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This page addresses scientific and technical issues. More general questions are answered in our company FAQ.

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Disease models (CRO)

Short-term assays and mode of action models (CRO)




Kit questions - general

What is the difference between the multiple products with identical names (but different catalog numbers)?

Hooke Emulsion Kits™ with similar names may contain different amounts of killed Mycobacterium tuberculosis (Mtb), pertussis toxin (PTX), or other reagents.

The quantity of each reagent is chosen to optimize for the intended application of each Hooke Kit™ – disease induction, cellular immune response (T cell proliferation, cytokine production), or humoral immune response (antibody production), while minimizing side effects induced by CFA.

Reagent quantities are also adjusted so that each Hooke Kit™ has consistent potency, compensating for any lot-to-lot variation of kit components.

In some cases (especially control kits), products with identical names are in fact identical. In these cases multiple catalog numbers are listed to simplify ordering or for historical reasons, and the price is the same for all identical products.

I left my kit out at room temperature, can I still use it?

Our testing shows that Hooke Kit™ MOG35-55/CFA Emulsion PTX (cat. no. EK-2110) induces EAE after 4 days at room temperature. Other kits containing short peptides are likely also stable at room temperature for a similar period, but we have not tested this.

Other kits may be more sensitive. Kits containing collagen should be discarded if left at room temperature for longer than a few hours.

What is the "TC media" in your DS- products?

Tissue culture media, 10% fetal bovine serum in RPMI 1640. (See "Detailed contents" section of each product page.)

Can emulsion-based Hooke Kits™ be used past their expiration date?

Most of our emulsion-based Hooke Kits™ have a stability period of 20 days from the date of preparation (kits are normally prepared and shipped the same day).

The listed stability periods are conservative. They are the result of testing and are chosen to ensure the products are fully potent through the end of the period.

We recommend that expired kits should be discarded, and not used in experiments. We make no promises regarding expired kits.

In practice the kits will usually work for some time beyond the marked expiration date. This time is usually less than the original rated stability period (that is, a kit listed as stable for 20 days will usually not work after 40 days, but may work before then).

The limiting factor is normally emulsion separation (if the product is stored at the recommended temperature). Emulsions separate with time, and more quickly with rough handling. If the emulsion has not yet separated (separation is visible on close inspection of the emulsion syringe), it will usually still work.

Storing emulsion syringes upright (vertically) may somewhat delay separation.

CIA induction kit questions

Is the source of DBA/1 mice important?

CIA development is sensitive to DBA/1 mouse substrain. Hooke recommends use of Taconic Biosciences DBA1BO mice with these kits. Our testing shows arthritis will be consistently induced in 90 to 100% of DBA/1 mice from Taconic. Results may differ in mice from other breeders.

Is the booster dose (collagen with IFA) really necessary for CIA induction?

Yes, in our experience it is necessary. However, mouse substrains can differ, and a very few labs have reported that their mice develop CIA after a single immunization, without a booster. Most labs need a booster dose for good CIA development. With the booster, disease onset is 5-10 days after the booster in almost all mice. Without the booster, CIA usually develops in only 20-75% of mice, and onset is much more spread over time.

Are there gender differences in CIA development?

We recommend using male mice. CIA develops very similarly in males and females, but females are more likely to develop skin lesions near the injection site; in mice with lesions CIA develops poorly. Males rarely develop skin lesions.

Can these kits be used to induce CIA in Lewis rats?

If Hooke's protocol is followed, our bovine collagen CIA kits will induce CIA in Lewis rats (both males and females).

Use the same protocol recommended for mice, except at double the dose, so 0.1 mL/rat of Bovine Collagen/CFA Emulsion (EK-0220) for the first injection, and then 7 days later, Bovine Collagen/IFA Emulsion (EK-0221) again at 0.1 mL/rat. At this dose, each kit is sufficient for 10 rats.

EAE induction kit questions

Can I use isoflurane when I immunize?

Yes, our testing shows that isoflurane anesthesia does not negatively impact EAE development.

Can I use male mice?

