Amita Misra

Partial characterization of red gram (Cajanus cajan L. Millsp) polypeptides recognized by patients exhibiting rhinitis and bronchial asthma

We sought to assess the allergenic potential of red gram by identifying and characterizing the responsible proteins. Immunoblotting was performed to detect IgE binding proteins. Identities of these proteins were confirmed by mass spectrometry. To evaluate allergenic potential, BALB/c mice were sensitized with red gram proteins and levels of specific immunoglobulins, histamine, Th2 cytokines were measured. Allergenic response was evident by significant increase in specific IgE, IgG1, histamine and Th2 cytokine levels. Prominent anaphylactic symptoms, discernible histopathological responses and down regulation of IFN-gamma levels give strong support towards allergenicity of red gram proteins. IgE immunoblot detected five proteins; one of 66 kDa, three of 45 kDa (pI of approximately 5.3, 5.9 and 6.6) and one of 30 kDa. All these proteins showed homology to known allergens of soybean (different subunits of beta-conglycinin), lentil (Len c1 and Len c2), peanut (Ara h1) and pea (vicilin). In conclusion, five novel IgE binding proteins (namely Caj c1, Caj c2, Caj c3, Caj c4 and Caj c5) were identified as putative clinically relevant allergens.

Are nanomaterials a threat to the immune system

Nanoparticles can enter into the human body through several routes and interact with components of the immune system. This interaction leads to enhanced release of different cytokines that include both proinflammatory and inflammatory cytokines as shown by several laboratories. The use of different types of materials may have different effects on the immune system; for instance, cobalt and nickel nanoparticles have inflammogenic effects while hydroxyapatite crystals stimulate TNFa secretion from macrophages which subsequently activate other phagocytes. Nanoparticles used in cosmetics and skin care products cause low systemic toxicity on skin. Carbon nanoparticles produce allergic symptoms, while fullerene is useful in mitigating allergy. Thus, nanoparticles have immunomodulatory potential as these can stimulate or suppress the immune system. However, both the conditions are undesirable and the successful nanoparticle-based therapeutics should avoid immunostimulatory or immunosuppressive reactions to the nanomaterials once administered into the body. The interaction of nanoparticles with the immune system alters its bioavailability and prolongs exposure time. Therefore, more data should be generated through in vivo studies.

Probing novel allergenic proteins of commonly consumed legumes.

Leguminous crops are the main source of protein in Asian subcontinent including India and their proteins may induce allergic reactions in sensitized individuals. Pepsin resistance of proteins is a characteristic feature of most of the allergens. Simulated gastric fluid (SGF) assay as validated by digestion of purified known allergenic and non-allergenic proteins was the basis of this study. Purified allergenic proteins were stable to SGF digestion contrary to rapidly digested non-allergenic proteins. Crude proteins extracts (CPE) of soybean, peanut, chickpea, black gram, kidney bean and Bengal gram were digested in vitro to detect their non-digestible proteins. Six proteins from soybean and seven from peanut remained undigested after SGF digestion. Likewise, seven proteins from chickpea (70, 64, 55, 45, 35, 20 and 18 kDa), ten from black gram (47, 30, 29, 28, 26, 24, 22, 16, 14 and 12 kDa), five from kidney bean (45, 29, 24, 20 and 6.5 kDa) and one from Bengal gram (20 kDa) remained undigested in SGF. Most of the proteins stable in SGF for more than 2 min showed similarity with characterized allergens on the basis of their molecular weights as in case of soybean, peanut, chickpea and black gram. Also, soybean and chickpea stable proteins showed IgE binding property with respective allergic patient’s sera. The non-digestible proteins from the chickpea, black gram, kidney bean and Bengal gram are being reported for the first time by our group. IgE binding of SGF resistant soybean and chickpea proteins is being reported first time as well.

Prevalence of Legume Sensitization in Patients with Naso-Bronchial Allergy

Prevalence of legume allergy and concomitant sensitization to different allergens was evaluated in patients of asthma and/ or rhinitis. Skin prick test with 27 common food allergens and 61 aeroallergens in 76 subjects was performed. Out of 76 subjects, 41 perceived allergenic problems with different food items as contributing factor. Only six patients showed prick test positivity compatible with their anamnesis. However, 35 subjects showed sensitization to different food items, out of which thirty were sensitive to legumes. The common foods in decreasing order of allergenicity were chickpea, followed by green gram, egg white, and bean fresh/red gram. Concomitant sensitization to different legume crops was found in patients.

Bt Brinjal in India: A long way to go

Brinjal occupies the major proportion amongst all vegetable crops in India and is vulnerable to many diseases caused by insect-pests, fungus, bacteria and virus. Brinjal production is extensively affected by the insect brinjal fruit and shoot borer. Use of conventional chemical pesticides not only damage environment including the biotic and abiotic components but, also affect human health. Bt Brinjal was developed to combat brinjal fruit and shoot borer that has an advantage minimizing use of chemical pesticides. Extensive biosafety investigations, nutritional studies, substantial equivalence studies, relative toxicity and allergenicity assessment using animal models like Sprague Dawley rats, Brown Norway rats, rabbit, fish, chicken, goats, etc. revealed no significant differences between genetically modified brinjal and its native counterpart. Bt brinjal could effectively control the target pest and was found to be safe for environment and human health. In spite of all the scientific studies, release of Bt Brinjal has been put under moratorium. Indian government has constituted an expert committee to address this issue. In this review we have tried to explore the facts related to Bt Brinjal including its production, use of Bt toxin, use of chemical pesticides in controlling the FSB in native brinjal, along with perspective of public opinion and government initiatives. Key words: Bt Brinjal, agriculture, insecticides, GM foods, agrobacterium, transgenic crops