Evaluation of Anticancer and Epidermal Growth Factor Receptor Inhibition Activity by Benzochromeno Pyrimidin Derivatives in Three Human Cancer Cell Lines

BACKGROUND

Cancer therapy is one of the most important challenges that human being faces. The abnormal activity of epidermal growth factor receptor tyrosine kinase (EGFR1) in tumors has been reported in many studies. Tyrosine kinase inhibitors are now commercially available for the treatment of a variety of cancers. Based on our previous studies, we assumed that a hybrid of aminopyrimidine derivatives as EGFR inhibitors and benzocheromen derivatives as cytotoxic agents can induce apoptosis in EGFR positive cancer cells. In the present study, the cytotoxic effect, ability of EGFR inhibition and apoptosis induction of some syndfrthetic benzochromene pyrimidine derivatives were investigated on MDA-MB231, SKBR3 and PC3 cell lines.

METHODS

The EGFR inhibition activity was determined using cell-based EGFR ELISA kit. Cell viability was determined by MTT assay in 2D and 3D cultures. The apoptosis was confirmed through different methods such as fluorescent staining, annexin V- propidium iodide double staining, DNA-Ladder assay, caspase-3 colorimetric assay, and nitric oxide assay.

RESULTS

The Results of the MTT assay showed that derivatives with different substituent exhibited differential cytotoxicity in three cancer cell lines, although in MDA-MB231 the cytotoxicity effect of compounds are more obvious than the other cell lines. Production of nitric oxide, caspase-3 activity and DNA-fragmentation was significant in MDA-MB231 and PC3 cells. SKBR3 cells, despite having the lowest apoptosis among these three cell lines, showed a significant EGFR inhibition in the ELISA assay.

CONCLUSION

In this research we proved that hybrids of benzocheromen and amino pyrimidine could be effective on growth inhibition of cancer cell lines and may be used as a drug candidate for cancer therapy in the future.

Novel quinazolin-4(3H)-one linked to 1,2,3-triazoles: Synthesis and anticancer activity

In this work, a wide range of novel quinazolin-4(3H)-one linked to 1,2,3-triazoles was designed, synthesized, and evaluated against a panel of three human breast (MDA-MB-231, MCF-7, T-47D), lung (A549), and prostate (PC3) cancer cell lines. Our results revealed that the anticancer activity of the synthesized compounds was selectively affected by the presence of methoxy group on the linker between quinazolinone and 1,2,3-triazole moieties. According to the calculated IC₅₀ values, compounds 6q, 6w, and 6x showed good cytotoxicity against breast cancer cell lines even more effective than the reference drug, etoposide. Compounds 6q and 6u were found to be potent compounds against A549, non-small-cell lung cancer (NSCLC), comparing with erlotinib. Also, the morphological analysis by acridine orange/ethidium bromide double staining test and flow cytometry analysis indicated that potent compounds induced apoptosis in human cancer cell lines. Molecular docking studies were performed to clarify the inhibition mode of compounds 6g, 6u, 6w, and 6x over the EGFR active site. The most promising compounds, 6q and 6u, possessing 3-methoxy group were well oriented to the gatekeeper hydrophobic pocket of EGFR active site and interact well with Ala719, Val702, and Leu820 through hydrophobic interaction.

Correlation between MMP-9 and MMP-9/ TIMPs Complex with Pulmonary Function in Sulfur Mustard Exposed Civilians: Sardasht-Iran Cohort Study

BACKGROUND

Matrix metalloproteinases (MMPs) are a family of proteinases and have the vigorous capacity to degrade all parts of the extracellular matrix. MMP enzymes strongly participate in physiological processes such as normal tissue remodeling and wound healing and in pathology of pulmonary diseases. They are released in response to environmental stimuli such as toxins and regulated by endogenous tissue inhibitors of metalloproteinases (TIMPs). Sulfur mustard (SM) is a chemical toxic which can cause severe permanent damages to lung tissues. The aim of this study was assessing the possible role of MMP-9 and TIMPs in SM-induced lung symptoms and signs in exposed patients 20 years after exposure.

