T cell receptor V beta gene utilization in myelin basic protein specific clones from CXJ1 recombinant inbred mice

Myelin basic protein-specific T lymphocytes induce chronic relapsing experimental autoimmune encephalomyelitis in lymphocyte-deficient (SCID) mice

Myelin basic protein (BP)-specific T lymphocyte cell lines were selected from the lymph nodes (LN) of BP-immunized, H-2d, CXJ-1 mice prior to the onset of clinical disease. These CD4+ T cells induced severe acute experimental autoimmune encephalomyelitis (EAE) in MHC-compatible (H-2d), lymphocyte-deficient (SCID) mice (C.B-17scid/scid). The incidence of disease was much higher in immunodeficient SCID mice (71%) than in syngeneic immunocompetent CXJ-1 mice (5%). SCID mice with EAE had an acute progressive paralytic disease with inflammation and myelin loss detected in the spinal cord. Eighty-six percent (12/14) of mice followed for more than 2 weeks had 1 or more relapses of EAE. These results demonstrate that clinical remission and relapse of EAE can be induced by the single adoptive transfer of a LN-derived BP-specific T cell line in the absence of host-derived effector and regulatory lymphocytes. Furthermore, the data demonstrate that the pathogenic potential of BP-specific T cells is greater in lymphocyte-deficient SCID mice compared with immunocompetent mice, suggesting that autoreactive T cells are controlled by potent inhibitory mechanisms associated with regulatory lymphocytes. These results are relevant to mechanisms of disease remission and relapse mediated by lymphocytes involved in paralytic inflammatory diseases such as multiple sclerosis (MS).

Arthritis induced by proteoglycan aggrecan G1 domain in BALB/c mice. Evidence for t cell involvement and the immunosuppressive influence of keratan sulfate on recognition of t and b cell epitopes

Our previous work showed that the proteoglycan aggrecan can induce erosive polyarthritis and spondylitis in BALB/c mice, and that the G1 domain of the proteoglycan aggrecan (G1) is the arthritogenic region. In this study, two T cell epitopes residing on G1 within residues 70-84 (peptide G5) and 150-169 (peptide G9) were identified using synthetic peptides and aggrecan-specific T cell lines. Two G1-specific T cell hybridomas exclusively responded to peptide G5. When the G5-specific T cell line was injected intraperitoneally into BALB/c mice, it induced acute inflammatory arthritis in joints, but only in those that had been injected with the epitope recognized by these T cells. Furthermore, we also demonstrate that the keratan sulfate chain(s) (KS) on G1 possess immunosuppressive properties with respect to T and B cell epitope recognition. T cell lines that recognize both G1 and peptide G5 show an increased response to G1 after KS is removed. Antibodies in hyperimmune sera of mice immunized with G1 show increased epitope recognition (quantitative and qualitative) after KS removal before immunization. These studies reveal that a T cell line specific to an epitope on the G1 domain of aggrecan, also recognizing a corresponding mouse G1 epitope, can induce arthritis by adoptive transfer and homing to the intraarticular epitope, thereby implicating T cells in arthritis development caused by immunity to the G1 domain of aggrecan. Moreover, the presence of KS on G1 can inhibit arthritis development by suppressing T and B cell epitope recognition.

Induction of a heterogeneous TCR repertoire in (PL/JXSJL/J)F1 mice by myelin basic protein peptide Ac1-11 and its analog Ac1-11[4A]

Experimental autoimmune encephalomyelitis (EAE) serves as a rodent model of the autoimmune disease multiple sclerosis. In mice, EAE is induced by immunizing with spinal cord homogenate, components of the myelin sheath, such as myelin basic protein (MBP) or proteolipid protein (PLP), or peptides derived from these components. EAE can be induced in H-2u or (H-2u x H-2s)F1 mice with the N-terminal peptide of MBP, Ac1-11. Coimmunization with Ac1-11 and Ac1-11[4A], an analog in which lysine at position four is substituted with alanine, prevents EAE. The mechanism of inhibition has not been elucidated, but probably does not work through MHC blockade, T cell anergy or clonal elimination of encephalitogenic T cells. We have isolated T cell clones and hybridomas from (PL/J x SJL/J)F1 mice immunized with either Ac1-11 alone or Ac1-11 and Ac1-11[4A] and analysed these cells for differences in their T cell receptor repertoire and in vitro response. Although T cells elicited by coinjection of Ac1-11 and Ac1-11[4A] expressed TCR that used V alpha and Vbeta gene elements similar to those elicited by Ac1-11 alone, they differed in the sequences of the junctional region of the alpha chain. Most of these T cells also responded less well to Ac1-11 in vitro, suggesting that coinjection of Ac1-11 and Ac1-11[4A] preferentially activates T cells bearing TCR of different affinity for Ac1-11 bound to I-A(u), and which may therefore be less encephalitogenic. Furthermore, our results show that a more diverse repertoire of V alpha and Vbeta genes are elicited by Ac1-11 in (PL/J x SJL/J)F1 mice compared to PL/J and B10.PL mice, providing further evidence that a restricted TCR repertoire is not required for the development of autoimmune disease.