Short Communication: Manα1-2Man-Binding Anti-HIV Lectins Enhance the Exposure of V2i and V3 Crown Neutralization Epitopes on the V1/V2 and V3 Hypervariable Loops of HIV-1 Envelope.

This study aimed to explore the contribution of high-mannose glycans in the masking of conserved V3 crown (GPG) and V2i epitopes on the hypervariable loops of most exposed distal surface of HIV-1 Env. Using lectins specific to Manα1-2Man residue containing Man6-9GlcNAc2 glycans extensively decorating HIV-1 Env, we found that Manα1-2Man-binding lectins enhance the exposure of these partially and transiently exposed epitopes and consequentially increase the neutralization strength of antibodies against these epitopes.

The Cek1­mediated MAP kinase pathway regulates exposure of α­1,2 and ß­1,2­mannosides in the cell wall of Candida albicans modulating immune recognition.

The Cek1 MAP kinase (MAPK) mediates vegetative growth and cell wall biogenesis in the fungal pathogen Candida albicans. Alterations in the fungal cell wall caused by a defective Cek1­mediated signaling pathway leads to increased ß­1,3­glucan exposure influencing dectin­1 fungal recognition by immune cells. We show here that cek1 cells also display an increased exposure of α­1,2 and ß­1,2­mannosides (α­M and ß­M), a phenotype shared by strains defective in the activating MAPKK Hst7, suggesting a general defect in cell wall assembly. cek1 cells display walls with loosely bound material as revealed by transmission electron microscopy and are sensitive to tunicamycin, an inhibitor of N­glycosylation. Transcriptomal analysis of tunicamycin treated cells revealed a differential pattern between cek1 and wild type cells which involved mainly cell wall and stress related genes. Mapping α­M and ß­M epitopes in the mannoproteins of different cell wall fractions (CWMP) revealed an important shift in the molecular weight of the mannan derived from mutants defective in this MAPK pathway. We have also assessed the role of galectin­3, a member of a ß­galactoside­binding protein family shown to bind to and kill C. albicans through ß­M recognition, in the infection caused by cek1 mutants. Increased binding of cek1 to murine macrophages was shown to be partially blocked by lactose. Galectin-3(-/-) mice showed increased resistance to fungal infection, although galectin-3 did not account for the reduced virulence of cek1 mutants in a mouse model of systemic infection. All these data support a role for the Cek1­mediated pathway in fungal cell wall maintenance, virulence and antifungal discovery.

Highly purified mycobacterial phosphatidylinositol mannosides drive cell-mediated responses and activate NKT cells in cattle.

Mycobacterial lipids play an important role in the modulation of the immune response upon contact with the host. Using novel methods, we have isolated highly purified phosphatidylinositol mannoside (PIM) molecules (phosphatidylinositol dimannoside [PIM2], acylphosphatidylinositol dimannoside [AcPIM2], diacyl-phosphatidylinositol dimannoside [Ac2PIM2], acylphosphatidylinositol hexamannoside [AcPIM6], and diacylphosphatidylinositol hexamannoside [Ac2PIM6]) from virulent Mycobacterium tuberculosis to assess their potential to stimulate peripheral blood mononuclear cell (PBMC) responses in Mycobacterium bovis-infected cattle. Of these molecules, one (AcPIM6) induced significant levels of gamma interferon (IFN-γ) in bovine PBMCs. Three PIM molecules (AcPIM6, Ac2PIM2, and Ac2PIM6) were shown to drive significant proliferation in bovine PBMCs. AcPIM6 was subsequently used to phenotype the proliferating cells by flow cytometry. This analysis demonstrated that AcPIM6 was predominantly recognized by CD3(+) CD335(+) NKT cells. In conclusion, we have identified PIM lipid molecules that interact with bovine lymphocyte populations, and these lipids may be useful as future subunit vaccines or diagnostic reagents. Further, these data demonstrate, for the first time, lipid-specific NKT activation in cattle.

Chemistry and biology of oligovalent ß-(1→2)-linked oligomannosides: new insights into carbohydrate-based adjuvants in immunotherapy.

