also, in case of similar effects, to facilitate the extrapolation of the findings in the rat to anticipated effects in humans. After 28 days of treatment with dosages ranging from pharmacological up to clearly toxic levels for both compounds the immunotoxic potential was assessed by performing a T cell-dependent antibody response and a host resistance assay in rats. Selected ERA-63 dose levels (0.167-0.2, 1.67-2 and 16.7-20mg/kg) were expected to have comparable estrogenic activity to respective EE dose levels (0.05, 0.5 and 5mg/kg). General toxicity parameters reflecting estrogenic activity (i.e. decreased body- and organ weights of thymus and testis, and increased bilirubin and GGT levels) confirmed the comparable estrogenic activity for both compounds at the dose levels tested. Together with the comparable estrogen-related immune suppression (i.e. decreases in specific antibody responses and an increased susceptibility for Listeria monocytogenes infects) for both compounds, this indicates that available clinical data for EE facilitates the human risk assessment of ERA-63.

Activation of human lymphocyte subpopulations by Mycoplasma pneumoniae

B- and T-cell-enriched preparations of lymphocytes from human blood (5 cases), adenoids (10 cases), and tonsils (4 cases) were examined for the in vitro stimulation response to Mycoplasma pneumoniae (MP). B lymphocytes did not respond to MP by DNA synthesis except for the B cells from one adenoid. T lymphocytes and nonfractionated lymphocytes from blood, from three of the adenoids and two of the tonsils showed a stimulation response to MP. Nonfractionated adenoid lymphocytes from altogether 22 children were examined, and a stimulation response to MP was demonstrated in 8 cases. Lymphocyte cultures from 11 adenoids and 2 tonsils were examined for MP-induced non-antigen-specific antibody production by a hemolytic plaque assay. In all these cultures MP activated production of antibody-secreting cells to sheep erythrocytes. It is concluded that MP can induce non-antigen-specific angibody production in human B lymphocytes without stimulating DNA synthesis in these cells. The proliferative response of adenoid, tonsil, and blood lymphocytes to MP is interpreted as an antigen-specific T-cell response.

Polyclonal antibody secretion in human lymphocytes induced by killed staphylococcal bacteria and by lipopolysaccharide

Preparations of Staphylococcus aureus strains Cowan 1 and Wood 46 and of lipopolysaccharide (LPS) were found to act as polyclonal B-cell-activating substances for human splenic and blood lymphocytes. All three substances induced polyclonal antibody secretion in blood and spleen cell cultures, as tested against fluorescein isothiocyanate-coupled sheep erythrocytes by a modification of the local hemolysis-in-gel assay. Antibodies were of IgM class, as shown by inhibition of plaque formation by anti-IgM but not by anti-IgG or anti-IgA antisera. All these substances also consistently induced the formation of intracellular immunoglobulin and increased DNA synthesis in stimulated spleen cells. In blood lymphocytes Staph. aureus Cowan 1 induced a consistent increase in DNA synthesis, whereas Staph, aureus Wood and LPS often gave low or no increase in DNA synthesis. Peak antibody formation was observed on day 3 in spleen cells and on day 6 in blood lymphocyte cultures. Stimulation into high-rate immunoglobulin secretion occurred with all PBAs also in B-cell-enriched cell suspensions but not in T-cell-enriched cells. Optimal responses were, however, always noted in unseparated cell suspensions. It is concluded that preparations of killed bacteria can be useful tools for the clinical evaluation of both specific and nonspecific antibody-forming ability in cells from different groups of patients.

Studies of antibody-dependent cytotoxicity in a plaque assay: evidence of human monocyte-like effector cells

Two different methods for evaluating 'in vitro' cytotoxicity against antibody-coated target cells mediated by mononuclear leukocytes were compared. One was a plaque assay for identification of the cytotoxic cell and the other the classical chromium release assay for antibody-dependent cytotoxicity (ADCC). A marked decrease in plaque-forming cells (PFC) was observed in a cell suspension depleted of peroxidase-positive cells and cells with membrane-bound Ig (B lymphocytes) by fractionation on a nylon fiber column. In contrast, the ADCC activity was considerably increased by these depletions. A similar effect was obtained by removal of phagocytic cells with iron. These results, together with the observations after depletion of E-RFC (T lymphocytes) or EA-RFC (Fc-receptor-bearing cells), suggest that the PFC in the assay system used were of monocytic origin and differnet from the cells responsible for the ADCC.

