T-cell Immunoregulation and the Response to Immunotherapy

Harold S. Nelson. MDProfessor of Medicine

National Jewish Health and University of Colorado School of Medicine

Denver, Colorado, USA

Role of the T-cell in Asthma

L Cosmi, et al. Allergy 2011;

Immunologic Response:Summary

The immunologic response to allergen immunotherapy involves:1) A shift from Th2 to Th2 cytokine profile

2) The generation of regulatory T cells secreting IL-10 and TGF-,

Increases in IL-12 mRNA+

Accompany Inhibition of Allergen Late Skin Test Responses after

Successful Grass Pollen Immunotherapy

10 subjects who had received 4 years of grass pollen immunotherapy and 10 allergic controls had skin biopsies 24 hours afterintracutaneous injection of grass pollen extract.

QA Hamid,et al.J Allergy Clin Immunol 1997;99:254-60

100

80

60

40

20

0

Co

un

ts/m

Grass Pollen Count

Med

ian

Sco

re

80706050403020100

SymptomsIT Treatment

Placebo

Med

ian

Sco

re

150

120

90

60

30

0

DrugsIT Treatment

Placebo

24April

8 22May

5 19June

3 17 31July

14 28August

11 25September

Reduction in Rhinitis Symptoms and Medication from Immunotherapy

(Varney et al. BMJ. 1991;302:265-269.)

EarlyResponse

LateResponse

p<0.001 p<0.0001

50

40

30

20

10

0

Ski

n r

esp

on

se (

mm

)

140

120

100

80

60

40

20

0

Control Immunotherapy Control Immunotherapy

Hamid JACI 1997;99:254

Late Skin Response to Allergen Following Successful

Pollen Immunotherapy

• At site of late cutaneous response:- Increased cells with mRNA for IL-12- Principal source of IL-12 tissue macrophages

• IL-12+ cells correlated positively with IFN-+ cells and inversely with IL-4+

cells.

QA Hamid, et al JACI 1997

IL-12Control Immunotherapy

ns

p=0.02

Cel

ls/h

igh

po

wer

fie

ld

Diluent DiluentAntigen Antigen

Hamid JACI 1997;99:254

12

8

4

0

p=0.002

r = 0.64p < 0.05

r = -0.67p < 0.05

IFN

-

mR

NA

+ c

ells

/fie

ld

IL-4

m

RN

A+

cel

ls/f

ield

10

8

6

4

2

0 0

2

4

6

8

10

12

14

0 2 4 6 8 10 12

IL-12 mRNA+ cells/field IL-12 mRNA+ cells/field0 2 4 6 8 10 12

Hamid et al, JACI 1997;99:254

IL-10 and TGF- Cooperate in the Regulatory T Cell Response to

Mucosal Allergens in Normal Immunity and Specific Immunotherapy

Examined the normal immunoregulatory mechanism and the immunologic basis of specific immunotherapy (SIT) to Der p 1 and Bet v 1

M Jutel, et al. Eur J Immunol 2003;33:1205-14

Regulatory T Cell Response

• In normal immunity to HDM and birch pollen an allergen-specific peripheral T cell suppression to Der p 1 and Bet v 1 was observed.

• This was characterized by:- suppressed proliferative T cell, (Th1) INF-, and (Th2) IL-5, IL-13 responses- increased IL-10 and TGF- secretion by allergen-specific T cells.

Regulatory T Cell Response

• Specific immunotherapy induced an allergen-specific suppressive activity in CD4+ CD25+ T cells of allergic individuals.

• Suppression was induced by IL-10 and TGF-

• These results demonstrate a deviation towards a regulatory/suppressor T cell response during SIT similar to the “healthy” immune response to mucosal allergens.

Normal Immune Response: Downregulation of Th1 and Th2 Response by IL-10 and TGF-

*P < .01. TdR = thymidine. Jutel M et al. Eur J Immunol. 2003;33:1205-1214.

20

10

0

Contro

l

Anti-I

L-10

R

sTGFbR

Both

Contro

l

Anti-I

L-10

R

sTGFbR

Both

Der p 1Unstimulated

[3 H] T

dR (

cpm

× 1

0-9)

* ** * * *

Bet v 1Unstimulated

IL-10 and TGF- Mediated T-Cell Suppression During HDM-SIT

*P < .01 versus day 0. Jutel M et al. Eur J Immunol. 2003;33:1205-1214.

* *

**

* *

18

12

8

4

0

[3H

] TdR

[Stim

. In

dex]

0 7 28 70Days

+anti-IL-10R+sTGF-bRDer p 1+ Control Ab

Cytokine Production During HDM-SIT

HDM-SIT = house dust mite-specific immunotherapy. *P < .001. Jutel M et al. Eur J Immunol. 2003;33:1205-1214.

*4

3

2

1

00 7 28 70

Days

IL-10TGF-bIFN-gIL-13IL-5

Cyt

okin

e (

ng/m

L)

Antibody Response in Healthy Controls and Changes in Allergic Individuals During HDM-SIT

HDM-SIT = house dust mite-specific immunotherapy. *P < .01. †P < .001. Jutel M et al. Eur J Immunol. 2003;33:1205-1214.

