Preoperative dose-dense sequential chemotherapy of epirubicin/cyclophosphamide followed by docetaxel/capecitabine in patients with early breast cancer

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Background: The use of preoperative chemotherapy for breast cancer has been shown to result in similar disease-free and overall survival as postoperative adjuvant chemotherapy. Additionally, the rate of pathologic complete response (pCR) in the breast after preoperative chemotherapy has been shown to correlate with survival. The objective of this study was to evaluate the activity and safety of a dose-dense and sequential chemotherapy of epirubicin/cyclophosphamide (EC) followed by docetaxel/capecitabine (DXe) given preoperatively in patients with early breast cancer not candidate to breast-conserving surgery. Methods: Forty-one women with histologically/cytologically confirmed primary breast cancer (T2–3, N0–2, M0) received 4 cycles of EC (cyclophosphamide, 600 mg/m2 and epirubicin, 90 mg/m2) q2 weeks followed by two cycles of DXe (docetaxel, 36 mg/m2 days 1, 8, and 15 and capecitabine, 1250 mg/m2 days 5–18) q 28 days, with pegfilgrastim support. The study was designed as a Simon’s two-step phase II study. The primary end point of the study was the incidence of pCR defined as the absence of invasive cancer in the breast at definitive surgery. Results: Thirty-nine out of 41 enrolled patients were evaluable for response to treatment (one patient withdrew from the study for G4 neutropenia after the first EC cycle, and the other for therapy refusal after the 4 EC cycles). A pCR was observed in 10 patients for a total pCR rate of 25.6%. Interestingly, all but one of the 10 pCR cases showed ER/PR-negative/Her2-positive tumors. A clinical response (CR or PR) detected by palpation and by imaging was observed in 37 patients, for an overall response rate of 95%. Twenty-nine patients (75%) underwent breast-conserving surgery. The treatment was well tolerated: one patient experienced G3 mucositis and another patient required a 25% dose reduction of capecitabine because of hand-foot syndrome. There was no case of cardiac toxicity, thrombocytopenia or any other serious adverse event. Conclusions: The dose-dense sequential combination EC/DXe is endowed with good antitumor activity and limited toxicity, allowing a high rate of pCR and breast conservation. Thus, this regimen can be considered for further clinical trial.

No significant financial relationships to disclose.

Changes of Topoisomerase IIα Expression in Breast Tumors after Neoadjuvant Chemotherapy Predicts Relapse-Free Survival

PURPOSE

To assess the value of changes in the expression of topoisomerase IIalpha (TopoII) and the proto-oncogene erbB-2 (HER-2) as predictors of relapse-free survival in women with operable breast cancer treated with anthracycline-based neoadjuvant chemotherapy.

PATIENTS AND METHODS

Seventy-seven patients with primary breast cancer who had undergone neoadjuvant anthracycline-based chemotherapy were included in the present study. TopoII and HER-2 were measured by immunohistochemistry in prechemotherapy and postchemotherapy (at the time of surgery) tumor specimens, and the value of their changes as predictors of relapse-free survival were evaluated by Kaplan-Meier and Cox proportional hazard regression analyses.

RESULTS

Neoadjuvant chemotherapy resulted in a significant reduction in the percentage of cells expressing TopoII (P < 0.0001). No significant change was observed for HER-2. TopoII and HER-2 expression before chemotherapy predicted tumor response to treatment. Changes in TopoII expression after chemotherapy were strongly associated with a poor relapse-free survival (P < 0.0001) in a Cox multivariate analysis adjusted for other clinicopathologic prognostic factors.

CONCLUSION

Changes in TopoII expression after anthracycline-based neoadjuvant chemotherapy is an independent predictor of a poor relapse-free survival in patients with breast cancer. Tumor cells displaying an increased TopoII expression after treatment may be responsible for relapses, and may, therefore, define a group of patients with anthracycline-resistant breast cancer.

