Exploring the therapeutic potential of an antinociceptive and anti-inflammatory peptide from wasp venom

Animal venoms are rich sources of neuroactive compounds, including anti-inflammatory, antiepileptic, and antinociceptive molecules. Our study identified a protonectin peptide from the wasp Parachartergus fraternus' venom using mass spectrometry and cDNA library construction. Using this peptide as a template, we designed a new peptide, protonectin-F, which exhibited higher antinociceptive activity and less motor impairment compared to protonectin. In drug interaction experiments with naloxone and AM251, Protonectin-F's activity was decreased by opioid and cannabinoid antagonism, two critical antinociception pathways. Further experiments revealed that this effect is most likely not induced by direct action on receptors but by activation of the descending pain control pathway. We noted that protonectin-F induced less tolerance in mice after repeated administration than morphine. Protonectin-F was also able to decrease TNF-α production in vitro and modulate the inflammatory response, which can further contribute to its antinociceptive activity. These findings suggest that protonectin-F may be a potential molecule for developing drugs to treat pain disorders with fewer adverse effects. Our results reinforce the biotechnological importance of animal venom for developing new molecules of clinical interest.

An Experimental Model of Chromoblastomycosis Caused by Fonsecaea sp. Species

The experimental rodent models for the fungal disease are a handy tool for understanding host-fungus interactions. To Fonsecaea sp., one of the causative agents of chromoblastomycosis, there is an extra challenge because the animals preferably used show a spontaneous cure; so until now, there is no model to reproduce the long-term disease similar to human chronic disease. In this chapter, we described an experimental model using rats and mice with a subcutaneous route, with the checkpoints of acute-like and chronic-like lesion analysis comparable with human lesions, the fungal burden, and the lymphocytes investigation.

Zymosan enhances in vitro phagocyte function and the immune response of mice infected with Paracoccidioides brasiliensis

Paracoccidioides brasiliensis is the major etiologic agent of Paracoccidioidomycosis (PCM), the most frequent human deep mycosis in Latin America. It is proposed that masking of β-glucan in P. brasiliensis cell wall is a critical virulence factor that contributes to the development of a chronic disease characterized by a long period of treatment, which is usually toxic. In this context, the search for immunomodulatory agents for therapeutic purposes is highly desirable. One strategy is to use pattern recognition receptors (PRRs) ligands to stimulate the immune response mediated by phagocytes. Here, we sought to evaluate if Zymosan, a β-glucan-containing ligand of the PRRs Dectin-1/TLR-2, would enhance phagocyte function and the immune response of mice challenged with P. brasiliensis. Dendritic cells (DCs) infected with P. brasiliensis and treated with Zymosan showed improved secretion of several proinflammatory cytokines and expression of maturation markers. In addition, when cocultured with splenic lymphocytes, these cells induced the production of a potential protective type 1 and 17 cytokine patterns. In macrophages, Zymosan ensued a significant fungicidal activity associated with nitric oxide production and phagolysosome acidification. Importantly, we observed a protective effect of Zymosan-primed DCs delivered intranasally in experimental pulmonary PCM. Overall, our findings support the potential use of β-glucan-containing compounds such as Zymosan as an alternative or complementary antifungal therapy.

LAY SUMMARY

We report for the first time that Paracoccidioides brasiliensis-infected phagocytes treated with Zymosan (cell wall extract from bakers' yeast) show enhanced cytokine production, maturation, and fungal killing. Also, Zymosan-primed phagocytes induce a protective immune response in infected mice.

Anti-CEA tagged iron nanoparticles for targeting triple-negative breast cancer

Systemic therapy is generally required for breast cancer. However, treatment toxicity and side effects are a concern, especially for triple-negative breast cancer (TNBC), a subtype that usually develops resistance to chemotherapy. To overcome this issue, new nanoformulations capable of targeting cancer cells have been developed and alternative biomarkers have been explored as target molecules for TNBC management. In this study, we performed an in vivo assay in a murine orthotopic TNBC model to evaluate the targeting ability of anti-carcinoembryonic antigen (anti-CEA) loaded nanoparticles (labelled MFCEA), which had been previously synthetized by our research group. 4T1 cells were injected in the mammary gland of balb-c mice, and tumors were evaluated for CEA expression by immunohistochemistry. Tumor-bearing mice received targeted (MFCEA) and non-targeted (MF) nanoparticles intraperitoneally. Tumors were removed 1, 4, 15 and 24h after treatment, and Prussian blue iron staining was performed. Our results showed, as far as we know for the first time, that 4T1 induced tumors are CEA positive, and this opens up new prospects for treating TNBC. Furthermore, MFCEA nanoparticles were able to target malignant tissue and were retained in the tumor for longer than MF nanoparticles. The retention property of MFCEA, together with the absence of toxicity observed in the MTT assay, make these nanoparticles a promising device for management of CEA positive tumors and perhaps for TNBC. Nevertheless, further studies must be carried out to improve their performance and ensure safety for clinical studies.

