Receptors for interleukin-1 (α and β) in mouse brain: Mapping and neuronal localization in hippocampus

Neuro,wwnce Vol 43, No I, pp 21 30, 1991 Printed m Great Britain

0306-4522/91 $3 00 + 0 00 Pergamon Press pie ,," 1991 IBRO

RECEPTORS FOR INTERLEUKIN-1 (~ A N D fl) IN MOUSE BRAIN: MAPPING A N D N E U R O N A L LOCALIZATION. IN HIPPOCAMPUS E BAN,*'? G MILON,++ N PRUDHOMME,* G FILLION* a n d F HAOUR* *Pharmacologic Neuro-Immuno-Endocrlmenne et ~Immunophyslologle cellulaire, CNRS UA 1113. 28 rue du Dr Roux, 75724 Pans Cedex, France Abstraet--Interleukm-1 receptors were mapped and characterized in mouse brim by quantitative autoradlography using human recombinant [~251]mterleukm-lct and [L~'SI]lnterleukm-lfl as hgands Both hgands prowde Identical receptor mapping In terms of specificity, mterleukm-lct and mterleukln-l/3 were equally potent m binding competlt~ons assays with e~ther [1-'~I]mterleukm-lct or [~SI]lnterleukm-1/~ (ECs0 1 1 pM) These receptors were shown to be h~ghly concentrated m the dentate gyrus, m the choro~d plexus at vinous levels of the brim, m the pltmtary and m the meninges They were also present at low concentrations in the cortex but undetectable in other brain structures In the dentate gyrus, lnterleukm-I receptors were locahzed on the granular and molecular layers (granule cells) when wsuahzed on shdes &pped m nuclear emulsion Cellular localization of mterleukin-1 receptors was assessed usmg selectwe lesion by colchlcme The complete loss of [tzSI]lnterleukm-I binding m h~ppocampal areas where neurons were destroyed by colchlcme demonstrates that mterleukln-I receptors are located on granule cells Following les~on, sparse undestroyed cells, with ghal cell morphology, also showed s~gmficant labelhng In conclusion, mterleukm-I receptors are located on the granule cells m the mouse dentate gyrus These neurons may therefore be targets for neuromodulat~on by mterleukm-1 and they may play a key role m the central effect of mterleukm-1 as well as m the control of the immune response by the brim

Interleukm-1 (IL-1) describes two classes o f molecules k n o w n as I L - I ~ a n d IL-1/3 which are commonly p r o d u c e d by the cells of the m o n o n u c l e a r phagocytes w h e n they are triggered by a variety of stlmuh 14 However. they m a y also be synthesized by o t h e r cell types, and p r o d u c e d m v t t r o by cells recovered from m o u s e a n d rat brain, such as astrocytes and mlcroglla 17.|9.31 W h e n injected intravenously or int r a c e r e b r o v e n t n c u l a r l y , IL-1 induces h y p e r t h e r m l a in r a b b i t a n d rat, ~54~ slow-wave sleep in rabbit, 28 loss of appetite m rat 3a a n d produces a rapxd a n d transient decrease of peripheral cellular i m m u n e responses m rat ~L F u r t h e r m o r e , xt has been s h o w n in experiments c o n d u c t e d m t , li, o as well as m t , t t r o t h a t IL-I could act on the h y p o t h a l a m o - p l t u i t a r y - a d r e n a l axis to induce a d r e n e c o r t l c o t r o p m h o r m o n e ( A C T H ) secret~on in m o u s e a n d rat 2 5.7.39.42.5458 a n d on release of v i n o u s pituitary h o r m o n e s ~6 Recently, we have rep o r t e d the presence of hl,gh-affimty receptors for I L - I ~ m m o u s e b r i m c o n c e n t r a t e d in the dentate gyrus (KD = 300 p M a n d B ~ , 60 f m o l / m g protein)

and the c h o r o l d plexus of m o u s e 21 p r o w d l n g b~ochemical support for the central effects of IL-1 A l t h o u g h I L - I ~ and 1L-I~ are only 2 5 % h o m o l o gous in p r i m a r y sequence they have been reported to b m d a c o m m o n class of receptors on T cells ~526 or fibroblasts ~0 However, evidence for an alternatwe form o f IL- 1 receptor which brads I L- 1/3 with greater affimty t h a n IL-lct was found in B cells, 4114~ Because heterogeneity of IL-I receptors m various tissues might reflect heterogeneous functions of the two forms of lL-1, we Investigated the binding speclficity of h~ppocampal IL-1 receptors t o w a r d IL-lct a n d IL-1/] In terms o f biological activity, b o t h IL-Iz~ and IL-lfl stimulate b r i m functions W h e n assayed in I'll 0 m rats, IL-1/3 seemed to be more potent than IL-17 on A C T H release ~9.54171 t'ztro studies, conducted on rat n e u r o n a l or ghal cultures, showed biological activities of b o t h IL-I:~ a n d IL-I/3 On ghal cells, IL-1/4 was able to reduce p r o s t a g l a n d l n E, ( P G E 2 ) release m astrocyte cultures 25 whde IL-I~ was mefficxent On n e u r o n a l cultures, IL-13 has also been s h o w n to alter hypothalam~c thermosens~tlve n e u r o n actwIty 36 a n d to stimulate s o m a t o s t a t m synthes~s m b r i m primary cell cultures 44 O n the other h a n d , I L - I ~ was s h o w n to be a p o t e n t stimulator of astroghal cell growth a n d p r o h f e r a t l o n 2. Therefore,

