Deletion of Salmonella enterica serovar Typhi tolC reduces bacterial adhesion and invasion toward host cells.

Background: S. Typhi is a Gram-negative bacterium that causes typhoid fever in humans. Its virulence depends on the TolC outer membrane pump, which expels toxic compounds and antibiotics. However, the role of TolC in the host cell adhesion and invasion by S. Typhi is unclear. Objective: We aimed to investigate how deleting the tolC affects the adhesion and invasion of HT-29 epithelial and THP-1 macrophage cells by S. Typhi in vitro. Methods: We compared the adhesion and invasion rates of the wild-type and the tolC mutant strains of S. Typhi using in vitro adhesion and invasion assays. We also measured the expression levels of SPI-1 genes (invF, sipA, sipC, and sipD) using quantitative PCR. Results: We found that the tolC mutant showed a significant reduction in adhesion and invasion compared to the wild-type strain in both cell types. We also observed that the expression of SPI-1 genes was downregulated in the tolC mutant. Discussion: Our results suggest that TolC modulates the expression of SPI-1 genes and facilitates the adhesion and invasion of host cells by S. Typhi. Our study provides new insights into the molecular mechanisms of S. Typhi pathogenesis and antibiotic resistance. However, our study is limited by the use of in vitro models and does not reflect the complex interactions between S. Typhi and host cells in vivo.

Salivary Anti-50 kDa Antibodies as a Useful Biomarker for Diagnosis of Typhoid Fever.

INTRODUCTION: Typhoid fever remains a scourge of humanity, especially in developing and under-developed countries due to poor sanitation and food hygiene. Diagnostic methods available for detection of this disease are not satisfactory due to a lack of sensitive, specific, rapid and convenient diagnostic test kits available in the market. AIM: To evaluate the feasibility of a Dot-EIA method for Ig-class specific salivary antibody detection for diagnosis of typhoid fever. MATERIALS AND METHODS: Paired saliva and serum samples were collected in the year 2010 from patients and normal volunteers in Hospital Universiti Sains Malaysia, Kelantan, Malaysia, which is endemic for typhoid fever. A total of 11 culture-confirmed typhoid fever patients, 43 non-typhoid fever patients and 53 normal human control subjects were evaluated for antibodies against a 50 kDa antigen specific for Salmonella Typhi using Dot-EIA. RESULTS: Ig class-specific screening of the test samples showed a higher sensitivity for IgA (90.9%) compared to either IgG (72.7%) or IgM (72.7%) antibodies in saliva, but for serum, IgG (90.9%) had a higher degree of sensitivity compared to IgA (36.4%) and IgM (63.6%). Combining all isotypes (IgA, IgG or IgM), serum showed a higher sensitivity (100.0%) compared to saliva (90.9%). Also, the specificity for serum (100.0%) was much higher than saliva (85.4%). CONCLUSION: Salivary IgA anti-50kDa antibody was found to be more suitable biomarker for routine screening, whereas serum IgG was more suitable for confirmatory test as it has higher specificity. Nevertheless, salivary IgA Dot-EIA is a convenient method for rapid testing, such as for Point-of-Care Diagnostics (POCD) and field epidemiological studies, due to its non-invasive nature and ease of use.

Detection of Salivary IgA Antibodies Against the HlyE Antigen as a Diagnosis of Typhoid Fever.