A series of oligovalent carbohydrate assemblies (ranging from mono- to pentavalent), derived from three structurally different ß-linked or ß-(1→2)-linked mannosides, has been chemically synthesized, and the respective compounds have been biologically evaluated in order to investigate their immunostimulatory properties. The Crich methodology for ß-mannosylation was successfully utilized to introduce the ß-linkages, and a click chemistry protocol was utilized to generate the oligovalent derivatives. A convenient protecting group strategy involving the simultaneous use of both p-methoxybenzyl and benzylidene groups was employed, which allowed a simple and cost-effective global deprotection step. The immunomodulatory properties of the synthesized multivalent mannosides were evaluated by assessing cytokine production in human white blood cell cultures. The Th2-type cytokines interleukin-4 and interleukin-5 (IL-4 and IL-5), the Th1 cytokine interferon-γ (IFN-γ), the Treg cytokine IL-10, and the pro-inflammatory cytokine tumor necrosis factor (TNF) were included in the screening. A single trivalent acetylated mannobiose derivative was identified as a potent inducer of Treg and Th1 immune response, resulting in strong IL-10 and moderate IFN-γ productions dose-dependently, while inducing no Th2 cytokine response. The immunomodulatory properties of this trivalent mannoside were further studied in vitro in allergen (Bet v)-stimulated human peripheral blood mononuclear cell cultures of birch pollen allergic subjects. Stimulation with birch pollen induced strong IL-4 and IL-5 responses, which could be suppressed by the trivalent acetylated mannobiose derivative. The IL-10 response was also suppressed, whereas the production of IFN-γ was strongly enhanced. The results suggest that the identified lead compound has suppressive effects on the Th2-type allergic inflammatory response and shows potential as a possible lead adjuvant for the specific immunotherapy of allergies.

Physicochemical and biological characterization of synthetic phosphatidylinositol dimannosides and analogues.

Native phosphatidylinositol mannosides (PIMs), isolated from the cell wall of Mycobacterium bovis, and synthetic PIM analogues have been reported to offer a variety of immunomodulating properties, including both suppressive and stimulatory activity. While numerous studies have examined the biological activity of these molecules, the aim of this research was to assess the physicochemical properties at a molecular level and correlate these characteristics with biological activity in a mouse model of airway eosinophilia. To accomplish this, we varied the flexibility and lipophilicity of synthetic PIMs by changing the polar headgroup (inositol- vs glycerol-based core) and the length of the acyl chains of the fatty acid residues (C0, C10, C16, and C18). A series of six phosphatidylinositol dimannosides (PIM2s) and phosphatidylglycerol dimannosides (PGM2s) were synthesized and characterized in this study. Langmuir monolayer studies showed that surface pressure-area (π-A) isotherms were greatly influenced by the length of the lipid acyl chains as well as the steric hindrance and volume of the headgroups. In aqueous solution, lipidated PIM2 and PGM2 compounds were observed to self-assemble into circular aggregates, as confirmed by dynamic light scattering and transmission electron microscopic investigations. Removal of the inositol ring but retention of the three-carbon glycerol unit maintained biological activity. We found that the deacylated PGM2, which did not show self-organization, had no effect on the eosinophil numbers but did have an impact on the expansion of OVA-specific CD4(+) Vα2Vß5 T cells.

Beta-1,2 oligomannose adhesin epitopes are widely distributed over the different families of Candida albicans cell wall mannoproteins and are associated through both N- and O-glycosylation processes.

Beta-1,2-linked mannosides (beta-Mans) are believed to contribute to Candida albicans virulence. The presence of beta-Mans has been chemically established for two molecules (phosphopeptidomannan [PPM] and phospholipomannan) that are noncovalently linked to the cell wall, where they correspond to specific epitopes. However, a large number of cell wall mannoproteins (CWMPs) also express beta-Man epitopes, although their nature and mode of beta-mannosylation are unknown. We therefore used Western blotting to map beta-Man epitopes for the different families of mannoproteins gradually released from the cell wall according to their mode of anchorage (soluble, released by dithiothreitol, beta-1,3 glucan linked, and beta-1,6 glucan linked). Reduction of beta-Man epitope expression occurred after chemical and enzymatic deglycosylation of the different cell wall fractions, as well as in a secreted form of Hwp1, a representative of the CWMPs linked by glycosylphosphatidylinositol remnants. Enzyme-linked immunosorbent assay inhibition tests were performed to assess the presence of beta-Man epitopes in released oligomannosides. A comparison of the results obtained with CWMPs to the results obtained with PPM and the use of mutants with mutations affecting O and N glycosylation demonstrated that both O glycosylation and N glycosylation participate in the association of beta-Mans with the protein moieties of CWMPs. This process, which can alter the function of cell wall molecules and their recognition by the host, is therefore more important and more complex than originally thought, since it differs from the model established previously with PPM.

