Interaction between MHC-encoded products and cloned T cells

The interaction between class I major histocompatibility complex (MHC) products and T cells was studied using H-2K^b-specific alloreactive T-cell lines and clones obtained by repeated in vitro stimulation with allogeneic cells. Induction of proliferation of these T cells appeared to involve two signals: the H-2K^b alloantigen and interleukins. Immunopurified liposome-inserted H-2K^b, which stimulates specific secondary in vitro cytotoxic T lymphocyte (CTL) responses, could not replace cell-associated H-2K^b in the stimulation of these T-cell lines, even in the presence of feeder cells and interleukins. When T-cell lines were initiated in vitro and repeatedly stimulated with H-2K^b liposomes and feeder cells, it was possible to obtain T cells that could proliferate in response to H-2K^b liposomes in the presence of feeder cells and interleukin-2-containing supernatants or on H-2K ^b -expressing cells. Only stimulation with cells permitted maintenance of these T cells in culture for more than 12 weeks. Analyses of cell surface markers and of patterns of inhibition of proliferation by monoclonal antibodies (mAb) of T-cell lines induced in vitro with cell- or liposome-associated H-2K^b indicated that T-cell stimulation by class I antigen can occur in at least two ways. In the first, the H-2K^b-induced proliferation of Lyt-1^- Lyt-2⁺ T4^- T cells is inhibited by H-2K^b- and by Lyt-2-specific mAb, but not by Ia or T4-specific mAb. In the second, both Lyt-2⁺ and T4⁺ T cells are involved and the H-2K^b-induced proliferation is inhibited by H-2K^b- and Lyt-2-specific mAb and by Ia- and T4-specific mAb.Abbreviations used in this paper Ab antibody - mAb monoclonal antibody - C complement - i.p. intraperitoneally - PBS phosphate-buffered saline - PBS-B-N PBS containing bovine serum albumin and NaN₃ - CTL cytotoxic T lymphocyte - Th T helper cell - MHC major histocompatibility complex - PMA 4-phorbol 12-myristate 13-acetate - SCA concanavalin A-stimulated rat spleen cell supernatant - SC16 EL4 clone 16 supernatant - IL-1 interleukin-1 - IL-2 interleukin-2 (T-cell growth factor) - FCS fetal calf serum - H-2K^b-lip. H-2K^b inserted in liposomes - C. E. cell equivalents     

Fine specificity and T-cell receptor β-chain gene rearrangements of five H-2Db-specific cytotoxic T-cell clones

A panel of cytotoxic T lymphocyte clones that recognize H-2^b target cells has been established. Six different clones were distinguished according to the following criteria. First, the fine specificity of the clones was determined by testing proliferation and cytotoxicity on target cells of recombinant mice. Clone 221 recognized H-2K^b, and five other clones recognized H-2D^b. Clone 433 distinguished itself from the other five D^b-specific clones by cross-reacting with an antigen on H-2^k cells. Second, the presence of an idiotypic determinant as defined by the 3179 clone-specific monoclonal antibodies was investigated in cytotoxicity inhibition experiments. One of the D^b-specific clones, 653, was inhibited by these antibodies and was therefore clearly different from the other D^b-specific clones. The third criterion involved the rearrangement pattern of the DNA coding for the chain of the T-cell receptor. Southern blot analysis showed that each clone had a unique pattern. Interestingly, clone 653 , which expresses the same idiotypic determinant as clone 3F9, had deleted the C 1 gene cluster, whereas this gene is functionally expressed in clone 3179.Abbreviations used in this paper C constant gene segment - Con A concanavalin A - CTLs cytotoxic T lymphocytes - D diversity gene segment - ³H-dThd tritiated thymidine - J joining gene segment - kb kilobase pairs - LPS lipopolysaccharide - MHC major histocompatibility complex - MLC mixed lymphocyte culture - SDS sodium dodecyl sulfate - V ariable gene segment     

Selective destruction by formaldehyde fixation of an H-2Kb serological determinant involving lysine 89 without loss of T-cell reactivity

