Universal chimeric Fcγ receptor T cells with appropriate affinity for IgG1 antibody exhibit optimal antitumor efficacy

Developing universal CARs with improved flexible targeting and controllable activities is urgently needed. While several studies have suggested the potential of CD16a in tandem with monoclonal antibodies to construct universal CAR-T cells, the weak affinity between them is one of the limiting factors for efficacy. Herein, we systematically investigated the impact of Fcγ receptor (FcγR) affinity on CAR-T cells properties by constructing universal CARs using Fcγ receptors with different affinities for IgG1 antibodies, namely CD16a, CD32a, and CD64. We demonstrated that the activities of these universal CAR-T cells on tumor cells could be redirected and regulated by IgG1 antibodies. In xenografted mice, 64CAR chimeric Jurkat cells with the highest affinity showed significant antitumor effects in combination with herceptin in the HER2 low expression U251 MG model. However, in the CD20 high expression Raji model, 64CAR caused excessive activation of CAR-T cells, which resulted in cytokine release syndrome (CRS) and the decline of antitumor activity, and 32CAR with a moderate affinity brought the best efficacy. Our work extended the knowledge about FcγR-based universal CAR-T cells and suggested that only the FcγRCAR with an appropriate affinity can offer the optimal antitumor advantages of CAR-T cells.

Correlation between hemolysis degree and antibody IgG subtypes contained in infant serum and erythrocyte eluates / 中国输血杂志

【Objective】 To analyze the effects of IgG subtypes(IgG 1 and IgG3) of antibodies contained in infant serum and erythrocyte eluates on hemolytic disease of the newborn(HDN), so as to provide reference for its early clinical diagnosis and treatment. 【Methods】 49 newborns with HDN in our hospital from June 2019 to March 2020 were detected for three hemolytic tests(direct antiglobulin test, elution test and indirect antiglobulin test), as well as the components of IgG1 and IgG3 in eluates. The correlation analysis was conducted by combining birth hours (physiological jaundice) and hemolytic degrees (total bilirubin, indirect bilirubin, and hemoglobin). 【Results】 In the 44 cases of IgG1 and IgG3 subtype detection of infant RBC eluates, regression equations could be established between total bilirubin, indirect bilirubin and birth hours, and between hemoglobin and elution test, and linear regression relationships were found (P<0.05). In the 28 cases of IgG1 and IgG3 subtype detection of infant serum, regression equations could be established between total bilirubin, indirect bilirubin, birth time and IgG3 subtype, and between hemoglobin and IgG1 subtype (P<0.05), and linear regression relationships were found (all P<0.05). Three infants, presenting IgG1 and IgG2 subtypes(+ ) and three hemolysis tests(-), were all second pregnancy, constituted by Rh-HDN of 2 case and other-system-HDN 1. 【Conclusion】 The degree of HDN is directly related to IgG1 and IgG3 antibodies in infant blood plasma. In addition to the total bilirubin and indirect bilirubin, the changes of IgG3 antibodies in infant plasma and IgG1 antibody in anemic infants should be monitored. If IgG1 and IgG3 antibodies are yielded even with all negative ABO-HDN hemolysis tests, non-ABO-HDN should be considered in time to achieve accurate diagnosis and treatment.

Role of higher levels of post-challenge antibodies in protective vaccination against Leishmania tropica infection of BALB/c mice

Objective: To study the role of antibodies in protection against Leishmania tropica (L. tropica) infection in the experimental model of BALB/c mice. Methods: BALB/c mice were vaccinated against L. tropica by soluble Leishmania antigen or recombinant L. tropica stress-inducible protein-1 (LtSTI1) of L. tropica, and against Leishmania major (L. major) by soluble Leishmania antigen. Monophosphoryl lipid A was used as an adjuvant. The L. tropica- or L. major-vaccinated mice were challenged by L. tropica or L. major, respectively. The levels of anti-Leishmania antibodies (IgG1 and IgG2a) were determined after vaccination and after challenge. Results: All vaccinated groups caused a higher antibody response in comparison with the control group. The L. major-vaccinated group showed lower IgG1 response than the control group after the challenge. Conversely, in L. tropica-vaccinated mice, the levels of antibodies were higher than the control group. Moreover, the group receiving rLtSTI1 and monophosphoryl lipid A showed higher levels of antibodies than those of the rLtSTI1 group. In vaccinated mice, antibody responses against L. tropica remained high until 16 weeks after the challenge. Conclusions: The higher levels of post-challenge antibodies are associated with protective vaccination against L. tropica infection of BALB/c mice. Our findings provide new insight into the association of antibody with vaccine-induced protective immunity against L. tropica infection. More studies are needed to clarify the role of antibody in protection against L. tropica.

