Maternal schistosomiasis: IL-2, IL-10 and regulatory T lymphocytes to unrelated antigen in adult offspring mice

Abstract INTRODUCTION: We evaluated IL-10, IL-2 and regulatory T cells (Treg), in response to ovalbumin (OA), in offspring from schistosomotic mouse mothers. METHODS: We used animals born (BIM) or suckled (SIM) from infected mothers; and mice born/suckled from infected (BSIM) or non-infected mothers (CONTROL). After OA+adjuvant immunization, spleen cells were cultured, with or without OA, and doubly marked for cytometry. RESULTS: BIM showed fewer CD4+/IL-2+ and more B220+/IL-10+ cells, whereas the SIM group showed increased Treg frequency. BSIM had fewer B220+/IL-10+ and Treg cells. CONCLUSIONS: Separately, gestation or nursing induced immunosuppressive cells in infected mothers, but improved anti-OA immunity when combined.

Gestation and breastfeeding in schistosomotic mothers differently modulate the immune response of adult offspring to postnatal Schistosoma mansoni infection

Schistosoma mansoni antigens in the early life alter homologous and heterologous immunity during postnatal infections. We evaluate the immunity to parasite antigens and ovalbumin (OA) in adult mice born/suckled by schistosomotic mothers. Newborns were divided into: born (BIM), suckled (SIM) or born/suckled (BSIM) in schistosomotic mothers, and animals from noninfected mothers (control). When adults, the mice were infected and compared the hepatic granuloma size and cellularity. Some animals were OA + adjuvant immunised. We evaluated hypersensitivity reactions (HR), antibodies levels (IgG1/IgG2a) anti-soluble egg antigen and anti-soluble worm antigen preparation, and anti-OA, cytokine production, and CD4+FoxP3+T-cells by splenocytes. Compared to control group, BIM mice showed a greater quantity of granulomas and collagen deposition, whereas SIM and BSIM presented smaller granulomas. BSIM group exhibited the lowest levels of anti-parasite antibodies. For anti-OA immunity, immediate HR was suppressed in all groups, with greater intensity in SIM mice accompanied of the remarkable level of basal CD4+FoxP3+T-cells. BIM and SIM groups produced less interleukin (IL)-4 and interferon (IFN)-g. In BSIM, there was higher production of IL-10 and IFN-g, but lower levels of IL-4 and CD4+FoxP3+T-cells. Thus, pregnancy in schistosomotic mothers intensified hepatic fibrosis, whereas breastfeeding diminished granulomas in descendants. Separately, pregnancy and breastfeeding could suppress heterologous immunity; however, when combined, the responses could be partially restored in infected descendants.

Enhancement of anti-OVA IgG2c production in vivo by enalapril

Angiotensin-converting enzyme (ACE) inhibitors have non-hemodynamic, pleiotropic effects on the immune response. The effects of ACE inhibitors on the production of cytokines and T-cell functions are well established. However, little is known on the effects of these medicines on humoral response to foreign antigens. In this study, we investigated the effect of enalapril treatment on ovalbumin (OVA)-specific IgG1 and IgG2c production in mice determined by ELISA. Two groups of 8-week-old C57BL/6 females mice (3–4/group) were subcutaneously immunized with OVA (10 μg/animal) in presence of Alhydrogel (1 mg/mouse) and boosted at day 21. The mice were treated with enalapril (5 mg/kg daily, po) or were left without treatment for one month. The animals were bled from the orbital plexus on days 0, 7, 14, 21, and 28 after the first immunization and the sera were stored at –20°C until usage. OVA-specific serum IgG1 and IgG2c were determined by ELISA using serum from each individual animal. The results showed that enalapril significantly increased anti-OVA serum IgG2c in the secondary response without affecting IgG1 synthesis. These data expand our understanding on the properties of enalapril on the immune response, including antibody production.

Toxocara canis and the allergic process

The protective effect of infectious agents against allergic reactions has been thoroughly investigated. Current studies have demonstrated the ability of some helminths to modulate the immune response of infected hosts. The objective of the present study was to investigate the relationship between Toxocara canis infection and the development of an allergic response in mice immunised with ovalbumin (OVA). We determined the total and differential blood and bronchoalveolar lavage fluid cells using BALB/c mice as a model. To this end, the levels of interleukin (IL)-4, IL-5 and IL-10 and anti-OVA-IgE were measured using an ELISA. The inflammatory process in the lungs was observed using histology slides stained with haematoxylin and eosin. The results showed an increase in the total number of leukocytes and eosinophils in the blood of infected and immunised animals at 18 days after infection. We observed a slight lymphocytic inflammatory infiltrate in the portal space in all infected mice. Anti-OVA-IgE levels were detected in smaller proportions in the plasma of immunised and infected mice compared with mice that were only infected. Therefore, we concluded that T. canis potentiates inflammation in the lungs in response to OVA, although anti-OVA-IgE levels suggest a potential reduction of the inflammatory process through this mechanism.

