Immune Suppression

Eicosanoids are lipid mediators with multiple functions in vertebrate tissues and invertebrate organisms. In this review the roles of eicosanoids--mostly prostaglandins (PGs), thromboxanes and leukotrienes--in parasite physiology and host-parasite interactions are discussed. PGs are present in the saliva of blood-sucking arthropods facilitating feeding by increasing local blood flow and prolonged attachment of ticks by immune suppression. Release of various eicosanoids has also been demonstrated for a number of protozoan and metazoan endoparasites. These substances appear to play a role in penetration, immune suppression, inflammation or modulation of haemostasis, enabling parasite invasion and establishment. Moreover, endogenous eicosanoids serve various functions in parasite metabolism and physiology. In many parasitic infections eicosanoids are involved in host pathology, e.g. granuloma formation, coagulopathy, secretory diarrhoea, or fever. Immune suppression by induction of PG ...

Regulatory T-cells (Tregs) play important role in regulation of immune responses to self-antigens. Alterations in frequency and function of Tregs have been reported in Type 1 Diabetes (T1D) subjects. Tregs have the potential to prevent destruction of pancreatic beta cells by targeting effector T-cells (Teff) and other immune cells causing inflammation. Therefore, strategies to increase Treg cell numbers and function are being explored as potential immunotherapeutic approaches in treating T1D. Today, several groups are involved in exploring different Treg cell types, sources, induction procedures and experimental systems in pursuit of generation of highly efficacious and stable Tregs for their clinical applications. Various protocols have been developed for the induction and expansion of islet antigen specific Tregs and polyclonal Tregs. Studies have shown that antigen specific Tregs are required at less number and are more efficient than polyclonal Tregs in suppressing autoimmune diabetes and they do not cause generalized immune suppression. Alternatively, generation of colonic Tregs (cTregs) has also gathered attention in recent years as an approach to limit pancreatic inflammation via gut induced tolerance. With a definitive treatment for T1D still elusive, application of Tregs as a part of combination therapy seems promising in treatment of T1D.

The present paper focuses on the most important mycotoxins involved in human diseases and on their analysis in foodstuffs. Mycotoxins are metabolites produced by fungi causing acute and chronic adverse effects in humans and animals. The most mycotoxin exposures are chronic generating irreversible effects as cancer or immune suppression, so that mycotoxicoses are sometimes difficult to diagnose. Acute poisoning can

Summary in EnglishHIV/AIDS continues to be a huge global burden having claimed million lives worldwide. It targets the immune system and defence mechanisms against infections such as the human pa- pillomavirus(HPV). HPV can be classifi ed as low-risk or high-risk, with high-risk types (16 and 18) mainly being responsible for cancers, such as cervical cancer in women. HPV is a very common sexually transmitted infection that is given less attention, with many men and women living and spreading infection through unsafe sexual practices. In this thesis we present a mathematical model for the transmission dynamics of HPV in-host in the presence of immune response represented by Cytotoxic T-Lymphocytes cells (CTL). The model presented considers the effects of latent HPV infections and the model dynamics are effectively analysed. The model presents two important reproduction numbers, that is the basic reproduction number R0 and the CTL reproduction number RK. The simulation dynamics of the...

The present paper focuses on the most important mycotoxins involved in human diseases and on their analysis in foodstuffs. Mycotoxins are metabolites produced by fungi causing acute and chronic adverse effects in humans and animals. The most mycotoxin exposures are chronic generating irreversible effects as cancer or immune suppression, so that mycotoxicoses are sometimes difficult to diagnose. Acute poisoning can

The leaves of Cinnamomum tamala Linn (Lauraceae), component of Indian spices are associated with hypoglycemic property in Ayurveda; however, no report is available towards its immunomodulation property, which has been explored here. The dried powder of CT leaves was extracted with hexane and solvent free extract (CTH) was given orally to rats for 10 days, in various doses. Its effect was studied on peritoneal macrophage functions, and was compared with ascorbic acid (1,000 mg/kg, immune-stimulant) and cyclophosphamide (10 mg/kg, immune-suppressant). CTH significantly suppressed phagocytosis activity (EC50 2,355 ± 52.45 mg/kg), reduced production of superoxide (EC50 275.91 ± 10.21 μg/ml) and cellular NADPH (EC50 384.959 ± 4.85 μg/ml) content in concentration dependent manner. It also inhibited LPS induced production of nitric oxide (EC50 143.75 ± 3.40 μg/ml) and iNOS protein expression (EC50 183.132 μg/ml). Thus, it could be suggested that non-polar hexane fraction of leaves of C. tamala possesses immunosuppressive property, which is mediated through modulation of innate immunity.