Role of higher levels of post-challenge antibodies in protective vaccination against Leishmania tropica infection of BALB/c mice

Objective: To study the role of antibodies in protection against Leishmania tropica (L. tropica) infection in the experimental model of BALB/c mice.Methods: BALB/c mice were vaccinated against L. tropica by soluble Leishmania antigen or recombinant L. tropica stress-inducible protein-1 (LtSTI1) of L. tropica, and against Leishmania major (L. major) by soluble Leishmania antigen. Monophosphoryl lipid A was used as an adjuvant. The L. tropica- or L. major-vaccinated mice were challenged by L. tropica or L. major, respectively. The levels of anti-Leishmania antibodies (IgG1 and IgG2a) were determined after vaccination and after challenge. Results: All vaccinated groups caused a higher antibody response in comparison with the control group. The L. major-vaccinated group showed lower IgG1 response than the control group after the challenge. Conversely, in L. tropica-vaccinated mice, the levels of antibodies were higher than the control group. Moreover, the group receiving rLtSTI1 and monophosphoryl lipid A showed higher levels of antibodies than those of the rLtSTI1 group. In vaccinated mice, antibody responses against L. tropica remained high until 16 weeks after the challenge. Conclusions: The higher levels of post-challenge antibodies are associated with protective vaccination against L. tropica infection of BALB/c mice. Our findings provide new insight into the association of antibody with vaccine-induced protective immunity against L. tropica infection. More studies are needed to clarify the role of antibody in protection against L. tropica.

Diagnóstico neuroinmunológico de meningoencefalitis eosinofílica producida por Angiostrongylus cantonensis / Neuroimmunological diagnosis of eosinophilic meningoencephalitis caused by Angiostrongylus cantonensis

El diagnóstico de la meningoencefalitis por Angiostrongylus cantonensis se establece por la presencia de las larvas del helminto en el líquido cefalorraquídeo, pero esta evidencia es muy difícil de encontrar ya que las larvas son lábiles en este medio y no se hallan con frecuencia. Debido a que en Cuba, la presencia del parásito se remonta a 1981 y este parásito es el único que puede provocar esta enfermedad en el país, se realiza una revisión con el objetivo de revisar la literatura publicada sobre el tema para acopiar toda la evidencia que ayude al diagnóstico auxiliar de meningoencefalitis eosinofílica. Se propone que el estudio de la síntesis intratecal de IgE y C3c, unido al patrón de síntesis local de IgA+IgG principalmente y de IgG1+ IgG2 resultan las más indicadas. Existen otras proteínas que pudieran auxiliar como la síntesis intratecal de C4 y en menor proporción MBL(AU)

Diagnosis of meningoencephalitis due to Angiostrongylus cantonensis is based on the presence of helminth larvae in cerebrospinal fluid, but such evidence is very hard to find, since the larvae are labile in this medium and cannot be spotted easily. Based on the fact that presence of the parasite in Cuba dates back to 1981, and this is the only agent of the disease in the country, a review was conducted with the purpose of going over the published literature about the topic and gather evidence leading to the auxiliary diagnosis of eosinophilic meningoencephalitis. The study of the intrathecal synthesis of IgE and C3c, alongside the local synthesis pattern for IgA+IgG mainly and IgG1+IgG2, are proposed as the most appropriate. Other useful proteins are the intrathecal synthesis of C4 and to a lesser extent MBL(AU)