90K (Mac-2 BP) and galectins in tumor progression and metastasis

Galectins and their ligands have been implicated in cell transformation and cancer metastasis, and found to have prognostic value. Mac-2 BP, also known as 90K, is a highly glycosylated, secreted protein extensively studied in human cancer, which binds galectin-1, galectin-3 and galectin-7. High expression levels of 90K are associated with a shorter survival, the occurrence of metastasis or a reduced response to chemotherapy in patients with different types of malignancy. The mechanisms underlying the prognostic significance of 90K and galectins in cancer are far from being understood, although they may be related to the ability of these proteins to interact and, to some extent, modulate cell-cell and cell-matrix adhesion and apoptosis. The resulting scenario is even more complex, as data have been presented that all these proteins might be associated with either a positive or a negative outcome of the patients. It is hypothesised that different galectins and galectin ligands with overlapping or opposite functions, expressed in different tumors during the different steps of the metastatic cascade might play a crucial role in tumor progression.

90K (Mac-2 BP) and galectins in tumor progression and metastasis

Galectins and their ligands have been implicated in cell transformation and cancer metastasis, and found to have prognostic value. Mac-2 BP, also known as 90K, is a highly glycosylated, secreted protein extensively studied in human cancer, which binds galectin-1, galectin-3 and galectin-7. High expression levels of 90K are associated with a shorter survival, the occurrence of metastasis or a reduced response to chemotherapy in patients with different types of malignancy. The mechanisms underlying the prognostic significance of 90K and galectins in cancer are far from being understood, although they may be related to the ability of these proteins to interact and, to some extent, modulate cell-cell and cell-matrix adhesion and apoptosis. The resulting scenario is even more complex, as data have been presented that all these proteins might be associated with either a positive or a negative outcome of the patients. It is hypothesised that different galectins and galectin ligands with overlapping or opposite functions, expressed in different tumors during the different steps of the metastatic cascade might play a crucial role in tumor progression.

Timed flat infusion of 5-fluorouracil increases the tolerability of 5-fluorouracil/docetaxel regimen in metastatic breast cancer: a dose-finding study

A dose-finding study was undertaken to determine the maximum-tolerated dose, and the recommended dose of docetaxel in combination with 12-h timed (22:00–10:00) flat infusion of 5-fluorouracil (5-FU) in metastatic breast cancer patients. This schedule seems to reduce the occurrence of stomatitis of the docetaxel and infusional 5-FU regimen.

Cyclooxygenase-independent induction of p21WAF-1/cip1, apoptosis and differentiation by L-745,337, a selective PGH synthase-2 inhibitor, and salicylate in HT-29 cells

In order to dissect out cyclooxygenase-dependent from cyclooxygenase-independent mechanisms in the antiproliferative effects of selective prostaglandin H synthase (PGHS)-2 inhibitors, we compared the effects of L-745,337 (a highly selective PGHS-2 inhibitor) with sodium salicylate (a weak PGHS inhibitor) on prostanoid production, induction of the cyclin-dependent kinase inhibitor p21WAF-1/cip1, mutant p53 (m273-p53) levels, apoptosis and differentiation in human colon adenocarcinoma HT-29 cells. L-745,337 dose-dependently suppressed the cyclooxygenase activity of HT-29 cells (IC50: 0.24 microM). Four-day treatment with L-745,337 caused a concentration-dependent inhibition of cell growth (IC50: 0.9 mM) associated with the induction of p21WAF-1/cip1 and an increase in the proportion of apoptotic nuclei (EC50: 0.1 and 0.34 mM, respectively) while reducing the levels of m273-p53 (IC50: 0.2 mM). Sodium salicylate, at the concentration of 10 mM that did not affect prostanoid formation, caused a 60% reduction of cell growth associated with a 3-fold induction of p21WAF-1/cip1 and a 60% increase in the proportion of apoptotic nuclei. Ultrastructural analysis showed that L-745,337 (0.5 mM) and sodium salicylate (10 mM) caused the induction of a differentiated phenotype. We conclude that high concentrations of L-745,337 and sodium salicylate inhibit colon cancer cell growth by a mechanism unrelated to cyclooxygenase inhibition that may involve p53-independent induction of the tumor suppressor p21WAF-1/cip1.

Lack of expression of galectin-3 is associated with a poor outcome in node-negative patients with laryngeal squamous-cell carcinoma

PURPOSE

Galectin-3 is a pleiotropic carbohydrate-binding protein participating in a variety of normal and pathologic processes, including cancer progression. This study was aimed at evaluating the prognostic value of galectin-3 expression in node-negative laryngeal squamous-cell carcinoma (SCC).

PATIENTS AND METHODS

Galectin-3 expression was analyzed by immunohistochemistry using M3/38 monoclonal antibody, in a single-institution series of 73 node-negative laryngeal SCC patients (median follow-up, 52 months; range, 2 to 90 months).