Immunomodulatory activity of β-glucan-containing exopolysaccharides from Auricularia auricular in phagocytes and mice infected with Cryptococcus neoformans

Current antifungal drugs present poor effectiveness and there is no available vaccine for fungal infections. Thus, novel strategies to treat or prevent invasive mycosis, such as cryptococcosis, are highly desirable. One strategy is the use of immunomodulators of polysaccharide nature isolated from mushrooms. The purpose of the present work was to evaluate the immunostimulatory activity of β-(1,3)-glucan-containing exopolysaccharides (EPS) from the edible mushrooms Auricularia auricula in phagocytes and mice infected with Cryptococcus neoformans. EPS triggered macrophages and dendritic cell activation upon binding to Dectin-1, a pattern recognition receptor of the C-type lectin receptor family. Engagement of Dectin-1 culminated in pro-inflammatory cytokine production and cell maturation via its canonical Syk-dependent pathway signaling. Furthermore, upon EPS treatment, M2-like phenotype macrophages, known to support intracellular survival and replication of C. neoformans, repolarize to M1 macrophage pattern associated with enhanced production of the microbicidal molecule nitric oxide that results in efficient killing of C. neoformans. Treatment with EPS also upregulated transcript levels of genes encoding products associated with host protection against C. neoformans and Dectin-1 mediated signaling in macrophages. Finally, orally administrated β-glucan-containing EPS from A. auricular enhanced the survival of mice infected with C. neoformans. In conclusion, the results demonstrate that EPS from A. auricula exert immunostimulatory activity in phagocytes and induce host protection against C. neoformans, suggesting that polysaccharides from this mushroom may be promising as an adjuvant for vaccines or antifungal therapy.

Comparative Genomics of Sibling Species of Fonsecaea Associated with Human Chromoblastomycosis

Fonsecaea and Cladophialophora are genera of black yeast-like fungi harboring agents of a mutilating implantation disease in humans, along with strictly environmental species. The current hypothesis suggests that those species reside in somewhat adverse microhabitats, and pathogenic siblings share virulence factors enabling survival in mammal tissue after coincidental inoculation driven by pathogenic adaptation. A comparative genomic analysis of environmental and pathogenic siblings of Fonsecaea and Cladophialophora was undertaken, including de novo assembly of F. erecta from plant material. The genome size of Fonsecaea species varied between 33.39 and 35.23 Mb, and the core genomes of those species comprises almost 70% of the genes. Expansions of protein domains such as glyoxalases and peptidases suggested ability for pathogenicity in clinical agents, while the use of nitrogen and degradation of phenolic compounds was enriched in environmental species. The similarity of carbohydrate-active vs. protein-degrading enzymes associated with the occurrence of virulence factors suggested a general tolerance to extreme conditions, which might explain the opportunistic tendency of Fonsecaea sibling species. Virulence was tested in the Galleria mellonella model and immunological assays were performed in order to support this hypothesis. Larvae infected by environmental F. erecta had a lower survival. Fungal macrophage murine co-culture showed that F. erecta induced high levels of TNF-α contributing to macrophage activation that could increase the ability to control intracellular fungal growth although hyphal death were not observed, suggesting a higher level of extremotolerance of environmental species.

Evaluation of the antimicrobial activity of the mastoparan Polybia-MPII isolated from venom of the social wasp Pseudopolybia vespiceps testacea (Vespidae, Hymenoptera)