Phosphatidylinositol mannosides: synthesis and adjuvant properties of phosphatidylinositol di- and tetramannosides.

Phosphatidylinositol mannosides (PIMs) isolated from mycobacteria have been identified as an important class of glycolipids with significant immune modulating properties. We present here the syntheses of phosphatidylinositol dimannoside (PIM2, 1) and phosphatidylinositol tetramannoside (PIM4, 2) and evaluate their adjuvant properties in a transgenic mouse model. The key step in the synthetic methodology for the synthesis of 2 relies on the selective glycosylation of diol 3 with mannosyl donor 11. Both synthetic PIMs were effective at enhancing IFN-gamma when given as adjuvants with a model antigen, with PIM2 being the more active. These data suggest that in this assay the PIM core structure is responsible for the observed biological activity.

Comparative analysis of cell wall surface glycan expression in Candida albicans and Saccharomyces cerevisiae yeasts by flow cytometry.

The yeast Candida albicans is an opportunistic pathogen, part of the normal human microbial flora that causes infections in immunocompromised individuals with a high morbidity and mortality levels. Recognition of yeasts by host cells is based on components of the yeast cell wall, which are considered part of its virulence attributes. Cell wall glycans play an important role in the continuous interchange that regulates the balance between saprophytism and parasitism, and also between resistance and infection. Some of these molecular entities are expressed both by the pathogenic yeast C. albicans and by Saccharomyces cerevisiae, a related non-pathogenic yeast, involving similar molecular mechanisms and receptors for recognition. In this work we have exploited flow cytometry methods for probing surface glycans of the yeasts. We compared glycan expression by C. albicans and by S. cerevisiae, and studied the effect of culture conditions. Our results show that the expression levels of alpha- and beta-linked mannosides as well as beta-glucans can be successfully evaluated by flow cytometry methods using different antibodies independent of agglutination reactions. We also found that the surface expression pattern of beta-mannosides detected by monoclonal or polyclonal antibodies are differently modulated during the growth course. These data indicate that the yeast beta-mannosides exposed on mannoproteins and/or phospholipomannan are increased in stationary phase, whereas those linked to mannan are not affected by the yeast growth phase. The cytometric method described here represents a useful tool to investigate to what extent C. albicans is able to regulate its glycan surface expression and therefore modify its virulence properties.

Analysis of binding of mannosides in relation to Langerin (CD207) in Langerhans cells of normal and transformed epithelia.

Tandem-repeat C-type lectins (pattern-recognition receptors) with specificity for mannosides are intimately involved in antigen recognition, uptake, routing and presentation in macrophages and dendritic cells. In Langerhans cells, Langerin (CD207), a type-II transmembrane protein with a single C-type carbohydrate recognition domain attached to a heptad repeat in the neck region, which is likely to establish oligomers with an alpha-coiled-coil stalk, has been implicated in endocytosis and the formation of Birbeck granules. The structure of Langerin harbours essential motifs for Ca2+-binding and sugar accommodation. Lectin activity has previously been inferred by diminished antibody binding to cells in the presence of the glycan ligand mannan. In view of the complexity of the C-type lectin/lectin-like network, it is unclear what role Langerin plays for Langerhans cells in binding mannosides. In order to reveal in frozen tissue sections to what extent mannose-binding activity co-localizes with Langerin, we have used a synthetic marker, i.e. a neoglycoprotein carrying mannose maxiclusters, as a histochemical ligand, and computer-assisted fluorescence monitoring in a double-labelling procedure. Mannoside-binding capacity was detected in normal epithelial cells. Double labelling ensured the unambiguous assessment of the binding of the neoglycoprotein in Langerhans cells. Light-microscopically, its localization profile resembled the pattern of immunohistochemical detection of Langerin. This result has implications for suggesting rigorous controls in histochemical analysis of this cell type, because binding of kit reagents, i.e. mannose-rich glycoproteins horseradish peroxidase or avidin, to Langerin (or a spatially closely associated lectin) could yield false-positive signals. To show that recognition of carbohydrate ligands in dendritic cells is not restricted to mannose clusters, we have also documented binding of carrier-immobilized histo-blood group A trisaccharide, a ligand of galectin-3, which was not affected by the presence of a blocking antibody to Langerin. Remarkably, access to the carbohydrate recognition domain of Langerin appeared to be impaired in proliferatively active environments (malignancies, hair follicles), indicating presence of an endogenous ligand with high affinity to saturate the C-type lectin under these conditions.