yTo whom correspondence should be addressed at Umt+ de Pharmacologic Neuro-Immuno-Endocnmenne, Inst~tut Pasteur, 28 rue du Dr Roux, 75724 Pans Cedex 15, France A h b r e v ~ a t t o n s AC'IH, adrenocorucotropm hormone, CRF, cortlcotropm-releasmg factor, IL-1, mterleukm-1, IL-1~, mterleukln-l-alpha, 1L-lfl, lnterleukln-l-beta, NGF. nerve growth factor, PGE2, prostaglandln E,, TNF, lumour necros~s factor, PBS, phosphate-buffered sahne

clearly ~t appears t h a t specificity o f b r i m receptors should be analysed with respect to their cellular Iocahzatlon 21

22

I

B A \ cl a]

In this study we therefore used mtracerebral micetlon of colchicme, k n o w n to selectively destroy g r a n u l a r n e u r o n s of the dentate gyrus. ~ to determine the n a t u r e of the cell p o p u l a t i o n bearing IL-1 receptors EXPERIMENTAL PROCEDURES Animals and treatments Adult female CH3/He (IFFA-CREDO, L'Arbresle, France) were kept m specific pathogen-free conditmns (12 h light 12 h dark) and allowed to feed on sterilized laboratory chow and aci&fied water ad hbItum For lesmn experiments, 21 mice were used S~x mice received 0 9% sahne solution and were killed, either on day 2 or 8, by decapItatmn after 10 s in CO2 Twelve mice received 10 gl of a 2 mg/ml colchiclne solution rejected, between bregma and lambda (A 1 65-2 90 according to the atlas of A. Lehmann), 29~ on the right hemisphere above the lateral ventricles, with a needle shortened m order to reach the hlppocampus Six mice were killed on day 2 and s~x on day 8 S~tes ofmjectmn were checked by histological observation on adjacent slices Three mice m each group were actually rejected in the hlppocampus and three were rejected anterior to the hlppocampus, m caudate nucleus All brains were kept for binding experiments in order to check the hlppocampal specificity of colchlcme action The left hemlsphere was used as an internal control

Autora&ography Recombinant human [~2sI]IL-l~ (2000C1/mM) and [12sI]IL-tfl were obtamed from Amersham (Les Uhs, France) Unlabelled human recombmant IL-l~t and IL-lfl were a gift of Dr S Gilhs (Immunex Corporatmn, Seattle, WA, U S A ) Frozen sectmns (10/~m) were obtained using

................... •

.

.

.

.

.

.

8

t.,

o.5

a Relchert-Jung cryostat (Frigocut 2800) ,,nd sttJred ,it - 2 0 C untd use The slide-mounted sections were premcubated for 15 rain at room temperature in phosphate-buffered saline (PBS) pH 7 4 Incubation was performed m RPMI 1640 containing 1% bovine serum albumin and 0 15 nM [1251]IL-le or [I-'sI]IL-lfl at room temperature for 2 h Nonspecific binding was determined in the presence of I0 ' M IL-I~ or IL-lfl and was less than 8% under ,tandard conditions Following incubation, the slices were washed five times in PBS buffer at 4"C (25 mln), dried and exposed to Amersham 3H-Hyperfilm for six to 14 days

Fdm analysts and quanttficatmn Following exposure, films were processed and relative grain density was quantified by computerized densItometry usmg an image analyser (RAG 200. Biocom. Les Uhs. France) Standardization was achieved using polymer Amersham ~25I-microscale Results were expressed m fmol of hgand bound/rag protein following correction for ussue equivalent Histological processing After exposmon to Hyperfilms, the shdes from lesioned animals were fixed with 5% glutaraldehyde in 0 1 M phosphate buffer for 10mm at 4°C They were rinsed twice (15 min) in phosphate buffer at 4°C and dried. They were dipped in 50% Ilford K5 nuclear emulsmn and exposed for 30 days After developing with Kodak D19, the slides were stained with Tluonln (Serlabo) to identify cellular cornponents and mounted in Baume de Canada (Labosl) Observations and microphotographs were made using an Olympus microscope RESULTS

Specificity of mterleukm-1 receptors m the dentate gyrus, competition with interleukm-l ~t and mterleukm-

[~sI]IL-lfl (B) binding by a range o f c o n c e n t r a t i o n s o f untabelled I L - l e or IL-lfl is d e m o n s t r a t e d m Fig. 1 Both lsoforms were equally p o t e n t in competition with either hgand. The curves were representative of a single type o f high-affinity binding site with a n ECs0 of 11 pM. N o displacement was o b t a i n e d with 10 7 M o f IL-2, t u m o u r necrosis factor ( T N F ) nerve growth factor ( N G F ) or colchiclne It is w o r t h n o t i n g t h a t the intensity o f the binding as expressed in f m o l / m g protein is higher with [~25I]IL-lct (Ftg 1A) t h a n with [l:51]IL-lfl (Fig. 1B). In fact, s a t u r a t i o n curves have previously been obtained with [125I]IL-1~,21 whilst, due to the p o o r binding capacity o f the hgand, this could not be achieved with [125I]IL-lfl. F o r this reason, [~25I]IL-lct was used preferentially for m a p p i n g of IL-1 receptors t h r o u g h o u t the b r a i n

