The natural killer (NK) cell-specific p58 molecules EB6 and GL183 have been shown to represent the putative surface receptors for two distinct groups of human histocompatibility leukocyte antigen (HLA) C alleles. Interaction between p58 receptors and class I molecules expressed on target cells results in inhibition of the NK-mediated cytolytic activity and thus in target cell protection. In the present study, we show that EB6 molecules may also act as receptors mediating NK cell triggering. Activatory EB6 molecules were found to be confined only to certain donors. Moreover, in these donors, only a fraction of EB6+ NK clones expressed the activatory form of EB6 molecules, while the remaining clones expressed the conventional inhibitory form. Biochemical analysis of the activatory EB6 molecules revealed a molecular mass of approximately 50 kD (p50), thus differing from the 58-kD inhibitory form. This difference was not due to differential glycosylation of the same protein, as revealed by deglycosylation experiments of isolated EB6 molecules. Treatment of purified p58 or p50/EB6 molecules with proteolytic enzymes, including V8-protease, chymotrypsin, and papain, showed only minor differences in the resulting peptides. Treatment with pepsin followed by two-dimensional peptide mapping demonstrated that, although the majority of peptides migrated in identical positions, differences between the two forms could be detected for at least one major peptide. Anti-EB6 monoclonal antibody (mAb)-mediated cross-linking of p50 molecules was required to trigger the cytolytic activity and the intracellular calcium ([Ca+2]i) increases in appropriate NK clones. Likewise, mAb-mediated cross linking of the p58 EB6 molecules was needed to inhibit the cytolytic activity; however, in this case, no [Ca+2]i increases could be detected. In NK clones expressing the inhibitory p58 EB6 receptors, soluble anti-EB6 mAb prevented recognition of protective Cw4 molecules and reconstituted target cell lysis. In contrast, in clones expressing the activatory p50/EB6 receptor, EB6 masking frequently resulted in partial inhibition of the cytolytic activity against Cw4+ target cells. Therefore, it appears that NK clones expressing the p50/EB6 receptors are induced to lyse Cw4+ target cells upon specific interaction with Cw4 molecules. This concept was further substantiated by experiments in which target cells were represented by the HLA-negative LCL721.221 cell line transfected with the Cw4 allele. Phenotypic and functional analysis of a large number of NK clones showed that clones expressing the activatory p50/EB6 molecules consistently coexpressed inhibitory receptors for other HLA class I alleles.(ABSTRACT TRUNCATED AT 400 WORDS)
Skip Nav Destination
Article navigation
1 September 1995
Article|
September 01 1995
Existence of both inhibitory (p58) and activatory (p50) receptors for HLA-C molecules in human natural killer cells.
A Moretta,
A Moretta
Istiuto Nazionale per la Ricerca sul Cancro, Genova Italy.
Search for other works by this author on:
S Sivori,
S Sivori
Istiuto Nazionale per la Ricerca sul Cancro, Genova Italy.
Search for other works by this author on:
M Vitale,
M Vitale
Istiuto Nazionale per la Ricerca sul Cancro, Genova Italy.
Search for other works by this author on:
D Pende,
D Pende
Istiuto Nazionale per la Ricerca sul Cancro, Genova Italy.
Search for other works by this author on:
L Morelli,
L Morelli
Istiuto Nazionale per la Ricerca sul Cancro, Genova Italy.
Search for other works by this author on:
R Augugliaro,
R Augugliaro
Istiuto Nazionale per la Ricerca sul Cancro, Genova Italy.
Search for other works by this author on:
C Bottino,
C Bottino
Istiuto Nazionale per la Ricerca sul Cancro, Genova Italy.
Search for other works by this author on:
L Moretta
L Moretta
Istiuto Nazionale per la Ricerca sul Cancro, Genova Italy.
Search for other works by this author on:
A Moretta
Istiuto Nazionale per la Ricerca sul Cancro, Genova Italy.
S Sivori
Istiuto Nazionale per la Ricerca sul Cancro, Genova Italy.
M Vitale
Istiuto Nazionale per la Ricerca sul Cancro, Genova Italy.
D Pende
Istiuto Nazionale per la Ricerca sul Cancro, Genova Italy.
L Morelli
Istiuto Nazionale per la Ricerca sul Cancro, Genova Italy.
R Augugliaro
Istiuto Nazionale per la Ricerca sul Cancro, Genova Italy.
C Bottino
Istiuto Nazionale per la Ricerca sul Cancro, Genova Italy.
L Moretta
Istiuto Nazionale per la Ricerca sul Cancro, Genova Italy.
Online ISSN: 1540-9538
Print ISSN: 0022-1007
J Exp Med (1995) 182 (3): 875–884.
Citation
A Moretta, S Sivori, M Vitale, D Pende, L Morelli, R Augugliaro, C Bottino, L Moretta; Existence of both inhibitory (p58) and activatory (p50) receptors for HLA-C molecules in human natural killer cells.. J Exp Med 1 September 1995; 182 (3): 875–884. doi: https://doi.org/10.1084/jem.182.3.875
Download citation file:
Sign in
Don't already have an account? Register
Client Account
You could not be signed in. Please check your email address / username and password and try again.
Could not validate captcha. Please try again.
Sign in via your Institution
Sign in via your InstitutionSuggested Content
Email alerts
Advertisement