The effect of adenosine on lymphoid cell proliferation and antibody formation

The discovery of an association of certain primary defects in human purine metabolism with immunodeficiency disease has served to focus attention on the possible role of purine compounds in the functional activity of lymphoic cells. Considerable evidence has accumulated of the need within the intact organism for purine and pyrimidine compounds supplied by the liver as a supplementary nutritional requirement for the growth of the rapidly proliferating tissues of certain organ systems. Likewise, lymphoid cells cultured in vitro show evidence of an enhancement of indices of cellular proliferation and of antibody synthesis when exogenous adenosine is added to the medium. These functions are inhibited by high concentrations of adenosine and there is some evidence that T-cell proliferation shows a greater sensitivity to inhibition by adenosine than B-cells. These observations may be significant in relation to the known defects in human purine metabolism and their mechanism for producing immunodeficiency.

Modulation of humoral immunity by Cassia fistula and amoxy-cassia

Immonomodulatory effect of fruit of C fistula, a traditional medicinal plant and its synergistic antimicrobial combination with amoxicillin named Amoxy-cassia (Patent # 1371240, Government of Pakistant) studied on humoral immune system of BALB/c mice. Animal immunized with sheep RBC and treated with C. fistula fruit, amoxycassia, amoxicillin and saline Number of activated anti-SRBC producing cell in spleen calculated by haemolytic plaque assay. Antibody titer in blood was measured by haemagglutination test. Number of plaques formed by the animal treated with Amoxy-cassia, amoxicillin, C.fistula, and normal saline were 191, 86, 53, 34 per 10(5) spleen cells respectively. Haemagglutinating Antibody (HA) titer was evaluated on post-immunized day 4, 6, 8, 10. Rising antibody titer was observed in all animals but Amoxy-cassia treated mice serum had the highest HA titer through out the experiment suggesting its therapeutic usefulness. But further detailed studies of mechanisms of immunomodulation and its probable use in immuno compromised individual are still to be investigated and their possible use as an adjuvant during vaccination programs in order to reduce number of non-responder to vaccines need to be studied.

Inflammatory multiple-sclerosis plaques generate characteristic metabolic profiles in cerebrospinal fluid

Background

Multiple sclerosis (MS), an inflammatory disease of the central nervous system, manifests itself in numerous forms and stages. A number of brain metabolic alterations have been reported for MS patients vs. control subjects. However, metabolite profiles of cerebrospinal fluid (CSF) are not consistent among the published MS studies, most probably due to variations in the patient cohorts studied. We undertook the first investigation of highly homogeneous MS patient cohorts to determine characteristic effects of inflammatory MS plaques on the CSF metabolome, including only patients with clinically isolated syndrome (CIS) with or without inflammatory brain plaques, and controls.

Methodology/Principal Findings

CSF obtained by lumbar puncture was analyzed by proton magnetic resonance spectroscopy. 27 metabolites were quantified. Differences between groups of control subjects (n = 10), CIS patients with (n = 21) and without (n = 12) inflammatory plaques were evaluated by univariate statistics and principal component analysis (PCA). Seven metabolites showed statistically significant inter-group differences (p<0.05). Interestingly, a significant increase in β-hydroxyisobutyrate (BHIB) was detected in CIS with vs. without active plaques, but not when comparing either CIS group with control subjects. Moreover, a significant correlation was found, for the first time, between CSF lactate concentration and the number of inflammatory MS brain plaques. In contrast, fructose concentrations were equally enhanced in CIS with or without active plaques. PCA based on all 27 metabolites yielded group-specific clusters.

Conclusions/Significance

CSF metabolic profiles suggest a close link between MS plaque activity in CIS patients on the one hand and organic-acid metabolism on the other. Our detection of increased BHIB levels points to a hitherto unsuspected role for this compound in MS with active plaques, and serves as a basis for further investigation. The metabolic effects described in our study are crucial elements in the explanation of biochemical mechanisms involved in specific MS manifestations.

