Isolation and Characterization of Recombinant Variable Domain of Heavy Chain Anti-idiotypic Antibodies Specific to Aflatoxin B_1

Some unique subclasses of Camelidae antibodies are devoid of the light chain, and the antigen binding site is comprised exclusively of the variable domain of the heavy chain （VHH）. The recombinant VHHs have a high potential as alternative reagents for the next generation of immunoassay. In particular, they might be very useful for molecular mimicry. The present study demonstrated an alpaca immunized with the F（ab＇）z fragment of anti-aflatoxin B1 mAb and developed an important anti-idiotypic （anti-ld） responses. Antigen-specific elution method was used for panning private anti-ld VHHs from the constructed alpaca VHH library. The selected VHHs were expressed, renatured, purified, and then identified by a competitive enzyme-linked immunosorbent assay （ELISA）. Our findings indicated that the VHH would be an alternative tool for haptens mimicry studies.

Selected Aspects of Camel Immune System and Immune Responses

The camel economy is of considerable importance for arid countries. In the last decade, studies about camel immune system and immune responses have recorded increasing interest. However, drawing a comprehensive picture of the camel immune system remains far from reached. A major part of this review is to cover the studies of the primary and secondary immune organs and the markers of the camel immune cells and certain lymphoid tissues. At the same time, immune responses to different diseases and the nature of effective immunity were included, with an emphasis on the most important zoonotic diseases in camels such as MERS CoV;brucellosis. New findings on the diversity mechanisms of camel immunoglobulin genes were addressed. However, detail of the mechanism of MHC-restricted cellular immunity and the mechanism of B lymphocyte activation in camels await further attention. Interestingly, the gross and the histological structure of the lymphoid tissues of the camel’s thymus, tonsils, and peyer’s patches have indicated significant differences from other animals in terms of structure and function. The most peculiar CD expression, such as LPAM-I, MAdCAM-1 and CX3CR1, in certain camel cells and tissues refers to possible extraordinary mechanisms of immune hemostasis in camel in comparison to other ruminants. The widely applied immunodiagnostic techniques to control camel diseases and to assist in improving the camel resistance were considered. Extensive studies of the camel immune system were greatly hampered by lack of specific reagents to camel markers and low funds in the field of camel immunology.