Mapping of mterleukin-1 receptors m the mouse bram oo

, -,~ t~-~ ~ Fig 1 Competition curve obtained with [~:5I]IL-l~t (A) and [nsI]IL-1/~(B)lnmousedentategyrus Shces wereincubated with 30pM of [t25I]IL-l~t and 60pM of [t~l]IL-lfl w~th increasing doses of unlabelled IL-lct (C)) or IL-lfl ( ~ ) Each point ~s the mean of quadruphcate determinations _+ S D of the total binding measured on the autoradmgraphic film on the dentate area expressed in fmol/mg protein

Binding o f [125I]IL-1~ was carried o u t on coronal a n d longitudinal sections evenly spaced t h r o u g h o u t the m o u s e brain; a u t o r a d m g r a p h s representative of the labelled sections are shown m Figs 2 a n d 3 (F~g. 2 a - g a n d Fig 3a-d). The same localization was o b t a i n e d with [lz~I]IL-l~ or ['25I]IL-lfl (Fig. 4 A - C ) However, higher llgand c o n c e n t r a t i o n a n d longer exposure t~me were necessary w h e n labelled IL-lfl

Receptors for mterleukm-1 (,~ and /~) m mouse h]ppocampal neurons

,-" ,;.=.; ,

23

!£:"

e

; "';:,

b

:.

: >=,]

g"

f

¶, •:

•,

g

~ ; ~ .

C

d

f'

F]g 2 Hyperfilm autora&ograms of [125I]IL-1~ (30pM) binding on coronal mouse brain sections presented m a rostral to caudal direction (a g) Histological staining of section f is shown m f' Exposure time nine days ~1",dentate gyrus, m, chorold plexus, 0 , meninges, O, ep]thehum, A, cortex, I-7, p~tmtary was used as hgand in order to obtain the same images, No labelling was found in the olfactory bulb (Fig 2a) even after long exposure. The meninges (Figs 2a, b, 3a, c), between the two hemispheres, are labelled A faint labelling was seen in the frontoparietal cortex, which decreased in intensity in a caudal direction (Figs 2 b ~ , 3b, d) In the hlppocampal formation, high labelling was observed in the

dentate gyrus (Figs 2c-g, 3 a ~ l ) w i t h no labelling in the pyramidal ( C A 1 - C A 4 ) layer as was clearly demonstrated when autoradlograms were compared to the histological preparation of the same sections (Figs 2if', 3cc', dd') The chorold plexl were also heavily labelled in all slices where these formations could be identified by histology (Figs 2c--e, 3a~t) as well as the epithelial celllayers (Fig 2d-f, c) The very restricted labelling of the choroid plexus and the

24

E BA~ e'I al

k a

b

~

c

v

d

c'

d'

Fig 3 Hyperfilm autora&ograms of [:25I]IL-10t(30pM) binding on longitudinal mouse brain secuons (a~l) Histological staining of section c and d are shown on panel c' and d', respectwely. Exposure time nine days ~-, dentate gyrus; Is, chorold plexus, O, memnges; C), epithehum; A, cortex; [Z], pltmtary Higher magmficatlon of chorold plexus and epithelial cells is ln&cated m e and f, respectively

epithelial cells shown in Fig. 3c are at higher magmfication in Fig. 3e, f. The longitudinal sections (Fig. 3) allowed the visualization of the receptors in the fourth ventricle (Fig. 3a-d). The pituitary, shown m

Figs 2f and 3c, was highly labelled. It is worth noting that the nonspecific binding was higher in some areas of the cerebellum but no specific binding could be observed in this region.

Receptors for mterleukln-1 (~t and fl) In mouse hlppocampal neurons ~ ~i,.2~

i ~-~ ~f'/"~, ~-:.. "' ~ " -~" " ~ , ."

•

p~'"

¢.,% A • .'~ • ~.,~' '¢~W~t~] ~4: ~"dlm~~ "£'

. .~ ~.

" ¢

, ,, " ;~ ~'~,~~~ ~,

:;

"~ " ' ~ ,~ ql - . °';~ ,~. - >

• ~;~.~2,~dz, y f j ~ , ~ , . ~ .

• .,~,." '-": '':'

..,

, ,

completely destroyed granule neurons in the dentate gyrus close to the injection site, further from the site, the granular layer was thinner and paler in thlonln staining The concomitant disappearance of binding and neurons in the granular layer of the dentate 1s shown on Fig 6c at higher magnification, as compared to the control (Fig 6d, d') Figure 6 (d, d') shows the locahzatlon of IL-1 receptors on the darkly stained granular cell bodies (Gr) and on the dendrites m the molecular layer (MOL) The aspect of the destroyed granule cell is shown on Fig 6c', most of the cellular bo&es of neurons had disappeared and the few neurons still visible were pale with a watery cytoplasm The pyramidal cells of the CA4 region. which are also described in the literature as sensitive to colchlcxne, presented an unchanged aspect (Fig 6e) In contrast, specific binding still occurred in an area where the neurons were resistant to colchlcnne, such as the hllar region (Fig 6f) Some dark-stained undestroyed cells, sparsely distributed throughout the lesioned area, where no neurons are left visible, exhibited IL-I labelling (Fig 7)

B r i m m t e r l e u k m - I receptor spect3em'

~ ; , i .... ~ f l ' ) " ' ~ ": : "" "~ ] ~ " ~ ..