An interleukin-33/ST2 signaling deficiency reduces overt pain-like behaviors in mice

Interleukin (IL)-33, the most recent member of the IL family of cytokines, signals through the ST2 receptor. IL-33/ST2 signaling mediates antigen challenge-induced mechanical hyperalgesia in the joints and cutaneous tissues of immunized mice. The present study asked whether IL-33/ST2 signaling is relevant to overt pain-like behaviors in mice. Acetic acid and phenyl-p-benzoquinone induced significant writhing responses in wild-type (WT) mice; this overt nociceptive behavior was reduced in ST2-deficient mice. In an antigen-challenge model, ST2-deficient immunized mice had reduced induced flinch and licking overt pain-like behaviors. In the formalin test, ST2-deficient mice also presented reduced flinch and licking responses, compared with WT mice. Naive WT and ST2-deficient mice presented similar responses in the rota-rod, hot plate, and electronic von Frey tests, indicating no impairment of motor function or alteration in basal nociceptive responses. The results demonstrate that IL-33/ST2 signaling is important in the development of overt pain-like behaviors.

Effect of lipoarabinomannan from Mycobacterium avium subsp avium in Freund’s incomplete adjuvant on the immune response of cattle

The aim of the present study was to determine whether lipoarabinomannan (LAM), in combination with Freund’s incomplete adjuvant (FIA), was able to improve cell-mediated and antibody-mediated immune responses against ovalbumin (OVA) in cattle. Twenty-three calves were assigned to four treatment groups, which were subcutaneously immunized with either OVA plus FIA, OVA plus FIA and LAM from Mycobacterium avium subsp avium, FIA plus LAM, or FIA alone. Lymphoproliferation, IFN-γ production and cell subpopulations on peripheral blood mononuclear cells before and 15 days after treatment were evaluated. Delayed hypersensitivity was evaluated on day 57. Specific humoral immune response was measured by ELISA. Inoculation with LAM induced higher levels of lymphoproliferation and IFN-γ production in response to ConA and OVA (P < 0.05). Specific antibody titers were similar in both OVA-immunized groups. Interestingly, our results showed that the use of LAM in vaccine preparations improved specific cell immune response evaluated by lymphoproliferation and IFN-γ production by at least 50 and 25 percent, respectively, in cattle without interfering with tuberculosis and paratuberculosis diagnosis.

Downregulation of Orai1 expression in the airway alleviates murine allergic rhinitis

Orai1 is the key subunit of the Ca2+-release-activated Ca2+ channel. Our previous report has demonstrated that Orai1 expression in the airway was upregulated in the ovalbumin (OVA)-induced allergic rhinitis (AR) mouse models. To observe whether inhibition of Orai1 expression in the airway could suppress symptoms in a murine model of AR and to assess the impacts of this inhibition on the responses of local and systemic immunocytes, we administered recombinant lentivirus vectors that encoded shRNA against ORAI1 (lenti-ORAI1) into the nostrils of OVA-sensitized mice before the challenges, and analyzed its effect on allergic responses, as compared with the unsensitized mice and untreated AR mice. Administration of lenti-ORAI1 into the nasal cavity successfully infected cells in the epithelial layer of the nasal mucosa, and significantly decreased the frequencies of sneezing and nasal rubbing of the mice. Protein levels of leukotriene C4, OVA-specific IgE, and IL-4 in the nasal lavage fluid and serum and eosinophil cation protein in the serum were also significantly reduced by lenti-ORAI1, as were the mRNA levels of these factors in the nasal mucosa and spleen. These data suggested that administration of lenti-ORAI1 into the nasal cavity effectively decreased Orai1 expression in the nasal mucosa, alleviated AR symptoms, and partially inhibited the hyperresponsiveness of the local and systemic immune cells including T cells, B cells, mast cells and eosinophils that are involved in the pathogenesis of AR.