Antibody responses in hyperthyroid rats

This study evaluated antibody production against sheep red blood cells (SRBC) in hyperthyroid rats during treatment with triiodothyronine (T(3)). The immune response was evaluated by measuring plaque forming cells (PFC) in the spleen and by enzyme-linked immunosorbent assay (ELISA) in serum of male Wistar rats (180+/-10 g) treated with 25 mug/day of triiodotironine (T(3)) during 7-12 days and immunized with SRBC at the 8th day of treatment. The results showed that anti-SRBC antibody production was significantly decreased in animals treated for 12 days when compared to normal rats immunized with the same antigen, as evaluated by the two assays. These results show that in this experimental model hyperthyroidism decreases antibody response. We previously observed the opposite effect, that is, an increase in this response in hypothyroid rats resulting from the treatment with propylthyouracil, a blocker of thyroid hormone biosynthesis. It is suggested that antibody production is affected by thyroid hormone levels.

Effect of ivermectin on the cellular and humoral immune responses of rabbits

The objective of this paper is to determine the effect of ivermectin administration on cell mediated (CMI) and humoral immunity (HI) of rabbits. CMI against dinitrochlorobenzene (DNCB) and sheep red blood cells (SRBC) in rabbits was determined by delayed-type hypersensitivity and macrophage engulfment assay (MEA), respectively; whereas, HI to Pasteurella multocida B2 vaccine and SRBC was determined by indirect haemagglutination assay (IHA) and Jerne hemolytic plaque formation assay (JHPFA), respectively. The rabbits were divided into four major groups (A through D) each subdivided into four sub-groups (1 through 4). Rabbits of group A served as vehicle control while those of groups B, C and D were treated with ivermectin at the dose rates of 200 microg/kg, 400 microg/kg and 600 microg/kg b.w., respectively. Cellular immunity was determined in sub-groups 1 and 2 through DNCB and MEA, respectively while HI was determined in sub-groups 3 and 4 through IHA and JHPFA, respectively. The skin sensitivity to DNCB at 24 and 48 h and macrophage engulfment of SRBC were highest (P>0.05) in rabbits administered with 600 microg/kg b.w. The highest geometric mean titers (14.00+/-0.31) and number of plaque forming units (1860+/-0.75) were found in rabbits that received ivermectin at a dose of 600 microg/kg b.w. followed, in order by the groups that received 400 microg/kg, 200 microg/kg b.w. and controls. Leukocyte counts were significantly higher in ivermectin-treated groups (C and D) than group A (vehicle control) and B (ivermectin at the rate of 200 microg/kg). A graded dose immune response suggested an immunopotentiating effect of ivermectin at higher doses.

Microsomal Expoxide Hydrolase Is Required for 7,12-Dimethylbenz[a]anthracene (DMBA)-Induced Immunotoxicity in Mice

Microsomal epoxide hydrolase (mEH, EPHX1) is involved in the metabolism of chemicals to generate dihydrodiol intermediates in the presence of the cytochrome P450. We have previously shown that 7,12-dimethylbenz[a]anthracene (DMBA) can suppress both cell-mediated and humoral immune responses in wild-type (WT) C57BL/6N mice but not in CYP1B1 null mice. In the present studies, we hypothesized the critical metabolite responsible for DMBA-induced immunotoxicity is likely to be the 3,4-dihydrodiol-1,2-epoxide metabolite of DMBA, which requires mEH for formation. Mice were gavaged orally with DMBA (0, 17, 50, and 150 mg/kg) once a day for 5 days. Immune function and other assays were performed on day 7. Our data showed that unlike WT mice, DMBA treatment of mEH null mice produced no alterations in the body weight, spleen weight, or spleen cellularity. Similarly, DMBA treatments did not affect the PFC response in mEH null mice. Natural killer activity was not altered by DMBA treatment in mEH null mice. T-cell mitogenesis was partially suppressed by 50 and 150 mg/kg DMBA treatments of mEH null mice, but B-cell mitogenesis was not affected. Finally, we assessed the biodistribution of DMBA in both C57BL/6N WT and mEH null mice in spleen, thymus, and liver after 24 h and 7 days oral gavage. The concentrations of DMBA in each organ were not significantly different in WT and in mEH null mice. Collectively, these results demonstrate that mEH (EPHX1 gene) is a crucial enzyme for metabolic activation of DMBA in vivo leading to immunosuppression of spleen cells.