F~g 4 Hyperfilm autoradmgrams of [t25I]IL-lfl (60 pM) binding on coronal mouse brain sections presented m a rostral (A) to caudal (13)direction Sectmn C represents the nonspeofic binding obtained in the presence of 5 10 7 M IL-lfl Exposure time 14 days "A', dentate gyrus, II, choro~d plexus, ~ , cortex, [3, p~tmtary Cellular loeahzatlon o f b r i m mterleukm-1

25

receptors

Autoradlography was performed on brain sections obtained from colchlclne-pretreated mice to determine whether IL-I receptors were localized on neurons and/or ghal cells Colchiclne was chosen because it specifically destroys the granule neurons of the dentate gyrus, sparing the ghal cells ~0 The hlstological aspect of the disrupted dentate (A) and the lack of binding of [~sI]IL-I~ in the same area (B) are shown in Fig 5 Arrow n u m b e r 1 lndlcatesthe site of colchlclne injection Arrow n u m b e r 2 (Fig 5A, B) indicates granule cells of the dentate gyrus attesting the s y m m e t r y o f t h e s e c t l o n No signlficant difference could be seen between animals killed two days after injection and animals killed eight days after injection Animals injected with saline or with colchlclne outside or anterior to the hlppocampus did not show any histological modifications and the binding of [~2q]IL-lct was unaffected A high magnification of the lesioned (a) compared to the unlesloned dentate area (b) on the same section IS shown in Fig. 6 Local injection of colchlcane

tors bind IL-I~ and IL-lfl with similar Eel0 This is in agreement with the unique slope observed by Scatchard analysis 21 However, it is worth noting that the K o value reported was 300 pM while the ~c~0 is 11 pM, this clearly demonstrates that the receptor has greater affinity for the unlabelled IL-I than for the nodlnated hgand Recently, two forms of IL-1 receptors with molecular weights of approximately 80,000 and 60,000 were found in both murlne and human cells 1-"22,~434656 but their relative distributions showed no clear lineage restriction and did not correlate with preferential binding for IL-lc~ or IL-lfl 48 However, the B cell receptors appeared to bind IL-lfl with greater affinity 44~ The hypothesis of an alternative form of IL-I receptor in the brain was suggested by the fact that IL-lfl seemed to be more effective in regulating the rat brain functions when administered perlpherally or lntracerebroventrlcularly, Ik-lc~ was shown to be ineffective on A C T H release 39~5 Furthermore, the potency of unlabelled IL-17 to compete with [tzsI]IL-lfl binding on rat hypothalamlc membrane was considerably less than unlabelled lL-lfl 24 and, in t'ttro, it was shown that IL-I~ was 100 times less effective than Ik-lfl on PGE2 release from rat astrocyte cultures z~ The ability of IL-I~ and IL-lfl to reciprocally compete for the binding of the other provides an indication that the receptors for IL-lc~ and IL-I[t are identical In the brain Our results are in agreement with recent studies showing that the different forms of IL-I receptors could not be associated with preferential affinity for one IL-1 nsoform ~s

91

=.';7

[3 F~g 5. Change m granule cells two days after undateral mjectmn of colchlcme m the nght bem~sphere (A) H~stology, (B) autoradmgram of the same sectmn Arrow number 1 indicates the s~te of colch~cme mjectmn, arrows number 2 indicates undestroyed granule cells showing the good symmetry of the section Zones a and b (rectangles) correspond to fields a and b m Fig 6

Mappmg o f mterleukm-1 receptors tn mouse bram IL-I receptors are confined to highly discrete regions and, among these regions, exhibit marked chfferences m the density of sites. The highest receptor levels are found in the granular and molecular layers of the dentate gyrus, the chorold plexus and the pituitary. Low levels of receptor are observed m the meninges and m the frontopanetal cortex. In contrast, the very restricted localization of Inghdensity IL-l~t we found in mouse brain disagrees with a previous report on rat IL-I~ autoradiograpinc mapping showing a widespread binding throughout the brain 16 The best explanation for this discrepancy would probably be a species-specific d~stribuuon, There is a good correlation between the present findings and the anatomical tocahzat~on of the lmmunoreactive IL-lfl carried out recently m the rat. 29 Tins study showed that most lmmunoreactlwty was wslbte on neuronal processes m the Inlus of the dentate gyrus and m the stratum lucldum (CA3-CA4 regions). Immunoreactwe IL-1 was not detectable in the perikarya of the dentate granule cells. In contrast, IL-1 receptors appeared to be localized on dendntes and on soma of the granule cells with no labelling of the axons. Immunoreact~vity for IL-13 was also described in the hypothalamus9,29 and the olfactory tubercules;29 however, under our experimental condltions, we did not find any receptor for IL-1 m those