Immunomodulatory effects of astragalus gypsicolus hydroalcoholic extract in ovalbumin-induced allergic mice model

Several studies have demonstrated that herbal extracts possess various biological effects including anti-inflammatory and anti-cancer activities. The present study was aimed to investigate the protective effects of the Astragalus gypsicolus [AG] hydroalcoholic extract in early allergic sensitized mice induced by ovalbumin. Phytochemical assay was used to recognize the main active constituents in the AG hydroalcoholic extract. Mice were immunized with subcutaneous injection of ovalbumin and aluminum hydroxide. Efficiency of sensitization was assessed by serum IgE levels and eosinophil count. After sensitization, two doses of extract [250 mg/kg and 500 mg/kg] were injected intrapritoneally. On day 14, mice were challenged with intrapritoneal injection of ovalbumin. IL-4 and IFN gamma levels in broncoalveolar lavage fluid, which had been collected on day 15, were assessed by Enzyme-Linked Immunosorbent Assay [ELISA] kit. Our results indicate two main active constituents including flavonoids and terpenoids are present in the AG.hydroalcoholic extract. Intrapritoneal injection of the AG hydroalcoholic extract was able to decrease IL-4 and increase IFN gamma. It seems the AG hydroalcoholic extract has the potential to modulate the balance of Thl/Th2 cytokines in allergy

Alveolar macrophages modulate allergic inflammation in a murine model of asthma

The role of alveolar macrophages (AMs) in the pathogenesis of asthma is still unknown. The aim of the present study was to investigate the effects of AM in the murine model of asthma. AMs were selectively depleted by liposomes containing clodronate just before allergen challenges, and changes in inflammatory cells and cytokine concentrations in bronchoalveolar lavage (BAL) fluid were measured. AMs were then adoptively transferred to AM-depleted sensitized mice and changes were measured. Phenotypic changes in AMs were evaluated after in vitro allergen stimulation. AM-depletion after sensitization significantly increased the number of eosinophils and lymphocytes and the concentrations of IL-4, IL-5 and GM-CSF in BAL fluid. These changes were significantly ameliorated only by adoptive transfer of unsensitized AMs, not by sensitized AMs. In addition, in vitro allergen stimulation of AMs resulted in their gaining the ability to produce inflammatory cytokines, such as IL-1beta, IL-6 and TNF-alpha, and losing the ability to suppress GM-CSF concentrations in BAL fluid. These findings suggested that AMs worked probably through GM-CSF-dependent mechanisms, although further confirmatory experiments are needed. Our results indicate that the role of AMs in the context of airway inflammation should be re-examined.

TGF-beta-treated antigen presenting cells suppress collagen-induced arthritis through the promotion of Th2 responses

Collagen-induced arthritis (CIA) is mediated by self-reactive CD4+ T cells that produce inflammatory cytokines. TGF-beta2-treated tolerogenic antigen-presenting cells (Tol-APCs) are known to induce tolerance in various autoimmune diseases. In this study, we investigated whether collagen-specific Tol-APCs could induce suppression of CIA. We observed that Tol-APCs could suppress the development and severity of CIA and delay the onset of CIA. Treatment of Tol-APCs reduced the number of IFN-gamma- and IL-17-producing CD4+ T cells and increased IL-4- and IL-5-producing CD4+ T cells upon collagen antigen stimulation in vitro. The suppression of CIA conferred by Tol-APCs correlated with their ability to selectively induce IL-10 production. We also observed that treatment of Tol-APCs inhibited not only cellular immune responses but also humoral immune responses in the process of CIA. Our results suggest that in vitro-generated Tol-APCs have potential therapeutic value for the treatment of rheumatoid arthritis as well as other autoimmune diseases.

Boosting the suppressive effects of Ascaris suum components in IFN-γ-deficient mice / Potencialização do efeito supressor de componentes do Ascaris suum em camundongos deficientes em IFN-γ

High molecular weight components from Ascaris suum extract suppress ovalbumin-specific immunity in mice. In IFN-γ-deficient mice, ovalbumin-specific delayed-type hypersensitivity reactions are more strongly downregulated by these suppressive components. Here, the cellularity of the delayed-type hypersensitivity reaction in IFN-γ-deficient mice and the increased downregulation induced by Ascaris suum components were analyzed. IL-12p40-dependent neutrophilic influx was predominant. Suboptimal doses of the suppressive fraction from this nematode completely inhibited the hypersensitivity reaction, thus indicating intensification of the immunosuppression under conditions of intense recruitment of IFN-γ-independent neutrophils.