60

40

20

060

40

20

0

U/m

LU

/mL

Healthy 0 70

IgE

IgG1

Days (SIT)

60

40

20

060

40

20

0

†

Healthy 0 70

IgA

IgG4

Days (SIT)

U/m

LU

/mL

*

*

Gerald Gleich: Effect of 6 Years of Immunotherapy on IgE and IgG Antibodies to Ragweed (1982)

Antibody levels were monitored 2 years before and 4 years following institution of ragweed immunotherapy.

Before immunotherapy patients ragweed-specific IgE rose with each pollen season and declined off season.

With immunotherapy there was an abrupt rise in specific IgE, but the seasonal increases were blocked, and IgE levels gradually declined.

Specific IgG rose with immunotherapy and remained high.

G Gleich et al. J Allergy Clin Immunol 1982;70:261-71

J73O J74O J77O J79OM J76O J78O

1000

500

100

50

10

IgE

An

tibo

dy

to S

RW

, n

g/m

l

Effect of Ragweed Immunotherapy on Specific IgE Levels

Immunotherapy

G Gleich et al. J Allergy Clin Immunol 1982;70:261-71

Immunologic Response:Summary

The immunologic response to allergen immunotherapy involves:1) A shift from Th2 to Th1cytokine profile 2) The generation of regulatory T cells secreting IL-10 and TGF-,

What is the relationship between the two immune responses?

Sublingual Immunotherapy Induces IL-10-producing T Regulatory Cells, Allergen-specific T-cell Tolerance,

and Immune Deviation

• 9 subjects underwent SLIT with a 4-week build up to a daily dose of birch pollen extract containing 4.5 mcg Bet v 1.

• Assessments were made prior to treatment, on reaching maintenance after 4 weeks and after one year.

B Bohle, et al. J Allergy Clin Immunol 2007;120:707-13

Immune Response to Sublingual Immunotherapy: 4 Weeks

After 4 weeks of SLIT:• Circulating CD4+CD25+ cells were increased

(from 15% to 35%)• PBMC proliferation in response to Bet v 1, Mal d

1 (apple) and tetanus toxoid were decreased from baseline.

• Before treatment depletion of CD4+CD25+ cells decreased proliferation. After 4 weeks depletion resulted in increased proliferation with all 3 antigens.

B Bohle, et al. J Allergy Clin Immunol 2007;120:707-13

Immune Response to Sublingual Immunotherapy: 4 Weeks

• mRNA expression in antigen stimulated T-cells was decreased for IL-4 and IFN- and increased for IL-10.

• Neutralization of IL-10 in cultures significantly increased PBMC proliferation.

• FoxP3 expression in CD3+ T-cells was increased.

B Bohle, et al. J Allergy Clin Immunol 2007;120:707-13

Immune Response to Sublingual Immunotherapy: 52 Weeks

After 52 weeks of SLIT:• Circulating CD4+CD25+ cells were

decreased (from 35% to 21%)• PBMC proliferation in response to Bet v 1,

was decreased from baseline, but response to Mal d 1 and TT returned to baseline.

• CD4+CD25+ depletion decreased proliferation to antigen.

B Bohle, et al. J Allergy Clin Immunol 2007;120:707-13

Immune Response to Sublingual Immunotherapy: 52Weeks

• mRNA expression in antigen stimulated T-cells was decreased for IL-4 and IL-10 compared to baseline, while mRNA for IFN- was increased.

• FoxP3 expression in CD3+ T-cells was normal.

B Bohle, et al. J Allergy Clin Immunol 2007;120:707-13

Time (weeks)

*

**

Bet v 140

20

0 4 52

30

10

Pro

life

rati

on (

dp

m x

103 )

0

Allergen stimulated proliferation of PBMCs (solid bars) and CD25+ depleted PBMCs (open bars)

B Bohle, et al. J Allergy Clin Immunol 2007;120:707-13

Pro

lifc

rati

on (

SI)

Time (weeks)

0 4 52 0 4 52

Time (weeks)

**

**

Mal d 1 Tetanus toxoid

60

80

40

20

0

60

80

40

20

0

Allergen stimulated proliferation of PBMCs (solid bars) and CD25+ depleted PBMCs (open bars)

B Bohle, et al. J Allergy Clin Immunol 2007;120:707-13

Fol

d in

crea

se o

f m

RN

A

IL-4 IFN-

*

1.5

2.0

2.5

3.0

3.5

4.0

1.0

0.5

0

IL-10 TGF- FoxP3

Changes from Baseline in mRNA Expression in Unstimulated PBMCs

Open bars 4 weeks: Filled bars 52 weeks

B Bohle, et al. JACI 2007;120:707-13

P < .05

SLIT Induces IL-10-producing T Regulatory Cells, Allergen-specific

T-cell Tolerance, and Immune Deviation: Conclusions

• The early immune response to SLIT is IL-10 secreting regulatory T cells with non-allergen specific T cell suppression.

• By one year, regulatory T cells have declined, replaced by allergen-specific T cell suppression and enhanced IFN- production.

B Bohle, et al. J Allergy Clin Immunol 2007;120:707-13