IgG1 and IgG4 antibodies against core and NS3 antigens of hepatitis C virus

Abstract INTRODUCTION: IgG subclasses involved in the immune response to hepatitis C virus (HCV) antigens have been rarely studied. We investigated the immune response mediated by IgG1 and IgG4 antibodies against the recombinant core and NS3 antigens in patients with chronic hepatitis C. METHODS: Sixty patients infected with HCV genotype 1 without antiviral treatment and 60 healthy subjects participated in the study. Serum levels of alanine aminotransferase, HCV viremia, and the presence of cryoglobulinemia and liver fibrosis were determined. We investigated the serum IgG1 and IgG4 antibodies against recombinant HCV core and NS3 non-structural protein antigens using amplified indirect ELISA. RESULTS: Anti-core and anti-NS3 IgG1 antibodies were detected in 33/60 (55%) and 46/60 (77%) patients, respectively, whereas only two healthy control samples reacted with an antigen (NS3). Anti-core IgG4 antibodies were not detected in either group, while 30/60 (50%) patients had anti-NS3 IgG4 antibodies. Even though there were higher levels of anti-NS3 IgG4 antibodies in patients with low viremia (< 8 × 105 IU/mL), IgG1 and IgG4 antibody levels did not correlate with ALT levels, the presence of cryoglobulinemia, or degree of hepatic fibrosis. High production of anti-core and anti-NS3 IgG1 antibodies was observed in chronic hepatitis C patients. In contrast, IgG4 antibodies seemed to only be produced against the NS3 non-structural antigen and appeared to be involved in viremia control. CONCLUSIONS: IgG1 antibodies against structural and non-structural antigens can be detected in chronic hepatitis C, while IgG4 antibodies seem to be selectively stimulated by non-structural HCV proteins, such as the NS3 antigen.

Utility of immunoglobulin isotypes against LID-1 and NDO-LID for, particularly IgG1, confirming the diagnosis of multibacillary leprosy

BACKGROUND Leprosy remains a health problem in many countries, with difficulties in diagnosis resulting in delayed treatment and more severe disabilities. Antibodies against several Mycobacterium leprae antigens have, however, shown value as diagnostic and/or prognostic markers. OBJECTIVES The objective of this study was to evaluate serum immunoglobulin (Ig) IgM and IgG subclass reactivity against three M. leprae specific antigens: NDO-HSA, a conjugate formed by natural octyl disaccharide bound to human serum albumin; LID-1, the fusion protein product of the ml0405 and ml2331 genes; and NDO-LID, a combination of LID-1 and NDO. METHODS Sera from healthy controls, paucibacillary (PB) and multibacillary (MB) leprosy patients, and their respective household contacts, were evaluated for the presence of antigen-specific IgM, IgG, and IgG subclass antibodies by enzyme-linked immunosorbent assay (ELISA). The sensitivity and specificity of each ELISA were evaluated by receiver operating characteristic (ROC) curve analysis. FINDINGS Our data confirm that serum IgM antibodies against NDO-HSA and IgG antibodies against LID-1, as well as IgG/M antibodies against NDO-LID, are markedly increased in MB patients. For the first time, our data reveal a selective increase in IgG1 and IgG3 antibodies against LID-1 and NDO-LID in MB patients, demonstrating that these antibody isotypes are suitable for differentiation between MB and PB patients. ROC curve analysis indicates an improved capacity for diagnosing MB leprosy patients using the detection of IgG antibodies, particularly the IgG1 isotype, specific to LID-1 and NDO-LID over the performance levels attained with NDO-HSA. CONCLUSIONS Our findings indicate that serological tests based on the detection of antigen-specific IgG1 antibodies are a useful tool to differentiate MB from PB patients, and indicate the enhanced performance of the LID-1 and NDO-LID antigens in the serodiagnosis of leprosy.