INTRODUCTION: The Salmonella typhi (S. typhi) haemolysin E protein (HlyE) has been shown to be a sensitive and specific antigen for the detection of typhoid fever through the detection of anti-HlyE antibodies in sera. Saliva can also be a useful diagnostic fluid as it also contains antibodies against bacterial pathogens. AIM: This study aims to evaluate the potential detection of salivary anti-HlyE antibodies as a diagnosis of typhoid fever. MATERIALS AND METHODS: Saliva was collected from acute typhoid patients (n=16) who presented at Hospital Universiti Sains Malaysia with prolonged fever of more than five days and were positive for S. Typhi blood culture. Saliva was also collected from convalescent typhoid patients (n=11), patients with other febrile fevers (n=15), and from healthy individuals (n=25). An ELISA was developed to detect the presence of IgA antibodies against HlyE in the saliva of typhoid patients. RESULTS: The acute typhoid group had a higher mean absorbance value of 1.496 compared to the convalescent typhoid (0.538), other febrile fevers (0.678), and healthy individuals (0.457) group. CONCLUSION: This study demonstrated the utility of salivary anti-HlyE IgA antibody as a biomarker for the diagnosis of typhoid fever. Follow-up studies with a larger sample size will allow the optimization of the sensitivity and specificity of the assay. This non-invasive method can be useful for mass screening programs.

MK886 inhibits the pioglitazone-induced anti-invasion of MDA-MB-231 cells is associated with PPARα/γ, FGF4 and 5LOX.

The goal of this study was to determine the effects of PGZ and MK886 on the mRNA expression of PPARα and other associated genes in MDA-MB-231 cells, and the biological mechanisms induced by both drugs were also assessed. The levels of PPARα mRNA expression in PGZ-treated and MK886-treated MDA-MB-231 cells were determined using real-time PCR; the growth inhibitory effects of PGZ and MK886 were determined using the trypan blue exclusion assay; the induction of apoptosis by PGZ and MK886 was determined using DNA fragmentation assay and real-time PCR; and the invasion of PGZ-treated and MK886-treated MDA-MB-231 cells was determined using the wound healing and transwell migration assays. In addition, we correlated the expression of PPARα mRNA with other genes, including PPARγ, FGF4 and 5LOX, in drug-treated MDA-MB-231 cells. Our results demonstrated that the treatment of MDA-MB-231 cells with PGZ increased the expression of PPARα/γ mRNA and that this expression could be inhibited by treatment with MK886. Both drugs reduced the viability of MDA-MB-231 cells independently of PPARα/γ mRNA expression but did not induce apoptosis. The wound caused by invasion was not healed by PGZ-treated MDA-MB-231 cells, but it was healed by MK886-treated cancer cells, indicating that the reduction of invasion in PGZ-treated MDA-MB-231 cells was eliminated by treatment with MK886, and this finding was validated by the transwell migration assay. This phenomenon might also be associated with the expression of PPARα/γ, FGF4 and 5LOX mRNA in the treated cancer cells. This study provides useful information regarding the mRNA expression levels of PPARα and other related genes in MDA-MB-231 cells. These genes could be attractive targets for reducing the invasion of breast cancer.

The expression of retinoblastoma tumor suppressor protein in oral cancers and precancers: A clinicopathological study.

BACKGROUND: The role of retinoblastoma (Rb) protein in cell cycle regulation prompted us to take up this study with the aim of assessing its role in the progression of oral cancer and to correlate with various clinicopathological parameters, including habits such as smoking, Paan chewing, and alcoholism. MATERIALS AND METHODS: This observational study included surgical specimens from 10 apparently normal oral mucosa, 14 oral reactive lesions (ORL), 29 precancerous lesions and 43 oral cancers. The expression of Rb protein in tissue samples were evaluated by immunohistochemistry and correlated with clinicopathological data. The percentage and mean expression of Rb protein were statistically analyzed using Student's t-test and P < 0.05 was considered as statistically significant difference. RESULTS: The expression of Rb protein was found to increase from normal, ORL, precancerous lesions to cancers. A consistently high expression of Rb protein was seen in oral cancers, with an increase in well-differentiated and moderately differentiated tumors. Patients with combined habits of Paan chewing, smoking, and alcohol consumption had a higher expression compared with those without habits. CONCLUSION: Within the limitations of this study, it seems that overexpression of Rb protein noted in oral cancer, with an increase in well and moderately differentiated tumors suggest a possible role of Rb in differentiation. The high expression of Rb in patients with combined habits of Paan chewing, smoking and alcohol consumption indicates that Rb pathway may be altered in habit-related oral malignancies.