METHODS

Totally, 372 male volunteers with a history of SM- exposure and 128 age- and sex-matched unexposed controls participated and were divided into three groups: normal, mild and moderate-severe. All participants underwent clinical evaluation and pulmonary function tests and serum concentrations of MMP-9 and its inhibitors were measured using the ELISA technique.

RESULTS

Serum level of MMP-9 was increased in the SM exposed group who had moderate-severe pulmonary complications compared with the SM exposed with normal lung (2.321 ± 2.836 vs. 1.546 ± 2.176, P = 0.001) while only the MMP-9/TIMP-4 complex was elevated in the SM exposed with normal lung individuals compared to its corresponding control group (85 ± 265 vs. 82 ± 222, P = 0.025). Although MMP-9 and its inhibitors did not show any correlation with spirometry findings, elevated circulating MMP-9 was detected in SM exposed patients with chronic chough and hemoptysis (P = 0.013 and P = 0.013 respectively).

CONCLUSION

High level of tissue disruption and remodeling mediators could influence lung structure in long-term after SM-exposure. The correlation of clinical evaluation with these factors efficiently helps us to identify important effectors.

Synthesis and Leishmanicidal Activity of 1-[5-(5-Nitrofuran-2-yl)-1, 3, 4-Thiadiazole-2-yl]-4-BenzoylePiperazines

A series of (5-nitrofuran-2-yl)-1, 3, 4-thiadiazole-2-yl derivatives 6a-6e have been synthesized and screened for in-vitro anti-leishmanial activity against the promastigote form of L. major. The structure of Schiff bases were confirmed by ¹H NMR, IR. Screening results indicate that all of the designed and synthesized final compounds (6a-6e) significantly reduced the viability of promastigotes of L. major in comparison toglucantime (IC₅₀ 3× 10³ μg/mL). Meta and Para substitutions in benzene ring containing compounds were more potent than other derivative and the most potent compounds were 6d, 6e with IC₅₀ value 94 µm and 77.6 µm, respectively. The experimental data proposes that (5-nitrofuran-2-yl)-1, 3, 4-thiadiazole-2-yl derivatives may be further investigated as a candidate drug for treatment of cutaneous leishmaniasis.

Anticancer effects of synthetic hexahydrobenzo [g]chromen-4-one derivatives on human breast cancer cell lines

BACKGROUND

Cancer results from a series of molecular changes that alter the normal function of cells. Breast cancer is the second leading cause of cancer death in women. To develop novel anticancer agents, new series of chromen derivatives were synthesized and evaluated for their cytotoxic activity against human breast cancer cell lines.

METHOD

The growth inhibitory activities of synthesized hexahydrobenzo chromen-4-one were screened against six human cancer cell lines using an in vitro cell culture system (MTT assay). Fluorochrome staining (acridine orange/ethidium bromide double staining) and DNA fragmentation by the diphenylamine method were used to investigate the effects of most potent compounds on the process of apoptosis in breast cancer cell lines. To determine the mechanism of apoptosis, ROS and NOX production in treated breast cancer cells with compounds was evaluated.

RESULTS

The cytotoxicity data of tested compounds demonstrate these compounds had varying degree of toxicity. Compound 7h was the most potent compound with IC₅₀ = 1.8 ± 0.6 µg/mL against T-47D cell line. Analyses of the compounds treated (MCF-7, MDA-MB-231, and T-47D) cells by acridine orange/ethidium bromide double staining and DNA fragmentation by the diphenylamine method showed that the synthetic compounds induce apoptosis in the cells. A significant increase in ROS production was observed in T-47D cells treated with IC₅₀ value of compound 7g. Incubation with IC₅₀ value of synthetic compounds increased the NOX production in cell lines, especially T-47D cells.

CONCLUSION

Our results show that most compounds have a significant anti-proliferative activity against six human cancer cell lines. The observations confirm that chromen derivatives have induced the cell death through apoptosis.

