Changes in immunological and virological parameters in HIV-1 infected subjects following leukapheresis

In order to assess immune responses during HIV-1 therapeutic immunization, a large number of blood mononuclear cells (PBMC) are needed. Clinical tolerance and safety, as well as changes in immunological and virological parameters, were assessed, following leukapheresis in HIV-1 infected subjects with CD4(+) cell count >200 x 10(6)/l. PBMC were collected using a Fenwal CS3000 cell separator in 29 subjects with mean CD4(+) cell counts of 503 x 10(6)/l (range 172-1,119) and viral load of 2.5 log(10) copies/ml (range <1.7-5.4). Twenty-four (83%) subjects were on antiretroviral therapy while 5 (17%) were untreated. The blood volume processed was 7 L over a period of 3 hours. A mean value (+/- standard error) of 82 +/- 26 x 10(9)/l lymphocytes was collected by a single apheresis in a mean volume of 200 +/- 1.8 ml, containing 9.0 +/- 1.3 x 10(9)/l CD4(+) and 10.2 +/- 1.3 x 10(9)/l CD8(+) cells. The leukapheresis procedures were well tolerated and no immediate or delayed side effects were observed within 90 days of follow-up. No changes from blood pre-leukapheresis values were detected for white blood cells, lymphocytes, monocytes, CD8(+), CD34(+), naive and memory CD4(+) cell counts immediately after, 1 h, 7 days, or within 90 days after leukapheresis. However, absolute CD4(+) cell counts and percentage significantly increased from pre-leukapheresis values after 1 h (530 +/- 43 vs. 700 +/- 75 cell x 10(6)/l; 32.6 +/- 1.6 vs. 36.9 +/- 1.9%; P < 0.001 for both paired t-tests) before returning to pre-leukapheresis levels on day 7. No significant changes in viral load from pre-leukapheresis levels in treated or untreated subjects were detected at any time points. We conclude that leukapheresis in HIV-1 infected subjects with CD4(+) cell counts >200 x 10(6)/l is safe and induces a transient increase in the absolute and percentage of CD4(+) cell count without enhancing viral replication.     

Antimicrobial susceptibilities of Campylobacter strains isolated from Finnish subjects infected domestically or from those infected abroad

The in vitro susceptibilities of 678 Campylobacter jejuni and Campylobacter coli strains isolated from stool samples of the same number of Finnish subjects were studied. A total of 523 patients, representing inhabitants from throughout Finland, had not traveled abroad within the 2 weeks prior to becoming ill, whereas 155 persons had presumably acquired their infections abroad. The antimicrobial agents studied were erythromycin, ciprofloxacin, levofloxacin, trovafloxacin, and moxifloxacin. The MICs of these antimicrobial agents were determined by the agar dilution method. The growth of all domestic isolates was inhibited by erythromycin at concentrations of 4 microg/ml, and for these isolates the fluoroquinolone MICs at which 90% of isolates are inhibited (MIC(90)s) ranged from 0.06 to 0.5 microg/ml. For the foreign isolates, the erythromycin MIC(90) was still low (4 microg/ml), but their susceptibilities to fluoroquinolones were clearly reduced (MIC(90)s, 8 to 64 microg/ml). Of the four different fluoroquinolones studied, ciprofloxacin was the least active (MIC(90), 64 micro g/ml).     

Initial antibodies binding to HIV-1 gp41 in acutely infected subjects are polyreactive and highly mutated

The initial antibody response to HIV-1 is targeted to envelope (Env) gp41, and is nonneutralizing and ineffective in controlling viremia. To understand the origins and characteristics of gp41-binding antibodies produced shortly after HIV-1 transmission, we isolated and studied gp41-reactive plasma cells from subjects acutely infected with HIV-1. The frequencies of somatic mutations were relatively high in these gp41-reactive antibodies. Reverted unmutated ancestors of gp41-reactive antibodies derived from subjects acutely infected with HIV-1 frequently did not react with autologous HIV-1 Env; however, these antibodies were polyreactive and frequently bound to host or bacterial antigens. In one large clonal lineage of gp41-reactive antibodies, reactivity to HIV-1 Env was acquired only after somatic mutations. Polyreactive gp41-binding antibodies were also isolated from uninfected individuals. These data suggest that the majority of gp41-binding antibodies produced after acute HIV-1 infection are cross-reactive responses generated by stimulating memory B cells that have previously been activated by non-HIV-1 antigens.     

Absence of HIV-1 infection in antibody-negative sexual partners of HIV- 1 infected hemophiliacs

In order to confirm the presence and determine the frequency of human immunodeficiency virus, type 1 (HIV-1) infection prior to antibody production, 23 healthy women with histories of repeated unprotected sexual exposure to HIV-1 infected hemophiliacs were tested for evidence of HIV-1 infection. Female subjects were tested for HIV-1 antibody (enzyme immunoassay [EIA] and Western blot), HIV-1 serum antigen, HIV-1 DNA gag sequences by the polymerase chain reaction, and HIV-1 virus isolation from peripheral mononuclear cells. Twenty-two of 23 (96%) women were negative by all HIV-1 assays. One woman was positive by all the HIV-1 assays including an EIA screening test for HIV-1 antibody. These preliminary results suggest that the frequency of HIV-1 infection in antibody-negative sexual partners of HIV-1 infected individuals is probably very low.     