regions The corUcal locahzatlon of IL-1 receptors is in agreement with previous findings obtained on rat membrane preparations which described IL-t receptors in cerebral cortex and hypothatamus. 24 Neuronal locahzatton of bram lnterleukm-1 receptor The neuronal locahzatlon of IL-I receptors in the dentate gyrus was clearly demonstrated by the d~sappearance of the IL-1 binding m relation to the selective destruction of granule neurons after colcinclne treatment This treatment has been shown to destroy granule cells while spanng GABAerglc network in the rat Inppocampus.4° The Inghly restncted distribution of the receptors, contrasting with the uinquitous occurrence of astrocytes and m~crogha, 23'3s already suggested that IL-I was bound to neurons. However, ~t must be pointed out that the presence of receptors for IL-1 on ghal cells has been suggested by in vttro studies 19,20,25Tins is supported by the fact that, m our lesion experiments, some undestroyed cells, sparsely distributed throughout the lesmned area, exinbited IL-1 labelling when wzual~zedin a nuclear emulsion process. The hypothes~s of the presence of both neuronal and ghal IL-1 receptors would account for the multiple levels of action of IL-1 within the brain It ~s worth noting that, accordmg to the characterization presented m tins report, the putative different cell-type receptors are binding IL-1 with the same affimty

"~

7''

~i..,~

t.

~

Q~

./~

,,~.

~!%.,

,

*~ *

,.

r ..t.

,

•

b

v~ 7~:;~;

•

.

.

~.'..... ~.:

.

:

.

Fig 6 H~stolog~cal staining and nuclear emulsion autoradlography of selected regions ol the dentate gyrus Areas a and b correspond to the regions defined m Fzg 5 (a) colch~cme-les]oned hemisphere, (b) control (× 49) Higher magmficat]on of granule cell layer m the lesioned area (rectangle c) ~s indicated m c ( × 328) and c' ( × 467), Hngher magmficat~on of the granule cell layer m the control hemisphere (rectangle d) ]s nndncated in d ( × 328) and d' (× 410) Gr, granular layer, MoL, molecular layer Area e corresponds to an enlargement (× 410) of the pyramidal cells of the les~oned area (rectangle e from a) Area f shows the aspect of the granular cells of the hnlar region of the lesioned hemisphere whxch are unaffected by the colch~cme treatment ( × 328) ")'7

28

k Bah ct a/

Ii

,.

.r,

Fig 7 Labelled cells m the lesmned area Panel a shows astrocyte-hke labelled cells found m clusters m the lesioned area and panel b nonspec~ficbinding m the same area ( x 369) Role o f granular cells mterleukm-1 receptors m rater-

I m e r l e u k m - I and neuronal modulation

On the other hand, a recent study s~ showed that mtracerebroventncular infusion of IL-1 to normal The presence of IL-l-sensitive neurons together and adrenalectomized animals transiently decreased with the IL-1-~mmunoreactive fibres2~ in the dentate the ability of their immune cells to be reactive to mltogyrus imphes that, under basal conditions, IL-I mflu- gens m vitro The short delay (15 min) and the very ences brain functions through neuron-to-neuron low effective doses, suggested that these effects, partly Interactions. independent of IL-I stimulatmn of hypothalamoMoreover, IL-1 might act as a mediator, signalling pituitary-adrenal axis, revolved a neural pathway the brain that the immune system is triggered. We IL-1 receptors on granule cells might be the mediator have already shown that, after m wvo reJection of of these effects. However, the messages triggered by llpopolysaccharides, IL-le-free binding site number this IL-1 receptor interaction remain to be deterdecreased in the dentate gyrus through a mechanism mined. Several studies have shown that IL-1 could probably Implying local synthesis of IL-I. 2~ trigger the release of neurotransmitters, such as soSimilarly, the relatlonstnp between stress and matostatm in rat brain cultures," acetylcholine~ from ~mmune response is well documented. ~'s~ The effect hlppocampal slices, and N G F from rat hippocampal of IL-1 on cort~cotropm-releasing factor (CRF) cell cultures and scmtlc nerve, ~8.~2Somatostatin being release at the hypothalamlc level has been demon- absent from granule cells ~ could be secondarily restrated ~.~9,~.54.~s However, the mechanism by which leased by l~lar rater-neurons in close association with IL-1 may act on the hypothalamus is not known, granule cells. N G F receptors have been described on The presence of lmmunoreact~ve IL-1 in the hypo- cells of the immune system and are thought to play thalalmus9'~9constituted the sole indication of a puta- an important role in the modulation of immune tire induced synthesis of IL-1 by hypothalamic responses (see Ref 30 for a review). It IS striking that neuronal cells. Since the largest efferent pathway of IL-1 receptors are present in regmns where N G F the hippocampus, constituting the fornlx, possesses synthesis has been descnbed, in the granule cells and fibres ending in thalamlc and hypothalamlc nucleisz an in the cortex 1,27,45Thus IL- 1 might act on the immune indirect effect on the hypothalamus through IL-I- functions through N G F release or through acetylsensitive neurons of the dentate can be proposed. The choline release since N G F receptors are located on effect of IL-1 was further supported by the fact chohnerglc neurons. Recently it has been shown that that intracerebroventncular administration of IL-1 N G F binding in the hippocampus was reduced after reduced a stress-like behavlour m m~ce and rat. 49'~° stress exposure ~3 suggesting that N G F plays a role m Moreover the granule cells of the dentate gyms have the mechanisms revolved m stress reactions. been shown to be very sensitive to cortlcolds since adrenalectomy induced a selective loss of these cells. 47 CONCLUSION These cells rmght be subjected to secondary feedback loop regulations by elevated cortlcosteroids during Besides ~ts important role in the peripheral reguinfectious episodes latIon of the immune responses, IL-1 may also play leukin-1 effects on the hypothalamo-p~tu~tarv-adrenal