Structural and functional consequences of peptide-carbohydrate mimicry. Crystal structure of a carbohydrate-mimicking peptide bound to concanavalin A.

The functional consequences of peptide-carbohydrate mimicry were analyzed on the basis of the crystal structure of concanavalin A (ConA) in complex with a carbohydrate-mimicking peptide, DVFYPYPYASGS. The peptide binds to the non-crystallographically related monomers of two independent dimers of ConA in two different modes, in slightly different conformations, demonstrating structural adaptability in ConA-peptide recognition. In one mode, the peptide has maximum interactions with ConA, and in the other, it shows relatively fewer contacts within this site but significant contacts with the symmetry-related subunit. Neither of the peptide binding sites overlaps with the structurally characterized mannose and trimannose binding sites on ConA. Despite this, the functional mimicry between the peptide and carbohydrate ligands was evident. The peptide-inhibited ConA induced T cell proliferation in a dose-dependent manner. The effect of the designed analogs of the peptide on ConA-induced T cell proliferation and their recognition by the antibody response against alpha-d-mannopyranoside indicate a role for aromatic residues in functional mimicry. Although the functional mimicry was observed between the peptide and carbohydrate moieties, the crystal structure of the ConA-peptide complex revealed that the two peptide binding sites are independent of the methyl alpha-d-mannopyranoside binding site.

Association of concentration of asbestos and asbestos-like fibers with the patient's survival and the binding capacity of lung parenchyma to galectin-1 and natural alpha-galactoside- and alpha-mannoside-binding immunoglobulin G subfractions from human serum.

Our aim in this study was to search for lung parenchyma alterations associated with asbestos and/or asbestos-like fiber concentration. This was done by means of immuno- or glycohistochemistry. The hot-ashing technique determined the asbestos and asbestos-like fiber concentrations in the lung tissues of 100 patients of whom 52 were treated for primary lung and 25 for secondary lung tumors; fiber concentration was also measured for 23 patients whose disease was benign. The results were correlated to smoking habits, survival of the patients, and expression of binding capacities for endogenous lectins, natural carbohydrate-binding and lectin-specific antibodies. The cohort with proven asbestos exposure revealed a mean fiber concentration 114 f/g compared to 95 f/g in the non-exposed group. An increased asbestos fiber concentration was correlated to galectin-1-binding and the presence of epitopes for natural immunoglobulin G subfractions with selectivity to alpha-galactosides and alpha-mannosides. The survival of patients with primary and secondary lung tumors was negatively associated with the fiber concentration. The data indicate that increased presence of asbestos is correlated with an alteration of defined glycohistochemical features of alveolar lining cells.

Cryptosporidium parvum sporozoite pellicle antigen recognized by a neutralizing monoclonal antibody is a beta-mannosylated glycolipid.

The protozoan parasite Cryptosporidium parvum is an important cause of diarrhea in humans, calves, and other mammals worldwide. No approved vaccines or parasite-specific drugs are currently available for the control of cryptosporidiosis. To effectively immunize against C. parvum, identification and characterization of protective antigens are required. We previously identified CPS-500, a conserved, neutralization-sensitive antigen of C. parvum sporozoites and merozoites defined by monoclonal antibody 18.44. In the present study, the biochemical characteristics and subcellular location of CPS-500 were determined. CPS-500 was chloroform extractable and eluted with acetone and methanol in silicic acid chromatography, consistent with being a polar glycolipid. Following chloroform extraction and silicic acid chromatography, CPS-500 was isolated by high-pressure liquid chromatography for glycosyl analysis, which indicated the presence of mannose and inositol. To identify which component of CPS-500 comprised the neutralization-sensitive epitope recognized by 18.44, the ability of the monoclonal antibody to bind CPS-500 treated with proteases, or with alpha- or beta-glycosidases, was determined. Monoclonal antibody 18.44 did not bind antigen treated with beta-D-mannosidase but did bind antigen treated with alpha-D-mannosidase, other alpha- or beta-glycosidases, or a panel of proteases. These data indicated that the target epitope was dependent on terminal beta-D-mannopyranosyl residues. By immunoelectron microscopy, 18.44 binding was localized to the pellicle and an intracytoplasmic tubulovesicular network in sporozoites. Monoclonal antibody 18.44 also bound to antigen deposited and released onto substrate over the course travelled by gliding sporozoites and merozoites. Surface localization, adhesion and release during locomotion, and neutralization sensitivity suggest that CPS-500 may be involved in motility and invasion processes of the infective zoite stages.