Mastoparans, a class of peptides found in wasp venom, have significant effects following a sting as well as useful applications in clinical practice. Among these is their potential use in the control of micro-organisms that cause infectious diseases with a significant impact on society. Thus, the present study describes the isolation and identification of a mastoparan peptide from the venom of the social wasp Pseudopolybia vespiceps and evaluated its antimicrobial profile against bacteria (Staphylococcus aureus and Mycobacterium abscessus subsp. massiliense), fungi (Candida albicans and Cryptococcus neoformans) and in vivo S. aureus infection. The membrane pore-forming ability was also assessed. The mastoparan reduced in vitro and ex vivo mycobacterial growth by 80% at 12.5 µM in infected peritoneal macrophages but did not affect the shape of bacterial cells at the dose tested (6.25 µM). The peptide also showed potent action against S. aureus in vitro (EC₅₀ and EC₉₀ values of 1.83 µM and 2.90 µM, respectively) and reduced the in vivo bacterial load after 6 days of topical treatment (5 mg/kg). Antifungal activity was significant, with EC₅₀ and EC₉₀ values of 12.9 µM and 15.3 µM, respectively, for C. albicans, and 11 µM and 22.70 µM, respectively, for C. neoformans. Peptides are currently attracting interest for their potential in the design of antimicrobial drugs, particularly due to the difficulty of micro-organisms in developing resistance to them. In this respect, Polybia-MPII proved to be highly effective, with a lower haemolysis rate compared with peptides of the same family.

HPV load and anal cytological abnormalities

OBJECTIVES

The objective of this study was to evaluate the association between estimated human papillomavirus (HPV) viral load and abnormal cytology on anal samples.

METHODS

Anal cytological samples of 42 HIV-positive patients were analysed by conventional cytology and Hybrid Capture II.

RESULTS

On cytology, 30.95% (13 of 42) anal samples were positive for cytological abnormalities, 47.61% (20 of 42) were negative and 21.42% (nine of 42) were unsatisfactory. High-risk HPV infection was more frequent in anal samples with cytological abnormalities than in negative samples (P = 0.0002, Fisher's exact test), it was detected in all samples with cytological abnormalities and in 35% (seven of 20) of the negative samples. On samples with cytological abnormalities, the median of the relative light unit/cutoff (RLU/CO) value (viral load estimate) was 10.39 (1.02-572.6) and in negative samples it was 0.51 (0.26-51.70). The median of the RLU/CO value was higher in samples with cytological abnormalities when compared with the median in negative samples (P = 0.0001, Mann-Whitney U-test) and only samples with cytological abnormalities showed RLU/CO values > 100.

CONCLUSIONS

The estimated high-risk HPV viral load is significantly higher in samples with cytological abnormalities than in negative anal samples and may be useful as an adjunct to anal cytology for triage of patients to high-resolution anoscopy and biopsy.

Activity and in vivo tracking of Amphotericin B loaded PLGA nanoparticles

The development of biocompatible polymeric nanoparticles has become an important strategy for optimizing the therapeutic efficacy of many classical drugs, as it may expand their activities, reduce their toxicity, increase their bioactivity and improve biodistribution. In this study, nanoparticles of Amphotericin B entrapped within poly (lactic-co-glycolic) acid and incorporated with dimercaptosuccinic acid (NANO-D-AMB) as a target molecule were evaluated for their physic-chemical characteristics, pharmacokinetics, biocompatibility and antifungal activity. We found high plasma concentrations of Amphotericin B upon treatment with NANO-D-AMB and a high uptake of nanoparticles in the lungs, liver and spleen. NANO-D-AMB exhibited antifungal efficacy against Paracoccidioides brasiliensis and induced much lower cytotoxicity levels compared to D-AMB formulation in vivo and in vitro. Together, these results confirm that NANO-D-AMB improves Amphotericin B delivery and suggest this delivery system as a potential alternative to the use of Amphotericin B sodium deoxycholate.

Effects of bromopride on expression of metalloproteinases and interleukins in left colonic anastomoses: an experimental study

Anastomotic dehiscence is the most severe complication of colorectal surgery. Metalloproteinases (MMPs) and interleukins (ILs) can be used to analyze the healing process of anastomosis. To evaluate the effects of bromopride on MMP and cytokine gene expression in left colonic anastomoses in rats with or without induced abdominal sepsis, 80 rats were divided into two groups for euthanasia on the third or seventh postoperative day (POD). They were then divided into subgroups of 20 rats for sepsis induction or not, and then into subgroups of 10 rats for administration of bromopride or saline. Left colonic anastomosis was performed and abdominal sepsis was induced by cecal ligation and puncture. A colonic segment containing the anastomosis was removed for analysis of gene expression of MMP-1α, MMP-8, MMP-13, IL-β, IL-6, IL-10, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ). On the third POD, bromopride was associated with increased MMP-1α, MMP-13, IL-6, IFN-γ, and IL-10 gene expression. On the seventh POD, all MMP transcripts became negatively modulated and all IL transcripts became positively modulated. In the presence of sepsis, bromopride administration increased MMP-8 and IFN-γ gene expression and decreased MMP-1, TNF-α, IL-6, and IL-10 gene expression on the third POD. On the seventh POD, we observed increased expression of MMP-13 and all cytokines, except for TNF-α. In conclusion, bromopride interferes with MMP and IL gene expression during anastomotic healing. Further studies are needed to correlate these changes with the healing process.