苏州地区儿童感染流感嗜血杆菌β内酰胺酶基因检测

目的了解苏州地区儿童感染流感嗜血杆菌(Hi)对氨苄西林的耐药情况．并从分子生物学的角度研究其耐药机制。方法对135株Hi临床分离株用K—B法作药敏试验，头孢硝噻吩显色法进行β内酰胺酶测定．PCR法进行β内酰胺酶基因TEM、ROB测定。结果本地区儿童感染Hi对氨苄西林的耐药率为17．8％，所有耐药株均产β内酰胺酶，未发现β内酰胺酶阴性耐氨苄西林Hi(BLNAR)菌株。β内酰胺酶基因TEM的检出率为27．4％(10．4％氨苄西林敏感株也检出TEM基因)，ROB为0．7％(该ROB型株同时携带TEM基因)，发现1株非TEM非ROB型产β内酰胺酶Hi。结论本地区儿童感染Hi对氨苄西林的耐药情况不容乐观，其耐药机制主要是产生β内酰胺酶，且以TEM型为主．携带TEM基因的氨苄西林敏感株的出现．是否预示新一轮氡苄西林耐药株的产生，值得关注。     

Emergence of the H208Y mutation in the reverse transcriptase (RT) of HIV-1 in association with nucleoside RT inhibitor therapy

OBJECTIVES: The aim of the study was to determine whether mutations at RT codon 208 are associated with nucleoside RT inhibitor (NRTI) exposure, NRTI resistance patterns and HIV-1 subtype. METHODS: Six thousand three hundred and fifty two genotypic resistance tests linked to a clinical database were analysed. RESULTS: The prevalence of mutations at codon 208 was 6/2347 (0.3%) in treatment-naive and 165/4005 (4.1%) in treatment-experienced persons. H208Y was the most common mutation in both groups (0.2% and 3.8%, respectively) and occurred in 4.5% of treatment-experienced persons with Subtype B, 1.7% of those with Subtype C and 0.7% of those with other non-B subtypes (P=0.001). The association with subtypes was independent of treatment experience. H208Y showed a strong association with NRTI experience, which persisted after adjusting for subtype [odds ratio (OR) 19.34; 95% confidence interval (CI) 7.87-47.54; P=0.0001]. The prevalence of H208Y was highest in genotypes harbouring M184V and the thymidine analogue mutations (TAMs) M41L, D67N, L210W and T215Y. The median number of TAMs was 4 and 0 in genotypes with and without H208Y, respectively (P=0.0001). The prevalence of H208Y declined over time, being highest in 1998 (9.9%) and lowest in 2003 (0.9%) (P=0.0001). CONCLUSIONS: There is a strong association between H208Y and NRTI experience, particularly in persons with Subtype B harbouring multiple NRTI resistance mutations. These findings indicate an accessory role for H208Y in NRTI resistance.     

Identification of HIV-1 infected seropositive subjects by a direct diagnostic test involving hybridization of amplified viral DNA

We describe a simple slot-blot hybridization procedure with an oligo-probe for identification of amplified HIV-1 DNA in seropositive subjects. Comparison are realized, on the same DNA samples, with other methods DNA detection including Southern blot tests after hybridization with a labelled probe, and autoradiographic patterns after digestion with a restriction enzyme of the amplified product hybridized. This new direct approach towards diagnosis of HIV-1 infection easily be carried out on a large scale.     

The first isolation of Nocardia nova from an HIV-1 infected individual in Japan

 Nocardia species are opportunistic pathogens of immunocompromised patients. We report a case of Nocardia nova infection complicating Pneumocystis carinii pneumonia (PCP) in an HIV-1 infected individual. A 27-year-old man with hemophilia A was admitted on October 17, 2000, with fever and dyspnea. CD4 cell counts were 5/μl on admission. Prophylaxis against PCP was administered by inhalation of pentamidine isethionate because he was allergic to sulfamethoxazole-trimethoprim (SMZ-TMP). He was diagnosed with PCP from chest X-ray and bronchoalveolar lavage. The sputum obtained for culture on admission was positive for Gram-positive branching rods; the organism was later identified as Nocardia nova. He died from respiratory failure on November 7, 2000. Although PCP might be a principal factor in respiratory failure, this case shows the need to consider pulmonary nocardiosis as a cause of respiratory illness in patients with advanced HIV-1 infection. Received: March 22, 2002 / Accepted: June 13, 2002     

The function of accessory genes of HIV-1

Human immunodeficiency virus type 1 (HIV-1) has 4 auxiliary genes, vpr, vpu, nef, and vif, which are dispensable for viral replication in vitro. However, many studies with animal model revealed that these genes play important roles on the viral replication and the development of AIDS in vivo through many complicated mechanisms. Although several key factors involved in the function have been identified, further studies are required for the complete understandings of the action mechanisms. The elucidation of the function of the auxiliary genes on molecular bases leads to the discovery of new therapeutic strategies against HIV and the understanding of basic cellular mechanisms. In this review, we summarize new observations mainly about the interactions between auxiliary genes and host cell functions.