Production and evaluation of egg derived hot start antibodies

BACKGROUND: Hot start can greatly improve specificity, sensitivity and yield of PCR. Non-specific amplification can occur in PCR when reaction mixture is prepared at room temperature, because Taq DNA polymerase is active and the primers can hybridize non-specifically. Hot start Taq DNA polymerases remain inactive at room temperature and are activated after heating at 95°C preventing non-specific amplification. Monoclonal antibodies against Taq DNA polymerase is the first line of reagents used for turn on regular Taq DNA polymerase into Hot start one. The goal of this research was to produce and evaluate Hot Start antibodies derived from chicken eggs. RESULTS: We performed affinity purification of yolk immunoglobulin (IgY) and obtained polyclonal Hot Start antibodies. The yield of specific antibodies was 0.36 mg per egg or 0.2% of total yolk antibodies. The protocol for real time measurement and Hot start IgY activity assessment was developed. We found that Hot start IgY can reversibly block Taq DNA polymerase activity at 50°C and have no negative impact neither on the Taq DNA polymerase activity after denaturation nor on the reverse transcriptase. We estimated that 1.0 µg of Hot start IgY effectively blocks 5 U activity of Taq DNA polymerase. CONCLUSIONS: Egg derived Hot Start polyclonal antibodies are the cheapest source of Hot start antibodies, from one immune egg we can isolate 0.36 mg IgY, this quantity is enough for producing 1800 U activity of Hot start Taq DNA Polymerase.

Anti-Trimeresurus albolabris venom IgY antibodies: preparation, purification and neutralization efficacy

Snakebite incidence in southwestern China is mainly attributed to one of the several venomous snakes found in the country, the white-lipped green pit viper Trimeresurus albolabris. Since antivenom produced from horses may cause numerous clinical side effects, the present study was conducted aiming to develop an alternative antivenom antibody (immunoglobulin Y - IgY) from leghorn chickens. Methods IgY in egg yolk from white leghorn chicken previously injected with T. albolabris venom was extracted by water, precipitated by ammonium sulfate and purified by affinity chromatographic system. IgY was identified by SDS-PAGE, ELISA and Western blot, and its neutralizing assay was conducted on mice. Results Chickens injected multiple times with T. albolabris venom elicited strong antibody responses, and from their egg yolk IgY was isolated and purified, which exhibited a single protein band on SDS-PAGE and two bands (about 65 and 35 kDa, respectively) under reduced conditions. Immunoblot analysis revealed that these IgY are polyclonal antibodies since they bind with most venom components. In the neutralizing assay, all mice survived while the ratios of IgY/venom reached up to 3.79 (50.0 mg/13.2 mg). Conclusions IgY antibody response was successfully conducted in white leghorn chicken injected with T. albolabrisvenom. IgY against T. albolabris venom was obtained for the first time, and it exhibited strong neutralizing potency on mice. These results may lay a foundation for the development of IgY antivenom with clinical applications in the future.

CORAL SNAKE ANTIVENOM PRODUCED IN CHICKENS (Gallus domesticus) / Antiveneno de serpiente coral producido en gallinas (Gallus domesticus)

The production of anti-snake venom from large mammal's blood has been found to be low-yielding and arduous, consequently, antivenom immunoglobulins for treatment are achieved regularly as polyvalent serum. We have standardized an undemanding technique for making purified immunoglobulin IgY antivenom consisting of polyclonal antibodies against coral snake venom in the egg yolk of immunized hens. We have adapted a reported process of antibody purification from egg yolks, and achieved 90% antibody purity. The customized technique consisted of the removal of lipids from distilled water-diluted egg yolks by a freeze–thaw sequence. The specific immunoglobulins were present in the egg yolk for up to 180 days postimmunization. Therefore, by means of small venom quantities, a significant amount of immunoglobulins were found in an adequately purified state (The obtained material contained about 90% pure IgY). The antigen binding of the immunoglobulins was detected by a double immunodiffusion test. Titers of antibodies in the yolk were estimated with a serum protection assay (Median effective dose = ED50) (ED50= 477 mg/kg). Given that breeding hens is economically feasible, egg gathering is noninvasive and the purification of IgY antibodies is quick and easy, chicken immunization is an excellent alternative for the production of polyclonal antibodies. To the best of our knowledge, this is the first coral snake antivenom prepared in birds.