axis

Receptors for mterleukm-1 (e and fl) m mouse hlppocampal neurons a central role in the b r a m as a n e u r o m o d u l a t o r and thus may also indirectly affect the Immune response The presence o f IL-I brain receptors m the hmblc system, a region revolved in m e m o r y and adaptation, may constitute a major link in the relation between stress, behavlour and Immunity Acknowledgements--Thanks are due to Dr R Fauve for his continuing interest and support, to Drs S Gdhs (Immunex),

29

L Sarhevre and A Represa for providing high quahty reagents, to Dr F Fitzpatrick for technical help wtth ammals, to Mr J Lobrot and colleagues and M Coqms for photography and to Dr K Drleu (IPSEN-BEAUFOUR Laboratories) for financml support Th~s work was supported by Inst~tut Pasteur, CNR UA I113 and INSERM (CRE 873012 awarded to G M and CRE 874007 awarded to F H ) E B was supported by a joint fellowship from 1PSEN-BEAUFOUR and Mmlst&e de la Recherche et de la Technologic

REFERENCES 1 Ayer-Le Llevre C , Olson L , Ebendal T , Selger A and Persson H (1988) Expressmn of fl-nerve growth factor gene m hlppocampal neurons Scwnce 24, 1339-1341 2 Barbanel (3, Ixart (3, Szafarczyk A , Malaval F and Assenmacher I (1990) Intrahypothalamlc infusion of mterleukln-l-beta increases the release of cortlcotropm-releasmg hormone (CRH-41) and adrenocomcotroplc hormone (ACTH) m free-moving rats bearing a push~ull cannula in the median eminence Brain Res 516, 31 36 3 Beach J E,Smallndge R C , K m z e r C A , Bernton E W , H o l a d a y J W and Feln H (3 (1989) Rapid release of multiple hormones from rat pituitary perfused with recombinant lnterleukln-1 Lzfe Set 44, 1 5 4 Benjamin D , Wormsley S and Dower S K (1990) Heterogeneity In lnterleukln (IL)-I receptors expressed on human B-cell hnes~lfferences m the molecular properties of 1L-l-alpha and IL-l-beta binding sites J hlol Client 265, 9943-9951 5 Berkenbosch F , Van Oers J , Dei Rey A , Tilder F and Besedovsky H (1987) Cortlcotropln-releasmg factor-producing neurons m the rat actwated by lnterleukm-1 Science 238, 524 526 6 Bernton E W , Beach J E , Holaday J W , Smallndge R C and Fern H G, (1987) Release of multiple hormones by a direct actmn of lnterleukm-I on pltmtary cells S~lence 238, 519 521 7 Besedovsky H , Del Rey A , Sorkm E , Dmarello C A and Saper C B (1986) Immunoregulator~ feedback between interleukm-I and glucocortlcold hormones Scwnce 233, 652~54 8 Blanchl S, Bonito I , Clavenna A , Algen S and De Slmom M (3 (1990) IL-lfl and IL-2 effects on acetylchohne release m rat hlppocampal shces In First Internatwnal Congre~ o f ISN1M, abstr No 64, 111 9 Breder C D , Dinarello C A and Saper C B (1988) Interleukm-1 lmmunoreactlve mnervatmn of the human hypothalamus Scwnce 240, 321 324 10 Chin J , Cammeron P M and Rupp E (1987) Identlficatmn of a hlgh-affimty receptor for native human IL-lfl and IL-I:¢ on normal human lung fibroblasts J exp Med 165, 70-80 11 Chlzzonlte R , T r m t t T , KfllanP L , S t e r n A S , N u n u e s P , Parker K P , Kaffka K L , C h u a A O , Lugg D K and Gubler U (1989) Two hlgh-affimty lnterleukln 1 receptors represent separate gene products Proc nam 4~ad S~I U S A 86, 8029-8033 12 CurtIsB M , G a l l l s B , O v e r e l l R W , M a c M a h a n C J , D e R o o s P , l r e l a n d R , E l s e n m a n J , D o w e r S K andSlms J E (1989) T-Cell mterleukm 1 receptor cDNA expressed m chinese hamster ovary cells regulates functional responses to mterleukm 1 Proc natn Acad Scl U S A 86, 3045- 3049 13 Dantzer R and Kelley K W (1989) Stress and lmmumty an integrative view of relationship between the brain and the immune system Life Sct 44, 1995-2008 14 Dmarello C A, (1988) Biology of mterleukln-1 FASEB 2, 108 114 15 DowerS K , K r o n h e l m S R , M a r c h C J , C o n l o n P J , H o p p T P , G d h s S a n d U r d a l D L (1985) Detection and charactenzatmn of high affimty plasma membrane receptors for human mterleukm 1 J exp Med 162, 50t 515 16 Farrar W L, Kdlan P L , RuffM R , Hdl J M and Pert C B (1987) Vlsuallsatlon and charactensatlon ofmterleukm 1 receptors in brain J Immunol 139, 459-463 17 Fontana A , Weber E and Dayer J M (1984) Synthesis of Interleukm l/endogenous pyrogen m the brain of endotoxm-treated mice a step in fever reduction9 J lmmunol 133, 169(~1698 18 Friedman W J , Ayer-Le Llevre L L , Ebental T , Olson L and Persson H (1990) Regulation of NGF expressmn m rat hlppocampal cultures by mterleukm-I and other inflammatory medmtors In First International Con gte~ o[ I S N I M , abstr 69, 116 19 Gmhan D and Lachman L B (1985) Interleukm-1 stmmlatlon of astroghal prohferatmn after brain injury S~wnce 228, 497-500 20 Gudlan D , Young D G , Woodward J , Brown D C and Lachman L B (1988) Interleukm-I is an astroghal growth factor m developing brain J Neurosel 8, 709 714 21 Haour F , Ban E , Mdon G , Baran D and Fdhon G (1990) Brain mterleukm-1 receptors, characterlsatmn and modulatxon after hpopolysacchande (LPS) mjectmn Prog Neuro-Endoer Immunol 3, 201 208 22 Horuck R , Huang J J , Covington M and Newton R C (1987) A biochemical and kinetic analysis of lnterleukm 1 receptor Evidence for &fferences m molecular propemes of IL-I receptors J bwl Chem 262, 16275 16278 23 Kalman M and Halos F (1989) Dlstnbutmn of ghal fibnllary aodlc protein (GFAP)qmmunoreactwc astrocvtes in the rat brain Expl Bram Res 78, 147 163 24 Katsuura G , Gottshall P E and Anmura A (1988) Identification of high-affinity receptor for mterleukln beta in the rat Biochem Bwphys Res Commun 156, 61~i7 25 Katsuura G., Gottshall P E , Dahl R R and Anmura A (1989) Interleukm-1 beta Increase prostaglandln E2 m rat astrocytes cultures, modulatory effect of neuropept~des Endocrinology 124, 3125 3127 26 Kdmn P L , Kaffka K L , S t e r n a S , W o e h l e D B, Benjamin W R , Dechmra T M , Gubler U , Farrar J J , Mizel S B and Lomedmo P T (1986) Interleukm 1 alpha and mterleukm 1 beta bind to the same receptor of T cells J lmmunol 136, 4509-4515 27 Korschmg S, Auburger G , Heumann R , Scott J and Thoenen H (1985) Levels of nerve growth factor and its mRNA m the central nervous system of the rat correlate with chohnerglc lnnervatmn Eur molec Btol Or~ J 4, 1009