The intracellular life of Cryptococcus neoformans

Cryptococcus neoformans is a fungal pathogen with worldwide distribution. Serological studies of human populations show a high prevalence of human infection, which rarely progresses to disease in immunocompetent hosts. However, decreased host immunity places individuals at high risk for cryptococcal disease. The disease can result from acute infection or reactivation of latent infection, in which yeasts within granulomas and host macrophages emerge to cause disease. In this review, we summarize what is known about the cellular recognition, ingestion, and killing of C. neoformans and discuss the unique and remarkable features of its intracellular life, including the proposed mechanisms for fungal persistence and killing in phagocytic cells.

Nanobiotechnological approaches to delivery of DNA vaccine against fungal infection

Vaccines play an essential role in keeping humans healthy. Innovative approaches to their use include the utilization of plasmid DNA encoding sequences to express foreign antigens. DNAhsp65 from Mycobacterium leprae is suitable for this purpose due to its ability to elicit a powerful immune response. Controlled release systems represent a promising approach to delivering vaccines. In this work, we used liposomes or PLGA systems to deliver DNAhsp65 to treat the pulmonary fungal infection Paracoccidioidomycosis. Both formulations modulated a protective immune response and reduced the pulmonary fungal burden even in the groups receiving less than four times the amount of the DNAhps65 entrapped within the nanoparticles. Although both systems had the same effective therapeutic results, the advantage of the liposome formulation was that it was administered intranasally, which may be more easily accepted by patients. These systems are a great alternative to be considered as adjuvant vaccine therapy for systemic mycosis.

Foxp3 expression in lesions of the different clinical forms of American tegumentary leishmaniasis

As the diversity in clinical presentation of American tegumentary leishmaniasis (ATL) is determined mainly by the immune response of host, our aim was to evaluate the in situ expression of Foxp3 [marker of regulatory T (Treg) cell] in lesions of the different clinical forms of ATL. Foxp3(+) cells were observed in 39.5% (32/81) of the samples and the number of positive cells was low in all the clinical forms. Even presenting a significantly lower number of CD4(+) T cells, diffuse cutaneous leishmaniasis (DCL) showed a higher expression of Foxp3 when compared with localized cutaneous leishmaniasis (LCL) and mucocutaneous leishmaniasis (MCL). In LCL and MCL, the number of Foxp3(+) cells correlated positively with the number of apoptotic cells (active caspase-3(+) cells). A positive correlation was also observed between the expression of active caspase-3 and FasL in these clinical forms. Our data suggest that increased number of Treg cells may be associated to the hyporesponsiveness observed in DCL and also indicate that the apoptosis may be a possible mechanism of action of Foxp3(+) Treg cell in LCL and MCL. However, further studies are required to better understand the mechanism of action of Treg cell.

Prognostic value of morphologic and clinical parameters in pT2 - pT3 prostate cancer

OBJECTIVES

Verify the efficacy of clinical and morphologic parameters currently applied, including an immunohistochemical panel, in the prognostic of prostate cancer, in specific stages of the disease.

MATERIALS AND METHODS

In the period from 2002 to 2005, 40 surgical specimens were selected from patients submitted to radical prostatectomy, with their respective diagnostic biopsies. Based on the pathological stage pT2 or pT3, the specimens were separated into two groups, each one with 20 specimens. The results were confronted with pre- and postoperative clinical data. Between the groups studied, the following was also analyzed: the profile of the expression of molecular markers such as PSA, E-caderin, chromogranin-A, synaptofisin, P53 and Ki-67, both in the material coming from the prostatic biopsy and from the surgical specimens of all patients.

RESULTS

Data showed that patients with prostate-confined disease (pT2) presented lower PSA and Gleason score rates, in relation to the group with extra-prostatic disease (pT3). Quantitative measures obtained for the percentage of positive fragments from the biopsy revealed that patients from the pT2 group presented a lower mean percentage when compared to the pT3 group. Positive margins of both groups influenced the need for complementary treatment before biochemical progression. The comparison of the molecular marker expression in both stages was not significantly different.

