Controlled-release and local delivery of therapeutic antibodies

Introduction: As HIV continues to spread worldwide, new therapies which have the potential to treat and cure infected patients need to be developed. The results observed with the “Berlin patient” who received a bone marrow transplant with HIV-resistant hematopoietic stem cells highlight the potential of HIV gene therapy to be used as an alternative treatment. With the discovery of TRIM5α, an HIV inhibitor and species-specific restriction factor, a new molecule can be evaluated as an HIV gene therapeutic. Nonhuman primate TRIM5α orthologs restrict HIV infection, whereas human TRIM5α does not. However, upon genetic modification, variations to human TRIM5α have been made which are capable of potent HIV restriction.

Areas covered: This review seeks to cover the discovery and biology of various HIV-restrictive nonhuman primate TRIM5α orthologs, modifications made to human TRIM5α to enable HIV restriction, and the use of these molecules in an HIV gene therapy setting.

Expert opinion: Engineered human TRIM5α molecules, demonstrated to be strong inhibitors of HIV infection, have the potential of being used as new HIV therapeutics in human gene therapy clinical trials. By combining TRIM5α with other highly potent anti-HIV molecules, the generation of an HIV-resistant immune system and potential cure for infected patients may be accomplished.     

Effects of nitric oxide synthase inhibitors 1‐(2‐trifluoromethylphenyl) – imidazole (TRIM) and 7‐nitroindazole (7‐NI) on learning and memory in mice

Nitric oxide (NO) plays an important role in hippocampal long‐term potentiation (LTP), which is involved in memory processes. This led to the hypothesis that nitric oxide synthase (NOS) inhibitors will have disturbing effects on learning and memory. The aim of our study was to investigate the effects of the new selective neuronal and inducible NOS inhibitor 1‐ (2‐trifluoromethylphenyl) imidazole (TRIM) (10–50 mg/kg) on learning and memory and compare it to the nonselective NOS inhibitor 7‐NI (15–45 mg/kg) using different behavioral tests in Swiss mice, thus clarifying the role of neuronal NOS (nNOS) and endothelial NOS (eNOS) in cognitive processes. TRIM had no specific effect on either learning or memory parameters, while 7‐NI (30 mg/kg) disturbed spatial memory in the probe trial of the Morris water maze test, which was performed on the last day of the test. No differences between TRIM and the control groups were observed, while 7‐NI (30 and 45 mg/kg) significantly disturbed memory in the novel object recognition test. In the social transmission of food preference test, both TRIM (50 mg/kg) and 7‐NI (45 mg/kg) impaired hippocampal olfactory memory, but the total food consumption was also significantly decreased at these doses. In the passive avoidance test, TRIM did not disturb the performance, while memory impairment was observed, even with lower doses of 7‐NI. All of these results suggest that TRIM has no clear effect on cognitive impairment compared to 7‐NI and that inhibition of both nNOS and eNOS are necessary for the deterioration of memory processes.     

C9、CD59在大鼠急性脊髓损伤组织中的表达

目的探讨补体系统固有成分C9及补体调节因子CD59在大鼠急性脊髓损伤组织中的表达。方法采用改良Allen重物打击法制成SD大鼠脊髓急性损伤模型,观察各组伤后12h、1、3、5、7d各时间点脊髓损伤组织的变性坏死、中性粒细胞浸润情况及C9、CD59阳性反应物的表达部位及时程。结果伤后12h损伤组织中开始有C9、CD59阳性表达,在伤后3d达到高峰,之后表达逐渐减少,伤后1周趋于稳定,随时间延长存在动态变化过程,且与脊髓损伤组织的变性坏死、中性粒细胞浸润程度相一致。结论在急性脊髓损伤组织中有补体固有成分C9及补体调节因子CD59的表达,补体系统参与了继发性脊髓损伤。     

Involvement of DFNB59 mutations in autosomal recessive nonsyndromic hearing impairment

In a consanguineous Turkish family, a locus for autosomal recessive nonsyndromic hearing impairment (ARNSHI) was mapped to chromosome 2q31.1-2q33.1. Microsatellite marker analysis in the complete family determined the critical linkage interval that overlapped with DFNB27, for which the causative gene has not yet been identified, and DFNB59, a recently described auditory neuropathy caused by missense mutations in the DFNB59 gene. The 352-amino acid (aa) DFNB59 gene product pejvakin is present in hair cells, supporting cells, spiral ganglion cells, and the first three relays of the afferent auditory pathway. A novel homozygous nonsense mutation (c.499C>T; p.R167X) was detected in the DFNB59 gene, segregating with the deafness in the family. The mRNA derived from the mutant allele was found not to be degraded in lymphocytes, indicating that a truncated pejvakin protein of 166 aa may be present in the affected individuals. Screening of 67 index patients from additional consanguineous Turkish families with autosomal recessive hearing impairment revealed a homozygous missense mutation (c.547C>T; p.R183W) that segregates with the hearing impairment in one family. Furthermore, in a panel of 83 Dutch patients, two additional novel mutations (c.509_512delCACT; p.S170CfsX35 and c.731T>G; p.L244R), which were not present in ethnically matched controls, were found heterozygously. Together, our data indicate that also nonsense mutations in DFNB59 cause nonsyndromic hearing loss, but that mutations in DFNB59 are not a major cause of nonsyndromic hearing impairment in the Turkish and Dutch population.     