RESULTS

Forty-two (57.5%) of 73 patients expressed galectin-3. Galectin-3 expression was positively associated with tumor keratinization and histologic grade. A significant correlation was found between galectin-3 tumor positivity and longer relapse-free and overall survival. In univariate analysis, high-grade (grade 3 or 4) tumors, nonkeratinizing tumors, and galectin-3-negative tumors showed a significantly increased risk of relapse and death. In multivariate analysis, only galectin-3 expression retained an independent prognostic significance for both relapse-free and overall survival.

CONCLUSION

We conclude that the absence of galectin-3 expression is an independent negative prognostic marker in laryngeal SCC patients. Thus, histochemical detection of galectin-3 in these tumors could be useful for the selection of node-negative patients with potentially unfavorable outcomes, to establish adjuvant therapy protocols.

Expression of glycoprotein 90K in human malignant pleural mesothelioma: correlation with patient survival

The expression of the tumour-associated glycoprotein 90K in patients with malignant pleural mesothelioma (MM) has not been described. This study used enzyme-linked immunoassay (ELISA) to measure 90K in pleural effusions (PEs) and sera from patients with MM (n=28), lung cancer (LC) (n=14) and benign pleural disease (BPD) (n=15). Immunohistochemistry was used to investigate 90K expression in MM and LC tissue sections. The expression of 90K was further evaluated in vitro by ELISA and western blot analysis of conditioned media and cellular extracts of MM, LC and normal human mesothelial (NHM) cell cultures. Finally, the relationships between 90K expression in MM and patient age and survival were studied. The mean 90K level was significantly higher (p<0.05) in PEs of MM patients (11.0+/-6.6 microg/ml) than in LC (6.1+/-3.2 microg/ml) or BPD (6.2+/-5.0 microg/ml) patients. Immunohistochemistry showed a positive reaction for 90K in MM biopsy sections and positive staining limited to inflammatory infiltrates in LC sections. The level of 90K was significantly higher in cell culture media of MM than of LC or NHM (p<0.001). Bands representing proteins with molecular weight of approximately 90 kDa were detected by western blot in MM cellular extracts. An inverse correlation between PE 90K levels and MM patient age (r=-0.45; p=0.017) and a positive correlation between serum 90K levels and MM patient survival (r=0.62; p=0.006) were detected by linear regression analysis. Kaplan-Meier univariate analysis showed increased survival probability for MM patients with serum 90K level >7.3 microg/ml (log rank, p<0.05). This is the first report in MM of the expression of 90K and of its potential diagnostic and prognostic application.

Galectins and their ligands: amplifiers, silencers or tuners of the inflammatory response?

Recent evidence has implicated galectins and their ligands as master regulators of immune cell homeostasis. Whereas some members of this family, such as galectin-3, behave as amplifiers of the inflammatory cascade, others, such as galectin-1, trigger homeostatic signals to shut off T-cell effector functions. These carbohydrate-binding proteins, identified by shared consensus amino acid sequences and affinity for beta-galactoside-containing sugars, participate in the homeostasis of the inflammatory response, either by regulating cell survival and signaling, influencing cell growth and chemotaxis, interfering with cytokine secretion, mediating cell-cell and cell-matrix interactions or influencing tumor progression and metastasis. The current wealth of new information promises a future scenario in which individual members of the galectin family or their ligands will be used as powerful anti-inflammatory mediators and selective modulators of the immune response.

Adhesion to 90K (Mac-2 BP) as a mechanism for lymphoma drug resistance in vivo

A cell-adhesive protein of the human serum, 90K binds galactin-3, beta1-integrins, collagens, and fibronectin, and it is of importance in cell-cell and cell-extracellular matrix adhesion. Serum 90K levels in 137 patients with lymphoma were measured by enzyme-linked immunosorbent assay. Compared with healthy controls, pretreatment serum 90K levels in patients with lymphoma were elevated (P <.001). Of 97 patients who showed objective response to treatment, 20 (21%) had pretreatment 90K levels above the normal cutoff compared with 17 (53%) of 32 patients who did not respond (P =.002). When used as a plastic-immobilized substrate, 90K caused a significant reduction in chemotherapy-induced apoptosis of Jurkat T lymphoma cells. This finding could explain the lack of response in lymphoma patients with high 90K serum levels.