Chemo-immunotherapy using saffron and its ingredients followed by E7-NT (gp96) DNA vaccine generates different anti-tumor effects against tumors expressing the E7 protein of human papillomavirus.

Saffron and its components have been suggested as promising candidates for cancer prevention. Carotenoids and monoterpene aldehydes are two potent ingredients of saffron. The goal of the current study was to investigate the anti-tumor effect of chemo-immunotherapy using saffron and its ingredients followed by E7-NT (gp96) DNA vaccine against tumors expressing the E7 protein of human papillomavirus. The in vitro cytotoxic and apoptotic effects of aqueous saffron extract and its components were evaluated in malignant TC-1 and non-malignant COS-7 cell lines. Then, multimodality treatments using E7-NT (gp96) DNA vaccine combined with saffron extract and its ingredients as well as single-modality treatments were tested for their efficacy in inhibiting large and bulky tumor growth. Saffron and its components exerted a considerable anti-tumor effect through prevention of cell growth and stimulation of programmed cell death. Furthermore, 100 % of mice treated with crocin were tumor-free, in contrast to DNA vaccine alone (~66.7 %) and DNA + crocin (~33.3 %) indicating the high potency of crocin as a chemotherapeutic agent. Interestingly, the multimodality treatment using DNA vaccine along with picrocrocin augmented the anti-tumor effects of picrocrocin. Thus, the combination of DNA vaccine with saffron extract and crocin at certain concentrations did not potentiate protective and therapeutic effects compared to mono-therapies for the control of TC-1 tumors.

TRAIL-based tumor sensitizing galactoxyloglucan, a novel entity for targeting apoptotic machinery.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is an attractive target for cancer therapy due to its ability to selectively induce apoptosis in cancer cells, without causing significant toxicity in normal tissues. We previously reported that galactoxyloglucan (PST001) possesses significant antitumor and immunomodulatory properties. However, the exact mechanism in mediating this anticancer effect is unknown. This study, for the first time, indicated that PST001 sensitizes non-small cell lung cancer (A549) and nasopharyngeal (KB) cells to TRAIL-mediated apoptosis. In vitro studies suggested that PST001 induced apoptosis primarily via death receptors and predominantly activated caspases belonging to the extrinsic apoptotic cascade. Microarray profiling of PST001 treated A549 and KB cells showed the suppression of survivin (BIRC5) and anti-apoptotic Bcl-2, as well as increased cytochrome C. TaqMan low density array analysis of A549 cells also confirmed that the induction of apoptosis by the polysaccharide occurred through the TRAIL-DR4/DR5 pathways. This was finally confirmed by in silico analysis, which revealed that PST001 binds to TRAIL-DR4/DR5 complexes more strongly than TNF and Fas ligand-receptor complexes. In summary, our results suggest the potential of PST001 to be developed as an anticancer agent that not only preserves innate biological activity of TRAIL, but also sensitizes cancer cells to TRAIL-mediated apoptosis.

Identification of carriers among individuals recruited in the typhoid registry in Malaysia using stool culture, polymerase chain reaction, and dot enzyme immunoassay as detection tools.

Chronic carriers of Salmonella Typhi act as reservoirs for the organism and become the agents of typhoid outbreaks in a community. In this study, chronic carriers in Kelantan, Malaysia were first identified using the culture and polymerase chain reaction method. Then, a novel serological tool, designated Typhidot-C, was evaluated in retrospect using the detected individuals as control positives. Chronic carriage positive by the culture and polymerase chain reaction method was recorded at 3.6% (4 out of 110) among individuals who previously had acute typhoid fever and a 9.4% (10 out of 106) carriage rate was observed among food handlers screened during outbreaks. The Typhidot-C assay was able to detect all these positive carriers showing its potential as a viable carrier screening tool and can be used for efficient detection of typhoid carriers in an endemic area. These findings were used to establish the first carrier registry for S Typhi carriers in Malaysia.

Maintenance of immunological homeostasis by Indukantha ghritha in patients with recurrent upper respiratory tract infections-a pilot study.