La producción de antiveneno de serpiente usando sangre de grandes mamíferos se ha encontrado que es de bajo rendimiento y de trabajo arduo, en consecuencia, las inmunoglobulinas antiveneno para el tratamiento se obtienen generalmente, como suero polivalente. Hemos estandarizado una técnica poco exigente para la fabricación de inmunoglobulina purificada IgY, que consistió en generar anticuerpos policlonales contra el veneno de la serpiente coral en huevos de gallinas inmunizadas. La técnica consistió en la eliminación de lípidos de las yemas del huevo, diluidas en agua y en una secuencia de congelación-descongelación. Las inmunoglobulinas específicas estuvieron presentes en la yema de huevo hasta 180 días después de la inmunización. La unión del antígeno a las inmunoglobulinas se detectó mediante un ensayo de inmunodifusión doble. Los títulos de anticuerpos en la yema fueron estimados con un ensayo de protección (dosis efectiva media = ED50). Dado que las gallinas reproductoras son económicamente viables, la recolección de huevos es no invasiva y la purificación de anticuerpos IgY es rápida y fácil, la inmunización de la gallina es una excelente alternativa para la producción de anticuerpos policlonales. A nuestro entender, esta es el primer anti-veneno contra serpiente de coral preparado en aves.

Production and evaluation of chicken antibodies against a synthetic peptide from glial growth factor / Producción y evaluación de anticuerpos de gallinas contra un péptido sintético del factor de crecimiento glial

Neuregulins (NRG) are proteins that belong to the family of epidermal growth factors. It is well established that these factors are essential for the development and maintenance of the nervous system. Due to the difficulty of purifying enough quantities of these factors and the lack of specificity from commercially available antibodies, the aim of this work was to produce antibodies against a synthetic peptide capable to detect and identify neuregulin GGFb isoforms. To accomplish this goal, polyclonal antibodies were raised in hens against a synthetic peptide designed from the GGFb1 extracellular sequence. The sequence analysis was made using different epitope-predicting programs. Our results showed that the peptide sequence selected was immunogenic because it was capable of inducing a specific type B immune response in the experimental animal model. These antibodies were also capable of recognizing a recombinant GGF protein and GGF isoforms present in different samples. Our results suggest that the development of immunoglobulin Y (IgY) using synthetic peptides represents, a valuable tool for neuroscience research.

Las Neuregulinas (NRG) son proteínas que pertenecen a la familia de los factores de crecimiento epidermal. Se ha demostrado que estos factores son esenciales para el desarrollo y mantenimiento de la funcionalidad del sistema nervioso. Debido a la dificultad para purificar estas proteínas y la falta de especificidad de los anticuerpos disponibles comercialmente, el objetivo de este trabajo fue producir anticuerpos contra un péptido sintético capaz de detectar e identificar una isoforma de la Neuregulina (GGFb). Para lograr este objetivo, se desarrollaron anticuerpos en gallinas (IgY) contra un péptido sintético diseñado a partir de la secuencia aminoacídica de la región extracelular de GGFb, utilizando programas de predicción de epítopes. Los resultados demuestran que el péptido seleccionado fue immunogénico debido a que estimuló una respuesta inmune específica tipo B en el modelo utilizado. Estos anticuerpos fueron también capaces de reconocer una proteína recombinante e isoformas de GGF presentes en diferentes muestras biológicas. Nuestros resultados demuestran el potencial valor de las inmunoglobulinas Y (IgY) contra péptidos sintéticos como una herramienta de aplicación para la investigación en neurociencia.

Cerebrospinal fluid analysis in the context of CNS demyelinating diseases / Analise do liquido cefalorraquiano no contexto das doencas desmielinizantes do SNC

The central nervous system demyelinating diseases are a group of disorders with different etiologies, characterized by inflammatory lesions that are associated with loss of myelin and eventually axonal damage. In this group the most studied ones are multiple sclerosis (MS), neuromyelitis optic (NMO) and acute disseminated encephalomyelitis (ADEM). The cerebrospinal fluid is essential to differentiate between these different syndromes and to define multiple sclerosis, helping to assess the probability of Clinical Isolated Syndrome turn into multiple sclerosis.