Componentes de alto peso molecular do extrato de Ascaris suum suprimem a imunidade específica à ovalbumina em camundongos. Em camundongos geneticamente deficientes de IFN-γ a reação de hipersensibilidade tardia específica para ovalbumina foi mais fortemente prejudicada por estes componentes supressivos. Aqui, a celularidade da reação de hipersensibilidade tardia em camundongos deficientes de IFN-γ e o incremento na supressão induzida por componentes do Ascaris suum foram analisados. Influxo neutrofílico, dependente de IL-12p40, foi predominante. Dose sub-ótima da fração supressiva do nematódeo inibiu completamente a reação de hipersensibilidade, indicando uma intensificação da imunossupressão em condições de recrutamento intenso de neutrófilos independente de IFN-γ.

Suppressive effect of strychnos nux-vomica on induction of ovalbumin-specific IgE antibody response in mice.

Strychnos nux-vomica Linn. (SNV; Loganiaceae), a medicinal plant has been used as folk medicine for alleviating inflammation, joint pains and allergic symptoms. In the present study, we examined its possible immunomodulatory effect on induction of ovalbumin (OVA)-specific IgE antibody response in a murine model, as evaluated by passive cutaneous anaphylaxis (PCA). The OVA-specific IgE antibody response was significantly suppressed in BALB/c mice (H-2d), following intraperitoneal administration of aqueous stem extract of the plant along with OVA. Furthermore, the different doses of SNV extract were found to significantly suppress the induction of OVA-specific IgE antibody response. The anti-OVA IgE antibody response was suppressed in different haplotypes of mice viz., C57BL/6 (H-2b) and SWR/J (H-29). However, preliminary findings revealed no significant change in the total IgG antibody response against OVA, as evaluated by ELISA. These results confirm the suppressive activity of S. nux-vomica on allergen-specific IgE antibody response and suggest its possible application in allergic conditions. Keywords: Strychnlos nux-vomica, Immunomodulation, Immunosuppression, IgE antibody response, Passive cutaneous anaphylaxis, ELISA

Attenuation of phosphamidon-induced oxidative stress and immune dysfunction in rats treated with N-acetylcysteine

The effect of N-acetylcysteine, a thiolic antioxidant, on attenuation of phosphamidon-induced oxidative stress and immune dysfunction was evaluated in adult male Wistar rats weighing 200-250 g. Rats were divided into four groups, 8 animals/group, and treated with phosphamidon, N-acetylcysteine or the combination of both for 28 days. Oral administration of phosphamidon (1.74 mg/kg), an organophosphate insecticide, increased serum malondialdehyde (3.83 ± 0.18 vs 2.91 ± 0.24 nmol/mL; P < 0.05) and decreased erythrocyte superoxide dismutase (567.8 ± 24.36 vs 749.16 ± 102.61 U/gHb; P < 0.05), catalase activity (1.86 ± 0.18 vs 2.43 ± 0.08 U/gHb; P < 0.05) and whole blood glutathione levels (1.25 ± 0.21 vs 2.28 ± 0.08 mg/gHb; P < 0.05) showing phosphamidon-induced oxidative stress. Phosphamidon exposure markedly suppressed humoral immune response as assessed by antibody titer to ovalbumin (4.71 ± 0.51 vs 8.00 ± 0.12 -log2; P < 0.05), and cell-mediated immune response as assessed by leukocyte migration inhibition (25.24 ± 1.04 vs 70.8 ± 1.09%; P < 0.05) and macrophage migration inhibition (20.38 ± 0.99 vs 67.16 ± 5.30%; P < 0.05) response. Phosphamidon exposure decreased IFN-у levels (40.7 ± 3.21 vs 55.84 ± 3.02 pg/mL; P < 0.05) suggesting a profound effect of phosphamidon on cell-mediated immune response. A phosphamidon-induced increase in TNF-α level (64.19 ± 6.0 vs 23.16 ± 4.0 pg/mL; P < 0.05) suggests a contributory role of immunocytes in oxidative stress. Co-administration of N-acetylcysteine (3.5 mmol/kg, orally) with phosphamidon attenuated the adverse effects of phosphamidon. These findings suggest that oral N-acetylcysteine treatment exerts protective effect and attenuates free radical injury and immune dysfunction caused by subchronic phosphamidon exposure.