TRIM25: A central factor in breast cancer

TRIM25 is emerging as a central factor in breast cancer due to its regulation and function. In particular, it has been shown that: (1) Estrogens modulate TRIM25 gene expression; (2) TRIM25 has activity as an E3-ligase enzyme for ubiquitin; and (3) TRIM25 is also an E3 ligase for interferon-stimulated gene 15 protein in the ISGylation system. Consequently, the proteome of mammary tissue is affected by TRIM25-associated pathways, involved in tumor development and metastasis. Here, we discuss the findings on the mechanisms involved in regulating TRIM25 expression and its functional relevance in breast cancer progression. These studies suggest that TRIM25 may be a biomarker and a therapeutic target for breast cancer.     

High TRIM44 expression in endometrial carcinoma is associated with a poorer patient outcome

Background

Tripartite motif‐containing protein 44 (TRIM44) has been recently identified as a novel oncogene that is overexpressed in several types of human cancers; however, its role in endometrial cancer (EC) remains unknown. The purpose of the current study was to investigate the TRIM44 protein expression and clinicopathological significance of TRIM44 in EC.

Pharmacokinetics and red cell utilization of 52Fe/59Fe-labelled iron polymaltose in anaemic patients using positron emission tomography

Parenteral iron-polysaccharide complexes are increasingly applied. The pharmacokinetics of iron sucrose have been assessed by our group using positron emission tomography (PET). A single intravenous injection of 100 mg iron as iron (III) hydroxide-polymaltose complex, labelled with a tracer in the form of 52Fe/59Fe, was similarly assessed in six patients using PET for about 8 h. Red cell utilization was followed for 4 weeks. Iron polymaltose was similarly distributed to the liver, spleen and bone marrow. However, a larger proportion of this complex was rapidly distributed to the bone marrow. The shorter equilibration phase for the liver, about 25 min, indicates the minimal role of the liver for direct distribution. Splenic uptake also reflected the reticuloendothelial handling of this complex. Red cell utilization ranged from 61% to 99%. Despite the relatively higher uptake by the bone marrow, there was no saturation of marrow transport systems at this dose level. In conclusion, high red cell utilization of iron polymaltose occurred in anaemic patients. The major portion of the injected dose was rapidly distributed to the bone marrow. In addition, the reticuloendothelial uptake of this complex may reflect the safety of polysaccharide complexes. Non-saturation of transport systems to the bone marrow indicated the presence of a large interstitial transport pool, which might possibly be transferrin.     

Expression of complement regulatory proteins CR1, DAF, MCP and CD59 in haematological malignancies

Host cells are protected from the lytic effect of the complement system by complement regulatory proteins. This study was designed to investigate the expression of complement regulatory proteins on leukemic blasts which may be susceptible to the lytic effects of the complement system in the circulation. The surface expressions of complement regulatory proteins, complement receptor 1 (CR1, CD35), decay accelerating factor (DAF, CD55), and homologous restriction factor 20 (HRF20, CD59), on peripheral blood and bone marrow blasts were evaluated by using flow cytometry in 16 acute myeloblastic leukemia (AML), 16 acute lymphoblastic leukemia (ALL), 4 chronic lymphocytic leukemia (CLL), 3 chronic myelocytic leukemia (CML) patients and control granulocytes and lymphocytes obtained from 15 healthy volunteers. mRNA expression was investigated by Northern blot analysis. mRNA abundances were calculated after normalization according to 28s rRNA. Surface expressions of CRI and DAF were marginally (p = 0.08 and p = 0.08, respectively) lower in AML, and DAF expression was significantly lower (p=0.0008) in ALL patients in comparison to their normal counterparts. Except from a slight increase that is detected for CD59 in CML patients (p=0.06), there was no significant difference between the surface expressions of CD59 in any of the groups studied. Densitometric analysis of autoradiographs obtained from Northern blots revealed that in AML patients, CR1 mRNA expression were 5.5-fold lower than controls (p=0.06), while DAF mRNA expression was significantly higher (p=0.0046). Furthermore, the mRNA expression of CRI in ALL patients was found significantly lower than in the control group (p = 0.0419). None of the values obtained from the other groups were significantly different from each other. These results suggest that leukemic blasts are protected from the lytic attack of the complement system at all levels, since all of the complement membrane regulatory proteins were expressed in all leukemia types (although at lower amounts in some cases), and it is also possible to use CRI and DAF as differentiation markers in acute leukemias.