Peritoneal mesothelial cells as a significant source of ascitic immunostimulatory protein 90K

The tumor associated antigen 90K is known to possess cytokine-like modulatory properties on the cellular immune system, whereby accessory cells are the primary target of this molecule. In 67 ovarian cancer patients presenting with significant amounts of ascites, immunostimulatory protein 90K was detected in all ascitic fluid samples examined. Furthermore, 90K levels correlated to ascitic s-IL-2R content. To elucidate the source of protein 90K in ascitic fluid; its in vitro release was investigated in primary cultured normal human peritoneal mesothelial cells (HPMC). Peritoneal mesothelium was found to produce five-fold more 90K than ovarian cancer cells. Release of protein 90K was significantly increased by treatment with IFN-gamma in both mesothelial and ovarian cancer cells. In contrast neither IL-1 beta nor TNF-alpha treatment consistently influenced the secretion of 90K in either cell type.

Galectin-3 overexpression protects from cell damage and death by influencing mitochondrial homeostasis

Galectins are a family of proteins involved in several cell processes, including their survival and death. Galectin-3 has in particular been described as an anti-apoptotic molecule entangled with a number of subcellular activities including anoikis resistance. In this work we partially address the mechanisms underlying this activity pointing at two key factors in injury progression: the alteration of mitochondrial membrane potential and the formation of reactive oxygen species. Overexpression of galectin-3 appears in fact to exert a protective effect towards both these events. On the basis of these data, we propose a reappraisal of the role of galectin-3 as a regulator of mitochondrial homeostasis.

Concentrations of galectin-3 in the sera of normal controls and cancer patients

Galectin-3, a member of the beta-galactoside-binding animal lectins, has been implicated in tumor invasion and metastasis. Using an immunoligand assay, we assessed the circulating levels of galectin-3 in sera from cancer patients as well as from healthy controls. Low serum levels of galectin-3 were detected in healthy individuals (median, 62 ng/ml; range, 20-313 ng/ml; 95th percentile, 184.3 ng/ml). Compared with healthy individuals, galectin-3 serum levels in patients with breast, gastrointestinal, lung, or ovarian cancer, melanoma, and non-Hodgkin's lymphoma were significantly elevated (P = 0.014). Moreover, galectin-3 concentrations in sera from patients with metastatic disease were higher than in sera from patients with localized tumors. Maximum serum concentrations of galectin-3 (median, 320 ng/ml; range, 20-950 ng/ml) were found in patients with metastatic gastrointestinal carcinoma. These results suggest that circulating galectin-3 may play a role in tumor progression. The possibility of using this assay in early-stage cancer to predict metastasis should be studied.

Lack of mother-to-child HIV-1 transmission is associated with elevated serum levels of 90 K immune modulatory protein

BACKGROUND

90 K is a secreted human serum glycoprotein with immune modulatory activity.

METHODS

Serum 90 K levels were determined by an enzyme-linked immunosorbent assay in 19 HIV-1-infected mothers at the time of delivery, in their new-borns (11 HIV-1 infected and eight uninfected), in 26 HIV-1-uninfected mothers and in 86 new-borns of HIV-1-uninfected mothers.

RESULTS

90 K levels in HIV-1-infected transmissive mothers (22.4 +/- 13.9 microg/ml) were similar to those of HIV-1-uninfected mothers (21.1 +/- 7.6 microg/ml; P = 0.715), but lower than those of HIV-1-infected non-transmissive mothers (45.5 +/- 24.8 microg/ml; P = 0.019). The levels were higher in HIV-1-uninfected (47.6 +/- 22.4 mg/ml) than HIV-1-infected (23.7 +/- 15.6 microg/ml; P = 0.014) new-borns of HIV-1-infected mothers. The new-borns of HIV-1-uninfected mothers had lower levels (11.7 +/- 5.3 microg/ml) than both HIV-1-infected and HIV-1-uninfected new-borns of HIV-1-infected mothers (all differences, P < 0.001).

CONCLUSION

These results suggest that high 90 K protein serum levels in HIV-1-infected mothers and their new-borns are associated with lack of mother-to-child HIV-1 transmission.