Change of connexin 37 in allergen-induced airway inflammation

Gap junction channels formed with connexins directly link to the cytoplasm of adjacent cells and have been implicated in intercellular signaling. Connexin 37 (Cx37) is expressed in the gas-exchange region of the lung. Recently, Cx37 has been reported to be involved in the pathogenesis of inflammatory disease. However, no data are available on the role of Cx37 in allergic airway inflammatory disease. In the present study, we used a murine model of ovalbumin (OVA)-induced allergic airway disease and primary murine epithelial cells to examine the change of Cx37 in allergic airway disease. These mice develop the following typical pathophysiological features of asthma: airway hyperresponsiveness, airway inflammation, and increased IL-4, IL-5, IL-13, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, eotaxin, and RANTES levels in lungs. Cx37 protein and mRNA expression were decreased in OVA-induced allergic airway disease. Immunoreactive Cx37 localized in epithelial layers around the bronchioles in control mice, which dramatically disappeared in allergen-induced asthmatic lungs. Moreover, the levels of Cx37 protein in lung tissues showed significantly negative correlations with airway inflammation, airway responsiveness, and levels of Th2 cytokines in lungs. These findings indicate that change of Cx37 may be associated with the asthma phenotype.

A novel thiol compound, N-acetylcysteine amide, attenuates allergic airway disease by regulating activation of NF-kappaB and hypoxia-inducible factor-1alpha

Reactive oxygen species (ROS) play an important role in the pathogenesis of airway inflammation and hyperresponsiveness. Recent studies have demonstrated that antioxidants are able to reduce airway inflammation and hyperreactivity in animal models of allergic airway disease. A newly developed antioxidant, small molecular weight thiol compound, N-acetylcysteine amide (AD4) has been shown to increase cellular levels of glutathione and to attenuate oxidative stress related disorders such as Alzheimer's disease, Parkinson's disease, and multiple sclerosis. However, the effects of AD4 on allergic airway disease such as asthma are unknown. We used ovalbumin (OVA)-inhaled mice to evaluate the role of AD4 in allergic airway disease. In this study with OVA-inhaled mice, the increased ROS generation, the increased levels of Th2 cytokines and VEGF, the increased vascular permeability, the increased mucus production, and the increased airway resistance in the lungs were significantly reduced by the administration of AD4. We also found that the administration of AD4 decreased the increases of the NF-kappaB and hypoxia-inducible factor-1alpha (HIF-1alpha) levels in nuclear protein extracts of lung tissues after OVA inhalation. These results suggest that AD4 attenuates airway inflammation and hyperresponsiveness by regulating activation of NF-kappaB and HIF-1alpha as well as reducing ROS generation in allergic airway disease.

An antioxidant modulates expression of receptor activator of NF-kappaB in asthma

Oxidative stress plays critical roles in airway inflammation that is usually accompanied by increased vascular permeability and plasma exudation. VEGF increases vascular permeability and leads to airway inflammation. In addition, VEGF has been shown to enhance receptor activator of NF-kappaB (RANK) expression in endothelial cells. An aim of the study was to determine the potential role of antioxidant in the regulation of RANK expression in murine model of asthma. We have used a C57BL/6 mouse model of allergic asthma to evaluate the effect of L-2-oxothiazolidine-4-carboxylic acid (OTC), a prodrug of cysteine, which acts as an antioxidant, and VEGF receptor inhibitor on RANK mRNA expression. The mice develop the following pathophysiological features of asthma in the lungs: increased expression of RANK mRNA, increased number of inflammatory cells of the airways, increased vascular permeability, and increased levels of VEGF. Administration of OTC and VEGF receptor inhibitor markedly reduced plasma extravasation and VEGF levels in allergen-induced asthmatic lungs. We also showed that the increased RANK mRNA expression at 72 h after ovalbumin inhalation were reduced by the administration of OTC or VEGF receptor inhibitor. The results indicate that OTC and VEGF receptor inhibitor which inhibit up-regulation of VEGF expression modulate RANK expression that may be in association with the regulation of vascular permeability, and suggest that VEGF may regulate the RANK expression. These findings provide a crucial molecular mechanism for the potential use of antioxidants to prevent and/or treat asthma and other airway inflammatory disorders.