Novel N-2-(Furyl)-2-(chlorobenzyloxyimino) Ethyl Piperazinyl Quinolones: Synthesis, Cytotoxic Evaluation and Structure-Activity Relationship

Quinolone antibacterials are one of the most important classes of pharmacological agents known as potent inhibitors of bacterial DNA gyrase and topoisomerase IV that efficiently inhibit DNA replication and transcription by generating several double-stranded DNA break. Some quinolone derivatives demonstrated inhibitory potential against eukaryote topoismarase II and substantial dose-dependent cytotoxic potential against some cancerous cells. In present study, synthesis and cytotoxic activity evaluation of new series of N-pipearzinyl quinolones containing N-2-(furyl-2 or 3-yl)-2-(chlorobenzyloxyimino) ethyl moiety 7a-i have been studied. Reaction of quinolone, with 2-bromo-1-(furan-2 or 3-yl)ethanone-O-substituted chlorobenzyloxime in DMF in presence of NaHCO3 at room temperature, gave the title compounds N-2-(furan-2 or 3-yl)-2-(chlorobenzyloxyiminoethyl) quinolone 7a-i. Synthesized compounds were further evaluated in-vitro against three human breast tumor cell lines. Preliminary screening indicated that compound 7 g demonstrated significant growth inhibitory potential against all evaluated cell lines. The results of structure-activity relationship study exhibited that quinolone derivatives are superior in cytotoxic potential compared to 1, 8-naphthyridone series. Furthermore, ethyl quinolone derivatives were more potent cytotoxic agents comparing with cyclopropyl quinolones.

Evaluation of multilayer coated magnetic nanoparticles as biocompatible curcumin delivery platforms for breast cancer treatment

A novel biocompatible multi-layer iron oxide magnetic nanoparticles with sustained sensitive release profile, and improved cellular uptake.

Synthesis and In vitro cytotoxic activity evaluation of (E)-16-(substituted benzylidene) derivatives of dehydroepiandrosterone

Background and the purpose of the study

Modified androsterone derivatives are class of steroidal compounds with potential anticancer properties. Various steroidal derivatives containing substitution at position 16 have shown diversified pharmacological activities. In the present study, a new series of cytotoxic 16-(substituted benzylidene) derivatives of dehydroepiandrosterone (DHEA) were synthesized and evaluated against three different cancer cell lines.

Methods

The cytotoxic 16-(substituted benzylidene) derivatives of DHEA were synthesized via aldol condensation of DHEA with corresponding benzaldehyde derivatives. The cytotoxic activity of synthesized derivatives was evaluated against three different cancer cells including KB, T47D and SK-N-MC cell lines by MTT reduction colorimetric assay.

Results

The results indicated that 16-(substituted benzylidene) derivatives of DHEA could be served as a potent anti-cancer agent. The 3-cholro benzylidene derivatives of DHEA was the most potent synthesized derivative especially against KB and T47D cell lines (IC₅₀ values were 0.6 and 1.7 μM; respectively).

Conclusion

The cytotoxic potential of novel benzylidene derivatives of DHEA is mainly attributed to the position and nature of the substituted group on the benzylidene pendant.

Synthesis and cytotoxic properties of novel (E)-3-benzylidene-7-methoxychroman-4-one derivatives

Background and the purpose of the study

There has been increscent interest in the field of cancer chemotherapy by discovery and development of novel agents with high efficacy, low toxicity, and minimum side effects. In order to find new anticancer agents, we replaced the pyrazolone part of well-known cytotoxic agent SJ-172550 with 7-methoxychroman-4-one. Thus, a novel series of 3-benzylidene-4-chromanones were synthesized and tested in vitro against human cancer cell lines.

Methods

The title compounds were prepared by condensation of 7-methoxychroman-4-one with suitable aldehydes in appropriate alcohol in the presence of gaseous HCl. The antiproliferative activity of target compounds were evaluated against MDA-MB-231 (breast cancer), KB (nasopharyngeal epidermoid carcinoma) and SK-N-MC (human neuroblastoma) cell lines using MTT assay.

Results

Although the direct analog of SJ-172550 (compound 5d) did not show any cytotoxic activity against tested cell lines, but 2-(2-chloro-6-methoxyphenoxy)acetic acid methyl ester analog 5c showed some activity against MDA-MB-231 and SK-N-MC cells. Further modification of compound 5c resulted in the 3-chloro-4,5-dimethoxybenzylidene derivative 5b which demonstrated better cytotoxic profile against all tested cell lines (IC₅₀ values = 7.56–25.04 μg/ml).