Toll-like Receptor 1/2 Agonist Pam3CSK4 Suppresses Lipopolysaccharide-driven IgG1 Production while Enhancing IgG2a Production by B Cells

Interaction between pathogen-associated molecular patterns and pattern recognition receptors triggers innate and adaptive immune responses. Several studies have reported that toll-like receptors (TLRs) are involved in B cell proliferation, differentiation, and Ig class switch recombination (CSR). However, roles of TLRs in B cell activation and differentiation are not completely understood. In this study, we investigated the direct effect of stimulation of TLR1/2 agonist Pam3CSK4 on mouse B cell viability, proliferation, activation, Ig production, and Ig CSR in vitro. Treatment with 0.5 µg/ml of Pam3CSK4 only barely induced IgG1 production although it enhanced B cell viability. In addition, high-dosage Pam3CSK4 diminished IgG1 production in a dose-dependent manner, whereas the production of other Igs, cell viability, and proliferation increased. Pam3CSK4 additively increased TLR4 agonist lipopolysaccharide (LPS)-induced mouse B cell growth and activation. However, interestingly, Pam3CSK4 abrogated LPS-induced IgG1 production but enhanced LPS-induced IgG2a production. Further, Pam3CSK4 decreased LPS-induced germline γ1 transcripts (GLTγ1)/GLTε expression but increased GLTγ2a expression. On the other hand, Pam3CSK4 had no effect on LPS-induced plasma cell differentiation. Taken together, these results suggest that TLR1/2 agonist Pam3CSK4 acts as a potent mouse B cell mitogen in combination with TLR4 agonist LPS, but these 2 different TLR agonists play diverse roles in regulating the Ig CSR of each isotype, particularly IgG1/IgE and IgG2a.

Investigation on serum IgG subclass concentrations in the adult population of Hunan region and their influencing factors / 临床检验杂志

Objective To investigate serum IgG subclass concentrations in the adult population of Hunan region,and the effects of age,gender and lifestyle on them.Methods Serum IgG1,IgG2,IgG3,IgG4 and IgG concentrations from 170 adults making a health examination were detected by the immunonephelometric assay.Results The concentrations (mean or median [P25,P75]) of serum IgG1,IgG2,IgG3,IgG4 and IgG were (7.53 ± 0.14) g/L,3.99 (3.13,5.02) g/L,0.49 (0.30,0.70) g/L,0.53 (0.26,0.93) g/L and 12.2 (10.5,14.1) g/L,respectively.The serum IgG1/IgG,IgG2/IgG,IgG3/IgG and IgG4/IgG were (61.3 ±0.69)％,33.38％ (27.8％,38.8％),3.97％ (2.5％,5.3％) and 4.44％ (2.1％,7.3％),respectively.The serum IgG3 concentrations and IgG3/IgG ratios in female adults were significantly higher than that in male adults (P =0.005 and 0.014).However,there were no significant difference in serum IgG1,IgG2 and IgG4 concentrations and IgG1/IgG,IgG2/IgG and IgG4/IgG ratios between male and female adults.The serum IgG3 concentrations in the 31-40 years old adults were significantly higher than that in the 41-50 years old (P =0.03),while there were no significant difference in serum IgG1,IgG2 and IgG4 concentrations between different age groups.The serum IgG1 concentrations in the adults with heavy smoking were significantly lower than that without smoking (P =0.023),while the serum IgG4/IgG ratios were the opposite (P =0.018).The serum IgG1 and IgG3 concentrations and IgG3/IgG ratios in the adults with midrange or heavy drinking were significantly lower than that without ethanol consumption (P =0.05,0.004 and 0.015,respectively).The serum IgG3 concentrations and IgG3/IgG ratios in the adults with low-risk metabolism syndrome were significantly higher than that with the high-risk (P =0.034 and 0.038).Conclusion Gender and age have the significant effect on serum IgG3 concentration.Heavy smoking may reduce serum IgG1 concentration and increase IgG4/IgG ratio.The decrease of serum IgG1,IgG3 and IgG3/IgG may be related to ethanol consumption.