CONCLUSION

It is evident the need to improve new methods, predominantly morphologic and molecular, that are able to further exploit the study of the material from the prostatic biopsy. As to the profile of the molecular markers used in both studied groups, there was no significant difference in the sense of outlining an additional prognostic factor in the clinical practice.

Inhibition of Nitric Oxide Production by Macrophages in Chromoblastomycosis: A Role for Fonsecaea pedrosoi Melanin

Chromoblastomycosis is a chronic and progressive deep mycosis that is usually found in tropical and subtropical areas. Fonsecaea pedrosoi is considered its most frequent etiologic agent and causes a typical granulomatous inflammatory response, whose degree reflects the immune status of the host. Since macrophages play a fundamental role in the control of the infection, this study aimed at investigating the production of oxygen reactive specimens, the phagocytic capacity and the production of nitric oxide (NO) by macrophages employing in vitro assays and an in vivo model of chromoblastomycosis. Our results demonstrated that, during the infection, peritoneal macrophages show an increased phagocytic capacity and H2O2 production, but also a reduced ability to produce NO. Moreover, F. pedrosoi stimulated H2O2 production in vitro but not the synthesis of NO. The incubation of IFNgamma and LPS-stimulated macrophages with melanin, obtained from the fungus, inhibited NO production. Examination of the liver and spleen of infected animals, at day 30 or 60 following inoculation, showed a progressive increase in the number and size of granulomas, indicating that macrophages are properly mobilized and activated. Our data suggest that the inability of the host to clear F. pedrosoi, leading to a chronic disease, is due, at least in part, to the inhibition of NO synthesis by macrophages by fungus-produced melanin.

Prevalence of coeliac disease: unexplained age-related variation in the same population

BACKGROUND

The aims of this work were (a) to evaluate the prevalence of coeliac disease (CD) in a large sample of the Brazilian general population and (b) to compare CD prevalence between children and adults.

METHODS

The study group comprised 4405 subjects (2629 F and 1776 M). Age distributions were 2034 (1-14 years), 848 (15-29), 584 (30-44), 667 (45-59) and 272 above 60. The immunoglobulin A antiendomysial antibody (IgA-EMA) test was used as the serological screening tool. All sera were submitted to turbidimetric measurement of IgA levels and those with IgA deficiency to the IgG antigliadin (IgG-AGA) test. The small intestinal biopsy was recommended for subjects showing either (a) IgA-EMA positivity or (b) selective IgA deficiency (SigAD) and IgG-AGA positivity.

RESULTS

There were 16 EMA positive out of 4405 sera tested. SigAD was found in five cases (one adult and four children). Two of these children tested positive for IgG-AGA and underwent jejunal biopsy that, in both cases, disclosed a normal mucosa. Overall, 17 out of 18 eligible subjects performed the small intestinal biopsy. The prevalence of biopsy-proven CD in this study group was 3.41 per 1000 individuals. If all 18 EMA-positive patients were included, the overall prevalence would become 3.63 per 1000. The prevalence in adults and children was 2.11 per 1000 and 5.44 per 1000, respectively.

CONCLUSION

This work supports previous findings showing that CD is not a rare disorder in Brazil and that there is an unexplained difference in the prevalence of CD between adults and children.

Macrophage expression of class II major histocompatibility complex gene products in Paracoccidioides brasiliensis-infected mice

C57B1/6 isogenic mice infected with Paracoccidioides brasiliensis strains showed a disruption in the expression of Ia antigen. Expression slowly decreased during the course of the infection with a slight variation dependent on the route of inoculation and the fungal strain used, but production of interferon-gamma and tumor necrosis factor-alpha were observed. Suppression of Ia antigen expression and depression of the immunoproliferative responses of spleen cells were strongly correlated with nitric oxide levels. These parameters were inhibited when the animals were treated with nitro-L-arginine, which resulted in inhibition the activation of nitric oxide (NO) production. Analysis of the data showed that changes in the expression of the Ia antigen occur in P. brasiliensis infection and are strongly correlated with NO levels. These phenomena may be interrelated and reflect macrophage activation that contributes to the control of the disease and to the immunosuppression observed during the course of the infection.

