Alloantiserum-Induced Inhibition of Immune Response Gene Product Function

We have previously demonstrated that guinea pig alloantisera directed at strain 2 and strain 13 membrane antigens block specific lymphocyte activation in immune response gene-controlled systems. In this communication we describe the partial characterization of the antigens against which these antisera are directed (the 2 and 13 antigens) and, in addition, that of the B antigen which by distribution resembles the human HL-A and mouse H-2 major histocompatibility antigens. Lymphoid cells from strain 2 and strain 13 guinea pigs were surface labeled with 125I by the lactoperoxidase technique. Nonidet P-40 extracts of these labeled cells were precipitated by sandwiches of strain 2 antistrain 13, strain 13 antistrain 2, or outbred anti-B antisera, followed by rabbit antiguinea pig immunoglobulin antisera. Precipitates were dissolved in sodium dodecyl sulfate (SDS) and electrophoresed on SDS polyacrylamide gels. Radioactive peaks representing the 2 and B-cell membrane antigens were obtained from strain 2 lymph node cells, as well as from a B-lymphoid cell population (L2C leukemia cells) and a T-lymphocyte population (STRAIN 2 PERITONEAL EXUDATE LYMPHOCYTES [PELs]). Radioactive peaks representing the 13 and B-cell membrane antigens were obtained from strain 13 lymph node cells and strain 13 PELs. All anti-B precipitates produced two peaks when electrophoresed on SDS polyacrylamide gels; one representing an antigen with a mol wt of approximately 45,000, and one representing an antigen with a mol wt of about 12,000. Both may be components of a single protein. All anti-2 and anti-13 precipitates produced a single peak when electrophoresed on SDS polyacrylamide gels. Both the 2 and 13 antigens were found by this technique to have mol wt of approximately 25,000. By molecular weight criteria, as well as by previously investigated distributional criteria, the B antigen is similar to the human LA and Four antigens, and to the mouse D and K antigens, and the 2 and 13 antigens are similar to the mouse Ia antigens.

Section: Discussionmentioning

confidence: 99%

Guinea pig immune response-related histocompatibility antigens. Partial characterization and distribution.

Findelman¹,

Shevach²,

Vitetta³

et al. 1975

“…Whereas most researchers fail to detect conventional immunoglobulins on or in T lymphocytes (4,7-9) others report contrariwise (2,3) . The finding that immune response genes linked to the major histocompatibility locus systems are of major importance for T-lymphocyte function, has also led to the hypothesis that T lymphocytes may use the products of such response genes as their specific antigen-binding receptors instead of using classical immunoglobulin genes (5,6). In support of this have been reports that antigen-binding specific factors from T lymphocytes may carry antigenic markers indicating them to be products of such response genes (10,11).…”

mentioning

confidence: 50%

“…The molecules with the same function on T lymphocytes, however, are still a matter of dispute (2)(3)(4)(5)(6)(7)(8)(9)(10) . Whereas most researchers fail to detect conventional immunoglobulins on or in T lymphocytes (4,7-9) others report contrariwise (2,3) .…”

mentioning

confidence: 99%

Shared idiotypic determinants on B and T lymphocytes reactive against the same antigenic determinants. II. Determination of frequency and characteristics of idiotypic T and B lymphocytes in normal rats using direct visualization.

Binz¹,

Wigzell²

1975

122

Anti-idiotypic antibodies made against the antigen-binding receptors of T lymphocytes for a given antigen (Ag-B locus antigens in rats) can be shown to react with IgG antibodies of the same antigen-binding reactivity. Using such anti-idiotypic antibodies, normal Lewis T lymphocytes of B and T type can be visualized by the use of anti-(Lewis-anti-DA) antibodies. Visualization was made possible by the use of direct fluorescent antibody tests or by autoradiography. Using the first technique and naked eye observations 6.2% of normal Lewis T lymphocytes expressed idiotypic markers signifying anti-DA reactivity, whereas anti-DA-reactive B lymphocytes as measured by this approach was in the order of 1.1%. Autoradiography was purified normal Lewis T lymphocytes gave similar figures. When comparing the intensity of fluorescence at the single cell level using quantitative cytofluorometry anti-idiotypic antibodies reactive with T lymphocytes gave a similar degree of intensity as was obtained using anti-Ig antibodies against B lymphocytes.

“…Direct attachment of the antibody to the receptor is unlikely. The antistrain 2 alloantisera do not suppress GA responses in lymphocytes from responder guinea pigs who, as the result of a crossover, inherited the ability to respond to GA but did not inherit the genes coding for the strain 2 histocompatibility antigens (7,19). Furthermore, if the suppression were due simply to the combining of antibody to the receptor, the monovalent Fab fragment should effectively suppress, and it does not.…”

Section: Discussionmentioning

confidence: 99%

“…The antihistocompatibility antibodies contained in the alloantisera are responsible for the observed immunosuppression (7,19). The experiments described in this report were aimed at elucidating the mechanisms through which antibodies directed at histocompatibility antigens alter the responsiveness of lymphocytes to antigenic stimulation.…”

Section: Discussionmentioning

confidence: 99%

ALLOANTISERUM-MEDIATED SUPPRESSION OF HISTOCOMPATIBILITY-LINKED Ir-GENE-CONTROLLED IMMUNE RESPONSES

Bluestein

1974

Fab, Fc, and F(ab)'2 fragments were prepared by enzymatic hydrolysis of the IgG fraction of strain 13 antistrain 2 alloantisera. These fragments were not cytotoxic to lymphocytes bearing strain 2 histocompatibility antigens, but the Fab and F(ab)'2 fragments retained functional combining sites as indicated by their ability to suppress the cytotoxicity mediated by the intact antistrain 2 antibodies. The F(ab)'2 fragments were much more efficient as inhibitors in this system than the Fab fragments. F(ab)'2 at 0.06 mg/ml and 0.45 mg/ml Fab produced comparable degrees of suppression. The F(ab)'2 at 0.06 mg/ml completely suppressed DNP copolymer of L-glutamic acid and L-lysine (GL)-stimulated tritiated thymidine incorporation. The monovalent Fab at 0.45 mg/ml, however, had no significant effect on the in vitro responses to DNP-GL. Addition of the intact alloantisera can be delayed 3 h after initiation of the antigen-stimulated cultures with no loss of suppression. After a delay of 6 h 45% suppression was observed. The requirement for the divalent molecule and the observation that effective suppression of the in vitro responses is still obtained when the alloantiserum is added several hours after initiation of the cultures both suggest that the immunosuppression results from an active process affecting the lymphocyte membrane that renders the cell refractory to the antigenic stimulus.