A Long-Term Nonprogressor’s Journey into HIV-1 Disease:

Association with Escape from Cellular Immune Control

Kimdar S. Kemal, Ph.D.Wadsworth Center Albany, New York

COLLABORATORSMRC, HumanImmunology Unit,Oxford, UK – Tara Beattie – Tao Dong– Julian Sutton– Hongbing Yang – Yang Chun Peng– Sarah Rowland-Jones

U. Toronto

Rupert Kaul

Wadsworth Center

– Harold Burger

– Barbara Weiser

– Sean Philpott

Los Alamos National Laboratory

– Carla Kuiken

– Dorothy LangU. Pennsylvania Ronald Collman

BACKGROUND

A small proportion (1-5%) of patients remain free of HIV-related disease without antiretroviral therapy for at least 10 years of infection.

Such individuals are known as long term nonprogressors (LTNP).

Background cont.

Transition from LTNP infection to HIV-1 disease presents an opportunity to investigate pathogenesis and disease progression in a defined immunogenetic background.

PATIENT We studied a Caucasian male, who was exposed to HIV-1 in May 1982 by sexual contact with a man who later developed AIDS.

He remained disease-free without ART for over 18 years; however he recently showed signs of progression.

Viral Load and CD4+ T Cell Count.

0

100

200

300

400

500

600

700

Jan-96

Dec-96

Nov-97

Oct-98

Sep-99

Aug-00

Jul-01

Jun-02

May-03

Apr-04

Sample Collection Dates

CD

4 +

T c

ell

co

un

t/m

m3

0

1

2

3

4

5

6

HIV

-1 R

NA

lo

g

co

pie

s/m

l

CD4 + T cell count

HIV-1 RNA copies/ml

ART started

Objective

To examine the virologic and cellular immunologic aspects of the transition from LTNP to progressive disease.

METHODS

We obtained full-length and serial HIV-1 genomic RNA sequences from plasma.

Methods cont.

A total of 50 autologous peptide epitopes (37 HLA class I and 13 class II peptides), based on the patient’s viral sequences and described for his HLA alleles, were screened by using IFN- ELISpot assays.

Methods cont.The assays were performed using PBMC obtained before and after disease progression.

RESULTS

Virology

No clearly attenuating mutations or

deletions in the patient’s HIV-1

sequences were identified.

The length of the V2 region increased from 44/45 amino acids in 1998-2001 to 51/52 amino acids in 2002-2004 .

HIV-1 gp120, V2 sequence alignmentsV2 insertion site Length

pNL4-3 FFYKLDIVPI ~~~~~~~~~~ ~~~~~~~~~~ DNTSYRLISC 38

WC3-498 L..R..V... KNNSTSY~~~ ~~~~~~~~~~ -.......N. 44

WC3-999 L..R..V... GN~~~~~DTA SF~~~~~~~~ -.N.....N. 44

WC3-901 L..R..V..L KN~~~~~DSA SYY~~~~~~~ -.......N. 45

WC3-602 L..R..V... GN~~~~~DTA SFNNSYNNSY --N.....N. 51

WC3-1202 L..R..VT.. KN~~~~~DEN NTSEGNNTS~ ........N. 52

WC3-603 L..R..V... GN~~~~~DTN SFNNSYNNSY .--.....N. 51

WC3-704 L..R..V... EN~~~~~DTN SFNNSYNNSY .--.....N. 51

. Identity with pNL4-3 strain, - deletions, ~ absence of

insertions

Results cont.

Throughout the course of infection the patient’s virus utilized the CCR5 coreceptor.

Insertions in the HIV-1 gp120, V2 domain, have been described to enhance CCR5 coreceptor usage.

Results cont.

Immunology Before disease progression, PBMC from this patient made detectable IFN- responses to 8 class I (CD8) and 3 class II (CD4) epitopes targeting 4 HIV-1 genes (env, gag, pol and nef).

Results cont.

After disease progression, his PBMC made detectable IFN- response to 12 class I (CD8) and 4 class II (CD4) epitopes spanning 4 genes (env, gag, pol, and nef).

CD4+ and CD8+ T cell responses before and after disease progression.

0 200 400 600 800 1000

A1, B8 Nef VT15

A6801 RT AK9

B51 gp160 LI9

B51 p24 NL10

B51 RT VL9

B8 gp160 RL12

B8 gp160 YL8

B8 Nef FL8

B8 Nef WM8

B8 p17 EI9

B8 p17 EL9

B8 p17 GL8

B8 p24 GI9

DR gp160 TR13

DR p24 KY15

DR Int QR15

DR p24 GI15

DR Int KR15

Au

tolo

go

us

pep

tid

e ep

ito

pe

SFU / Million PBMC

CD4+ T cell responses

CD8+ T cell responses

2002

2004

Results cont.

The transition from LTNP to progressive disease was associated with CTL escape and targeted depletion of HIV-1-specific CD4+ T cells.

Results Cont.

A dramatic loss in T cell recognition was seen to the emerging env gp160 YL8 and Nef AL9 epitope variant.

A concomitant loss of recognition was seen towards the p24 KY15 CD4+ T cell epitope despite the absence of sequence variation over time in this epitope.

gP160 B8 YL8 epitope

04/1998 QARVLAVERY LKDQQLLGLW GCSGKLICTT 09/1999 .......... .......... .......... 09/2001 .......... .R........ ..........06/2002 .......... .R........ ..........12/2002 .......... .R........ ..........06/2003 .......... .R........ ..........07/2004 .......... .R........ .......... 

0

200

400

600

800

1000

1999 2002 2004

Sample year

SF

U /

Mil

lio

n P

BM

C

YLKDQQLL

YLRDQQLL

gp160 YL8 CD8+ T cell epitope

NT

Nef: B51 AL9 180 190 20008/1992 MEDPEKEVLV WKFDSRLAFH HMARELHPEY 03/1993 .......... .......... ..........10/1993 .......... .......... ..........04/1998 .........M .......... ..........06/2002 .......... .........R .........12/2002 .......... .........R ..........06/2003 .......... .........R ..........07/2004 .......... .........R ..........

0

200

400

600

800

1000

2004Sample year

SF

U/M

illio

n P

BM

C

WKFDSRLAFHHMARELHPEY

WKFDSRLAFRHMARELHPEY

Nef AL9 CD8+ T cell epitope

gag: DR KY15 270 280 290

08/1992 IYKRWIILGL NKIVRMYSPT SILDIRQGPK 03/1993 .......... .......... ..........10/1993 .......... .......... ..........04/1998 .......... .......... ..........12/2002 .......... .......... ..........06/2003 .......... .......... ..........07/2004 .......... .......... ..........

gag KY15 CD4+ T cell epitope.

CONCLUSIONS

In this patient the LTNP phase was associated with: A broadly directed T cell immune response.

The presence of elongated V2 domain. Consistent usage of coreceptor CCR5 throughout the course of infection.

Conclusions cont.

The transition from LTNP to progressive disease was associated with:

The acquisition of viral mutations conferring CTL escape.

Targeted depletion of HIV-1-specific CD4+ T cells.

Conclusions cont.

These data help to identify the correlates of protection from disease progression.

We thank the patient for his long-term participation in the study.