Indukantha Ghritha (IG), a polyherbal drug used for centuries in Ayurveda, is claimed to be successful in the treatment of respiratory diseases and as a rejuvenating drug. To date, little is known about the immunomodulatory role of IG in recurrent upper respiratory tract infections (RURIs). This study was designed to scientifically validate and evaluate the immunological response mechanisms in patients with RURI. Primarily, immunological functioning of the lymphocyte subsets, Th1 and Th2 cytokines, and immunoglobulins was evaluated before and after administration of IG in patients (n=48) and normal subjects (n=25) for a period of 28 days. Flow cytometry revealed a significant increase in the CD3+, CD4+ T cells and CD56+ natural killer cells with a concomitant reduction of percentage of B cells during IG treatment. Increased Th1 cytokines, IL-2 and IFN-γ, and decreased Th2 cytokine, IL-4, were also observed with IG treatment. IgG was markedly decreased, and IgM was increased with no changes in IgA. Assessment of liver and kidney functions and cholesterol levels was within normal limits in patients administered IG, which reinforces its drug utility as a non-toxic polyherbal drug. Overall, IG provides symptomatic relief by functioning as a potent immunostimulator that can induce type 1 and decrease type 2 immune responses thereby maintaining immunological homeostasis in RURI patients.

Chemopreventive efficacy of Aegle marmelos on murine transplantable tumors.

Emerging trends for cancer chemotherapy show promising developments with the better understanding of molecules delivering more potent and powerful capabilities. But these are severely limited because of increased side effects and higher probability of tumor recurrence. In this scenario, putative exploration of the indigenous and untapped resources modulating immune system to deliver adequate but potent chemopreventive effects appeals considerable interest. However, these require rigorous scientific validation with regard to potency compared with the existing drugs. Aegle marmelos (Linnaeus) Correa (family Rutaceae), a plant component of polyherbal formulation, Indukantha Ghritha, is known for its widespread medicinal values. But the chemopreventive potential has not been explored in comparison to existing anticancer agents. Our attempt contributes the scientific evidence for beneficial immunoprophylactic and antitumor functions in mice challenged with ascites tumors, Dalton's lymphoma ascites, and Ehrlich's ascites carcinoma either alone or in combination with cyclophosphamide and 5-fluorouracil. Specifically, the petroleum ether extracts of this plant (AM(PE)) prophylactically activated a cascade of host defense mechanisms by stimulating or restoring total white blood cell count, macrophage phagocytosis, hematopoiesis, lymphocyte proliferation and functions (CD4+ and CD8+) either naturally or under conditions of impaired immunity like in ascites tumor or during standard agent chemotherapy. Overall, AM(PE) also elicited strong antitumor effects by increasing median survival time and life span, while reducing murine ascites tumor volume and viable tumor counts on par with cyclophosphamide and 5-fluorouracil especially when administered prophylactically. This study also identified 2 putative components, xanthorrhizol and marmelosin, which could be imparting the immunoprophylactic and antitumor effects in transplantable tumor models. Thus, our attempts provide sufficient proof to warrant further to test this drug in higher animal models or in patients with high risk for tumor recurrence and/or immunocompromised diseases.

Modification of MCF-10A cells with pioglitazone and serum-rich growth medium increases soluble factors in the conditioned medium, likely reducing BT-474 cell growth.

