Electrophoretic, size-exclusion high-performance liquid chromatography and liquid chromatography-electrospray ionization ion trap mass spectrometric detection of hemoglobin-based oxygen carriers.

Hemoglobin-based oxygen carriers (HBOCs) are blood substitutes based on hemoglobin of either bovine or human origin and they can potentially be misused in elite sports to improve endurance performance. Recently, three methods have been proposed in doping control analysis to allow HBOCs screening and identification by application of electrophoresis, size-exclusion chromatography coupled with HPLC and LC coupled with tandem mass spectrometry (LC/MSMS). In view of the Athens 2004 Olympic Games, modifications were introduced in order to increase the specificity of these methods. The sample preparation protocols of the electrophoretic and SEC-HPLC methods were modified with the introduction of sequential ultra filtration steps to remove all heme containing material below 100 kDa, thus leaving only HBOCs material for analysis. Furthermore, a modification of the LC/MSMS methodology was introduced to allow full scan MS-MS spectra of peptide segments arising from the tryptic digestion of bovine HBOCs. These relatively simple methodological modifications have major impact, as far as time and cost effectiveness is concerned in doping control procedures, because they provide a useful tool in order to identify which suspect samples from the initial visual screening are due to hemolysis and exclude them from further analysis.

The effect of Edrecolomab (Mo17-1A) or fluorouracil-based chemotherapy on specific immune parameters in patients with colorectal cancer. A comparative study.

OBJECTIVES: We investigated the immune profile of patients with resected Dukes' stage C colorectal cancer (CRC), receiving adjuvant therapy with edrecolomab (Mo17-1A) or first-line 5-fluorouracil (5-FU)-based chemotherapy. PATIENTS AND METHODS: Patients received either 5 doses of Mo17-1A over 13 weeks, or 5-FU/leucovorin, or 5-FU/levamisole over 6 and 12 months, respectively. Peripheral blood was collected postoperatively and 4 months after therapy initiation. Peripheral blood mononuclear cells were tested in the autologous mixed lymphocyte reaction (AMLR), for natural killer (NK) and lymphokine-activated killer (LAK) cell activity. Serum cytokines were quantified by ELISA. RESULTS: Fifty-two patients entered the study. Postoperatively, they exhibited decreased levels of interleukin (IL)-2, interferon-gamma, IL-12, granulocyte-macrophage colony-stimulating factor and IL-15, low cellular immune responses (AMLR, NK- and LAK-cytotoxicity) and increased levels of IL-1beta, tumor necrosis factor-alpha, IL-6, IL-10 and prostaglandin E(2). After four months of therapy, patients receiving edrecolomab demonstrated enhanced AMLR, NK, LAK activity, increased serum levels of cytokines regulating such responses and reduced levels of acute-phase cytokines and immune suppressors, compared to patients treated with conventional chemotherapy. CONCLUSIONS: Postoperative adjuvant therapy with edrecolomab restores the in vivo deficient immune responses of patients with resected Dukes' C CRC despite its clinical ineffectiveness in recent randomized adjuvant trials. These results suggest that further immunological studies with the combination of edrecolomab and chemotherapy are required.

Evidence for a LPS-binding protein in medfly hemocyte surface: mediation in LPS internalization but not in LPS signaling.

A doublet of medfly hemocyte proteins with a molecular mass of about 55 and 50 kDa were precipitated with LPS. Antibodies raised against human CD14 recognize the same doublet of proteins. These results support that mammalian CD14 and the doublet of protein bands in medfly hemocytes share common epitopes. This doublet of protein bands is released from hemocytes upon LPS triggering. A portion of the released protein is clustered on the surface of a distinct hemocyte type and the other remains soluble. The membrane-bound LPS-binding protein is involved in LPS internalization and Escherichia coli phagocytosis but not in LPS signaling.

A skeletal muscle troponin T specific ELISA based on the use of an antibody against the soluble troponin T (16-31) fragment.

Proteolytic degradation of muscle, which occurs post-mortem as part of the meat-ageing process, results in the production of protein fragments. In beef, degradation of skeletal muscle troponin T (TnT) results in the generation of a 16-residue long peptide (TnT (16-31)), identified in trichloroacetic acid (TCA) soluble extracts. We report the development of a competitive enzyme-linked immunosorbent assay (ELISA) for the quantification of TnT (16-31), using polyclonal antibodies raised against synthetic TnT (16-31). The ELISA procedure is based on inhibition of binding of the antibodies to immobilised TnT (16-31) by TnT (16-31) present in solution. Its useful range is 30 pmol to 2 nmol TnT (16-31)/ml. Quantification of TnT (16-31) in TCA muscle extracts showed that its concentration was enhanced with ageing. Moreover, a correlation between TnT (16-31) levels and meat tenderness was observed. The ELISA developed herein may prove advantageous for future use at the research and industrial level.

HER-2/neu-derived peptide epitopes are also recognized by cytotoxic CD3(+)CD56(+) (natural killer T) lymphocytes.

The human HER-2/neu gene encodes a 185 kDa transmembrane glycoprotein recognized by MHC class I-restricted CTLs. Here, we report that HER-2/neu peptide CTL epitopes can also be recognized by cytotoxic NK-T lymphocytes. Unfractionated peptides derived from HLA-A2(+), HER-2/neu(+) tumor cells acid cell extract (ACE), collected from patients with metastatic ovarian cancer, were used as antigen to generate in vitro cytotoxic effectors. ACE was able to elicit from cancer patients' PBMCs both alphabetaTCR(+)CD3(+)CD56(-) and alphaTCR(+)CD3(+)CD56(+) (NK-T) CTLs that lysed ACE-sensitized T2 cells in an HLA-A2-restricted manner. The same CTL lines also recognized T2 cells pulsed with HER-2/neu-derived CTL peptide epitopes, a HER-2/neu-transfected HLA-A2(+) cell line and autologous tumor cells. alphaTCR(+)CD3(+)CD56(+) CTL lines also exhibited NK-like cytotoxicity against autologous tumor cells. CTL clones were isolated from alphaTCR(+)CD3(+)CD56(+) bulk cultures displaying both MHC- and non-MHC-restricted cytotoxicity, thus confirming the dual cytolytic function of such cells. Our data demonstrate that ACE from metastatic ovarian tumors can be used as multiepitope vaccines for generating in vitro, besides classical CTLs, NK-T cells exerting efficient MHC- and non-MHC-restricted cytotoxicity against autologous tumor targets. Such NK-T cells expressing dual cytotoxic activity may prove advantageous in cancer immunotherapy.