As doenças desmielinizantes do sistema nervoso central são um grupo de desordens de diferentes etiologias, caracterizadas por lesões inflamatórias associadas a perda da mielina e eventualmente dano axonal. Neste grupo de doenças, as mais estudadas são a esclerose múltipla (EM), a neuromielite óptica e a encefalomielite aguda disseminada. O estudo de liquido cefalorraquiano é essencial para o diagnóstico diferencial entre as diferentes síndromes e para a definição de EM, ajudando a estimar a probabilidade da transformação da síndrome clínica isolada em EM.

Comparison of techniques of detecting immunoglobulin-binding protein reactivity to immunoglobulin produced by different avian and mammalian species / Comparación de las técnicas de detección de la reactividad de la proteína de unión de la inmunoglobulina frente a la inmunoglobulina producida por diferentes especies aviarias y mamíferas

The rationale of this study was to use several immunological assays to investigate the reactivity of immunoglobulin binding protein (IBP) to immunoglobulins from various avian and mammalian species. The IBP studied were Staphylococcal protein A (SpA), Streptococcal protein G (SpG), Peptostreptococcal protein L (SpL) and recombinant protein LA (SpLA). The various immunological techniques used were double immunodiffusion (Ouchterlony technique) that tested positive high protein reactivities, direct and competitive enzyme-linked immunosorbent assays (ELISAs) that tested moderate and low positive protein binding capacities, respectively. In addition to sandwich ELISAs, immunoblot analyses and Ig-purification by SpA-affinity chromatography, which were sensitive tests and helpful in the screening and confirmatory tests were also used. The Ouchterlony technique showed that compared to the other proteins, SpLA had the highest range of reactivity with animal sera and purified immunoglobulins while SpL was least reactive. With the direct ELISA, SpL reacted with the raccoon sera, rabbit IgG and with IgY from bantam hens and pigeons. While with the direct ELISA, SpA reacted with sera from skunk, coyote, raccoon, mule, donkey and human. The sandwich ELISA revealed high reactivity of both SpG and SpLA with mammalian sera titres ranging from 1:32 (raccoon serum) to 1:1024 (mule and donkey sera).These results suggest that IBP can be used for the detection of immunoglobulin using various immunological assays and this is important for the diagnosis of infectious diseases in animal and bird populations studied and in the purification of immunoglobulins.

El fundamento de este estudio radica en el uso de varios ensayos inmunológicos para investigar la reactividad de la proteína de unión de la inmunoglobulina (IBP) frente a las inmunoglobulinas de varias especies aviarias y mamíferas. Las proteínas IBP estudiadas fueron la proteína estafilocócica A (SpA), la proteína estreptocócica G (SpG), la proteína peptoestreptocócica L (SpL), y la proteína recombinante LA (SpLA). Las varias técnicas inmunológicas usadas fueron: la inmunodifusión doble (técnica de Ouchterlony) para examinar las reactividades positivas de la proteína alta; el ensayo por inmunoabsorción ligado a enzimas(ELISA), de tipo directo y competitivo, para examinar la capacidad de realizar uniones positivas de proteína moderada y baja, respectivamente, además del ensayo ELISA 'Sándwich', los análisis inmunoblot, yla purificación de IgG, mediante cromatografía de afinidad, los cuales fueron pruebas sensibles y útiles en el tamizaje y las pruebas de confirmación. La técnica de Ouchterlony mostró que - en comparación con otras proteínas - la SpLA tenía el grado más alto de reactividad con los sueros animales y las inmunoglobulinas purificadas, mientras que la SpL fue la menos reactiva. Con el ELISA directo, la SpL reaccionó con los sueros de mapache, la IgG de conejo, así como con la IgY de palomas y gallinas de Bantam, en tanto con el ELISA directo, la SpA reaccionó con sueros de mofeta, coyote, mapache, mula, asno y seres humanos. ELISA "sándwich" reveló una alta reactividad tanto de SpG como de SpLA, con títulos séricos mamíferos que iban desde 1:32 (suero de mapache) hasta 1:1024 (sueros de mula y de asno). Estos resultados sugieren que la proteína de unión IBP puede usarse en la detección de la inmunoglobulina usando varios ensayos inmunológicos, lo cual es importante para el diagnóstico de enfermedades infecciosas en las poblaciones animales y aviarias bajo estudio, así como para la purificación de inmunoglobulinas.