Baicalein, wogonin, and Scutellaria baicalensis ethanol extract alleviate ovalbumin-induced allergic airway inflammation and mast cell-mediated anaphylactic shock by regulation of Th1/Th2 imbalance and histamine release / 대한해부학회지

Asthma is characterized by chronic inflammation, goblet cell hyperplasia, the aberrant production of the Th2 cytokines, and eosinophil infiltration into the lungs. In this study, we examined the effects of baicalein, wogonin, and Scutellaria baicalensis ethanol extract on ovalbumin (OVA)-induced asthma by evaluating Th1/Th2 cytokine levels, histopathologic analysis, and compound 48/80-induced systemic anaphylaxis and mast cell activation, focusing on the histamine release from rat peritoneal mast cells. Baicalein, wogonin, and S. baicalensis ethanol extract also decreased the number of inflammatory cells especially eosinophils and downregulated peribronchial and perivascular inflammation in the lungs of mice challenged by OVA. Baicalein, wogonin, and S. baicalensis ethanol extract significantly reduced the levels of tumor necrosis factor α, interleukin (IL)-1β, IL-4, IL-5 and the production of OVA-specific IgE and IgG1, and upregulated the level of interferon-γ and OVA-specific IgG2a. In addition, oral administration of baicalein, wogonin, and S. baicalensis ethanol extract inhibited compound 48/80-induced systemic anaphylaxis and plasma histamine release in mice. Moreover, baicalein, wogonin, and S. baicalensis ethanol extract suppressed compound 48/80-induced mast cell degranulation and histamine release from rat peritoneal mast cells. Conclusively, baicalein and wogonin as major flavonoids of S. baicalensis may have therapeutic potential for allergic asthma through modulation of Th1/Th2 cytokine imbalance and histamine release from mast cells.

Passive acquisition of anti-Staphylococcus aureus antibodies by newborns via transplacental transfer and breastfeeding, regardless of maternal colonization

OBJECTIVE: To investigate the transmission of anti-Staphylococcus aureus (Sa) IgG, IgG1 and IgG2 via placental transfer and the transfer of IgA via the colostrum according to maternal Sa carrier status at delivery. METHODS: We evaluated anti-Sa IgG, IgG1 and IgG2 in maternal and cord sera and IgA in colostrum from a case (n=49, Sa+) and a control group (n=98, Sa-). RESULTS: Of the 250 parturients analyzed for this study, 49 were nasally colonized with S. aureus (prevalence of 19.6%). Ninety-eight non-colonized subjects were selected for the control group. The anti-Sa IgG, IgG1 and IgG2 levels and the IgG avidity indexes in the maternal and cord sera did not differ between the groups, with a low transfer ratio of anti-Sa IgG to the newborns in both groups. The anti-Sa IgG2 titers were significantly higher than the IgG1 titers in the maternal and cord sera. Inversely, the transfer ratios were higher for anti-Sa IgG1 compared with IgG2; however, no differences between the groups were detected. The Sa-specific IgA levels and avidity indexes in the colostrum were equivalent between groups. CONCLUSIONS: Maternal Sa nasal colonization at delivery is not associated with higher antibody levels in the mother or newborns. The high titers of anti-Sa IgG2 found in the cord serum indicate a greater reactivity with non-protein antigens, which may further contribute to the susceptibility to staphylococcal infections at birth. The presence of IgA in the colostrum with avidity to S. aureus reinforces the importance of breastfeeding shortly after birth.

Thermodyn amic study on the interaction of excipients and protein / 中国生化药物杂志

Objective To determine the effects of different excipients ( amino acids, carbohydrates and nonionic surfactants) on thermal stability of the IgG1 monoclonal antibody, and to examine the interactions between the excipients and the protein.Methods Differential scanning calorimetry ( DSC) was used to study thermal stability of the protein in different solutions and got information on the solubility of the unfolded forms of the protein.Isothermal titration calorimetry ( ITC) was used to examine the binding interactions between the excipients and the protein.ResuIts Negatively charged amino acids could significantly reduce the denaturation temperature (Tm) of IgG1( Tm >9 ℃), and other excipients didn’t have a major effect ( Tm <1℃).Excipients shared different impacts on thermal stability of the IgG1 monoclonal antibody under different pH, and negatively charged amino acids result in a much lower Tm at pH 5 than at pH 7.The ITC binding isotherms of different excipients (including polysorbate 20 and 80) and IgG1 were almost straight lines, while there was strong binding interaction between polysorbate 20 or 80 and Human Serum Albumin (HSA).ConcIusion The results suggest that there is no binding interaction between these studied excipients and the IgG1 monoclonal antibody; instead electrostatic interactions seem to play a leading role between the excipients and the IgG1 monoclonal antibody.