In preparation for functional analyses, a study of the binding of H-2K^b-specific monoclonal antibodies (mAb) to formaldehyde (FOR)-fixed H-2^b spleen or tumor cells revealed that three of nine mAb tested had lost reactivity with the FOR-fixed cells, whereas the reactivity of the other mAb generally did not diminish. Comparison of the reactivity of these mAb on untreated H-2K ^bm mutant cells and on FOR-treated H-2K^b cells suggests that for three mAb the total loss of reactivity on the latter could be a consequence of the alteration by FOR of lysine 89, which is substituted by alanine in mutant bm3. H-2KP^b-specific alloreactive polyclonal or monoclonal CTL, all of which had retained reactivity with bm3 target cells, had also retained reactivity with FOR-fixed H-2^b cells as indicated by cold target inhibition studies. The H-2K^b-specific CTL were probably reactive with conformational determinants of H-2K^b, which are dependent on the integrity of both the 1 and the 2 domains of the H-2K^b molecule. Results are compatible with FOR treatment selectively affecting a serological determinant in the 1 domain without affecting conformational-type CTL determinants.Abbreviations used in this paper CTL cytotoxic T lymphocyte - FOR formaldehyde - PBS phosphatebuffered saline - FCS fetal calf serum - mAb monoclonal antibody - TNBS trinitrobenzene sulfonate     

Multiple cytolytic T-cell clones with distinct cross-reactivity patterns coexist in anti-self + hapten cell lines

C57BL/10 T cells sensitized with TNBS-treated syngeneic cells and maintained in culture by repeated stimulations exhibit high cytolytic activity toward syngeneic TNBS-treated target cells with marked cross-reactivity on TNBS-treated target cells from mice of independent H-2 haplotypes (ten tested). The analysis of the reactivities of 48 T-cell clones derived by limiting dilution from such T-cell populations revealed three types of cytotoxic T-cell clones: (1) clones restricted by H-2K^b + TNP without cross-reaction on TNBS-treated or untreated target cells of other tested mouse haplotypes; (2) clones that lysed H-2^b + TNP and also TNBS-treated target cells from not more than one, two or three different H-2 haplotypes; (3) clones that lysed untreated H-2^k target cells. No T-cell clone was found to exhibit the wide pattern of cross-reactivity on any TNBS-treated mouse cell, characteristic of the original T-cell populations, indicating that these were composed of individual T-cell clones specific for TNP + private or for TNP + distinct public H-2 determinants. Correlation with described serological public H-2 specificities was possible for some cytotoxic T-cell clone reactivity, but not for others. The general pattern of T-cell reactivity as revealed by clonal analysis in this study, as well as in published work, includes cross-reactions between self H-2^a + X and allogeneic H-2ⁿ + X, between self H-2^a + X and unmodified allogeneic H-2ⁿ, or between allogeneic H-2ⁿ and allogeneic H-2^m + X, and is consistent with the hypothesis that MHC-class restriction is the main rule in T-cell recognition.Abbreviations used in this paper CTL cytotoxic T lymphocyte - TNBS trinitrobenzene sulfonate - TNP trinitrophenyl - TNCB trinitrochlorobenzene - H-2 mouse major histocompatibility complex - IL-2 interleukin 2 - Con A concanavalin A - FCS fetal calf serum - SCA IL-2 containing supernatant - LPS E. coli lipopolysaccharide - X a non-H-2 conventional antigen     

Somatic cell variants of H-2k: b: A point mutation in the first extracellular domain results in altered immune recognition

A cell-surface-associated variant H-2K product was expressed by an Abelson virus-induced pre-B-cell line after chemical mutagenesis with ethyl methane sulfonate. The variant cell line (R8.313) was previously demonstrated to have altered allodeterminants in K^b as demonstrated by both K^b-specific monoclonal antibody binding and alloreactive cytotoxic T lymphocyte (CTL) cytolysis. The mutant H-2K ^b gene from R8.313 was cloned and characterized in detail. DNA sequence analysis of the region of the gene corresponding to the three extracellular domains identified a single point mutation resulting in a leucine-to-phenylalanine substitution at amino acid residue 82. The site of mutation within the 1 domain was confirmed by oligonucleotide hybridization analysis. Mouse L-cell fibroblasts transfected with the mutant gene were recognized with the same monoclonal antibody binding and CTL lytic pattern as the R8.313 cell line, confirming that the altered phenotype of the mutant cell line was due to a point mutation in the H-2K ^b gene. These data further extend the hypothesis that the region of amino acid residues 70–90 in the 1 domain is important in the formation of both antibody and CTL-defined recognition structures on major histocompatibility complex class I molecules.     