Chronomodulated infusion of cisplatin, 5-fluorouracil and folinic acid: lack of activity in advanced colorectal cancer

BACKGROUND

The chronomodulated infusion of 5-FU, FA and oxaliplatin allows a significant increase in dose intensity and antitumor efficacy in patients with metastatic colorectal cancer. Here we investigated if substitution of oxaliplatin with cisplatin produced a similar antitumor activity in previously untreated patients with advanced colorectal cancer.

METHODS

We enrolled 21 consecutively evaluated ambulatory patients with metastatic colorectal cancer. Each treatment cycle consisted of a 5-day course of continuous chronomodulated venous infusion of drugs. Daily doses were 600 mg/m2 5-FU, 150 mg/m2 FA (L-form), and 12 mg/m2 cisplatin. The cycles were repeated every 21 days.

RESULTS

All patients completed at least 3 cycles. Overall a total number of 105 cycles were administered. One partial response (lasting 3 months) and 13 stable disease (lasting from 3 to 12 months) were observed. The remaining 7 patients had progression of the disease. Hematologic and gastrointestinal toxicity was always < or = G2 in all cycles.

CONCLUSIONS

The results of this study discourage the substitution of cisplatin for the more active compound, oxaliplatin, in a chronomodulated schedule of infusion with 5-FU and FA in patients with metastatic colorectal cancer.

Galectin-3 overexpression protects from apoptosis by improving cell adhesion properties

Galectin-3 is a carbohydrate-binding protein endowed with affinity for beta-galactosides. It plays a role in cell-cell and cell-matrix interactions. Furthermore, it has been hypothesized to be involved in tumor progression and metastasis. To address the role of galectin-3 in the invasive and metastatic processes, we stably overexpressed galectin-3 in human breast carcinoma cell lines, and we evaluated the influence of elevated galectin-3 expression on several cell features, including cellular homotypic and heterotypic interactions and cell survival. No differences in various parameters related with cell growth features and proliferation were detected. By contrast, we found that galectin-3 overexpressing cells, with respect to low galectin-3 expressing cells, exerted: (1) a significantly enhanced adhesion to laminin, fibronectin and vitronectin exerted both directly or via increased expression of specific integrins, e.g., alpha-4 and beta-7; (2) a remodeling of those cytoskeletal elements associated with cell spreading, i.e., microfilaments; (3) an enhanced survival upon exposure to different apoptotic stimuli, such as cytokine and radiation. Collectively, our results indicate that overexpression of galectin-3 may play a role in tumor cell invasion and metastasis by specifically influencing cell adhesion to the extracellular matrix. This may confer selective survival advantage and resistance to the particular homeless-induced apoptosis called anoikia.

Viral and host factors in determining response of relapsers with chronic hepatitis C to retreatment with interferon

In chronic hepatitis C the rate of relapse after an end-of-treatment response to interferon may exceed 50%. The usefulness of retreatment of relapsers with interferon in obtaining a complete sustained response and the role of clinical, virological and immunological features in determining long-term efficacy of retreatment are unclear. We aimed to assess the efficacy of interferon retreatment in obtaining a complete sustained response, to evaluate whether increasing the dose may enhance responsiveness, and to identify possible predictors of sustained response. We enrolled 42 patients with biopsy-proven chronic hepatitis C without cirrhosis who had previously responded to a six-month course of Interferon-alpha2b (total dose: group A, 22 patients, 234 MU; group B, 20 patients, 468 MU) and then relapsed. All, except one, were HCV-RNA negative at the end of first cycle of interferon; most (31/42, 74%) were infected by HCV 1b. Subjects were randomly allocated to receive another cycle of interferon either at the original dose (group A1: 234 MU, 11 patients; group B1 468 MU, 10 patient) or twice the original dose (group A2: 468 MU, 11 patients; group B2: 936 MU, 10 patients). At the end of the second cycle of interferon, 24 subjects (57%) had normal ALT and were HCV-RNA negative, and 16 (39%) had normal ALT, but were HCV-RNA positive. A complete sustained response was obtained in eight patients (19%), at a similar rate in all treatment groups. Complete sustained responders were different from the other patients in terms of age (35.9 +/- 10.4 vs 44.1 +/- 8.8, P = 0.027), rate of infection with non-1b HCV (6/8 vs 5/34, P = 0.0005), serum HCV-RNA (74,016 vs 321,428 median copies/ml, P = 0.037) and serum levels of 90K/MAC-2 BP (5.76 +/- 3.01 vs 10.25 +/- 5.16 units/ml, P = 0.02), an N-glycoprotein implicated in cellular defense functions. Multivariate logistic analysis validated age and HCV genotype as independent predictors of CSR. Among noncirrhotic relapsers who received a total interferon dose > or = 234 MU in the first cycle, retreatment usually induced end-of-treatment response. A complete sustained response was obtained in only one of every five subjects. Increasing the dose of interferon above that of the first cycle did not enhance the rate of sustained response. In conclusion we might assert that young subjects infected by non-1b HCV and with low levels of HCV-RNA and of 90K/MAC-2 BP are the best candidates for retreatment.