In the present study, we aimed to preincubate MCF-10A cells with pioglitazone and/or serum-rich growth media and to determine adhesive and non-adhesive interactions of the preincubated MCF-10A cells with BT-474 cells. For this purpose, the MCF-10A cells were preincubated with pioglitazone and/or serum-rich growth media, at appropriate concentrations, for 1 week. The MCF-10A cells preincubated with pioglitazone and/or serum-rich growth media were then co-cultured adhesively and non-adhesively with BT-474 cells for another week. Co-culture of BT-474 cells with the preincubated MCF-10A cells, both adhesively and non-adhesively, reduced the growth of the cancer cells. The inhibitory effect of the preincubated MCF-10A cells against the growth of BT-474 cells was likely produced by increasing levels of soluble factors secreted by the preincubated MCF-10A cells into the conditioned medium, as immunoassayed by ELISA. However, only an elevated level of a soluble factor distinguished the conditioned medium collected from the MCF-10A cells preincubated with pioglitazone and serum-rich growth medium than that with pioglitazone alone. This finding was further confirmed by the induction of the soluble factor transcript expression in the preincubated MCF-10A cells, as determined using real-time PCR, for the above phenomenon. Furthermore, modification of the MCF-10A cells through preincubation did not change the morphology of the cells, indicating that the preincubated cells may potentially be injected into mammary fat pads to reduce cancer growth in patients or to be used for others cell-mediated therapy.

Molecular alterations in epidermal growth factor receptors as potential predictors of invasion in complete hydatidiform moles (CHM).

Molecular alterations in Epidermal growth factor receptor (EGFR) were investigated for the first time in molar placenta using protein expression, activation status, differential amplification status and mutational analysis. Invasive lesions showed upregulation of internal domain and downregulation of external domain with concomitantly high gene amplification and phosphorylation. Mutations distributed across different exons in non-invasive cases in contrast to single mutations restricted to exons 4 and 6 in invasive cases displayed a strong correlation to overexpression and phosphorylation status suggesting that higher copies of EGFR gene and mutations in exon 4&6 influence the invasive capacity of trophoblasts and can be used as a biomarker of invasion.

Autophagic cell death is induced by acetone and ethyl acetate extracts from Eupatorium odoratum in vitro: effects on MCF-7 and vero cell lines.

Eupatorium odoratum (EO) contains many biologically active compounds, the anticancer effects of which are not well documented. This study evaluates the cytotoxic effects and mechanism of action of EO extracts on MCF-7 and Vero cell lines. Evaluation of the cytotoxic activity using MTT assay, morphological alterations, and apoptosis were carried out. Autophagy was evaluated by LC3-A protein expression. Cytotoxic activity, membrane blebbing and ballooning at 24 hours, replacement by mass vacuolation, and double membrane vesicles mimicking autophagy and cell death were observed in the cancer cells. No apoptosis was observed by DNA fragmentation assay. Overexpression of LC3-A protein indicated autophagic cell death. Cell cycle analysis showed G0 and G2/M arrest. The Vero cells did not show significant cell death at concentrations <100 µg/mL. These results thus suggest that acetone and ethyl acetate extracts of EO induce cell death through induction of autophagy and hold potential for development as potential anticancer drugs.

Antitumor and immunopotentiating activity of polysaccharide PST001 isolated from the seed kernel of Tamarindus indica: an in vivo study in mice.

Antitumor activity of polysaccharide PST001 isolated from the seed kernel of Tamarindus indica was evaluated using different cancer cell lines. Human cancer cell lines A549, KB, and MCF-7 and murine cancer cell lines DLA and EAC were treated with PST001 and cell growth inhibition was assessed by MTT assay. In vivo studies were carried out for toxicity, tumor reduction and immunomodulation. The respective IC(50) of PST001 in A549, KB, and DLA was at 80.72, 190.99, and 91.14 µg/mL. Significant tumor reduction was obtained in both DLA and EAC tumors on treatment with PST001 which was more prominent when PST001 was administered with CTX/5-fluorouracil. Increase in total WBC, CD4(+) T-cell population, and bone marrow cellularity suggested strong immunomodulatory activity for this compound. No significant abnormality was observed in toxicity studies. Thus the results of the present study suggest that PST001 has immunomodulatory and tumor inhibitory activities and has the potential to be developed as an anticancer agent and immunomodulator either as a sole agent or as an adjuvant to other chemotherapeutic drugs.

Augmentation of T-cell immune responses and signal transduction proteins in oral cancer patients: potential for IL-2-mediated immunotherapy.