Expresión de células CD11b-positivas en mucosa rectal de conejos sensibilizados y desafiados con ovoalbúmina / CD11 b-positive cells expression in rectal mucosa from ovalbumin sensitized and challenged rabbits

El receptor MAC-1 de conejo, homólogo al CD11b humano, es una proteína presente en los macrófagos. El objetivo del presente trabajo es establecer las modificaciones cuantitativas y distributivas de células CD11bpositivas participantes en la respuesta inmune a nivel de la mucosa rectal, en un modelo animal de inmunidad mucosa. Se estudiaron conejos neocelandeses divididos en tres grupos: G1:control, G2:sensibilizado con ovoalbúmina (OVA) y G3:sensibilizado y desafiado por vía rectal con OVA. Los conejos de los grupos 2 y 3 fueron sensibilizados por vía subcutánea en dos oportunidades, con 2 ml de una suspensión de 70 µg de OVA en 30 mg de hidróxido de aluminio/ml. El desafío rectal se realizó con una solución de 50 mg OVA en 5 ml de solución salina. La prueba de anafilaxia cutánea pasiva (PCA) fue positiva en G2 y G3 a una dilución de 1/160. En el grupo sensibilizado y desafiado se observó edema mucoso parcheado, imágenes de linfangiectasias e infiltración de eosinófilos. Las células se contaron como número de células por campo de mayor ...

Proteomic Analysis of Differently Expressed Proteins in a Mouse Model for Allergic Asthma

Allergic asthma is associated with persistent functional and structural changes in the airways and involves many different cell types. Many proteins involved in allergic asthma have been identified individually, but complete protein profiles (proteome) have not yet been reported. Here we have used a differential proteome mapping strategy to identify tissue proteins that are differentially expressed in mice with allergic asthma and in normal mice. Mouse lung tissue proteins were separated using two-dimensional gel electrophoresis over a pH range between 4 and 7, digested, and then analyzed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MS). The proteins were identified using automated MS data acquisition. The resulting data were searched against a protein database using an internal Mascot search routine. This approach identified 15 proteins that were differentially expressed in the lungs of mice with allergic asthma and normal mice. All 15 proteins were identified by MS, and 9 could be linked to asthma-related symptoms, oxidation, or tissue remodeling. Our data suggest that these proteins may prove useful as surrogate biomarkers for quantitatively monitoring disease state progression or response to therapy.

Beta-2 agonista como imunomodulador da resposta inflamatória oulmonar crônica induzida em camundongos awnaibilizados com ovoalbumina / B2-agonist as immunomodulator of chronic lung inflammatory response induced in mice sensitized with ovallbumin

Agonista de receptor b2-adrenérgico pode apresentar efeito imunomodulador. Estudamos a influência do salbutamol sobre a inflamação pulmonar crônica induzida por ovoalbumina em camundongos Balb/c, nos regimes a cada 96 horas (IS) e no regime diário (DS). Houve aumento expressivo de eosinófilos e neutrófilos no lavado broncoalveolar no modelo, a qual foi reduzida após DS. A OVA aumentou a quantidade de células LMN e EPO+ na parede de vias aéreas e no parênquima pulmonar / Beta2-adrenergic receptor agonist showed a imunomodulator effects. We study the influence of intermittent (IS) and diary (DS) regimen of salbutamol on ovalbumin induced chronic lung inflammation. Expressive increasing of eosinophils and neutrophils were observed in bronchoalveolar lavage from our model...

Adjuvant effect of leishmania major promerstigotes on the immune response of mice to ovalbumin

The immune responses of mice immunized with ovalbumin [OVA] together with killed L. major [KLM] promastigotes as adjuvant were studied. Three doses [5 ' 107, 1 ' 108 and 2 ' 108] of KLM combined with OVA [100 micro g] were injected into the groups of C57BL/6 mice. BCG and complete Freund's adjuvant [CFA] were used as control adjuvants. Lymphocyte proliferation and antibody titers were determined, and IFN-gamma and IL-4 were measured in the supernatants of lymph node cell cultures. Results showed that immunization using OVA mixed with KLM enhanced the in vitro proliferative response of T-cells to the antigen and resulted in the production of increased levels of IFN-gamma [2800-3700 pg/ml] relative to the mice injected with OVA alone [1750 pg/ml]. In the mice receiving OVA + 5 ' 107 KLM, the production of IL-4 remained lower [18, 20 pg/ml] than OVA alone [105, 109 pg/ml] and almost was similar to that of observed in mice inoculated with OVA + BCG, leading to high IFN-gamma /IL-4 ratios. Using higher doses of KLM [1 ' 108], the IL-4 responses were of the same magnitude as or higher than the responses of mice inoculated with OVA + CFA. Antibody titers to OVA were also strongly boosted at the highest KLM dose. These findings indicate that KLM may function as an adjuvant, and its dose plays a role in the eventual outcome of the response. Inoculation of the mice with a low dose of KLM [5 ' 107] tends to promote a Th1-type response