Campylobacter jejuni induces diverse kinetics and profiles of cytokine genes in INT-407 cells

To examine the kinetic ability of embryonic human epithelial INT-407 cells to express messenger ribonucleic acid [mRNA] for various cytokines and chemokines in response to Campylobacter jejuni [C. jejuni] stimulation. In an experimental single-blind study, cultured embryonic human epithelial INT-407 cells were treated with different concentrations of viable C. jejuni, its sonicated, and filtered supernatant. A modified non-radioactive in situ hybridization using probe cocktails was used to measure mRNA levels for the pro-inflammatory cytokines interleukin [IL]- 1beta, IL-6, interferon-gamma [IFN-gamma], tumour necrosis factor [TNF]-alpha, transforming growth factor [TGF]-beta1, and IL-8, and the anti-inflammatory cytokines, IL-4 and IL-10. The study was carried out from September 2005 to March 2007 at the Department of Microbiology; Immunology, and Infectious Diseases, College of Medicine, Arabian Gulf University; Bahrain. Viable C. jejuni, sonicated bacteria and filtered supernatant induced high mRNA expression for the pro-inflammatory cytokines IL-1beta IL-6, IFN-gamma, TNF-alpha, TGF-beta1, and IL-8, which peaked at the 12 hours post stimulation. Anti-inflammatory cytokines IL-4 and IL-10 mRNA expression were induced maximally at 3 hours post stimulation mainly by sonicated bacteria and filtrated supernatant, however, not with living bacteria. Untreated embryonic human epithelial INT-407 cells expressed low amount of mRNA for the various cytokines and chemokines at all time points. For each cytokine, 4 samples were used per time hour. This study demonstrated that embryonic human epithelial INT-407 cells in response to viable C. jejuni or its cytotoxins can alter cytokine and chemokine mRNA expression patterns and kinetics suggesting a potential role for theses mediators in the immunopathogenesis of the infection caused by this pathogen, which might be relevant for future immunotherapeutic interventions during severe bacterial infections

Progress towards a Leishmania vaccine

Leishmaniasis is a vector-born protozoan disease. Approximately 12 million individuals are affected worldwide with an estimated annual incidence of 1.5-2 million. Two clinical manifestations are recognized, cutaneous, and visceral, both of which are common in the Middle East. In both forms, infection is chronic, with potential deformities, persistence following cure, and lifelong risk of reactivation. Attempts to develop an effective human Leishmania vaccine have not yet succeeded. Leishmanization, a crude form of live vaccination historically originated in this part of the world. Experimental vaccination has been extensively studied in model animals in the past 2 decades. In this review, major human killed vaccine trials are surveyed, and modern trends in Leishmania vaccine development, including subunit vaccines, naked DNA vaccines, and transmission blocking vaccines are explored. Recent findings of a link between persistence of live parasites, and maintenance of long-term immunity suggest live vaccination with attenuated strains, as a future vaccination strategy

Serodiagnosis of toxoplasmosis in Bahrain

We report here an analysis of results of anti-Toxoplasma immunoglobulin M [IgM] and immunoglobulin G [IgG] measurements reported from the Central Laboratory of Bahrain over a period of 3 years and 9 months. This study included all blood samples received at the Salmaniya Medical Complex, Manama, Bahrain serology laboratory for the determination of Toxoplasma-specific antibodies during the period of January 2000 to September 2003. A total of 4,739 specimens were assayed for IgG and 1,947 for IgM. An overall seropositivity of 21.8% for IgG and 10.3% for IgM antibodies were found with no gender differences for either IgG or IgM. In addition, no statistically significant positivity rate differences [p=0.723] were observed between Bahrainis and non-Bahraini residents. The prevalence of Toxoplasma gondii [T. gondii]-specific IgG amongst post partum women was 15.8% and 6.3% for IgM, while for women of child-bearing age IgG was higher at 22.3% and 11.6% for IgM. The IgG seropositivity in neonates [<1 month old] was 16.5%, decreasing to 9.3% in preschool children, while for IgM, it was 3.7% at birth increasing to 7.3% in the preschool group. The IgG seroprevalence increased within the first 15 years of life, and leveled thereafter, for IgM however, it was low at birth and increased within the first 12 months of life then leveled-off at the age of 20-40 to approximately 11-14%, with a further increase after 40 years to 17%. The seropositivity rates of T. gondii in the samples examined during the present study fall within the range of other Gulf Cooperative Council countries. True prevalence in the general population may actually be lower

Coinfection with listeria monocytogenes potentlxtes the response of balb/c mice against leishmania major

The protection against L. major is dependent on the stimulation of an anti-leishmanial T helper 1 [Th1] response and the production of interferon-gamma [IFN-gamma]. BALB/c mice develop a Th2 response and fatal infection with Leishmania major. Strategies that boost IL-12 production have shown to be protective. The innate response to Listeria monocytogenes is associated with IL-12 production. The co- infection of BALB/c mice with L. Monocytogenes attenuates the course of L. Major infection. In this study, 8-16 weeks old female BALB/c mice were used. The lesion sizes were smaller and co-infected mice out-survived the controls injected with L. major alone. The parasite load was reduced at the site of injection, in draining lymph nodes [LN] and spleen. During the first week of infection, in vitro Leishmania re-stimulated LN cells from co-infected mice produced higher levels of IFN-7 and undetectable levels of IL-4 compared with the controls. Significant IL-4 mRNA expression was detected in LN cells of the controls, but not in the co-infected mice