Application of flow cytometry in detection of red-cell-bound IgG in Coombs-negative AIHA

Coombs negative autoimmune hemolytic anemia (AIHA) is characterized by laboratory evidence of in vivo hemolysis along with a negative direct antiglobulin test (DAT) performed by conventional tube technique (CTT) in clinically suspected AIHA patients. The sensitive gel test (GT) and flow cytometry (FC) can effectively diagnose such patients where CTT does not detect low level of red cell autoantibodies. We investigated the use of FC in the serological evaluation of CTT DAT negative AIHA and its comparison with GT DAT. Of the 50 patients with suspected AIHA, CTT DAT was negative in 5 patients (Coombs negative AIHA). GT DAT could detect red cell autoantibodies in 4 of these 5 patients. Monospecific GT DAT showed IgG and/or C3d as the responsible autoantibody. FC was considered as reactive when MFI was >3.6 (mean of 20 healthy negative volunteers +2SD). FC was reactive in all five Coombs negative AIHA patients. The mean MFI in five known CTT DAT positive samples taken for comparison was significantly higher compared to 5 DAT negative AIHA (18.3 +/- 7.78 vs. 7.88 +/- 1.35, p < 0.05). There was poor correlation between strength of GT DAT and MFI by FC. We conclude that FC is more sensitive test than the CTT and helps in the serological diagnosis of Coombs negative AIHA. However, in resource poor settings, GT DAT can be a good alternative to FC.

Immunomodulatory effects of two sapogenins 1 and 2 isolated from Luffa cylindrica in Balb/C mice

Two Triterpenoids (sapogenins 1 and 2) isolated from Luffa cylindrica were subjected to immunomodulatory activity in male Balb/c mice. Mice were treated with three doses of sapogenins 1 and 2 (10, 30 and 100 mg/kg) and levamisole (2.5 mg/kg) used as a standard reference drug for 15 days. Immune responses to T-dependent antigen SRBCs were observed using parameters like HA, PFC, DTH, lymphocyte proliferation and phagocytosis. As regards these parameters, sapogenins 1 and 2 elicited a significant increase in the HA, PFC and DTH response at dose 10 mg/kg (P<0.01) and 100 mg/kg (P<0.001), respectively. Sapogenins 1 and 2 also showed significant dose-dependent decrease and increase in lymphocyte proliferation assay and phagocytic activity of macrophages. Overall, sapogenins 1 and 2 showed dose relative immunostimulatory effect on in vivo immune functions in mice.

Studies on the mode of action of the antifungal hexapeptide PAF26

The small antimicrobial peptide PAF26 (Ac-RKKWFW-NH(2)) has been identified by a combinatorial approach and shows preferential activity toward filamentous fungi. In this work, we investigated the mode of action and inhibitory effects of PAF26 on the fungus Penicillium digitatum. The dye Sytox Green was used to demonstrate that PAF26 induced cell permeation. However, microscopic observations showed that sub-MIC concentrations of PAF26 produced both alterations of hyphal morphology (such as altered polar growth and branching) and chitin deposition in areas of no detectable permeation. Analysis of dose-response curves of inhibition and permeation suggested that growth inhibition is not solely a consequence of permeation. In order to shed light on the mode of PAF26 action, its antifungal properties were compared with those of melittin, a well-known pore-forming peptide that kills through cytolysis. While the 50% inhibitory concentrations and MICs of the two peptides against P. digitatum mycelium were comparable, they differed markedly in their fungicidal activities toward conidia and their hemolytic activities toward human red blood cells. Kinetic studies showed that melittin quickly induced Penicillium cell permeation, while PAF26-induced Sytox Green uptake was significantly slower and less efficient. Therefore, the ultimate growth inhibition and morphological alterations induced by PAF26 for P. digitatum are not likely a result of conventional pore formation. Fluorescently labeled PAF26 was used to demonstrate its specific in vivo interaction and translocation inside germ tubes and hyphal cells, at concentrations as low as 0.3 muM (20 times below the MIC), at which no inhibitory, morphological, or permeation effects were observed. Interestingly, internalized PAF26 could bind to cellular RNAs, since in vitro nonspecific RNA binding activity of PAF26 was demonstrated by electrophoretic mobility shift assays. We propose that PAF26 is a short, de novo-designed penetratin-type peptide that has multiple detrimental effects on target fungi, which ultimately result in permeation and killing.

Effect of AC II, a herbal formulation on radiation-induced immunosuppression in mice

A single dose of 6 Gy irradiation significantly reduced the total WBC count while in herbal formulation (AC II) treated groups it was found to be significantly increased. Similarly bone marrow cellularity and alpha-esterase positive cells, which were lowered by radiation, were partly restored in AC II treated groups. The data indicate that AC II can overcome the immunosuppression produced by irradiation.