PURPOSE: Immune impairment is hypothesized to be one of the reasons for the dismal treatment response in oral cancers. This study evaluates the immune impairment in patients with primary squamous cell carcinoma of the oral cavity and the effect of IL-2 administration on restoration of the immune responses. METHODS: T-cell populations were enumerated by flow cytometry; T-cell function by MTS proliferation assay to PHA and anti-CD3, expression of T-cell signaling proteins ZAP-70, TCRζ, p(56)lck, PKC and CD-ε in T cells with and without activation by IL-2 using Western blot and statistical analysis using X (2) test and bivariate correlation analysis in 112 patients. RESULTS: Reduction in proportion of CD3(+) and CD4(+) T lymphocytes, decrease in the CD4(+)/CD8(+) T-cell ratios, reduced lymphocyte transformation to PHA and anti-CD3 and reduced production of interleukin-2(IL-2) were observed in the patient group. Lymphocyte proliferation to anti-CD3 could be augmented in 59.5% of non-responders by IL-2 (range 10-90%) along with significant increase in the expression of TCR-ζ and ZAP-70, CD3ε, p(56) LCK and PKC to varying degrees. The expression of ZAP-70 and TCR-ζ was found to be closely related to treatment response and could be augmented by IL-2 in terms of proliferation and IL-2 production. CONCLUSIONS: The results suggest IL-2 to augment T-cell responses in a proportion of oral cancer patients with poor response to conventional therapy. IL-2 immunotherapy can be thought of as a personalized adjuvant therapy for oral cancer following the in vitro identification of IL-2 responders using the expression of TCRζ and ZAP-70 as biomarkers.

Toll-like receptor 4 Asp299Gly and Thr399Ile polymorphisms and typhoid susceptibility in Asian Malay population in Malaysia.

Typhoid fever is a major health problem with frequent outbreaks in Kelantan, Malaysia. Prevalence of TLR4 gene polymorphisms varies with ethnic groups (0-20%) and predisposean individual to gram-negative infections. The prevalence rate of TLR4 Asp299Gly and Thr399lle polymorphisms in the Malay population or the influence of these on typhoid fever susceptibility is not yet reported. 250 normal and 304 susceptible Malay individuals were investigated for these polymorphisms using allele-specific PCR and analysed for its association with typhoid fever susceptibility. The total prevalence of polymorphisms in the normal population was 4.8% in comparison to 12.5% in the susceptible population (p = 0.002). An increased frequency of both polymorphisms was observed in the susceptible population (p < 0.01) with no homozygous mutants observed. Co-segregation was observed in 2% of controls and 3.6% of the susceptible individuals. This study, for the first time, reports the prevalence of TLR4 gene polymorphisms in the Malay population and suggests that these polymorphisms confer a higher risk for typhoid, infection. The higher incidence of typhoid fever in Kelantan could be attributed to the higher percentage of Malays (95%) in this state. In order to reduce the incidence of this disease, people with these polymorphisms, can be prioritised for prophylactic strategies.

Apoptotic effects of chrysin in human cancer cell lines.

Chrysin is a natural flavonoid currently under investigation due to its important biological anti-cancer properties. In most of the cancer cells tested, chrysin has shown to inhibit proliferation and induce apoptosis, and is more potent than other tested flavonoids in leukemia cells, where chrysin is likely to act via activation of caspases and inactivation of Akt signaling in the cells. Moreover, structure-activity relationships have revealed that the chemical structure of chrysin meets the key structural requirements of flavonoids for potent cytotoxicity in leukemia cells. It is possible that combination therapy or modified chrysin could be more potent than single-agent use or administration of unmodified chrysin. This study may help to develop ways of improving the effectiveness of chrysin in the treatment of leukemia and other human cancers in vitro.

Signaling defects and functional impairment in T-cells from cervical cancer patients.