Conclusion

The results demonstrated that the cytotoxic activity of compound 5b against MDA-MB-231 and SK-N-MC cells is more than etoposide. Therefore, compound 5b prototype could be considered as novel cytotoxic agent for further developing new anticancer chemotherapeutics.

2-Amino-4-(nitroalkyl)-4H-chromene-3-carbonitriles as New Cytotoxic Agents

A series of 2-amino-4-(nitroalkyl)-4H-chromene-3-carbonitriles were synthesized by an efficient multicomponent reaction in aqueous media using DBU as a catalyst at room temperature. Mild condition, environment friendly procedure and excellent yields are the main advantages of this procedure. The cytotoxic activity of target compounds were evaluated against three cancer cell lines MDA-MB-231, MCF-7 and T47D in comparison with etoposide as reference drug. Generally, all compounds showed good cell growth inhibitory activity with IC(50) values less than 30 μg/mL. Their activities were comparable or more potent than standard drug etoposide. The 6-bromo- derivatives 7e and 7f showed promising cytotoxic activity with IC50 values in the range of 3.46-18.76 μg/mL, being more potent than etoposide against all tested cell lines.

Halogenated flavanones as potential apoptosis-inducing agents: synthesis and biological activity evaluation

A series of halogenated flavanones were synthesized from 2-hydroxychalcones and tested for their cytotoxicity against a panel of human cancer cell lines. Among the synthesized compounds, 3',7-dichloroflavanone (2d) showed the highest activity against MCF-7, LNCaP, PC3, Hep-G2, KB and SK-N-MC cells. However, 3',6-dichloroflavanone (2g) with IC(50) value of 2.9 ± 0.9 μM was the most potent compound against MDA-MB-231 cells, being approximately 12 times more active than etoposide as reference drug. According to the flow-cytometric analysis, compound 2g can induce apoptosis by 66.19 and 21.37% in PC3 and MDA-MB-231 cells, respectively. The results of acridine orange/ethidium bromide staining and TUNEL assay suggested that the cytotoxic activity of this compound in PC3 and MDA-MB-231 cells occurs via apoptosis.

Premedication with peppermint oil capsules in colonoscopy: a double blind placebo-controlled randomized trial study

BACKGROUND

Colonic spasm is an important problem in colonoscopy for endoscopists to advance the colonoscope and visualize the mucosa.

STUDY AIMS

In the present study, we evaluated the efficacy of enteric-coated peppermint oil capsules (Colpermin) as an orally administered antispasmodic premedication in colonoscopy.

PATIENTS AND METHODS

Sixty-five adult patients undergoing colonoscopy were randomized to receive either Colpermin (n = 33) or placebo capsules (n = 32) as premedication, 4 hours before the procedure. An experienced endoscopist performed colonoscopy. Outcome measures included cecal intubation and total procedure time, spasm score, pain score, endoscopist satisfaction and patients' willingness to repeat colonoscopy.

RESULTS

Duration of both total procedure time and cecal intubation time in patients in the Colpermin group were shorter than that in ones in the placebo group. Scores for colonic spasm and pain were significantly lower in the Colpermin group. The endoscopist satisfaction score was higher in the Colpermin group and patients in the Colpermin group were more willing to repeat colonoscopy in the future.

CONCLUSIONS

Premedication with Colpermin was beneficial in terms of the time required for cecal intubation and total procedure time, reducing colonic spasm, increasing endoscopist satisfaction and decreasing pain in patients during colonoscopy.

