Chatchawann Apichartpiyakul

Broad usage spectrum of G protein-coupled receptors as coreceptors by primary isolates of HIV.

OBJECTIVE HIV-1 can use various G protein-coupled receptors (GPCRs) in addition to CCR5 and CXCR4 as coreceptors; however, this type of HIV-1 infection has hardly been detected in vivo. The objective of this study was to elucidate the spectrum of GPCR usage by HIV-1 populations in vivo. DESIGN CD4-expressing glioma cell line, NP-2/CD4, becomes highly susceptible to HIV-1 when the cells express GPCRs with coreceptor activities. This cell system was advantageous for detecting the inefficient use of GPCRs by HIV-1. METHODS We developed NP-2/CD4/GPCR cells that express each of 23 GPCRs: 21 chemokine receptors (CCR1, CCR2b, CCR3, CCR4, CCR5, CCR6, CCR7, CCR8, CCR9B, CCR10, CCR11, CXCR1, CXCR2, CXCR3, CXCR4, CXCR5, CXCR6, CX3CR1, XCR1, D6, and DARC) and two other GPCRs (a formylpeptide receptor, FPRL1, and an orphan GPCR, GPR1). NP-2/CD4/GPCR cells were directly cocultured with HIV-1-positive peripheral blood lymphocytes and HIV-1 infection was detected. RESULTS Primary HIV-1 isolates were obtained from NP-2/CD4/GPCR cells expressing CCR5, CXCR4, FPRL1, or GPR1 cocultured with 11 of 17 peripheral blood lymphocytes. Surprisingly, these isolates showed extremely expanded GPCR usage, such as CCR1, CCR3, CCR5, CCR8, CXCR4, D6, FPRL1, and GPR1 as coreceptors. We found that CCR9B, CCR10, and XCR1 also work as novel HIV-1 coreceptors. CONCLUSION FPRL1 and GPR1 have the potential to work as significant HIV-1 coreceptors in vivo next to CCR5 and CXCR4. HIV-1 populations that can use various GPCRs as coreceptors are already circulating in vivo, even in the early stage of HIV-1 infection.

A formylpeptide receptor, FPRL1, acts as an efficient coreceptor for primary isolates of human immunodeficiency virus

BackgroundMore than 10 members of seven-transmembrane G protein-coupled receptors (GPCRs) have been shown to work as coreceptors for human immunodeficiency virus type 1 (HIV-1), HIV type 2 (HIV-2), and simian immunodeficiency viruses (SIVs). As a common feature of HIV/SIV coreceptors, tyrosine residues are present with asparagines, aspartic acids or glutamic acids in the amino-terminal extracellular regions (NTRs).We noticed that a receptor for N-formylpeptides, FPRL1, also contains two tyrosine residues accompanied by glutamic acids in its NTR. It was reported that monocytes expressing CCR5 and FPRL1 in addition to CD4 are activated by treatment with ligands or agonists of FPRL1. Activated monocytes down-modulate CCR5 and become resistant to infection by HIV-1 strains. Thus, FPRL1 plays important roles in protection of monocyptes against HIV-1 infection. However, its own coreceptor activity has not been elucidated yet. In this study, we examined coreceptor activities of FPRL1 for HIV/SIV strains including primary HIV-1 isolates.ResultsA CD4-transduced human glioma cell line, NP-2/CD4, is strictly resistant to HIV/SIV infection. We have reported that when NP-2/CD4 cells are transduced with a GPCR having coreceptor activity, the cells become susceptible to HIV/SIV strains. When NP-2/CD4 cells were transduced with FPRL1, the resultant NP-2/CD4/FPRL1 cells became markedly susceptible to some laboratory-adapted HIV/SIV strains. We found that FPRL1 is also efficiently used as a coreceptor by primary HIV-1 isolates as well as CCR5 or CXCR4.Amino acid sequences linked to the FPRL1 use could not be detected in the V3 loop of the HIV-1 Env protein. Coreceptor activities of FPRL1 were partially blocked by the forymyl-Met-Leu-Phe (fMLF) peptide.ConclusionWe conclude that FPRL1 is a novel and efficient coreceptor for HIV/SIV strains. FPRL1 works as a bifunctional factor in HIV-1 infection. Namely, the role of FPRL1 in HIV-1 infection is protective and/or promotive in different conditions. FPRL1 has been reported to be abundantly expressed in the lung, spleen, testis, and neutrophils. We detected mRNA expression of FPRL1 in 293T (embryonal kidney cell line), C8166 (T cell line), HOS (osteosarcoma cell line), Molt4#8 (T cell line), U251MG (astrocytoma cell line), U87/CD4 (CD4-transduced glioma cell line), and peripheral blood lymphocytes. Roles of FPRL1 in HIV-1 infection in vivo should be further investigated.