Target-cell recognition by cloned lines of influenza virus-specific cytotoxic T lymphocytes. Selective inhibition by a monoclonal H-2-specific antibody

A monoclonal H-2^d-specific antibody markedly inhibits target-cell lysis mediated by two influenza virus A/JAP/57-specific, H-2K ^d -restricted cloned CTL lines. Three other A/JAP/57-specific, H-2 ^d -restricted CTL clones (two of which are also restricted to H-2K ^d in target-cell recognition) are only minimally inhibited by this monoclonal antibody. The inhibitory effect of the antibody is not due to selective binding to certain cloned CTL lines but rather is due to blocking of a determinant on the target cell. The monoclonal antibody produces partial inhibition of lysis mediated by a heterogeneous population of A/JAP/57-specific, H-2 ^d -restricted CTL. Likewise the profound, selective inhibition of cytolysis produced by the H-2^d-specific monoclonal antibody could not be reproduced with a conventional H-2^d alloantiserum. These observations suggest that more than one site on a particular H-2K or H-2D molecule can serve as a determinant for H-2-restricted CTL recognition. They furthermore imply that there is more than one recognition structure (receptor) for self MHC products clonally distributed among a population of H-2-restricted CTL directed to a particular antigen.     

Variable spread of X inactivation affecting the expression of different epitopes of the Hya gene product in mouse B-cell clones

Cloned B-cell lines from a female T16H/XSxr mouse in which Tdy expression was suppressed due to X inactivation and from a male X/XSxr mouse, both of the (kxb)F₁ haplotype, were examined for H-Y expression. This was determined both by their ability to act as targets for H-2^k and H-2^b-restricted H-Y-specific cytotoxic T cells and by their ability to stimulate the proliferation of H-2K^k, H-2D^b (class I) and A^b (class II)-restricted T-cell clones. In B-cell clones from the T16H/XSxr mouse, expression of H-Y/D^b exhibited partial X inactivation and only a proportion ( 30%) of the cells were targets for or stimulated H-2D^b-restricted H-Y-specific T cells. In contrast, H-Y eiptopes restricted by H-2^k (H-Y/K^k, H-Y/D^k) and A^b (H-Y/A^b) exhibited no X inactivation. Furthermore, no inactivation of H-Y/D^b, H-Y/A^b, or H-Y^k was observed in the male X/XSxr mouse. These results indicate that the T16H/XSxr female is a mosaic, as a result of the variable spread of X inactivation into the Sxr region. They further suggest that the H-Y antigen recognized in association with H-2^k and H-2D^b class I molecules and A^b class II molecules may be the product of more than one gene.     

MHC recognition by clones of Mls specific T-lymphocytes

To test whether M1s determinants, like other non-MHC or nominal antigens, are recognized by T-cells in association with H-2 determinants, the in vitro proliferative responses of T-cell lines and clones were studied. Lines and clones were prepared by soft agar cloning (B10.BR x BALB/c)F₁ (H-2^k/H-2^d, M1s^b/M1s^b) T-cells responding in a primary MLR to AKD2F1 (H-2^k/H-2^d, M1s^a/M1s^a) stimulator cells. All the T-cell clones obtained could respond equally well in a proliferative assay to the Mls^a determinant in association with the H-2 haplotype of either parent, i. e., DBA/2 (H-2^d, M1s^a), and AKR (H-2^k, M1s^a) both stimulated equally well. When the T-cell lines and clones were screened against stimulators from recombinant inbred (RI) strains, it became apparent that strains exhibiting the H-2^b, M1s^a genotype stimulated poorly or not at all. This shows that the T-cell response to M1s^a involves MHC recognition, and raises the possibility that the response to M1s^a can involve recognition of H-2 specificities shared between the H-2 ^k and H-2 ^d haplotypes.Abbreviations used in this paper MHC major histocompatibility complex - MLC mixed lymphocyte culture - IL-2 interleukin 2 - Con A concanavalin A - RI recombinant inbred Howard Hughes Medical Institute     