Nitroimidazolyl-1,3,4-thiadiazole-based anti-leishmanial agents: synthesis and in vitro biological evaluation

A series of 1-[5-(1-methyl-5-nitro-1H-imidazol-2-yl)-1,3,4-thiadiazol-2-yl]-4-aroylpiperazines were synthesized and evaluated in vitro against Leishmania major. Most of the target compounds exhibited good anti-leishmanial activity against the promastigote form of L. major at non-cytotoxic concentrations. The most active compound was 1-[(5-chloro-2-thienyl)carbonyl]-4-[5-(1-methyl-5-nitro-1H-imidazol-2-yl)-1,3,4-thiadiazol-2-yl]piperazine (5f) with an IC(50) value of 9.35+/-0.67 microM against L. major promastigotes. In addition, this compound was effective against intracellular L. major and significantly decreased the infectivity index.

Characterization of a moderate thermophilic Nocardia species able to grow on polycyclic aromatic hydrocarbons

AIMS

Our goal was the characterization of a new moderate thermophilic polycyclic aromatic hydrocarbon (PAH)-utilizing Nocardia strain.

METHODS AND RESULTS

A thermophilic bacterium, strain TSH1, was isolated from a contaminated soil. The macroscopic and microscopic features fit well with the description of Nocardia species. The results of 16S rRNA gene analysis showed 100% match to the type strain of N. otitidiscaviarum DSM 43242(T). Strain TSH1 showed the same mycolic acid pattern as the type strain of N. otitidiscaviarum but its fatty acid profile did not permit identification to the species level. The carbon utilization profile of strain TSH1 was different from N. otitidiscaviarum. The results of hydrophobicity measurements showed that PAHs-grown cells were significantly more hydrophobic than LB-grown cells. Furthermore, biosurfactant production was detected during bacterial growth on different culture media.

CONCLUSIONS

Strain TSH1 is capable of growing on a range of PAHs. When grown in PAHs-supplemented media, strain TSH1 showed a high affinity for the organic phase, suggesting that it can develop a hydrophobic surface.

SIGNIFICANCE AND IMPACT OF THE STUDY

High cell surface hydrophobicity and capability of strain TSH1 to degrade different PAHs at 50 degrees C may make it an ideal candidate to treat PAH-contaminated desert soils.

Prevention of immune dysfunction and vitamin E loss by dehydroepiandrosterone and melatonin supplementation during murine retrovirus infection

Female C57BL/6 mice infected with the LP-BM5 leukaemia retrovirus developed murine acquired immune-deficiency syndrome (AIDS). Dehydroepiandrosterone (DHEA) and melatonin (MLT) modify immune dysfunction and prevent lipid peroxidation. We investigated whether DHEA and MLT could prevent immune dysfunction, excessive lipid peroxidation, and tissue vitamin E loss induced by retrovirus infection. Retrovirus infection inhibited the release of T helper 1 (Th1) cytokines, stimulated secretion of Th2 cytokines, increased hepatic lipid peroxidation, and induced vitamin E deficiency. Treatment with DHEA or MLT alone, as well as together, largely prevented the reduction of B- and T-cell proliferation as well as of Th1 cytokine secretion caused by retrovirus infection. Supplementation also suppressed the elevated production of Th2 cytokines stimulated by retrovirus infection. DHEA and MLT simultaneously reduced hepatic lipid peroxidation and prevented vitamin E loss. The use of DHEA plus MLT was more effective in preventing retrovirus-induced immune dysfunction than either DHEA or MLT alone. These results suggest that supplementation with DHEA and MLT may prevent cytokine dysregulation, lipid oxidation and tissue vitamin E loss induced by retrovirus infection. Similarly, hormone supplementation also modified immune function and increased tissue vitamin E levels in uninfected mice.

Dehydroepiandrosterone (DHEA) sulfate prevents reduction in tissue vitamin E and increased lipid peroxidation due to murine retrovirus infection of aged mice

Dietary effects of dehydroepiandrosterone sulfate (DHEAS) supplementation on tissue antioxidants and lipids were investigated in retrovirus infected mice. DHEA is a powerful antioxidant and immunomodulator whose production declines with age. For this study, twenty-four female, 15-month-old C57BL/6 mice were left uninfected while twenty-four were infected with LP-BM5 murine leukemia virus, causing murine AIDS. The retroviral infection caused immune dysfunction and loss of hepatic and cardiac vitamins E and A, resulting in increased lipid peroxides. Treatment with DHEAS at 0.01 or 0.005% in drinking water for 10 weeks post-infection significantly (P < 0.05) lowered lipid peroxidation in both heart and liver tissues. Treatment with DHEAS also largely prevented loss of the antioxidants, such as vitamin E and A, and prevented loss of phospholipid in the hearts and livers of the old uninfected as well as infected mice. This study suggests that DHEAS supplementation reduces damage associated with elevated oxidation due to aging and retrovirus infection.