Acetone in drinking water does not modulate humoral immunity in mice as measured by the antibody, plaque-forming cell assay

It has been reported that the repeated topical, nonoccluded application of acetone may modulate antibody production in mice, thus producing humoral immunosuppression. However, the evaporative loss expected following nonoccluded dermal application of acetone makes the systemic effect seem unlikely. This study was designed to investigate the immunotoxicity potential of acetone in mice following a more direct systemic route of dosing via drinking water for 28 days. CD-1 male mice consumed average daily acetone doses of 121, 621 or 1144 mg/kg/day. The antibody, plaque-forming cell (AFC) assay was performed to measure the T cell-dependent, anti-sheep red blood cell immunoglobulin M (IgM) response, and hematology and thymus weights were evaluated to provide additional insight into the potential effects to the immune system. Body weights, white blood cell (WBC), numbers, red blood cell (RBC) counts, and hemoglobin and hematocrit levels showed no treatment-related effects at any dose of acetone. Eosinophil percentages were variable but also showed no dose-related trends. Spleen and thymus weights were not statistically different from controls and there were no effects on spleen cellularity or AFC response as a result of acetone administration. The AFC responses ranged from 1088 to 1401 AFCs/10(6) splenocytes and were not statistically different from controls (1277 AFCs/10(6) cells). Mice treated with cyclophosphamide (20 mg/kg) on days 25 to 28 demonstrated a 94% reduction in AFC/10(6) cells. Thus, the direct systemic administration of acetone did not produce evidence for immunotoxicity in CD-1 mice and the no observed adverse effect level (NOAEL) in this study was determined to be 1144 mg/kg/day.

Induction of neutralizing antibodies and T cell responses by dengue virus type 2 envelope domain III encoded by plasmid and adenoviral vectors

Dengue is a re-emerging public health problem in many developing nations. There is neither a specific antiviral therapy to treat nor a licensed vaccine to prevent dengue infections. In recent years, the carboxy-terminal region of the major dengue virion envelope (E) protein, known as domain III, has emerged as a significant sub-unit vaccine candidate. In this study, we created a recombinant adenovirus capable of expressing the E domain III (EDIII) of dengue virus type 2 (DEN-2) and tested it in combination with a plasmid encoding the same domain to determine its potential as a possible dengue vaccine candidate. We examined the relative efficacies of plasmid prime/Ad boost (P/A) and Ad prime/plasmid boost (A/P) regimens in eliciting DEN-2 virus-specific immune responses. Both regimens resulted in the induction of antibodies that specifically bound to and neutralized the infectivity of DEN-2 virus. Splenocytes from immunized mice, stimulated in vitro, manifested a significant proliferative response accompanied by the production of high levels of interferon-gamma, but moderately elevated levels of interleukin-4, indicative of a predominantly Th1 type response. Based on a comparison of the parameters investigated, the immune response induced by the A/P regimen appeared to be relatively more potent. Our data suggest that EDIII may be valuable in the efforts to develop plasmid- and Ad-vectored dengue vaccines.

Blockade of beta1 integrin-laminin-5 interaction affects spreading and insulin secretion of rat beta-cells attached on extracellular matrix

When attached on a matrix produced by a rat bladder carcinoma cell line (804G matrix), rat pancreatic beta-cells spread in response to glucose and secrete more insulin compared with cells attached on poly-l-lysine. The aim of this study was to determine whether laminin-5 and its corresponding cell receptor beta1 integrin are implicated in these phenomena. By using specific blocking antibodies, we demonstrated that laminin-5 is the component present in 804G matrix responsible for the effect of 804G matrix on beta-cell function and spreading. When expression of two well-known laminin-5 ligands, beta1 and beta4 integrin, was assessed by Western blot and RT-PCR, only the beta1 integrin was detected in beta-cells. Anti-beta1 integrin antibody reduced the spreading of beta-cells on 804G matrix. Blockade of the interaction between beta1 integrins and laminin-5 resulted in a reduction in glucose-stimulated insulin secretion. Blocking anti-beta1 integrin antibody also inhibited focal adhesion kinase phosphorylation induced by 804G matrix. In conclusion, anti-beta1 integrin and -laminin-5 antibodies interfere with spreading of beta-cells, resulting in decreased insulin secretion in response to glucose. Our findings indicate that outside-in signaling via engagement of beta1 integrins by laminin-5 is an important component of normal beta-cell function.