Cell type-specific glycoforms of Fc gamma RIIIa (CD16): differential ligand binding.

Fc gamma RIIIa, considered an intermediate affinity receptor, can variably bind monomeric IgG and appears to have a higher affinity for IgG than the lower affinity Fc gamma Rs, Fc gamma RII and Fc gamma RIIIb. We explored this property for both NK cell and monocyte Fc gamma RIIIa and found higher affinity ligand binding by Fc gamma RIIIa expressed on NK cells compared with Fc gamma RIIIa on monocytes. In normal whole blood or plasma (containing 8-11 mg/ml IgG), NK cell Fc gamma RIIIa was fully blocked, but in monocytes Fc gamma RIIIa showed approximately 60% blockade of the binding of mAb 3G8, which binds in or near the ligand binding site. The ligand binding site of NK cell Fc gamma RIIIa was blocked with as little as 2 mg/ml of human IgG, while monocyte Fc gamma RIIIa was only partially (30%) blocked by 2 mg/ml of human IgG. In contrast, plasma containing approximately 26 mg/ml of IgG (obtained from patients receiving therapeutic gamma-globulin) showed complete saturation of monocyte Fc gamma RIIIa with blockade of mAb 3G8 binding. These binding differences are not due to allelic polymorphisms or primary sequence differences between donors. Although NK cell and monocyte Fc gamma RIIIa have identical protein cores, they each undergo differential cell type-specific glycosylation. NK cell Fc gamma RIIIa is glycosylated with high mannose- and complex-type oligosaccharides, while monocyte Fc gamma RIIIa has no high mannose-type oligosaccharides. These results indicate that natural glycoforms of Fc gamma RIIIa (cell type-specific glycosylation variants) bind ligand differently, conferring a lower affinity on monocyte/macrophage Fc gamma RIIIa, which makes the receptor ideal for initial immune complex capture and sensitive to moderate changes in serum IgG levels.

CD1c restricts responses of mycobacteria-specific T cells. Evidence for antigen presentation by a second member of the human CD1 family.

Previous studies suggest that CD1 is a family of Ag-presenting molecules distantly related to those encoded by the MHC. However, of the four known human CD1 proteins, only CD1b has been shown to restrict Ag-specific T cell responses. In this study, we have shown that a second member of the human CD1 family, CD1c, could also mediate Ag presentation to T cells. Three T cell lines recognizing mycobacterial Ags in a CD1c-restricted manner were isolated from normal donor blood. These T cells were MHC unrestricted, and their recognition of Ag was independent of the products of the transporter associated with Ag presentation-1/2 and DMA/B genes that are generally required for Ag presentation by MHC-encoded Ag-presenting molecules. Furthermore, unlike MHC-restricted responses to peptides, the CD1c-restricted T cell lines recognized protease-resistant mycobacterial lipid Ags. These T cell lines also showed significant cytotoxicity toward CD1c-expressing target cells even in the absence of mycobacterial Ags, which was shown by clonal analysis to be mediated by a subpopulation of T cells directly reactive to CD1c molecules. Our findings establish the ability of a second member of the CD1 family to restrict responses of Ag-specific T cells, and thus support the general hypothesis that the CD1 family comprises a third lineage of Ag-presenting molecules that presents a novel class of foreign and self Ags to MHC-unrestricted T cells.

Mapping of beta-1,2-linked oligomannosidic epitopes among glycoconjugates of Candida species.

The distribution of beta-1,2-linked oligomannosides among glycoconjugates of various Candida species was investigated by Western blotting, using monoclonal and polyclonal antibodies which react with these epitopes. Expression of beta-1,2-linked oligomannosidic epitopes on a 14-18 kDa polydisperse antigen nonreactive with concanavalin A (ConA), previously identified as a C. albicans serotype A phospholipomannan (PLM), appeared to be restricted to C. albicans serotypes A and B (including var. C. stellatoidea types I and II) and C. tropicalis. In C. albicans, beta-1,2-linked oligomannosidic epitopes also appeared to be slightly associated with high molecular mass (> 100 kDa) polydisperse ConA-reactive mannoproteins. For all the other Candida strains investigated, belonging to the species C. parapsilosis, C. krusei, C. glabrata and C. robusta (S. cerevisiae), beta-1,2-linked oligomannosidic epitopes were found to be present in association with medium molecular mass (18-100 kDa) and high molecular mass ConA-reactive mannoproteins, giving reproducible labelling profiles that varied between species.