Eficacia experimental de anticuerpos IgY producidos en huevos, contra el veneno de la serpiente peruana Bothrops atrox / Experimental efficacy of IgY antibodies produced in eggs against the venom of the Peruvian snake Bothrops atrox

Objetivos. Desarrollar un protocolo de inmunización para producir inmunoglobulinas IgY de origen aviar contra el veneno de la serpiente peruana Bothrops atrox y evaluar la capacidad neutralizante. Materiales y métodos. Se inmunizaron seis gallinas de postura de la raza hy line brown con 500 μg/dosis de veneno de B. atrox en un periodo de dos meses. Cada semana, los huevos fueron colectados para el aislamiento de inmunoglobulinas IgY a partir de la yema, usando dos pasos consecutivos con αcido caprνlico y sulfato de amonio. La detecciσn de anticuerpos se realizσ por inmunodifusiσn doble mientras que el tνtulo y reactividad cruzada se determinaron por las técnicas de ELISA y Western blot. El cálculo de DL50 y de la DE50 del antiveneno IgY producido se realizó utilizando el método de Probits. Resultados. La masa de anticuerpos aislados fue de 8,5 ± 1,35 mg de IgY/mL de yema. Asimismo, la DE50 del antiveneno aviar fue calculada en 575 μL de antiveneno/mg de veneno. Adicionalmente, los ensayos de reactividad cruzada mostraron que el veneno de B. atrox comparte mas epνtopes comunes con el veneno de B. brazili (47%) que con otros veneno del mismo género, en tanto que los venenos de Lachesis muta (19%) y Crotalus durissus (12%) mostraron una baja reactividad cruzada. Conclusiones. Se ha obtenido IgY purificada contra el veneno de B. atrox con capacidad neutralizante y se ha demostrado su utilidad como herramienta inmunoanalítica para evaluar la reactividad cruzada con venenos de otras especies.

Objectives. To develop an immunization protocol in order to produce avian IgY immunoglobulins against Bothrops atrox Peruvian snake venom and to evaluate its neutralizing capacity. Materials and methods. Six Hy Line Brown hens were immunized each two weeks using 500μg/doses of B. atrox venom in a period of two months. Each week, eggs were collected for IgY isolation from yolk using two consecutive steps with caprilic acid and ammonium sulfate. Detection of IgY anti-B. atrox were performed by double immunodiffusion, whereas title and cross-reactivity were analyzed using ELISA and Western Blot technics, respectively. Furthermore, letal dose (DL50) and Medium Effective Dose (DE50) were obtained by Probit analysis. Results. As a result of this protocol, chicken IgY’s were obtained in a concentration of 8,5 ± 1,35 mg/yolk mL. DE50 from avian antivenom was 575 μL/venom mg. Cross-reactivity studies showed Bothrops atrox venom share more commom epitopes with Bothrops brazili (47%) than others Bothrops venoms showing Lachesis muta (19%) and Crotalus durissus (12%) venoms a low crossing reactivity, instead. Conclusions. Using this procedure, we could purify chicken IgY with a neutralizant capacity of B. atrox venom which is comparable to the antivenom of equine origin and demonstrate its capacity as a immunoanalitical tool to evaluate the cross reactivity with others peruvian snakes.

Trypanosoma cruzi high infectivity in vitro is related to cardiac lesions during long-term infection in Beagledogs

Trypanosoma cruzi is a hemoflagelate parasite associated with heart dysfunctions causing serious problems in Central and South America. Beagle dogs develop the symptoms of Chagas disease in humans, and could be an important experimental model for better understanding the immunopathogenic mechanisms involved in the chagasic infection. In the present study we investigated the relation among biological factors inherent to the parasite (trypomastigote polymorphism and in vitro infectivity) and immunoglobulin production, inflammation, and fibrosis in the heart of Beagle dogs infected with either T. cruzi Y or Berenice-78 strains. In vitro infectivity of Vero cells as well as the extension of cardiac lesions in infected Beagle was higher for Y strain when compared to Berenice-78 strain. These data suggested that in vitro infectivity assays may correlate with pathogenicity in vivo. In fact, animals infected with Y strain, which shows prevalence of slender forms and high infectivity in vitro, presented cardiomegaly, inflammation, and fibrosis in heart area. Concerning the immunoglobulin production, no statistically significant difference was observed for IgA, IgM or IgG levels among T. cruzi infected animals. However, IgA together IgM levels have shown to be a good marker for the acute phase of Chagas disease.