30

E B ~ et al

28. Krueger J. M , Walter J . Dmarello C A , Wolff S M and Chedld L (1984) Sleep-promoting effects ot endogenous pyrogen (mterleukm 1) Am J Physzol 246, R994-R999 29 Lechan R M , Tom R , Clark B D , Cannon J G , Shaw A R , Dmarello C A and Relchhn S (1990) Immunoreactwe mterleukm-l-beta locahzatlon m the rat forebram Brain Res $14, 135-140 29a Lehmann (1974) Atlas Sterkotaxtque de la Sourzs Editions du CNRS, Pans, France 30 Levl-Montalcml R , Aloe L and Alleva E (1990) A role for nerve growth factor in nervous, endocnne, and ~mmune systems Prog Neuro-Endocr Immunol 3, I 10 31 L~eberman A P , Pltha P M , Shin H S and Shin M L (1989) Production of tumor necrosis factor and other cytokmes by astrocytes stimulated with hpopolysacchande or a neurotroplc virus Proe natn Acad Scz U S A. 86, 6348-6352 32 Lmdholm D , Heumann R , Meyer M and Thoenen H (1989) Interleukm-I regulates synthesis of nerve growth factor m non-neuronal cells of rat semuc nerve Nature 330, 658-659 33 Matsushlma K . Akahoshl T , Yamada M . Furutam Y and Oppenhmm J J (1986) Properties of a spec,fic mterleukm 1 (ILl) receptor on human Epstein Barr wrus transformed B lymphocytes Identity of ILl alpha and ILl beta J Immunol 136, 449G4502 34 McCarthy D O , Kluger M J and Vander A J (1985) The effect of peripheral and lntracerebroventncular admlmstratlon of mterleukm 1 on food intake of rat In The Physlologw, Metabohc, and Immunologl~ Actwn.~ o! lnterleukm L p 171 Alan R Llss, New York 35 Monmoto A , Murakam~ N , Nakamon T and Watanabe T (1987) Evidence for separate mechamsms of reduction of blphaslc fever reside and outside the blood-brain-barrier m rabbits J. Physwl. 383, 629-634 36 Nakashlma T , Horl T , Mort T , Kuzufuml K and M~zuno K. (1989) Recombinant human mterleukm-l/~ alters the acuwty of preopt~c thermosensmve neurons m vttro Brain Res Bull. 23, 209-213 37 Obata-Tsuto H L (1987) Light and electron microscopic study of somatostatm-hke immunoreactwe neurons m rat hlppocampus Brain Res Bull 18, 613-620 38 Perry V H , Hume D A and Gordon S (1985) Immunohlstochemlcal locahsatmn of macrophages and mlcrogha m the adult and developing mouse brain. Neuroscwnce 15, 313 326 39 Rwler C , Chlzzomte R and Vale W (1989) In the mouse, the actwatlon of the hypothalarmc-pitmtary-adrenal axis by a hpopolysacchande (endotoxm) ,s medmted through mterleukm-1. Endocrinology 125, 2800-2805 40 Robmn O , Repressa A , Jardm L and Ben-Hart Y (1989) Selechve destruction of mossy fibers and granule cells with preservation of the GABAerg~c network m the inferior regmn of the rat hippocampus after colchlcme treatment J comp Neurol 2,85, 274-287 41 Rothwell N (1989) CRF is revolved m the pyrogemc and thermogemc effects ofmterleukm-l~ m the rat Am J Phvs~ol 256, E l l l Ell5 42 Sapolsky R . Rlwer C . Yamamoto G . Plotsky P and Vale W (1987) Interleukm-I stimulates the secreuon of hypothalamlc cortlcotropm-releasmg factor. Scwnce 238, 522-524 43. Scapagliata G , Ghiara P , Bartahm M and Taghabue B. D (1989) Dlfferentml bmdmg of IL-l~ and IL-lp to