One case report and analysis of patient with renal immunoglobulin light and heavy chain deposited disease / 中国综合临床

Objective To report 1 case with renal immunoglobulin light and heavy chain deposited disease (IgG-κ light chain and γ1 heavy chain).Methods The clinical manifestations,serum immunofixation electrophoresis,light and heavy chain abnormalities of blood and urine,bone marrow biopsy and renal biopsy data laboratory data were recorded and analyzed.Results A 63-year-old woman presented with massive proteinuria,microscopic hematuria,hypertension,anemia and serum IgG-κ light chain.Bone marrow aspirate revealed 4％ plasma cells.Renal biopsy revealed nodular glomerulopathy with congo red staining-negative.Immunofluorescence showed that κ light chain and IgG1 (γ1 heavy chain) were deposited along the glomerular basement membranes (GBM) and tubular basement membranes (TBM).Electron-microscopy revealed electrondense deposits that delineate the outer aspect of TBM and endothelial aspect of GBM.Conclusion The diagnosis of renal immunoglobulin light and heavy chain deposited disease (IgG-κ light chain and γ1 heavy chain) should be addressed combine with clinical and is pathology,especially with immune pathological examination.

Alum Directly Modulates Murine B Lymphocytes to Produce IgG1 Isotype

Aluminum hydroxide (alum) is the most widely used adjuvant in human vaccines. Nevertheless, it is virtually unknown whether alum acts on B cells. In the present study, we explored the direct effect of alum on Ig expression by murine B cells in vitro. LPS-activated mouse spleen B cells were cultured with alum, and the level of isotype-specific Ig secretion, IgG1 secreting cell numbers, and Ig germ-line transcripts (GLT) were measured using ELISA, ELISPOT, and RT-PCR, respectively. Alum consistently enhanced total IgG1 production, numbers of IgG1 secreting cells, and GLTgamma1 expression. These results demonstrate that alum can directly cause IgG1 isotype switching leading to IgG1 production.

Dectin-1 Stimulation Selectively Reinforces LPS-driven IgG1 Production by Mouse B Cells

Dectin-1, which specifically recognizes beta-glucan of fungal cell walls, is a non-Toll-like receptor (TLR) pattern recognition receptor and a representative of C-type lectin receptors (CLRs). The importance of Dectin-1 in innate immune cells, such as dendritic cells and macrophages, has previously been well studied. However, the function of Dectin-1 in B cells is very poorly understood. To determine the role of Dectin-1 in B cell activation, we first investigated whether mouse B cells express Dectin-1 and then assessed the effect of Dectin-1 stimulation on B cell proliferation and antibody production. Mouse B cells express mRNAs encoding CLRs, including Dectin-1, and surface Dectin-1 was expressed in B cells of C57BL/6 rather than BALB/c strain. Dectin-1 agonists, heat-killed Candida albicans (HKCA) and heat-killed Saccharomyces cerevisiae (HKSC), alone induced B cell proliferation but not antibody production. Interestingly, HKSC, HKCA, and depleted zymosan (a selective Dectin-1 agonist) selectively enhanced LPS-driven IgG1 production. Taken together, these results suggest that, during fungal infection, beta-glucan-stimulated Dectin-1 may cooperate with TLR4 to specifically enhance IgG1 production by mouse B cells.

Evaluation of host humoral antibody production against Plasmodium falciparum recombinant circumsporozoite antigen in Nigerian children.