Cytokine and antibody responses of reactivated murine toxoplasmosis upon administration of dexamathasone

Toxoplasma gondii has been shown to result in life-threatening encephalitis in immunocompromised patients after reactivation of dormant parasites. In order to obtain information on immune responses related to this phenomenon, BALB/c mice were infected with 25 cysts of the 76K strain of T. gondii, then, treated orally with dexamethasone (Toxo/Dexa-treated group) in order to reactivate the chronic toxoplasmosis. None of the T. gondii-infected mice died during the experimental periods, whereas the Toxo/Dexa-treated mice evidenced a significant attenuation of survival periods. Toxoplasma-specific IgG2a, IgA and IgM titers in sera were significantly depressed in the Toxo/Dexa-treated mice; however, the IgG1 sera titers were similar to those seen in the Toxoplasma-infected mice. The percentages of CD4+ and CD8 alpha + T cells in the Toxo/Dexa-treated mice were significantly reduced 2 weeks after dexamethasone treatment. IFN-gamma and IL-10 production levels in the Toxo/Dexa-treated mice were depressed significantly, whereas IL-4 production was increased temporarily. The expression levels of the Toxoplasma-specific P30 and B1 genes were found to have been increased in the Toxo/Dexa-treated mice in comparison with the Toxoplasmainfected mice. Collectively, the findings of this study demonstrate that reactivation of murine toxoplasmosis as the result of dexamethasone treatment induced a depression in Th1 immune responses, whereas Th2 immune responses were not significantly influenced.

Effect of different adjuvants in equines for the production of equine rabies immunoglobulin.

BACKGROUND: Implementation of the recommended post-exposure prophylaxis by vaccination and specific immunoglobulin therapy for rabies is largely hampered by its high cost and inadequate production. Therefore, the development and availability of an economic preparation of rabies immunoglobulin is a high priority for India, where rabies is a major cause of death. We studied the efficacy of four different adjuvants in raising antibodies to rabies antigen in older, discarded equines. METHODS: Eleven equines, 23-26 years old, were divided into 4 groups to receive four different adjuvants in small amounts (1-2 ml)-Freund complete adjuvant with Mycobacterium tuberculosis, Freund complete adjuvant with M. butyricum, Freund incomplete adjuvant and bentonite--along with purified chick embryo cell vaccine. The immunization schedule was spread over 105 days and the antibody titres were measured on days 56, 91 and 119. RESULTS: On day 119 (third sampling), Freund complete adjuvant with M. tuberculosis provided a geometric mean titre of 654.03 IU/ml in comparison with a titre of 459.19 IU/ml with Freund complete adjuvant with M. butyricum, 630.95 IU/ ml with Freund incomplete adjuvant and 172.18 IU/ml with bentonite. CONCLUSION: Purified chick embryo cell vaccine in combination with Freund complete adjuvant containing M. tuberculosis and Freund incomplete adjuvant were better at eliciting an immune response. The low quantity of adjuvants used possibly helped by causing very few side-effects but without compromising the antibody titres.

Production of IgY anti-mouse IgG antibodies from chicken eggs.

IgY technology offers several advantages over antibody production in mammals. In this study, we applied IgY technology for the production of anti-mouse IgG polyclonal antibodies and developed a FITC conjugate reagent. Two hens were immunized 3 times with mouse IgG, one via the pectoralis and the other via the calf muscles. Specific antibodies could be detected in the sera two weeks after the immunization, and maximum levels were reached at week 10. The hen which was immunized via the pectoralis muscle produced a much higher antibody response than the hen immunized via the calf muscle. In egg yolk, specific antibodies appeared 2 weeks after the first immunization, reached a plateau after week 11 and remained high until week 20. IgY were extracted from egg yolk by sodium sulfate precipitation. Approximately 40 mg of IgY could be extracted from a single egg. The extracted IgY was labeled with FITC. The so-produced antibody-FITC conjugate reacted to all mouse IgG isotypes and could be used to determine leukocyte sub-populations in blood samples by flow cytometry.

Multiple myeloma presenting as primary non-secretory plasma cell leukemia.

Primary plasma cell leukemia is a rare manifestation of multiple myeloma, whose neoplastic hierarchy in the classification of malignant hematological disorders is not yet very clearly defined. Morphological and immunological criteria indicate that the cells are at end stage of B cell maturation pathway. This unusual disorder is diagnosed by the presence of more than 2 x 10(9) plasma cells per liter of peripheral blood or more than 20% of the leucocytes being plasma cells on differential count. This occurs either denovo or as a terminal event in patients with long standing multiple myeloma. A case report of a young male patient with primary plasma cell leukemia is presented.