The ability of T-lymphocytes to recognize antigens and transduce signals to the nucleus successfully is a key component in the initiation and maintenance of an immune response. The present study addressed the expression status of the signal-transducing proteins in relation to the immune impairment in cervical cancer patients. Immune response was measured by evaluating lymphocyte subpopulations CD3(+), CD4(+), and CD8(+), using flowcytometry, natural killer cell activity, using the single-cell cytotoxicity assay, lymphocyte function, using mitogenic response to PHA and T-cell activation following anti-CD3 stimulation, and production of IL-2. Expression of the T-cell signal transduction proteins, TCR-zeta, CD3-epsilon, zap-70, p(56)lck, PKC, NFkappabeta p50, Rel-A, Rel-B, and c-rel, was evaluated by using Western blot assay. A generalized depression of the immune response with respect to the different parameters evaluated was observed. Exogenous interleukin-2 (IL-2) could increase the response in all the controls and in 30% of the patients to different degrees varying from 10% to 90%. Low levels of the signaling molecules (TCR-zeta, CD3-epsilon, zap-70, p(56)lck, and PKC) and impairment in the transduction of NFkappabeta components (p50, Rel-A, Rel-B, and c-rel) to the nuclei were observed in these lymphocytes. Decreased CD4(+)/CD8(+) ratio with an increase in suppressor cells, reduced lymphocyte proliferation, and production of IL-2 suggest a defective immune regulation in cervical cancer. Impairment in the translocation of NFkappabeta p50, Rel-A, and Rel-B to the nucleus and the reduced levels of signal-transducing proteins might be responsible for the decreased production of IL-2 and immune impairment in cervical cancer patients.

Toll-like receptors and cytokines in immune responses to persistent mycobacterial and Salmonella infections.

Bacterial persistence is of major concern worldwide in the control of a number of bacterial infections. The carriers who are asymptomatic act as reservoirs of the bacteria. Knowledge of the host response, of the persistence process, and of the potential of biological mediators as diagnostic markers is essential towards development of prophylactic and treatment modalities for these diseases. Immune mechanisms related to recognition and elimination of the bacteria play pivotal roles in the control of bacterial infections. The majority of the studies on bacterial infections detail the immune mechanisms in the active phase of infection, and reports on the immune status in carriers are scanty. The present review describes the role of recognition molecules (TLRs) and the immune mediators (cytokines) in bacterial persistence. It appears that the TLR-mediated induction of cytokine profiles differs in active infection and bacterial persistence, with an active Th1 response being beneficial for the clearance of a high load of bacteria and at the same time conducive for the persistence of low bacterial load. Immunomodulation aiming at stimulation of the immune responses should be carried out with care as it could give rise to a carrier state in individuals with low load of the bacteria.

A polyherbal ayurvedic drug--Indukantha Ghritha as an adjuvant to cancer chemotherapy via immunomodulation.

Indukantha Ghritha (IG) is a polyherbal preparation consisting of 17 plant components widely prescribed by ayurvedic physicians for various ailments. Though it is a known ayurvedic drug, no attempt has been made to scientifically validate its mechanism of action. Preliminary studies in our laboratory showed IG to possess considerable immunomodulatory effects with a Th1 type of immune response. In this regard, we attempted to elucidate its role as an adjuvant to cancer chemotherapy. BALB/c mice were administered IG, for a period of 14 days and parameters such as Hb, total and differential WBC count, bone marrow cellularity, lymphocyte proliferation and function, macrophage phagocytosis and tumor remission were studied. Administration of IG could inhibit tumor development in mice challenged with Dalton's lymphoma ascites. IG-induced leukopoiesis and enhanced median survival time as well as life span in tumor bearing animals. Macrophage phagocytic capacity was also elevated. Flow cytometric analysis of lymphocyte subsets and MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulphophenyl)-2H-tetrazolium salt] assay for lymphocyte proliferation, yielded promising results which reinforces its use as an adjuvant to cancer chemotherapy. The polyherbal drug could reverse cyclophosphamide-induced myelosuppression in control tumor bearing animals significantly to values near or above normal levels. These results demonstrate the potential of IG, especially in several immunosuppressed conditions and patients suffering from leukopenia as a consequence of cancer chemotherapy.