Mechanism of lymphocyte-mediated cytolysis: functional cytolytic T cells lacking perforin and granzymes - PubMed (original) (raw)
Mechanism of lymphocyte-mediated cytolysis: functional cytolytic T cells lacking perforin and granzymes
G Berke et al. Immunology. 1993 Jan.
Abstract
Involvement of the lytic protein perforin (c. 65,000 MW) and of granule proteases (granzymes) in cell lysis induced by cytolytic T lymphocytes (CTL) has been suggested, but is still controversial. For example, in vivo-primed peritoneal exudate CTL (PEL) have been found to express perforin and granzyme activity in amounts comparable to those found in non-lytic lymphocytes, although PEL are the most potent of all CTL. Exploiting several cloned CTL hybridomas developed in this laboratory and newly available molecular probes for detecting perforin, granzymes, protein and mRNA, we now directly demonstrate killer T lymphocytes which kill effectively and specifically, but are free from perforin, lytic granules and granzymes, all three of which have been postulated to be involved in lymphocyte-mediated killing. The CTL hybridomas are completely devoid of perforin and granzymes prior to, during, and after activation by antigen, mitogen or interleukin-2 (IL-2). The induction of lytic granules, perforin, and granzymes in the in vivo-primed PEL, but not in the cloned CTL hybridomas, upon cultivation in IL-2, further suggests the involvement of these constituents in antigen/lymphokine-induced CTL activation and differentiation rather than directly in their cytocidal activity. Together, these findings support a perforin- and granzyme-independent CTL lytic mechanism.
References
- Nature. 1970 Aug 15;227(5259):680-5 - PubMed
- Immunol Today. 1991 Nov;12(11):396-9; discussion 402 - PubMed
- Nature. 1974 Nov 1;252(5478):81-3 - PubMed
- J Immunol. 1977 Jan;118(1):71-6 - PubMed
- Prog Allergy. 1980;27:69-133 - PubMed
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