Functional requirements of (Phe,G)-A--L-specific T-cell clones of (H-2 b x H-2 kF1 origin

T-cell clones specific for the synthetic polypeptide antigen poly(LPhe, LGlu)-poly(DLAla)--poly(LLys) of (C57BL/6 x C3H/HeJ)F₁ origin were tested for their biological activities. One group of clones was restricted in its proliferative response to the H-2 ^b haplotype, the second to the H-2 ^k haplotype, and the third to the F₁ unique Ia determinants. All the clones which proliferated in response to antigen secreted interleukin-2 (IL-2) following stimulation. The H-2 restriction of the IL-2 secretion was the same as that of the proliferation. Two of the clones tested, C.6 and C.10, could provide help to B cells in antibody production. However, the genetic restriction profile of the helper activity was less stringent than that for the proliferative response. Thus, C.6, which proliferated in the presence of F₁ antigen-presenting cells only, could help B cells and accessory cells of C3H/HeJ. C.10, which was restricted in its proliferative response to the H-2 ^b haplotype, could collaborate with B cells and accessory cells of the H-2 ^k haplotype as well. The antibody response of both clones was restricted to the parental or F₁ strains.Abbreviations used in this paper (T, G)-A-L poly-(LTyr, LGlu)poly(DLAla)--poly(LLys) - (Phe, G)-A--L poly(LPhe, LGlu)-poly(DLAla)--poly(LLys) - APC antigen-presenting cells - Con A concanavalin A - FCS fetal calf serum - IL-2 interleukin-2     

Host-determined T cell fine specificity for self-H-2 in radiation bone-marrow chimeras of standard C57BL/6 (H-2b) mutantHz1 (H-2ba), and F1 mice

Reciprocal radiation bone-marrow chimeras were produced between the standard C57BL/6 (=B6) and the mutant B6.C-H-2 ^ba (=Hz1) strain. When infected with vaccinia virus, these chimeras, as well as an (Hz1 × B6)= Hz1 chimera, produced cytotoxic cells that killed vaccinia-infected H-2K^kH-2D^b target cells but failed to kill virus-infected H-2K^bH-2D^d cells. Virus-infected (Hz1 × B6)F₁ B6 chimeras, however, killed both types of target. These experiments demonstrate strict T-cell specificity capable of differentiating between two molecules that apparently differ by a single amino acid substitution.     

The complete amino acid sequence of the murine transplantation antigen H-2Db as deduced by molecular cloning

A mouse cDNA library derived from the EL4 cell line (b-haplotype) was screened with a probe containing a small part of the H-2K^b coding region. One of the clones isolated, pH203, encodes a protein whose deduced amino acid sequence is identical with the known sequence of H-2D^b in 141 of 141 positions available for comparison. The clone, therefore, is believed to code for the H-2D^b transplantation antigen. The cDNA insert of pH203 contains the coding region for residues 82 through the carboxy-terminus of H-2D^b, and includes 476 nucleotides of the 3-untranslated sequence. Comparison between the H-2D^b cDNA clone and a previously isolated H-2K^b cDNA clone shows homologies of 83% and 91% at the amino acid and nucleotide levels, respectively. Analysis of DNA sequences at the 3-coding and untranslated regions suggests that the mRNAs of H-2K^b and H-2D^b are spliced differently at their 3-coding ends.     