Randomized Controlled Trial of Pyrimethamine Plus Sulfadiazine Versus Trimethoprim Plus Sulfamethoxazole for Treatment of Toxoplasmic Encephalitis in AIDS Patients

Background: Toxoplasmic encephalitis (TE), caused by Toxoplasma gondii, is common in AIDS patients. TE can result in tissue destruction via massive inflammation and brain abscess formation. Methods: Randomized controlled trials were performed in AIDS patients to assess which drug regimen was optimally effective for the treatment of TE. AIDS patients with TE were randomly divided into 3 groups that received a 6-week course of either pyrimethamine (50 mg/ day or 100 mg/day) plus sulfadiazine (4 g/day) and folinic acid (25 mg/day) or trimethoprim (10 mg/kg/day) plus sulfamethoxazole (50 mg/kg/day) (TMP-SMX), and results were evaluated with respect to clinical response, mortality, morbidity, and serious adverse events. The primary outcome was defined as death in the first 6-week period. The secondary outcome was successful treatment within 6 weeks without severe adverse events, bone marrow suppression, drug-induced rash, or any other event that caused a change in the treatment regimen. Results: The results from this study showed that in AIDS patients, TE was most successfully treated with the combination of pyrimethamine (50 mg/day) plus sulfadiazidine (4 g/day) and folinic acid (25 mg/day); failure rates were not significantly different among the 3 treatment groups. Conclusions: Available data suggest that of the currently available options, treatment of TE with pyrimethamine at 50 mg/day plus sulfadiazidine at 4 g/day provides the best primary outcome for AIDS patients with TE; however, because this study was terminated prematurely, we suggest that treatment with intravenous TMP-SMX be further evaluated to determine its efficacy.

GB virus C/hepatitis G virus (GBV-C/HGV) infectionin Chiang Mai, Thailand, and identification of variants on the basis of 5′-untranslated region sequences

SummaryBy using reverse transcription and PCR for NS3 and 5′-untranslated regions (5′UTR) of the viral genome, prevalence of GB virus C/hepatitis G virus (GBV-C/HGV) infection in Chiang Mai, Thailand, was studied. High prevalence of GBV-C/HGV infection was observed among intravenous drug users (32%) and hemodialyzed patients (25%). The prevalence was also considerably high among patients with chronic liver disease, such as chronic hepatitis (9%), liver cirrhosis (12%) and hepatocellular carcinoma (10%). On the other hand, the prevalence among healthy blood donors (1%) was significantly lower than that of the above high-risk groups. GBV-C/HGV RNA positivity was significantly higher in individuals with antibodies against hepatitis C virus (24%) than in those without (5%). Phylogenetic analysis of the 5′UTR sequences classified Thai GBV-C/HGV isolates into three groups; (i) a group of isolates that are commonly found in the United States and Europe, (ii) a group of isolates that are commonly found in Asia, and (iii) a group of novel sequence variants.