Brazilein, an important immunosuppressive component from Caesalpinia sappan L

Caesalpinia sappan has been shown to have interesting immunosuppressive properties. Its heartwood has long been used in Chinese medicines for treating a variety of immune-mediated pathology and inflammatory disease. The purpose of this work was to evaluate the immunocompetence effects of brazilein on mice lymphocytes in vitro and in vivo. The results showed that brazilein and Caesalpinia sappan ethanol extract (SME) could distinctly inhibit the proliferation of T lymphocyte stimulated by Concanavalin A (Con A) and the proliferation of B lymphocyte stimulated by lipopolysaccharides (LPS), and brazilein could suppress mice humoral immune response by plaque forming cell (PFC) test. In addition, immune organs (thymus and spleen) in mice treated with brazilein were notably atrophied and weight loss in vivo (intraperitoneal injection, i.p.). In attempting to investigate the mechanisms of the immunosuppressive activity of brazilein, we discovered that brazilein can induce apoptosis in mice spleen lymphocytes by flow cytometry analysis and DNA fragmentation assay, which may be one of the pathways that brazilein inhibited immunocompetence of mice lymphocytes.

A tailoring activity is responsible for generating polyene amide derivatives in Streptomyces diastaticus var. 108

We recently characterized rimocidin B (3b) and CE-108B (4b) as two polyene amides with improved pharmacological properties, produced by genetically modified Streptomyces diastaticus var. 108. In this work, genetic and biochemical analysis of the producer strain show that the two amides are derived from the parental polyenes rimocidin (3a) and CE-108 (4a) by a post-PKS modification of the free side chain carboxylic acid. This modification is mediated by an amidotransferase activity operating after the biosynthesis of rimocidin (3a) and CE-108 (4a) are completed. Two polyenes, intermediates of the biosynthetic pathway of rimocidin (3a) and CE-108 (4a), were also isolated and shown to have some improved pharmacological properties compared with the final products.

Antimicrobial activity of some hydroxamic acids

Several hydroxamic acids, viz., N-benzyl-N'-hydroxysuccinamide (BHS), poly[alpha,beta-(N-hydroxy)-DL-aspartamide] (PHA), poly[alpha,beta-(N-hydroxy-N-methyl-DL-aspartamide)] (PMHA) and poly[alpha,beta-(N-hydroxy)-DL- aspartamide]/poly[alpha,beta-(N-2-hydroxyethyl)-DL-aspartamide] (PHA-PHEA 1:1) were prepared and screened for their antimicrobial activity. Ten Gram-positive and 7 Gram-negative species of bacteria, 5 Candida species, 4 dermatophyte species and 3 mould species were used in tests. Compound showed no antimicrobial activity on any of the tested microorganisms. Other compounds showed a narrow spectrum of antibacterial activity, but no antifungal activity.

Antibody Response of Autogenous Splenic Tissue Implanted in the Abdominal Cavity of Mice

There is still controversy about the immunologic function of autotransplanted splenic tissue. In this study, splenic autotransplantation was performed in the abdominal cavity of mice, and the plaque-forming cell (PFC) assay was used to investigate the frequency of antibody-forming cells in response to sheep red blood cell (SRBC) immunization. BALB/c mice were divided into four groups according to the location of the autogenous graft: intraomental (IO), free peritoneal splenosis (FPS), retroperitoneal (RP), and nongrafted control (CT). Thirty days after surgery the mice were immunized intraperitoneally with SRBCs, and 4 days later splenic immunoglobulin M anti-SRBC-secreting cells were determined by counting the number of PFCs. All the immunized mice showed increased numbers of PFCs that were about 2 logs higher than those in the the nonimmunized controls (P < 0.005). The frequencies of anti-SRBC-producing cells in the tissues grafted in various sites of the abdominal cavity (IO, FPS, RP), in the normal spleen from nonoperated controls (CT), or in the sham-operated control group (SCT) were not notably different (5582 +/- 2475 PFC/10(7) cells for IO; 4849 +/- 1856 for FPS; 6604 +/- 2903 for RP; 5940 +/- 5029 for CT; and 6172 +/- 2203 for SCT). Similar histology with small architectural variations was observed in all implants; less white pulp was involved, and there was more congestion in the red pulp, with extensive sinusoids and reticular fiber proliferation. This study shows that the T cell-dependent antibody response in implanted splenic tissues is as efficient as in the intact spleen, with no difference between the graft sites studied. This immune response does not depend on the slight architectural variations observed in the splenic implants.