Effects of Combination Dietary Conjugated Linoleic Acid with Vitamin A (Retinol) and Selenium on the Response of the Immunoglobulin Production in Mice

The dietary effect of conjugated linoleic acid (CLA) on the response of the immunoglobulin (serum and tissue) production in Balb/C mice was examined at three doses: 0 %(control), 0.5% and 1.5%. The combination effects of CLA with vitamin ADE or selenium also were investigated. CLA at 0.5% increased serum immunoglobulin A, G, mesenteric lymp node (MHN) and gut luminal IgA (secretory IgA) levels. However, 1.5% CLA decreased SIgG slightly. CLA both alone and combined with vitamin ADE and selenium did not affect serum IgE. The levels of immunoglobulin concentration in the 0.5% CLA group were higher than those in the1.5% CLA group. The level of serum IgG in 1.5% CLA combined with selenium was maintained at the same level as that of control. It is considered that over- doses of CLA (1.5%) even depressed the production of immunoglobulin but selenium and/or vitamin inhibited this activity to a certain extent.In this study, dietary CLA increased immunoglobulin production in a dose-dependent manner. Vitamin ADE and Selenium combined with CLA also increased the immunoglobulin production response except serum IgE.

Anticuerpos y receptores de células B / Antibodies and B cell receptors

Las inmunoglobulinas o anticuerpos son glicoproteínas que se encuentran en la superficie de los linfocitos B y son secretadas por las células plasmáticas, linfocitos B terminalmente diferenciados, en respuesta a un antígeno y, como tal, representan la inmunidad humoral de los vertebrados. Existen 5 formas o isotipos principales: IgG, IgM, IgA, IgD e IgE. Las Igs presentan una estructura básica que posee dos cadenas pesadas (H) idénticas y dos cadenas livianas (L) idénticas, unidas entre sí por puentes disulfuro e interacciones no covalentes. Ambos tipos de cadenas presentan un patrón estructural que consiste de segmentos o dominios de 110 aminoácidos. El análisis de su secuencia de aminoácidos revela la existencia de un dominio variable (V) hacia el extremo aminoterminal y varios dominios constantes (C) hacia el extremo carboxilo terminal. Las cadenas pesadas también poseen un dominio variable (VL) y uno constante (CL). Las cadenas pesadas también poseen un dominio variable (VH) pero tienen 3 ó 4 dominios constantes (CH). Los dominios variables de mabas cadenas contienen zonas de alta variabilidad no contiguas en la secuencia de aminoácidos, son las denominadas regiones hipervariables o CRD (determinantes de complementariedad) y son las principales responsables de la diversidad de los anticuerpos...

Inmunología y aparato digestivo / Immunology and digestive tract

El intestino es un órgano inmunológico mayor, que está relacionado con la producción de IgA secretora, pero también con la inmunidad celular. La IgA secretora juega un rol muy importante en la protección del organismo contra antígenos bacterianos y alimentarios que ingresan por vía digestiva. Cálculos relacionados con la determinación de la vida media de las diferentes inmunoglobulinas y con su pérdida por vía digestiva, indican que el intestino sintetiza diariamente una mayor cantidad de inmunoglubulinas que todo el resto del organismo. El sistema inmunológico intestinal representa un mecanismo defensivo y protector de vital importancia, cuya deficiencia predispone a diversas enfermedades y en especial a numerosas infecciones crónicas bacterianas y/o parasitarias. A la inversa, la respuesta inmune intestinal excesiva o inapropiada es capaz de desencadenar procesos linfomatosos locales e incluso afecciones inmunológicas de carácter sistémico

Regulation of immunoglobulin secretion by T lymphocytes in human malaria.

In vitro studies were carried out on the nature of immunoglobulin synthesis and secretion by peripheral blood mononuclear leukocytes (PBMLs) and on the function of T and B cells from malaria patients. The mean values of secreted IgG and IgM concentrations of 22 malaria patient PMBLs were significantly higher than those of 20 normal PBMLs. When the suppressor T cell activity and the function of B cells in response to suppressor T cells were assayed by the cell co-culture technique, it was found that there was a decrease in suppressor T cell activity and the B cell function in response to normal suppressor T cells in malaria patients. The defects of these T and B cell functions may play some role in the immunological abnormalities seen in some malaria patients.