Resistance to cell-mediated cytotoxicity is correlated with reduction of H-2K gene products in AKR leukemia

AKR leukemia cell lines differing in the amount of H-2K and H-2D antigens expressed on the cell surface were used to assess cell-mediated immune responses in syngeneic mice against Gross/AKR murine leukemia virus (MuLV)-induced tumors. Leukemic cells with reduced expression of H-2K^k antigens were inactive as inducers of Gross-MuLV/H-2^k-specific cytotoxic T lymphocytes (CTL) and resistant to lysis by CTL raised against H-2K^k positive AKR leukemia cells. H-2K^k positive leukemias induced cytotoxic effectors, which upon restimulation in vitro, lysed the stimulating and other H-2K^k positive leukemia cells. In antibody inhibition experiments, T-cell-mediated cytotoxicity to these leukemias could only be inhibited by antisera and monoclonal antibodies specific for the H-2K^k antigens. Due to this specific role of H-2K^k antigens in T-cell cytotoxicity to Gross/AKR MuLV-induced tumors, reduced expression of H-2K^k antigens on spontaneous AKR leukemic cells could have important implications for surveillance of these neoplastic cells.Abbreviations used in this paper CTL cytotoxic T lymphocytes - MuLV murine leukemia virus     

Dissociation ofH-2 recognition by antibody and cytotoxic T cells of a cloned murine leukemia cell line

The differential expression of H-2 specificities recognized by antibody and by cytotoxic T lymphocytes (CTL) has been studied using a clone (FY7) of the C57BL/6 leukemia cell line FBL-3 (H-2 ^b /H-2 ^b ). Unlike C57BL/10 spleen cells, EL-4 lymphoma cells and Y57-2C leukemia cells (allH-2 ^b /H-2 ^b ), FY7 failed to induce the primary in vitro generation of anti-H-2^b CTL by (B10.A x A)F₁ (H-2 ^a /H-2 ^a or (B10.D2 x BALB/c)F₁ (H-2 ^d /H-2 ^d ) responder spleen cells. In addition, FY7 was not lysed by, and did not competitively inhibit anti-H-2^b CTL. Quantitative absorption tests with H-2K^b and H-2D^b antisera revealed that FY7 expressed these antigens in quantitatively similar amounts to EL-4. The H-2K^b product of FY7 appeared to be identical with that of C57BL/10 spleen cells both in apparent molecular weight and isoelectric point. Yet FY7 failed to inhibit anti-H-2K^b CTL competitively in a cold target inhibition assay. Possible mechanisms are discussed for the lack of T-lymphocyte recognition of the H-2K^b-gene product expressed by FY7.Abbreviations used in this paper CTL cytotoxic T lymphocytes - MHC major histocompatibility complex - MLC mixed lymphocyte culture - PAGE polyacrylamide gel electrophoresis     

Anti-MHC immunity detected prior to intentional alloimmunization

Cell fusion was performed between spleen cells from young BALB/cBy (H-2 ^d) mice which have never been immunized and SP2/0 mouse plasmacytoma cells. A monoclonal H-2-specific cytotoxic IgM antibody was obtained (By-1) which detected a new public biregional H-2 specificity, H-2.m210. The mcAb By-1 reacted strongly with H-2K^d, D^d, and H-2^s antigens, gave weak cross-reactions with H-2K^k, D^q, H-2^r, and H-2^v antigens and was negative with H-2^b, H-2^f, H-2^p, and H-2L^d antigens. A polymorphic reaction pattern was also observed on a panel of lymphocytes from B 10.W strains. The intriguing finding on this reaction pattern was the reactivity on H-2^d cells, including the syngeneic BALB/cBy and truly autologous cells. As shown by capping and immunoprecipitation experiments on H-2^d cells and by studies on H-2^d-transfected mouse L cells, the target molecules for McAb By-1 were H-2K^d and H-2D^d molecules. The BALB/cBy mouse, from whose spleen cells the McAb By-1 was obtained, survived after the fusion experiment, and serum was examined for the presence of cytotoxic H-2-specific antibodies during the rest of its life. At the time of the fusion, no autoreactive serum antibodies were found, but about 4 months later, we found in the serum of this mouse autoreactive H-2-specific cytotoxic IgM antibodies. The serum antibodies followed the same reaction pattern as that of the McAb By-1. As far as we know, this is the first report of autoreactive H-2-specific antibodies in serum of a mouse which has never been immunized and of the first natural autoreactive H-2-specific monoclonal antibody.Abbreviations McAb monoclonal antibody - MHC major histocompatibility complex - H-2 major histocompatibility complex of mice - CTLs cytotoxic T cells - FMF flow microfluorometry - FITC fluorescein isothiocyanate - LPS lipopolysaccharide W.E. coli 0111:134 - PBS phosphate-buffered saline - Iodogen 1,3,4,6,-tetrachloro-3,6-diphenylglycoluril - GAMIg goat-antimouse immunoglobulin - Staph-A Staphylococcus aureus Cowan I     