Modulation of cytokine production by dehydroepiandrosterone (DHEA) plus melatonin (MLT) supplementation of old mice

Tissue levels of the antioxidants melatonin (MLT) and dehydroepiandrosterone (DHEA) decline with age, and this decline is correlated with immune dysfunction. The aim of the current study is to determine whether hormone supplementation with MLT and DHEA together would synergize to reverse immune senescence. Old (16.5 months) female C57BL/6 mice were treated with DHEA, MLT, or DHEA + MLT. As expected, splenocytes were significantly (P < 0.05) higher in old mice as compared to young mice. DHEA, MLT, and DHEA + MLT significantly (P < 0.005) increased B cell proliferation in young mice. However, only MLT and DHEA + MLT significantly (P < 0.05) increased B cell proliferation in old mice. DHEA, MLT, and DHEA + MLT help to regulate immune function in aged female C57BL/6 mice by significantly (P < 0.05) increasing Th1 cytokines, IL-2, and IFN-gamma or significantly (P < 0.05) decreasing Th2 cytokines, IL-6, and IL-10, thus regulating cytokine production. DHEA and MLT effectively modulate suppressed Th1 cytokine and elevated Th2 cytokine production; however, their combined use produced only a limited additive effect.

Melatonin, immune modulation and aging

Melatonin is a hormone secreted by the pineal gland in response to photoperiods and influences many important biological processes. For one, Melatonin has been shown to produce resistance to cancer and infectious diseases in aged animals. Studies in animals have demonstrated melatonin-related mechanisms of action on immunoregulation. Additionally, melatonin has been successfully used in humans, along with interleukin-2, as a treatment of solid tumors. In vivo and in vitro studies show melatonin enhances both natural and acquired immunity in animals. Despite all of this intriguing evidence, melatonin's mechanism of action on the immune system is only partially defined. It does, however, appear to act through lymphocyte receptors, and perhaps, receptors on other immune tissues, to modulate immune cells. In order to understand immunomodulation and anti-cancer effects, information on melatonin and it's interactions with other endocrine hormones are summarized.

Modulation of immune dysfunction during murine leukaemia retrovirus infection of old mice by dehydroepiandrosterone sulphate (DHEAS)

Ageing, leukaemia and acquired immune deficiency syndrome (AIDS) are conditions with dysregulated cytokine production. As dehydroepiandrosterone sulphate (DHEAS) restored normal cytokine production in old mice its effects on retrovirally infected old mice were investigated. Retrovirus infection and ageing-induced immune dysfunction. Murine retrovirus-infected old C57BL/6 female mice consumed 0.22 or 0.44 microgram of DHEAS/mouse/day beginning 2 weeks postinfection for 10 weeks. DHEAS largely prevented the retrovirus-induced reduction in T-cell and B-cell mitogenesis. DHEAS supplement prevented loss of cytokines [interleukin-2 (IL-2) and interferon-gamma] secretion by mitogen-stimulated splenocytes representing T helper 1 (Th1) cell phenotypes. It also suppressed the retrovirus-induced, excessive production of cytokines (IL-6 and IL-10) by Th2 cells. The highest dose of DHEAS reduced IL-6 production by splenocytes from uninfected old mice by 75% while increasing their IL-2 secretion by nearly 50%. Thus immune dysfunction induced by ageing, even when exacerbated by murine retrovirus infection, was largely prevented by DHEAS.