Effects of Brx-019 (acetic acid 3,6a,9-triacetoxy-6,6a,7, 11b-tetrahydro-indeno [2,1-c] chromen-10-yl ester), a Brazilin derivative, on T cell-mediated immune responses in multiple low dose streptozotocin-induced diabetic C57BL/6 male mice

Brx-019 (acetic acid 3,6a,9-triacetoxy-6, 6a,7,11b-tetrahydro-indeno [2,1-c] chromen-10-yl ester) was derived from brazilin (CAS 474-07-7) during a trial designed to search for immunomodulators with lower toxicity and more effective immunomodulating activities than brazilin. Brx-019 was selected as a potential immunomodulator based on its effects on Concanavalin A (Con A)-induced proliferation of splenocytes and the 3-[14,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Intraperitoneally administered Brx-019 significantly improved delayed type hypersensitivity and increased immunoglobulin M (IgM) plaque forming cells (PFCs) in multiple low dose streptozotocin-induced diabetic mice (MLDS-diabetic mice). This finding suggests that Brx-019 may increase suppressed humoral and cell-mediated immunity in type 1 diabetes. Brx-019 also significantly increased Con A- or alloantigen-induced proliferation of splenocytes, Con A-induced interleukin 2 (IL-2) production from splenocytes, and IL-2-induced proliferation of Con A-activated splenocytes in MLDS-diabetic mice. These results suggest that Brx-019 might improve immunity in diabetic mice by increasing IL-2 production in splenocytes and responsiveness of splenocytes to IL-2, which were suppressed in MLDS-diabetes.

Expression and secretion of alpha1-proteinase inhibitor are regulated by proinflammatory cytokines in human pancreatic islet cells

AIMS/HYPOTHESIS

Alpha1-proteinase inhibitor (alpha1-PI) has been considered a key player in inflammatory processes. In humans, the main production site of alpha1-PI is the liver, but other tissues, including pancreatic islets, also synthesise this molecule. The aims of this study were to assess the islet cell types that produce alpha1-PI, to determine whether alpha1-PI is actually secreted by islet cells, and to assess how its production and/or secretion are regulated.

METHODS

Expression of alpha1-PI in human islet cells was assessed by immunofluorescence, electron microscopy and western blotting. Release of alpha1-PI was analysed by reverse haemolytic plaque assay and ELISA. The effects of cytokines on alpha1-PI synthesis and secretion were tested.

RESULTS

Immunofluorescence showed that alpha and delta cells do express alpha1-PI, whereas beta cells do not. By electron microscopy, we demonstrated a colocalisation of alpha1-PI with glucagon and somatostatin within secretory granules. Immunolabelling also revealed localisation of alpha1-PI within the Golgi apparatus, related vesicles and lysosomal structures. The expression of alpha1-PI in islet cells was also demonstrated by western blotting and ELISA of protein extracts. ELISA and reverse haemolytic plaque assay showed that alpha1-PI is secreted into the culture medium. Treatment of islet cells with IL-1beta and oncostatin M for 4 days increased the production and release of alpha1-PI.

CONCLUSIONS/INTERPRETATION

Our results demonstrate that alpha1-PI is expressed by the alpha and delta cells of human islets, and that proinflammatory cytokines enhance the production and release of this inhibitor.

[Comparison between biotype of Vibrio cholerae O1 and genotype using polymerase chain reaction]

To compare between biotype of Vibrio cholerae O1 and genotype using polymerase chain reaction (PCR), 9 classical and 81 El Tor biovar strains were investigated for hemolysis, agglutination of avian erythrocytes, VP test reactivity, sensitivity to both polymyxin B and classical phage IV, and genotype using PCR amplification of hlyA, tcpA, rtxA and rtxC. One classical biovar strain showed atypical reaction upon agglutination of avian erythrocytes. Eighteen El Tor biovar strains showed atypical reactions, with the exception of sensitivity to polymyxin B. By PCR detection of hlyA, rtxA and rtxC amplifications, all classical biovar strains possessed only classical type hlyA, while all El Tor biovar strains possessed El Tor type hlyA, rtxA and rtxC. By PCR analysis of amplicons, all classical biovar strains possessed classical type tcpA. One ctx-negative El Tor biovar strain possessed degenerated classical type tcpA and 4 ctx-negative El Tor biovar strains had no detectable tcpA. These results indicated that genotype of V. cholerae O1 using PCR detection of hlyA, rtxA and rtxC was consistent with biotype of the organism, suggesting that analysis of the genotype of the organism was as effective as by biochemical properties. However, PCR detection of hlyA is most appropriate for the biotyping of V. cholerae O1, as compared to biochemical properties, since El Tor biovar was originally distinguished from classical biovar strains by the hemolytic reaction.