Inflammatory bowel disease (IBD) is increasing in many parts of the Asia-Pacific region. There is a need to improve the awareness of IBD and develop diagnostic and management recommendations relevant to the region. This evidence-based consensus focuses on the definition, epidemiology and management of ulcerative colitis (UC) in Asia. A multi-disciplinary group developed the consensus statements, reviewed the relevant literature, and voted on them anonymously using the Delphi method. The finalized statements were reviewed to determine the level of consensus, evidence quality and strength of recommendation. Infectious colitis must be excluded prior to diagnosing UC. Typical histology and macroscopic extent of the disease seen in the West is found in the Asia-Pacific region. Ulcerative colitis is increasing in many parts of Asia with gender distribution and age of diagnosis similar to the West. Extra-intestinal manifestations including primary sclerosing cholangitis are rarer than in t...

Since virus infections in AIDS patients are mostly inevitable and as they frequently cause disease deterioration and therapeutic failures, a comprehensive investigation was made of the influence of the coinfections of 9 well-known viruses on disease progression in patients infected with human immunodeficiency virus type 1 (HIV). A cross-sectional study of 62 HIV-positive patients was conducted to correlate the prevalence rates for the 9 viruses with the alanine aminotransferase (ALT) levels and CD4 cell counts of the patients. The rates of HIV-positive patients infected with the 9 viruses are significantly higher than those of the control groups. Furthermore, almost one third of the patients in the studied group was coinfected with transfusion-transmitted virus (TTV) and manifested significantly higher ALT levels (p = 0.020), and these were raised further if coinfection with TTV and human hepatitis C virus had occurred (p = 0.010). By analyzing CD4 cell counts, the only significant effect on AIDS progression which could be detected was coinfection with human herpesvirus 8. This result confirmed that immune-suppressed persons are more vulnerable to common virus infections. Unlike hepatitis B or C virus, TTV seems to accelerate the progression of chronic hepatitis in HIV-infected patients.

Recovery from ischemia/reperfusion and immune-mediated injury in the renal transplant is associated with reduced renal hemodynamics and increased leukocyte infiltration. In diverse models of renal failure, L-arginine supplementation improved hemodynamics and reduced inflammation. However in a proinflammatory environment, L-arginine can worsen renal injury. This study investigated the therapeutic potential of L-arginine supplementation in allogeneic renal transplantation: Brown Norway rat kidneys were transplanted into Lewis rat recipients, with one native kidney remaining. Recipients received low-dose cyclosporin A (2.5 mg/kg per d subcutaneously) to obtain moderate vascular and interstitial rejection, with or without 1% L-arginine in drinking water for 7 d posttransplantation. Transplantation increased renal vasoconstriction (from 16.9 +/- 1.33 to 35.1 +/- 8.6 units; P: < 0.01), thereby reducing GFR (from 0.96 +/- 0.09 to 0.48 +/- 0.10 ml/min; P: < 0.05). Treatment with L-arg...

The present study was designed to delineate the immuno- and hepatotoxicological roles of HRs-antagonists in vivo which is elementary in existing literature. The cohort comprised of two experimental studies. Experimental study 1 was designed for immunological investigations and consisted of seven groups and immunized with intravenous injection of SRBC at day 3 containing six rabbits each. Experimental study 2 was designed to assess the functional status of liver and comprised of seven groups containing five rabbits each. In both experimental studies group-I received sterile distilled water intramuscularly, and group II–VI received subcutaneous histamine, pheniramine (H1R-antagonist), ranitidine (H2R-antagonist), iodophenpropit (H3R-antagonist) and JNJ7777120 (H4R-antagonist), respectively while group-VII received DMSO intramuscularly. ELISA was used to assess the immunological investigations. The SRBC-specific immunoglobulins (Igs), IgM and IgG were significantly increased (p < 0.05). Hepatotoxicity due to same histamine and HRs-antagonists were demonstrated by biochemical and histopathological methods. Rabbits in group II–VI had significantly (p < 0.05) elevated levels of serum enzymes (ALT, AST, ALP) and bilirubin. Histopathological examination showed maintained hepatic lobular architecture in histamine and DMSO-treated groups a kin to control. Notable findings in other groups included increased binuclearity in H1R, trinuclearity in H2R, oxyphilic clusters of hepatocytes in H3R and moderate centrilobular necrosis in H3R and H4R-antagonist-treated groups without obvious inflammatory cell infiltration and Kupffer cell prominence. It is concluded that HRs-antagonist play immune suppressive role through H1R, H2R and H4R while immune enhancing role through H3R. In addition, HRs-antagonists appear moderately hepatotoxic in terms of altered serum enzyme levels and non-inflammatory hepatocellular damage.