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Effects of heme arginate in HIV-1 acute infection and in latency reversal
Prakash, Shankaran ; Mělková, Zora (advisor) ; Hirsch, Ivan (referee) ; Hejnar, Jiří (referee)
The available antiretroviral compounds can effectively suppress the replication of HIV-1 and block the disease progression. However it is impossible to eradicate the virus from the organism as the HIV-1 integrated in the genome is not affected by the existing anti-HIV-1 drugs. Therefore, new latency reversing agents are being actively developed as part of "shock and kill" therapy to reactivate the provirus and clear the reservoir. Normosang (heme arginate; HA) is a human hemin- containing compound used to treat acute porphyria. Heme is physiologically catabolised by heme oxygenases to form iron (Fe2+ ), carbon monoxide (CO) and biliverdin that is further converted to bilirubin by biliverdin reductase. In this study, we have demonstrated that HA inhibited HIV-1 replication during the acute infection, which was accompanied by the inhibition of reverse transcription. On the other hand, HA synergised with phorbol myristyl acetate (PMA) and reactivated the HIV-1 provirus in ACH-2 cells and the HIV-1 "mini-virus" in Jurkat cell clones A2 and H12. HIV-1 ''mini-virus'' was reactivated also by HA-alone. Further, we have studied the effects of heme degradation products on latent HIV-1 reactivation when added individually. We employed addition of ascorbate to generate Fe2+ , resulting in an increased...
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In vivo evaluation of the efficacy of the novel reactivator against tabun
Kuzmiaková, Natália ; Vopršalová, Marie (advisor) ; Hrdina, Radomír (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate: Natália Kuzmiaková Supervisor: PharmDr. Marie Vopršalová, CSc . Consultant: mjr. PharmDr. Vendula Hepnarová, Ph.D. Title of diploma thesis: In vivo evaluation of the efficacy of the novel reactivator against tabun. This study tackles the problem of irreversible inhibition of acetylcholinesterase (AChE). This enzyme degrades neurotransmitter acetylcholine (ACh), wich ensures transmisson of nerve impulses in central nervous system and in periphery. Organophospates (OP) are substances that cause irreversible blocade of AChE and that susubsequently leads to accumulation of AChE in synapses and inducing of muscarinic and nicotinic effects for life threatening condition. Oximic nature reactivators shown to this day the gratest potencial in inhibiting OP bond with AChE. Because reactivation abilities of to date synthesided oxime are not sufficient, new reactivators are being researched. The doal of my work was to test the potencial to reactivate AChe one of them (precisely oxime K 870). The method i used was colorimetric Ellman method modified by Bajgar, where the activity of AChE after reactivation was measured by absorbance in brain, diaphragm and blood of modeled orgamisms. The...
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Biological treatment and its influence on the course of latent viral infections in patients with psoriasis
Laurin, Josef ; Šmahelová, Jana (advisor) ; Janovec, Václav (referee)
There are more than 80 identified autoimmune diseases. One of the most prevalent ones is psoriasis. Its prevalence is around 2-5 % worldwide. The treatment of this inflammatory skin disease can be divided as follows: in cases of low severity, topical therapies are used for local treatment and in the cases of insufficient effect, stronger therapies are used. Phototherapy is used for moderate severity, and systemic therapy is used in moderate to severe disease. Systemic agents include cytostatic methotrexate, immunosuppressant cyclosporin, or retinoids (vitamin A analogues). However, even systemic therapies may not yield the desired effects or may have adverse effects on the overall condition of the patient. In those cases, biological therapy comes to use. Biological therapy is usually conducted using antibodies and fusion proteins, which are made using recombinant technologies. Tumour necrosis factor α (TNF-α) and interleukin 12, 17 and 23 (IL-12, IL-17 and IL-23) inhibitors are the most commonly used in the treatment of psoriasis. During the inhibition of the immune system, it has been confirmed that a reactivation of viral infections can occur. These reactivations may subsequently lead to the development of various diseases caused by latent viral infections.
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Effects of heme arginate in HIV-1 acute infection and in latency reversal
Prakash, Shankaran ; Mělková, Zora (advisor) ; Hirsch, Ivan (referee) ; Hejnar, Jiří (referee)
The available antiretroviral compounds can effectively suppress the replication of HIV-1 and block the disease progression. However it is impossible to eradicate the virus from the organism as the HIV-1 integrated in the genome is not affected by the existing anti-HIV-1 drugs. Therefore, new latency reversing agents are being actively developed as part of "shock and kill" therapy to reactivate the provirus and clear the reservoir. Normosang (heme arginate; HA) is a human hemin- containing compound used to treat acute porphyria. Heme is physiologically catabolised by heme oxygenases to form iron (Fe2+ ), carbon monoxide (CO) and biliverdin that is further converted to bilirubin by biliverdin reductase. In this study, we have demonstrated that HA inhibited HIV-1 replication during the acute infection, which was accompanied by the inhibition of reverse transcription. On the other hand, HA synergised with phorbol myristyl acetate (PMA) and reactivated the HIV-1 provirus in ACH-2 cells and the HIV-1 "mini-virus" in Jurkat cell clones A2 and H12. HIV-1 ''mini-virus'' was reactivated also by HA-alone. Further, we have studied the effects of heme degradation products on latent HIV-1 reactivation when added individually. We employed addition of ascorbate to generate Fe2+ , resulting in an increased...
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Immunity and polyomaviruses
Janovec, Václav ; Drda Morávková, Alena (advisor) ; Belovičová, Martina (referee)
Human polyomaviruses JC and BK belongs to the group of small non-enveloped DNA viruses, and are widespread in the human population. After usually asymptomatic primary infection subsequently persist throughout life in the body in a state of persistence. Thus, this thesis aims to summarize present knowledge concerning the involvement of immune mechanisms involved in immune surveillance against persistent JC and BK viruses. The published findings show that the immune surveillance against human polyomaviruses is a very complex process where an important factor is the involvement and cooperation of non-specific and specific immune defense. Long-term immune surveillance against persistent viruses is mainly mediated by specific T lymphocytes. If this immune surveillance disrupted, it can lead to reactivation of the virus. The change in cytokine environment and the genetic makeup of an individual are another important factors in cases of reactivation. The two human polyomaviruses were developed mechanisms that allow them seemed to partially escape immune surveillance. It also raises the question whether this immune escape contribute to induce tumorigenesis.
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