Background & objectives: The challenge of malaria and efforts targeted at developing malaria vaccines triggered this study on the reactivity of IgG and its subclasses in the test serum specific to CSP. This work was directed at assessing the influence of age and gender on host humoral antibody against Plasmodium falciparum recombinant circumsporozoite antigen in Nigerian children. Methods: In all, 67 serum samples (>10,000 parasites/μl of blood) collected from malaria-infected children at the University College Hospital, Ibadan during the transmission season were analyzed by ELISA. Results: The mean absorbance values of IgG subclasses reactive against P. falciparum CSP appeared to be agedependent and ranged from 0.01 for IgG4 in younger children to 0.95 for IgG3 in older children. The sixty-seven subjects investigated in this study had significantly higher mean IgG1 and IgG3 than the uninfected controls (p <0.01). This follows the order IgG3 >IgG1>IgG2>IgG4 which confirmed the prevalence of the cytophilic antibodies (IgG1 and IgG3) in 65% of the malaria infected children over the non-cytophilic subclasses (IgG2 and IgG4). Similarly, there was low production of IgG4 and IgG2 levels in 35% of the subjects compared with control. IgG was detected in the serum of North American Subjects (NAS) which served as negative control for CSP-specific IgG subclasses. Although the NAS titre was lower than that of the malaria subjects in Nigeria, its IgG2 was, however, higher (0.16) than that of other subclasses. The mean absorbance values of total serum IgG subclass were higher than those of IgG subclasses specific to P. falciparum circumsporozoite antigen. The mean absorbance values of the total serum IgG subclass follows the order IgG2>IgG1>IgG4>IgG3. Interpretation & conclusion: Age and gender-dependent correlations of results suggest that acquired immunity could play a significant role in protection from malaria. Antibody levels are higher in male than female children of the same age group. Antibody levels also increase with age in both the male and female children.

Antígenos de Plasmodium falciparum, blancos de la respuesta inmunitaria humoral en pacientes tratados con cloroquina / Antigens of Plasmodium falciparum, target of humoral immune response in patients treated with chloroquine

Se planteó identificar antígenos que pudieran ser reconocidos por los anticuerpos IgG1 e IgG3, descritos como protectores en la infección malárica, en personas con respuesta clínica adecuada (RCA) o falla al tratamiento (FT) antimalárico, provenientes de localidades con diferentes grados de endemicidad. Se evaluaron por Immunoblotting muestras de sueros de individuos provenientes de tres localidades del Edo. Amazonas (Venezuela): Puerto Ayacucho (Atures), San Juan de Manapiare (Manapiare) y Platanal (Alto Orinoco). La reactividad de IgG, IgG1 e IgG3 frente a componentes antigénicos del extracto de P. falciparum (FCB2), permitió identificar un mayor número de moléculas específicas en los pacientes con RCA que en los pacientes con FT. La frecuencia de reconocimiento de polipéptidos fue baja en las tres localidades, algunas moléculas con una frecuencia de reconocimiento igual o mayor al 20% pertenecían a sueros de individuos de las localidades de Puerto Ayacucho y Platanal, ambas con exposición permanente a P. falciparum. Dado el reconocimiento de polipéptidos por IgG, IgG1 e IgG3 en sueros de pacientes con RCA, estos podrían ser considerados como posibles blancos relevantes de la respuesta inmunológica protectora que coadyuven con el tratamiento antimalárico. Esto contribuiría al desarrollo y diseño de vacunas más efectivas, que prevengan la infección malárica y/o potencien la eficacia a la quimioterapia.

Here we studied the presence of antigens recognized by IgG1 and IgG3 antibodies, thought as protective, in patients with adequate clinical response (RCA) or treatment failure (FT), living in areas of different degrees of endemicity. Immunoblotting was evaluated from serum samples of individuals from three locations in the State Amazonas (Venezuela): Puerto Ayacucho (Atures), San Juan de Manapiare (Manapiare) and Pantanal (Alto Orinoco). The reactivity of IgG, IgG1 and IgG3 against antigenic components of the extract of P. falciparum (FCB2) identified a greater number of specific molecules in patients with RCA in patients with AFT. The frequency of recognition of polypeptides was low in all three locations, with some molecules having a recognition rate of greater than or equal to 20% sera of individuals belonging to the towns of Puerto Ayacucho and Platanal, both with cases of P. falciparum. Given the recognition of polypeptides by IgG, IgG1 and IgG3 in sera of patients with RCA, they could be considered as possible targets for relevant protective immune responses that contribute to malaria treatment. This would contribute to the development and design of more effective vaccines that prevent malaria infection and/or enhance the efficacy of chemotherapy.

