humm, masked mycotoxins, conjugation,danger signal

[Guest guest]

IgG,IgE, antigen presentation, vaccines, I kindof get the felling that some

mycotoxins might produce a IgE and/or IgG responce.

I'm not going to put it in a theroy, or ask the question.

2007,A New Competitive Fluorescence Assay

for the Detection of Patulin Toxin

CONCLUSIONS

The polyclonal antibodies produced against the mycotoxin

patulin, by means of two synthetic derivatives of the molecule

conjugated to bovine serum albumin as the carrier protein, after

affinity purification, showed a high titer for the recognition of the

haptene. The immunoglobulins were successfully used to develop

a competitive immunofluorescent assay for the detection of small

quantities of patulin. The method was based on the binding of

fluorescently labeled antibodies to the synthetic patulin derivative,

covalently immobilized on a Sepharose matrix. The displacement

of the antibodies by addition of free patulin was detected as a

fluorescence signal at the emission wavelength of the fluorophore.

The assay allowed the detection of 10 ¨ªg/L patulin and thus

represents a promising basis for the development of an alternative

methodology compared to the analytical chromatographic techniques

in use

" conjugation,danger signal " search

Carbohydrate-Based Targets and Vehicles for Cancer and Infectious Diseases

Vaccines

http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=eurekah & part=A30724

Targeting the Mannose Receptor for Antigen Delivery

Taken together these studies suggest that patients can successfully be immunized

for the generation of both humoral and cellular responses using mannan-antigen

conjugates. We are currently performing clinical trials where MR on

macrophage/DC is targeted ex vivo with

mannan-MUC1.http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=eurekah & part=A307\

24#A30724

Bacterial Carbohydrates as Danger Signals

The immune system has evolved a set of receptors on phagocytic and antigen

presenting cells (APCs) to recognize specifically and rapidly bacterial

carbohydrates, especially in the form of liposaccharides. The best characterized

are bacterial lipopolysaccharides (LPS) found abundantly on all Gram negative

bacteria such as Escherichia coli. Interaction of LPS with receptors, such as

CD14, on dendritic cells (DCs), monocytes and macrophages promotes phagocytosis

of the bacteria, and provides an activation or _danger_ signal to the cell.1-3

LPS-stimulated DCs express potent costimulatory molecules for T cell activation,

such as CD40, CD80 and CD86, which makes them uniquely potent at priming both

CD8 and CD4 T cell responses.4 LPS-activated monocytes and macrophages do not

only become more effective at destroying the bacteria, but also secrete large

amounts of proinflammatory molecules such as tumor necrosis factor alpha

(TNF¦Á), which cause general reactions to infection, such as fever.1 Although

these responses help to eliminate the bacteria, excessive proinflammatory

reactions can be deleterious to the host. Indeed, toxic shock induced by LPS

injection is lethal in many species.1 The diverse biological activities of LPS

may be further dissociated into chemical moieties with the lipid A portion being

the main determinant of toxicity.5

Although unmodified LPS may therefore not be a safe adjuvant, cell-wall skeleton

(CWS) fractions of mycobacterial cells (present in Freund's complete adjuvant,

the widely used adjuvant for experimental animals) have also been found to

contain carbohydrate-lipid or protein conjugates with immunostimulatory

activity.6 It has been suggested that DCs and macrophages express both Toll-like

receptors, TLR-2 and TLR-4, and a receptor for mycobacterial CWS whose signaling

pathways promote an activation state of the immune system. Synthetic adjuvants

such as muramyldipeptide (MDP) derivatives and trehalose-dimycolates (TDM) have

been developed to activate similar signaling pathways.6 Mycobacterial

lipoarabinomannan (LAM), mannosylated LAM (ManLAM) and LAM lacking the terminal

mannosyl units (AraLAM) induce distinct responses in human polymorphonuclear

(PMNs) and mononuclear phagocytes. Thus, AraLAM and ManLAM affect mononuclear,

but not PMN, phagocyte functions, but both forms are chemotactic for monocytes

and monocyte-derived macrophages (MDMs).7

Targeting the Scavenger Receptor for Vaccine Development

The scavenger receptor is primarily present on macrophages and can internalize

endotoxins, oxidized low density lipoproteins and other negatively charged

proteins. Maleylated ovalbumin has been demonstrated to bind to the scavenger

receptor, this enhances its presentation to ovalbumin-specific MHC class I

restricted CTL by macrophages and B cells.63 Maleylated diphtheria toxoid has

also been demonstrated to be more immunogenic than nonmaleylated diphtheria

toxoid which generated enhanced antibody and T cell proliferative responses.64

In chickens, immunization with maleylated-bovine serum albumin (BSA)

specifically bound to the scavenger receptor and modulated the Th1 immune

response with weak antibodies. In addition, splenocytes expressed high levels of

mRNA for IFN¦Ã. Non maleylated BSA induced Th2 immune responses.65

Alcohol metabolites malondialdehyde and acetaldehyde when combined form stable

adducts (oxidative product). These adducts when conjugated to proteins, such as

hen egg lysozyme (HEL), induced a strong antibody response and T cell

proliferation. Studies have suggested that the immune responses may be mediated

by scavenger receptors that recognize malondialdehyde and acetaldehyde adducted

proteins.66

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Biology.

a.The temporary union of two bacterial cells during which one cell transfers

part or all of its genome to the other.

b.A process of sexual reproduction in which ciliate protozoans of the same

species temporarily couple and exchange genetic material.

c.A process of sexual reproduction in certain algae and fungi in which temporary

or permanent fusion occurs, resulting in the union of the male and female

gametes.

conjugational con'ju¡¤ga'tion¡¤al adj.

conjugationally con'ju¡¤ga'tion¡¤al¡¤ly adv.