T cell receptor V beta complementarity-determining region 1 peptide administration moderates immune dysfunction and cytokine dysregulation induced by murine retrovirus infection

Murine AIDS, induced by LP-BM5 murine leukemia retrovirus infection, causes a progressive and profound immunodeficiency in female C57B1/6 mice. Previously, we reported that autoantibodies were elevated during the initiation phases of this murine retrovirus infection and bound peptide determinants corresponding to CDR1 of several TCR V beta-chains. Therefore, we designed studies to determine whether administration of a major autoimmunogenic TCR V beta CDR1 peptide before or after infection with LP-BM5 retrovirus would modulate retrovirus-induced dysregulation of T cell function. Administration of the TCR V beta CDR1 peptide before murine retrovirus infection significantly prevented its suppression of splenic NK cell activity, T and B cell proliferation, and monokine (IL-6 and TNF-alpha) and Th1 cytokine (IL-2 and IFN-gamma) release by splenocytes, and inhibited retrovirus-induced elevation of Th2 cytokine (IL-5 and IL-10). Similar data were obtained with peptide immunization 2 wk after murine retrovirus infection at 6 and 16 wk postinfection. However, delaying peptide immunization until severe suppression of T and B cell mitogenesis had occurred did not restore their functions. Immunization with TCR V beta peptide prevents development of retrovirus-induced immune dysfunction, which suggests a possible pathogenic role of autoreactive T cells as regulatory elements.

T cell receptor V beta complementarity-determining region 1 peptide administration moderates immune dysfunction and cytokine dysregulation induced by murine retrovirus infection

Murine AIDS, induced by LP-BM5 murine leukemia retrovirus infection, causes a progressive and profound immunodeficiency in female C57B1/6 mice. Previously, we reported that autoantibodies were elevated during the initiation phases of this murine retrovirus infection and bound peptide determinants corresponding to CDR1 of several TCR V beta-chains. Therefore, we designed studies to determine whether administration of a major autoimmunogenic TCR V beta CDR1 peptide before or after infection with LP-BM5 retrovirus would modulate retrovirus-induced dysregulation of T cell function. Administration of the TCR V beta CDR1 peptide before murine retrovirus infection significantly prevented its suppression of splenic NK cell activity, T and B cell proliferation, and monokine (IL-6 and TNF-alpha) and Th1 cytokine (IL-2 and IFN-gamma) release by splenocytes, and inhibited retrovirus-induced elevation of Th2 cytokine (IL-5 and IL-10). Similar data were obtained with peptide immunization 2 wk after murine retrovirus infection at 6 and 16 wk postinfection. However, delaying peptide immunization until severe suppression of T and B cell mitogenesis had occurred did not restore their functions. Immunization with TCR V beta peptide prevents development of retrovirus-induced immune dysfunction, which suggests a possible pathogenic role of autoreactive T cells as regulatory elements.

Anti-IL-4 monoclonal antibody and IFN-gamma administration retards development of immune dysfunction and cytokine dysregulation during murine AIDS

This study was designed to determine if administration of anti-interleukin-4 (IL-4) monoclonal antibody (mAb), interferon-gamma (IFN-gamma) and their combination after LP-BM5 retrovirus infection of female C57BL/6 mice would prevent retrovirus-induction of immunosuppression and cytokine dysregulation. Splenic natural killer (NK) cell activity, T- and B-cell proliferation, and T-helper type 1 (Th1) and Th2 cytokine (IL-2, IFN-gamma, IL-5 and IL-10) and monokine [IL-6 and tumour necrosis factor-alpha (TNF-alpha)] secretions were monitored, as they are usually altered dramatically after murine retrovirus infection. Administration of IFN-gamma and anti-IL-4 significantly prevented retrovirus-induced suppression of splenic NK cell activity, and splenic T- and B-cell proliferation. They also significantly slowed retrovirus-induced elevation of Th2 cytokine (IL-5 and IL-10) release and monokine (IL-6 and TNF-alpha) secretion by splenocytes. They prevented the loss of Th1 cytokine (IL-2 and IFN-gamma) release by splenocytes, and alleviated splenomegaly and hypergammaglobulinemia, precursor signs of development of acquired immune deficiency syndrome (AIDS). These findings could provide insight into the roles of immunomodulator in AIDS treatment as well as the mechanisms by which retrovirus infection induces cytokine dysregulation, facilitating immunodeficiencies in AIDS.