Receptor specificity,functional characteristics,and cell-surface phenotype of a highly selected anti-I-Ab-specific,long-term T-cell line

A highly selected alloreactive T-cell line was developed by repeated restimulation of B10.D2/n lymph-node cells with irradiated C57BL/10Sn (BIO) spleen cells in long-term MLC for up to 2 1/2 years. Continuous growth of the line requires restimulation every 2 to 4 weeks with fresh H-2^b stimulator cells. The line proliferates strongly against H-2^b but not againstH-2 ^d ,H-2 ^f ,H-2 ^q ,H-2 ^r , orH-2 ^s stimulators. Analysis of recombinant mouse strains showed that the proliferative response is directed against I-A^b but not K^b or D^b determinants. During the growth period of the line, strong cross-reactivity with H-2^p (B10.P) and weak cross-reactivity with H-2^k strains (e.g., CBA/J and B10.BR) was observed. A clone with exquisite specificity for I-A^b, but with no cross-reactivity with H-2^p or H-2^k was isolated from the line; thus clonal heterogeneity of the line still exists despite the highly selective growth conditions. — The majority of T cells from the line or clone were shown to bind I-A^b but not K^b or D^b determinants either spontaneously during restimulation with fresh B10 stimulator cells or via membrane vesicles expressing I-A^b determinants. No killing activity by the line in either specific or nonspecific cytolytic T-cell assays was observed nor was the T 145 glycoprotein, characteristic of killer T cells, detected.Abbreviations used in this paper B6 C57BL/6J - B10 C57BL/10Sn - Con A Concanavalin A - CTL cytotoxic T lymphocyte - FCS fetal calf serum - FDA fluorescein diacetate - FITC fluorescein isothiocyanate - Ia I-region-associated antigens - LPS lipopolysaccharide fromE. coli - Lyt T-lymphocyte-defined antigen - MLC mixed leukocyte culture - NP-40 nonidet P-40 - PAGE pofyacrylamide gel electrophoresis - PHA phytohemagglutinin fromPhaseolus vulgaris - PM plasma membrane - SDS sodium dodecyl sulfate - TCGF T-cell growth factor(s) - TdR thymidine     

Effect of anH-2 mutation on cytotoxic T cell recognition. Specific antigen can determine the pattern ofH-2 restriction

Hz1 (H-2 ^bm1 ) mice, an H-2 mutant strain derived from C57BL/6(H-2 ^b ), were either injected with vaccinia virus or had their spleen cells sensitized in vitro with syngeneic TNP-modified cells. The cytotoxic cells generated were tested for their activity against target cells that were either infected with vaccinia virus, TNP-modified, or both vaccinia infected and TNP-modified.Hz1 anti-TNP cytotoxic cells specifically lysed syngeneic target cells that were trinitrophenylated but not infected with vaccinia virus, while anti-vaccinia cells specifically lysed vaccinia infected target cells but not TNP-cells. Hz1 (H-2K ^bm1 D ^b ) anti-TNP effector cells killed B10.A(5R)-TNP (H-2K ^b D ^d ) targets, indicating that there is cross-reactivity between TNP-H-2K^b and TNP-H-2K^bm1. On the other hand, there is no cross-reactivity between vaccinia-H-2K^b and H-2K^bm1, since Hz1 anti-vaccinia effector cells did not kill vaccinia infected B10.A(5R) targets.Since Hz1 anti-TNP effector cells lysed B10.A(5R) target cells that were first infected with vaccinia virus and then derivatized with TNP, virus does not mask cross-reactive determinants shared by TNP-H-2K^b and H-2K^bm1. Additional experiments showed that Hz1 anti-TNP effector cells lysed TNP-modified and vaccinia infected B10.A(5R) target cells irrespective of the virus concentration used for infection or the time of addition of virus. Further, there are no detectable quantitative differences between C57BL/6 and Hz1 anti-TNP effector cells in their ability to kill TNP-5R targets.The cytotoxic effect of Hz1 anti-TNP effector cells on B10.A(5R)-TNP targets could not be blocked with TNP derivatized inhibitor cells that carry theH-2D ^d region allele. Thus, the ability of anti-TNP H-2K^b effector cells to cross-react with H-2K^bm1 cannot be explained by a cross-reaction between H-2K^bm1 and H-2D^d.Abbreviations used in this paper TNP trinitrophenol - PFU plaque forming unit - Con A Concanavalin A - BSS balanced-salt-solution - FCS fetal calf serum - TNBS trinitrobenzene sulfonic acid - PBS phosphate-buffered-saline     