Treatment of Paracoccidioides brasiliensis-infected mice with a nitric oxide inhibitor prevents the failure of cell-mediated immune response

The activation of the nitric oxide (NO) production system and its involvement in the control of the lung fungal burden and in immunosuppression mechanisms were studied during the course of Paracoccidioides brasiliensis-infected mice. Mice that had been infected with the fungus were treated daily with a specific inhibitor of NO synthesis, N omega-nitro-L-arginine, or with buffered saline (control); NO production was assessed on the basis of spontaneous NO2- production by bronchoalveolar and peritoneal macrophages (Mphi) and of serum NO3- levels. The infection coursed with an elevation of NO3- levels. The Mphi produced NO2- and released TNF-alpha only after stimulation with LPS. In addition, the immunoproliferative responses of spleen cells that had been stimulated with the fungus Ag or with Con A were depressed. An examination of the lungs of infected animals showed a progressive increase in the size of the lesions. Treatment of the animals, which resulted in an inhibition of NO2- production by Mphi and a reduction of serum NO3- levels, caused the spontaneous release of TNF-alpha from infected animals and prevented the failure of the lymphoproliferative capacity of spleen cells. Furthermore, the treatment resulted in less pulmonary damage despite the fact that the lung fungal burden increased. It was also demonstrated that the NO donors S-nitroso-acetyl penicillamine and 3-morpholino-sydnonimine-hydrochloride were able to inhibit the growth of P. brasiliensis in vitro. These results suggest that although NO is important for the killing of the fungi, the activation of NO production in P. brasiliensis infection contributes to the occurrence of the immunosuppression observed during the course of the infection.

The role of T cell subsets and cytokines in the regulation of intracellular bacterial infection

Cellular immune responses are a critical part of the host's defense against intracellular bacterial infections. Immunity to Brucella abortus crucially depends on antigen-specific T cell-mediated activation of macrophages, which are the major effectors of cell-mediated killing of this organism. T lymphocytes that proliferate in response to B. abortus were characterized for phenotype and cytokine activity. Human, murine, and bovine T lymphocytes exhibited a type 1 cytokine profile, suggesting an analogous immune response in these different hosts. In vivo protection afforded by a particular cell type is dependent on the antigen presented and the mechanism of antigen presentation. Studies using MHC class I and class II knockout mice infected with B. abortus have demonstrated that protective immunity to brucellosis is especially dependent on CD8+ T cells. To target MHC class I presentation we transfected ex vivo a murine macrophage cell line with B. abortus genes and adoptively transferred them to BALB/c mice. These transgenic macrophage clones induced partial protection in mice against experimental brucellosis. Knowing the cells required for protection, vaccines can be designed to activate the protective T cell subset. Lastly, as a new strategy for priming a specific class I-restricted T cell response in vivo, we used genetic immunization by particle bombardment-mediated gene transfer.

Cellular requirements for immunomodulatory effects caused by cell wall components of Paracoccidioides brasiliensis on antibody production

In a previous study, we reported an increase in the number of immunoglobulin-secreting cells and the augmentation of antibody production (IgM and IgG3) against unrelated antigens (sheep erythrocytes or bovine serum albumin (BSA)) in mice infected with the fungus Paracoccidioides brasiliensis as well as in mice inoculated with its cell wall preparation (CW). The immunomodulatory effect of the live fungus and CW preparation was dose-dependent and mainly restricted to the i.p. inoculation simultaneously to the BSA challenge by the i.v. route. In the present study, we investigated the active component of CW preparation upon the phenotype and also the degree of activation of possible target peritoneal cells involved in those phenomena. An insoluble polysaccharide fraction (F1 fraction) mainly composed of beta-glucan and chitin, and the purified beta-glucan (BGPb) behaved as CW in the augmentation of early antibody production. The peritoneal mononuclear inflammatory cells induced by CW, F1 fraction and BGPb were highly positive to alpha-naphthyl esterase staining; released low H2O2; expressed high levels of MHC-Ia(d) molecules and produced inflammatory cytokines such as tumour necrosis factor-alpha (TNF-alpha) and IL-6. Phenotypic analysis by flow cytometry and immunohistochemical techniques of the inflammatory cells responding to F1 fraction showed a prevalence of (CD11b/CD18, Mac-1)+ peritoneal macrophages. In addition, s.c. inoculation of F1 fraction resulted in the formation of nodular, localized and not progressive granulomatous lesions with an accumulation of (CD11b/C18)+ macrophages. Adoptive transferred Mac-1 macrophages to immunized syngeneic recipient mice were able to cause an increase in anti-BSA antibody production. These results suggest that inflammatory (CD11b/CD18)+ macrophages may be related to immunological disturbances, caused by cell wall components of P. brasiliensis.