Elevated levels of circulating immunostimulatory 90K in Henoch-Schoenlein purpura

In order to clarify the immunologic reaction present in Henoch-Schoenlein purpura (HSP), 20 children (11 boys and 9 girls; median age, 5.8 +/- 2.8 years) with HSP and 20 sex- and age-matched healthy children were studied. The 90K/Mac-2 BP serum concentrations were significantly higher in the patients than in the healthy controls (12.5 +/- 7.5 vs 4.5 +/- 2.7 micrograms/ml, respectively; P < 0.0001). 90K/Mac-2 BP values higher than the cutoff value were observed in 13 of 20 (65%) patient. The soluble intercellular adhesion molecule 1 concentrations were significantly higher in HSP patients than controls (P < 0.0001), with mean values of 1631 +/- 703 and 85 +/- 16 ng/ml, respectively. The 90K/Mac-2 BP serum levels were significantly correlated with soluble intercellular adhesion molecule 1 (r = 0.90, P < 0.0001). Although the underlying causes of these immunological abnormalities are unclear, these observations suggest that the 90K/Mac-2 BP protein may play a role in the immunological reactions involved in the development of HSP.

Human milk 90K (Mac-2 BP): possible protective effects against acute respiratory infections

Eighty-six children fed human milk were followed prospectively from birth to 12 months of age to assess the effect of milk 90K, a secreted glycoprotein with immune-stimulatory properties, on development of acute respiratory infections (ARI). The level of human milk 90K was inversely related to episodes of ARI (r = - 0.34; P = 0.001). The average 90K level in human milk fed to children who did not develop ARI was significantly higher than in milk fed to children in whom infection occurred on multiple occasions (156.6 +/- 144.8 microg/ml versus 70.9 +/- 92.3 microg/ml; P = 0.001). These data suggest that the protective effects of human milk against ARI may be due in part to immune maturation effects by secreted 90K.

Differential effect on TCR:CD3 stimulation of a 90-kD glycoprotein (gp90/Mac-2BP), a member of the scavenger receptor cysteine-rich domain protein family

We studied the effects of a 90-kD glycoprotein (gp90/Mac-2BP) belonging to the scavenger receptor family, present in normal serum and at increased levels in inflammatory disease and cancer patients, on some T cell function parameters. Whereas the lymphocyte proliferative response to non-specific mitogens such as phytohaemagglutinin (PHA) and concanavalin A (Con A), but not pokeweed mitogen (PWM), was strongly reduced, probably due to the lectin-binding properties of gp90/Mac-2BP, the response to T cell receptor (TCR) agonists such as superantigens and allogeneic cells was potentiated. When lymphocytes were stimulated with different anti-TCR:CD3 MoAbs, both in soluble and solid-phase form, gp90/Mac-2BP was able to down-regulate the proliferative response to anti-CD3 MoAb, whereas the response to anti-TCR alphabeta MoAb was enhanced. A similar differential effect was observed when a MoAb against CD5 (another member of the scavenger receptor superfamily) was added to anti-CD3 or anti-TCR-stimulated cells; anti-CD5 MoAb strongly down-modulated the CD3-mediated response, whereas its presence in culture was associated with potentiation of the response to TCR alphabeta agonists. gp90/Mac-2BP was able per se to up-regulate Ca2+ levels in freshly isolated lymphocytes; moreover, its presence in culture was associated with increased Ca2+ mobilization following stimulation with anti-TCR alphabeta, but not anti-CD3 MoAb. These data indicate that gp90/Mac-2BP could be able to influence some immune responses, possibly through multiple homologous interactions with other members of the scavenger receptor family; moreover, our findings suggest that signalling through the different components of the TCR:CD3 complex may follow distinct activation pathways into the cells.