Hapten Carrier Relationships in the DNP-Pll·foreign Albumin Complex System: Induction of Tolerance and Stimulation of Cells in Vitro

Abstract

The ability of guinea pigs to recognize poly-I,-lysine (PLL), and hapten conjugates of PLL (H-PLL) as antigens is under the control of a single autosomal dominant gene which we will refer to as the PLL gene (1-3). Responder animals carrying this gene form specific antihapten antibodies and display delayed hypersensitivity reactions after immunization with H-PLL conjugates such as 2,4-dinitrophenyl-PLL (DNP-PLL); guinea pigs lacking the PLL gene are incapable of an immune response to DNP-PLL but can nevertheless recognize this conjugate as a hapten. Thus, immunization with DNP-PLL complexed with a negatively charged foreign albumin elicits the formation of high levels of anti-DNP-PLL antibodies in genetic nonresponder guinea pigs (4). Two interesting observations were made concerning the response of these guinea pigs: (a) only an antigenic foreign albumin could act as a carrier for DNP-PLL and stimulate the production of high concentrations of anti-DNP-PLL antibodies in guinea pigs lacking the PLL gene; guinea pig albumin was only marginally effective in this capacity; and (b) nonresponder guinea pigs immunized with DNP-PLL complexed with ovalbumin or bovine serum albumin did not show delayed hypersensitivity reactions to DNP-PLL in spite of the production of high levels of anti-DNP-PLL antibodies. This finding demonstrates the haptenic behavior of DNP-PLL in nonresponder guinea pigs as it has been well established that haptens are incapable of eliciting delayed hypersensitivity reactions (5-10).The process controlled by the PLL gene in the immune response to hapten-P L L conjugates is unknown. Knowledge of the mechanism which allows an immunogenic carrier to elicit an immune response in a genetic nonresponder to the D N P -P L L hapten which it bears should eventually lead to a more complete understanding of the requirements for antigenicity and should also clarify the function of the PLL gene product. This system offers several distinct advantages over other, more complex, antigenic systems because first, the hapten P L L conjugate can behave either as a complete antigen or as a *

The Requirement of More Than One Antigenic Determinant for Immunogenicity

“…In both the LDH system and the DNP-PLL-BSA system it could be shown that the induction of tolerance to the carrier led to a reduced response to a subsequent injection of carrier-hapten complex (7,12,19). In this situation the reduction of the response was quantitatively similar for both antihapten and anti-carrier antibodies (7,12).…”

TRANSFER OF RESPONSIVENESS TO HAPTEN CONJUGATES OF POLY-L-LYSINE AND OF A COPOLYMER OF L-GLUTAMIC ACID AND L-LYSINE TO LETHALLY IRRADIATED NON-RESPONDER GUINEA PIGS BY BONE MARROW OR LYMPH NODE AND SPLEEN CELLS FROM RESPONDER GUINEA PIGS

“…The in vitro responses of lymph node ceils from such animals did not regularly reach the levels previously observed in responder guinea pigs (20). The lymph nodes of irradiated animals were small and may not have been ideal sources of immunocompetent ceils.…”

“…The immune response elicited by DNP-PLL in most irradiated nonresponder recipients after the transfer of bone marrow cells from animals with the PLL gene was characterized by delayed hypersensitivity and other evidence of cellular immunity to DNP-PLL, as well as by the synthesis of significant levels of anti-DNP antibodies. Although positively charged DNP-PLL can behave as a hapten in nonresponder guinea pigs, and elicit the formation of anti-DNP antibodies when associated with a variety of immunogenic carriers (14,15), DNP-PLL has never been able to elicit delayed sensitivity in either Hartley strain or strain 13 nonresponder guinea pigs, nor has it been able to stimulate the proliferation of their lymph node cells in vitro (14,15,20). These experiments therefore establish conclusively that the ability to recognize hapten-PLL conjugates as antigens can be transferred to guinea pigs lacking the PLL gene, and that the process controlled by this gene finds expression in bone marrow derived cells.…”

Genetic Control of the Immune Response

“…In guinea pigs, antigen induced secondary in vitro lymphocyte transformation appears to be primarily a T-cell dependent function (23). In the mouse, this reaction is highly sensitive to anti-Thy-l.2 plus complement.…”