Inhibitory effects of TLR7/8 ligand R-848 on IgE production of murine in vivo / 重庆医学

Objective To investigate whether R-848 could inhibit IgE production of mice immunized with OVA plus ALUM in vivo.Methods BALB/c mice were immunized s.c on the back with PBS,OVA,OVA plus R-848,OVA plus CpG,OVA plus ALUM,and OVA plus ALUM in R-848 or CpG every two weeks for three times.The blood from the mice was harvested after the last immunization,and the concentration of OVA specific or total IgE,IgG1 and IgG2a in the sera was determined;the splenocytes from the immunized mice were harvested and cultured with or without OVA for 3 days,and the concentration of IL-4 and IFNγ in the supernatants was determined.Results Firstly,we investigated that R-848 as Th1 adjuvant could enhance the production of OVA specific IgG2a in mice immunized with OVA.Secondly,further study showed that R-848 could inhibit the production of OVA specific IgE and total IgE,and promote the production of OVA specific IgG2a in the sera of mice immunized with OVA plus ALUM.Moreover,the results of ELISA showed that R-848 inhibiting IgE production was related to its reducing IL-4 production and enhancing IFNγ production.Conclusion R-848 could inhibit IgE production of mice immunized with OVA plus ALUM in vivo.

The Immunity Induced by Recombinant Spike Proteins of SARS Coronavirus in Balb/c Mice / 华中科技大学学报（医学）（英德文版）

The immune effect of two recombinant protein fragments of spike protein in severe acute respiratory syndrome coronavirus (SARS CoV) was investigated in Balb/c mice. Two partial spike gene fragments S1 (322-1464 bp) and S2 (2170-2814 bp) of SARS coronavirus were amplified by RT-PCR, and cloned into pET-23a prokaryotic expression vector, then transformed into competent Escherichia E.coli BL21 (DE3)(pLysS) respectively. Recombinant proteins were expressed and purified by Ni2+ immobilized metal ion affinity chromatography. The purified proteins mixed with complete Freund adjuvant were injected into Balb/c mice three times at a two-week interval. High titer antibody was detected in the serum of immunized Balb/c mice, and mice immunized with S1 protein produced high titer IgG1, IgG2a, IgG2b and IgG3, while those immunized with S2 protein produced high titer IgG1, IgG2a, but lower titer IgG2b and IgG3. Serum IFN-γ concentration was increased significantly but the concentrations of IL-2, IL-4 and IL-10 had no significant change. And a marked increase was observed in the number of spleen CD8+ T cells. The results showed that recombinant proteins of SARS coronavirns spike protein induced hormonal and cellular immune response in Balb/c mice.

Changes of cytokine mRNA expression and IgG responses in rats infected with Capillaria hepatica

The mRNA expression of several cytokines was evaluated in splenocytes and mesenteric lymph node (MLN) cells of rats infected with Capillaria hepatica by reverse-transcription (RT)-PCR until week 12 after infection. IgG1 and IgG2a, which are associated with Th1 and Th2 response, respectively, were also assessed by ELISA. The results indicated that the majority of cytokines, including the Th1 (IL-2 and IFN-gamma) and Th2 cytokines (IL-4, IL-5 and IL-10) were expressed at maximal levels during the early stage of infection (after week 1-2), and the ELISA data also evidenced a similar pattern of changes in IgG1 and IgG2a. Th1 and Th2 cytokines responded in a similar fashion in this rat model. The expression of cytokines in splenocytes was significantly higher than that in MLN cells, thereby indicating that cytokine production is controlled more by spleen than by MLN. In addition, the observation that IFN-gamma expression increased unexpectedly at the time of maximal egg production (6 weeks after infection) indicated that IFN-gamma is a cytokine reacting against egg production. However, increased IL-5 expression occurring in tandem with worm activity indicated that the activity of C. hepatica might be controlled by IL-5 expression.