Aberrancy in immunogenicity and cell-surface expression of H-2 antigens on erythrocytes

Immunogenicity for T cell-independent B-cell response assessed by splenic plaque-forming cell (PFC) response and cell-surface expression measured by laser flow cytometry of various class I H-2 antigens on mouse red blood cells (RBC) were compared. It was found that the order of magnitude of both immunogenicity and cell-surface expression on RBC is H-2D^d H-2D^b > H-2K^d, H-2K^b. Furthermore, H-2^d public antigens and H-2L^d antigens were neither immunogenic nor easily demonstrable on RBC. These findings contrasted with poor immunogenicity for PFC response (Nakashima et al. 1982, 1983) and proportionally strong expression of H-2 antigens on lymphoid cells. Immunogenicity and cell-surface expression of H-2D^d antigen on RBC were not shown to be controlled by the action of genes outside H-2D. It was therefore suggested that a number of H-2 antigens, including H-2K^d private, H-2K^b private, and H-2^d public specificities are at least functionally defective on RBC. This is possibly due to the structural characteristics of the antigens. Since immunogenicity and cell-surface expression were in parallel, the expression of H-2 antigens on RBC must be dictated by a subset of B cells whose activity was assessed by PFC response. This finding supports the view that the H-2 molecules display a new category of activity which is different from their ability to activate T cells and depends on their expression on RBC.     

H-2 control of expression of an idiotype shared by normal B cells and a B-cell lymphoma

The spleens of normal B10,H-2 ^a H-44^b p/Wts (2 ^a 4 ^b ) mice; contain cells which, in response to mitogen stimulation, secrete hemolytic antibody specific for a determinant present on both sheep and bromelain-treated mouse erythrocytes. These cells were found to be Ly-1 positive. Approximately 50% of these cells bear surface immunoglobulin (sIg) with the same idiotype as the sIg of a 2^a4^b-derived B-cell lymphoma, CH12. Backcross analysis revealed H-2 control of the frequency of the idiotype-positive B cell. The regulatory gene did not correlate with the Igh-1 allotype, and analysis of 22 inbred mouse strains mapped the gene to the I-E subregion. Surprisingly, only strains homozygous for E ^k expressed the idiotype, and expression was a recessive trait. Possible mechanisms for this control of idiotype expression and its relation to lymphomagenesis are discussed.Abbreviations used in this paper 2 ^a4^b B10.H-2 ^aH-4^bp/Wts - Br-MRBC bromelain-treated mouse erythrocytes - C complement - LPS lipopolysaccharide W - pfc plaque-forming cells - sIg surface immunoglobulin - SRBC sheep erythrocytes - Ts T suppressor.     

Recognition of Db and Kb gene products by influenza-specific cytotoxic T cells

A series of 16 H-2^b-restricted, A influenza virus-specific cytotoxic T-cell clones are described and characterized. One is K^b restricted, the others D^b restricted. The factors governing K^b or D^b restriction patterns seen in the mixed populations from which clones are derived are investigated. The K^b-restricted clone does not recognize K^b mutant bm1 and influenza and all 15 D^b-restricted clones do not recognize D^b mutant bm14 and A influenza virus; these results are discussed in the light of findings in a variety of other viral systems. Representative K^b- and D^b-restricted clones were used to assess the functional properties of cloned cosmids containing either K^b or D^b genes expressed in transformed L-cells (κ haplotype). The expression products of both cosmids functioned efficiently as mutually exclusive restriction elements for A influenza virus recognition.