Immunomodulation by Dok Din Daeng (Aeginetia indica Roxb.) extracts in female B6C3F1 mice

In the previous report, we have provided evidence that Aeginetia indica Roxbert (DDD) extracts enhance T cell-mediated immune responses. The study reported here was focused on the hematological and immunological effects, including B cells, natural killer (NK) cells, macrophages and neutrophils, of the whole plant extract using water (WDDD) or ethanol (EDDD) as the solvent. The extracts were administered to female B6C3F1 mice by gavage for WDDD (10-100%) and intraperitoneally for EDDD (0.25-250 mg/kg) for 28 days. In addition to hematological evaluation, several quantitative measures and functional assays (e.g., the splenic phenotypic analysis, IgM antibody-forming cell responses, natural killer cell activity, mononuclear phagocyte system [MPS] and neutrophil activity) were employed to examine the effects of DDD extracts on the innate and humoral immunities. The results from this study demonstrated that exposure to WDDD and EDDD produced minimal changes in the activities of B cells and natural killer cells, macrophages and neutrophils. Overall, hematological parameters were not affected by exposure to WDDD or EDDD. Taken together, the enhancing effect of DDD extracts on T cells may be primarily responsible for the successful and long-time use of this traditional herbal medicine in Thailand.

The accuracy of extended histopathology to detect immunotoxic chemicals

The accuracy of extended histopathology to detect immunotoxic chemicals in female B6C3F1 mice was evaluated under the auspices of the National Toxicology Program (NTP). A workgroup was formed consisting of four pathologists who conducted extended histopathological evaluation of lymphoid tissues obtained from a subset of NTP toxicology studies, in which previously detailed immunotoxicity assessment was performed. In addition, a positive control data set of three known immunosuppressive agents, one negative control data set, and an additional negative control group composed of the vehicle only treated groups were included. Data obtained from extended histopathology evaluations were compared to more traditional immune test results (both functional and nonfunctional) from previously conducted immunotoxicity assessments. Analyses of the data indicated that the ability to identify immunotoxic chemicals using histological endpoints decreased linearly as the level of stringency used to determine significant histopathological changes increased. A relatively high (80%) accuracy level was achieved when histological changes were considered in toto (i.e., any histological abnormality in the three tissues examined), using minimal or mild criteria for scoring. When minimal or mild histological changes were considered significant for a specific tissue, a 60% level of accuracy in identifying immunotoxic chemicals was obtained as compared to a 90% accuracy level that was achieved with this data set using the antibody plaque forming cell response, considered to represent the most predictive functional test. A minimal classification was obtained in the analyses of the negative control groups, suggesting that use of the minimal classification for hazard identification is inappropriate as it will likely result in a high incidence of false positives. This was not the case when mild classifications were used as an indicator of significance, which in most instances allowed the successful identification of negatives. When moderate to marked histopathological changes were used to identify immunotoxic chemicals, the level of accuracy that could be achieved was poor. A considerably higher level of accuracy was obtained for the positive control data set than the test chemical data set suggesting that the ability to detect an immunotoxic agent histologically is proportional to the potency of the immunotoxic agent. Comparison of immune function test results and histopathological results obtained from the high-dose treatment groups and the lower-dose treatment group did not reveal any significant differences between the two endpoints to predict immunotoxicity as a function of dose. Of the three lymphoid organs examined, (i.e., lymph node, thymus, and spleen), the most consistent and discernible histological lesions were observed in the thymus cortical region. These lesions correlated with thymus: body weight ratios and to a slightly lesser extent, the antibody plaque forming cell response. Addition of general toxicological endpoints such as body weight and leukocyte counts did not significantly improve the sensitivity of extended histopathology for this data set. Taken together, these data suggest that, while not as sensitive as functional analyses, extended histopathology may provide a reasonable level of accuracy as a screening test to identify immunotoxic chemicals, provided the level of stringency used to score histological lesions is carefully considered to allow for detection of immunotoxic agents while limiting false positives.