A short amino acid sequence containing tyrosine in the N-terminal region of G protein-coupled receptors is critical for their potential use as co-receptors for human and simian immunodeficiency viruses

Various G protein-coupled receptors (GPCRs) have the potential to work as co-receptors for human and simian immunodeficiency virus (HIV/SIV). HIV/SIV co-receptors have several tyrosines in their extracellular N-terminal region (NTR) as a common feature. However, the domain structure of the NTR that is critical for GPCRs to have co-receptor activity has not been identified. Comparative studies of different HIV/SIV co-receptors are an effective way to clarify the domain. These studies have been carried out only for the major co-receptors, CCR5 and CXCR4. A chemokine receptor, D6, has been shown to mediate infection of astrocytes with HIV-1. Recently, it was also found that an orphan GPCR, GPR1, and a formyl peptide receptor, FPRL1, work as potent HIV/SIV co-receptors in addition to CCR5 and CXCR4. To elucidate more about the domain of the NTR critical for HIV/SIV co-receptor activity, this study analysed the effects of mutations in the NTR on the co-receptor activity of D6, FPRL1 and GPR1 in addition to CCR5. The results identified a number of tyrosines that are indispensable for the activity of these co-receptors. The number and positions of those tyrosines varied among co-receptors and among HIV-1 strains. Moreover, it was found that a small domain of a few amino acids containing a tyrosine is critical for the co-receptor activity of GPR1. These findings will be useful in elucidating the mechanism that allows GPCRs to have the potential to act as HIV/SIV co-receptors.

Sequence features downstream of the primer-binding site of HIV type 1 subtype E shared by subtype G and a subset of subtype A

Two distinct sequence features downstream of the primer-binding site (PBS) were identified in a full-length HIV-1 subtype E clone amplified in this study. Both features are frequently found in HIV-1 subtypes A and G and in more than half of the full-length intersubtype recombinant clones. One of these is the absence of a trinucleotide sequence, which is located 14 nucleotides downstream of the PBS and found only in subtypes B, C, D, F, and H. The other is an insertion of 24 nucleotides immediately downstream of the PBS, which was previously reported as a sequence feature shared by subtypes A, E, and G. The analysis conducted here revealed that this 24-nucleotide insertion contained two sequence motifs duplicated in adjacent regions and was not found in all HIV-1 subtype A clones. Furthermore, our finding suggests that the PBS region of all known full-length subtype E clones, which are A/E intersubtype recombinants, is derived from the group of HIV-1 subtype A, which contains a similar insertion.

Clinical characteristics of gynecologic cancer patients who respond to salvage treatment with Lingzhi

Lingzhi or Ganoderma lucidum is a popular medicinal mushroom used as a health promotion herb in China and other Asian countries for thousands of years. There have many previous studies about the anti-cancer effects of lingzhi especially in vitro. The present study reports the clinical data of 5 gynecologic cancer patients who achieved stability in the disease after ingestion of lingzhi in the form of fruit body water extract and spores in a salvage setting. This report has been written to enhance the data describing the effect of lingzhi in cancer patients.

Frequent Detection of Hepatitis C Virus Subtype 3a (HCV-3a) Isolates in Thailand by PCR Using Subtype-Specific Primers

By means of a polymerase chain reaction (PCR) method using subtype‐specific primers for hepatitis C virus (HCV) subtypes 1a, 1b, 2a, 2b and 3a, the prevalence of each subtype among HCV isolates in Chiang Mai, Thailand, was determined. HCV‐3a appeared to be the most common subtype in blood donors, and was also frequently found in patients with liver disease. HCV‐1b, but not HCV‐2a or −2b, was also commonly found in this area, while a considerable percentage of the total HCV isolates still remained unclassifiable by the above methods. Serotype analysis of the HCV isolates using C14‐1 and C14‐2 recombinant peptides revealed that HCV‐3a was likely to carry an antigenic determinant(s) different from those of the major types 1 (HCV‐1a and −1b) and 2 (HCV‐2a and −2b).