EAE can be induced in B6 males. Our experience is that disease tends to be bimodal, with mice developing very severe (lethal) or very mild disease. We don't see that in B6 females.

We have not tested EAE in SJL males. Our understanding is that they are very aggressive and will kill each other if housed at more than 1 mouse/cage.

What are the advantages and disadvantages of the different EAE models and antigens?

We offer Hooke Kits™ for inducing EAE in:

Each model has advantages and disadvantages as follows:

ModelAdvantagesDisadvantages
MOG35-55
in
C57BL/6 mice

Well suited for study of onset and development of EAE, testing potential therapeutics.

Group size can be smaller (10–12 mice/group) as EAE develops in more than 90% of mice.

The first wave of EAE usually lasts 7 days, followed by partial recovery and then chronic paralysis, allowing a longer time to observe differences between experimental groups.

Poorly suited for study of EAE relapses and therapeutics targeting B cells. Antigen will not consistenly induce antibody production.

C57BL/6 mice mostly develop chronic EAE.

Peptide-induced EAE (MOG35-55 or MBP1-11) has been reported to be independent of B cell presence. [1, 2]. Because of this, peptide-induced EAE models may not be suitable for testing therapeutics aimed at B cell depletion or impairment of B cell function.

MOG1-125
in
C57BL/6 mice

Recommended for testing therapeutics aimed at impairing B cell function. Induces consistent anti-MOG1-125 antibody production.

B cells have been reported as necessary for development of EAE induced by human MOG1-125. [2, 4, 5]. It is therefore likely that MOG1-125-induced EAE is a good model for testing therapeutics which target B cells.

Antigen is expensive.

Spontaneous recovery is greater than when MOG35-55 is used as the antigen. Therefore the therapeutic window is smaller at the end of the study vs. use of MOG35-55.

[Ser140]-
PLP139-151

in
SJL mice

Well suited for study of EAE relapses. Most mice will recover from the first wave of EAE and 50 to 80% of mice will relapse.

EAE incidence 90 to 100%, with synchronized EAE onset..

EAE can be induced either with or without pertussis toxin (PTX).


First wave is short (2 to 5 days in most mice), followed by spontaneous recovery, resulting in a small therapeutic window at the end of the first wave of EAE.

Group size of 15 to 20 is recommended for study of relapses since relapse incidence is 50 to 80%.

Model lasts 40 days or longer when both first wave and relapses are followed.

If PTX is administered, relapse incidence and severity will be reduced.

Native mouse PLP139-151
in
SJL mice

Induces more severe EAE than [Ser140]-PLP139-151, without reducing relapse incidence (which often occurs if PTX is administered to enhance EAE severity).

Same as with [Ser140]-PLP139-151 (above). In addition, EAE can be too severe.

gpMBP69-88
in
Lewis rats

Consistent disease onset and severity. Short study duration (typically 18 days).


Rats are larger than mice; require larger compound amounts.

Therapeutic window is small at the end of the first wave of EAE, because rats spontaneously recover.

Lewis rats do not develop demyelination and do not experience chronic phase EAE.

In addition to the models listed above, Hooke offers a wider variety of EAE models as a CRO service. Click here for more information.

[1] Wolf SD et al, J Exp Med 184:2271 (1996)
[2] Lyons JA et al, Eur J Imm 29:3432 (1999)
[3] Hauser SL et al, NEJM 358:676 (2008)
[4] Svensson L et al, Eur J Imm 32:1939 (2002)
[5] Lyons JA et al, Eur J Imm 32:190 (2002)
[6] McFarlin DE, Blank SE, Kibler RF, J. Immunol. 1 13:712 (1974)
[7] Kardys E and Hashim GA, J Immunol 127:862 (1981)
[8] Mannie MD, Paterson PY, U'Prichard DC, Flouret G., Proc Natl Acad Sci USA 82:5515 (1985)
[9] Hashim GA, Day ED, Fredane L, Intintola P, Carvalho E, J Neurosci Res. 16(3):467-78 (1986)