receptors on B and T cell Fedn Eur bwchem Soc~ Lett 243, 394-398 44 Scarborough D E . Lee S L . Dmarello C A and Relchhn S (1989) Interleukm-1 beta sumulates somatostatm biosynthesis m primary cultures of fetal rat brain Endocrinology 124, 549-551 45 Shelton D L and Re,chart L F (1986) Stu&es on the expression of/~ nerve growth factor (NGF) gene m the central nervous system' level and regional d~stnbuuon of NGF mRNA suggest that NGF functions as a troph~c factor for several &street populations of neurons Proc natn. Acad Sc~ U S.A. 83, 2714 46 S~ms J E . March C J , Cosman D , W~dmer M., MacDonald H R., McMahan C J , Grubm C E , W~gnall J M . Jackson J L . Call S M , Friend D , Alpert A R , Gilhs S, Urdal D L. and Dower S K (t988) eDNA expression cloning of IL-I receptor, a member of the lmmunoglobuhn superfamdy Scwnce 241, 585-589 47 Slov~tzer R S. Vahquette G . Abrams G M , Ronk E C , Sollas A L , Paul L A. and Neubort S. (1989) Selective loss of h~ppocampal granule cells m the mature rat brain after adrenalectomy Science 2.43, 535-538. 48 Solan R (1990) Ident~ficauon and d~stnbuuon of two forms of mterleukm 1 receptors Cytokme 2, 21-28 49 Spadaro F , Berndge C W and Dunn A. J (1989) Interleukm-1 administration produces a stress-hke reduction of exploratory behawor m mice. Soc Neurovct Abstr 15, 8 50 Spadaro F and Dunn A J (1990) Intracerebroventncular administration of mterleukm-1 to mice alters investigation of sumuh m a novel enwronment Brain Behov Immun. 4, 252-267 51 Sundar S K , Becket K J . Oerpml M A , Carpenter M D , Rankm L A , Fleener S. L., R~tch~e J C , S~mson P E and Weiss J M. (1989) Intracerebroventncular infusion of mterleukm 1 rapidly decrease peripheral ~mmune response Proc natn Acad Sc~ U S A 86, 6398-6402 52. Swanson L W and Cowan W M (1977) An autoradmgraph~c study of the orgamsat~on of the efferent connections of the h~ppocampal formation m the rat J comp Neurol 17~, 49-84 53 Taghalatela G , Angelucc~ L , Ramacc~ M T , Foreman P J and Perez-Polo J. R (1990) 125I-/~-nerve growth factor binding ts reduced m rat brain after stress exposure. J. Neurosct. Res 25, 331-335 54 Tsagarak~s S, Gflhes G . Rees L H , Besser M and Grossman A (1989) Interleukm-I &rectly sUmulates the release of cort~cotrophm-releasmg factor from rat hypothalamus Neuroendocrmology 49, 98. 55 Uehara A., Gottschall P E , Dahl R R and Anmura A (1987) Interleukm-1 sUmulates ACTH release by an mdxrect action which reqmres endogenous corhcotropm releasmg factor. Endocrinology 121, 1580-1582 56 Urdal D. L , Call S M , Jackson S L and Dower S K (1989) Affimty purification and chemical analys~s of mterleukm-I receptor J bwl Chem. 263, 2870-2877 57. Wems J M , Sundar S K and Becker K, J (1989) Stress-reduced lmmunosuppress~on and ~mmunoenhancement cellular ~mmune changes and mechamsms In Neurotmmune Networks Physiology and Dtseases, pp 193-206 Alan R. L~ss, New York 58 Wolosk~ B M , Smith E. M , Meyer W J , Fuller G M and Blalock J E (1985) Cort~cotropm-releasmg acuv~ty of monokmes Science 2311, 1035 (Accepted 20 December 1990)