Probable presence of beta(1-2)-linked oligomannosides that act as human immunoglobulin G3 epitopes and are distributed over a Candida albicans 14- to 18-kilodalton antigen.

Kinetic analysis of candidosis patients' immunoglobulin G3 response has shown that reactivity towards beta(1-2)-linked mannan-derived oligomannosides was associated with the recognition through metaperiodate-sensitive epitopes of a 14- to 18-kDa Candida albicans antigen unreactive with concanavalin A.

Specificity analysis of antibodies formed in rabbits to a mannosyl trisaccharide: similarity with lectin binding activity. Para-aminophenyl O-alpha-D-mannopyranosyl-(1-->2)-alpha-D-mannopyranosyl- (1-->6)-alpha-D-mannopyranoside linked to bovine serum albumin as an antigen.

The para-aminophenyl derivative of Man alpha 1-->2Man alpha 1-->6Man alpha 1-->was coupled via a diazotization reaction to bovine serum albumin, and the resulting glycoconjugate was used to immunize two rabbits. The resultant antisera were tested for reactivity with a number of related mono, di- and trisaccharides to determine the immunodominant portion of this trisaccharide. Two populations of antibody resulted, one of which required the reducing end mannose, and could react with either an N-acetylglucosamine or a mannose as the penultimate sugar. The other population reacted with the Man alpha 1-->2Man alpha 1-->6Man alpha 1-->. The aglycone moiety and its configurations play an important role in determining the specificity of antibodies to this synthetic antigen. The similarity of this reactivity to the reactivity of mannose binding lectins is discussed.

Novel adjuvant action of lipopolysaccharides that possess mannose homopolysaccharides as O-specific polysaccharides on immune responses to nonimmunogenic autoantigens in mice.

The adjuvant action of various lipopolysaccharides on immune responses to syngeneic tissue extract in mice was examined. Only lipopolysaccharides possessing the linear mannose homopolysaccharides as O-specific polysaccharides exhibited definite adjuvant action on immune responses to the autoantigens. The intensity of this adjuvant activity of lipopolysaccharide from Klebsiella O3 seemed to be the strongest.

Antibodies directed against the thiomannose moiety of a glycoconjugate of 2-imino-2-methoxyethyl 1-thio-alpha-D-mannopyranoside and bovine serum albumin.

Anti-thiomannose antibodies were induced in rabbits immunized with a glycoconjugate of 2-imino-2-methoxyethyl 1-thio-alpha-D-mannopyranoside (Man-S) and bovine serum albumin (BSA). Also anti-BSA antibodies directed against the BSA moiety of the glycoconjugate were detected in low concentrations in the immune serum. However, antibodies against the combinatorial epitope of the hapten group and the carrier protein were not detected. The anti-thiomannose and the anti-BSA antibodies were isolated in pure forms by affinity chromatography on Sepharose 4B-bearing thiomannosyl-BSA ligands or BSA ligands. The anti-thiomannose antibodies constituted the major fraction of the antibodies, and these antibodies were isolated in pure form for the first time. The specificity of the thiomannose antibodies was established from data of experiments of periodate oxidation, perpropionic acid oxidation, hapten inhibition, and agar diffusion, Isoelectrofocusing showed that the anti-thiomannose antibody preparation consisted of at least six isomeric proteins, all of which exhibited antibody activity against the glycoconjugate of thiomannose and BSA.

Activation of mouse peritoneal macrophages by mannophosphoinositides of mycobacteria.

Peritoneal macrophages isolated from mannoside-methylated bovine serum albumin (MBSA)-immunized mice showed significantly enhanced phagocytosis of Mycobacterium smegmatis compared to control or MBSA-immunized groups. Immune macrophages also exhibited bacteriostatic activity against M. smegmatis. Pretreatment of mycobacteria with mannoside antibodies did not further alter the phagocytosis and bacteriostatic effect of immune macrophages.