HLAs, TCRs, and KIRs, a Triumvirate of Human Cell-Mediated Immunity

2020 ◽  
Vol 89 (1) ◽  
pp. 717-739 ◽  
Author(s):  
Zakia Djaoud ◽  
Peter Parham

In all human cells, human leukocyte antigen (HLA) class I glycoproteins assemble with a peptide and take it to the cell surface for surveillance by lymphocytes. These include natural killer (NK) cells and γδ T cells of innate immunity and αβ T cells of adaptive immunity. In healthy cells, the presented peptides derive from human proteins, to which lymphocytes are tolerant. In pathogen-infected cells, HLA class I expression is perturbed. Reduced HLA class I expression is detected by KIR and CD94:NKG2A receptors of NK cells. Almost any change in peptide presentation can be detected by αβ CD8+ T cells. In responding to extracellular pathogens, HLA class II glycoproteins, expressed by specialized antigen-presenting cells, present peptides to αβ CD4+ T cells. In comparison to the families of major histocompatibility complex (MHC) class I, MHC class II and αβ T cell receptors, the antigenic specificity of the γδ T cell receptors is incompletely understood.

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1711-1711
Author(s):  
Yong Zhang ◽  
Surbhi Goel ◽  
Aaron Prodeus ◽  
Utsav Jetley ◽  
Yiyang Tan ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
Nk Cell ◽  
Class Ii ◽  

Abstract Introduction. Despite the success of autologous chimeric antigen receptor (CAR)-T cells, barriers to a more widespread use of this potentially curative therapy include manufacturing failures and the high cost of individualized production. There is a strong desire for an immediately available cell therapy option; however, development of "off-the-shelf" T cells is challenging. Alloreactive T cells from unrelated donors can cause graft versus host disease (GvHD) for which researchers have successfully used nucleases to reduce expression of the endogenous T cell receptor (TCR) in the allogeneic product. The recognition of allogeneic cells by the host is a complex issue that has not been fully solved to date. Some approaches utilize prolonged immune suppression to avoid immune rejection and increase persistence. Although showing responses in the clinic, this approach carries the risk of infections and the durability of the adoptive T cells is uncertain. Other strategies include deletion of the B2M gene to remove HLA class I molecules and avoid recognition by host CD8 T cells. However, loss of HLA class I sends a "missing-self" signal to natural killer (NK) cells, which readily eliminate B2Mnull T cells. To overcome this, researchers are exploring insertion of the non-polymorphic HLA-E gene, which can provide partial but not full protection from NK cell-mediated lysis. Because activated T cells upregulate HLA class II, rejection by alloreactive CD4 T cells should also be addressed. Methods. Here, we developed an immunologically stealth "off-the-shelf" T cell strategy by leveraging our CRISPR/Cas9 platform and proprietary sequential editing process. To solve the issue of rejection by alloreactive CD4 and CD8 T cells, we knocked out (KO) select HLA class I and class II expression with a sequential editing process. Additionally, we utilize potent TCR-α and -β constant chain (TRAC, TRBC) gRNAs that achieve >99% KO of the endogenous TCR, addressing the risk of GvHD. An AAV-mediated insertion of a CAR or TCR into the TRAC locus is used in parallel with the TRAC KO step to redirect the T cells to tumor targets of interest. Alloreactivity by CD4 and CD8 T cells, NK killing, GvHD induction and T cell function was assessed in vitro and/or in vivo. Results. By knocking out select HLA class I and class II proteins, we were able to avoid host CD4- and CD8-T cell-mediated recognition. Edited T cells were protected from host NK cells, both in vitro and in an in vivo model engrafted with functional human NK cells. TRAC edited donor T cells did not induce GvHD in an immune compromised mouse model over the 90-day evaluation period. Using our proprietary T cell engineering process, we successfully generated allogeneic T cells with sequential KOs and insertion of a tumor-specific TCR or CAR with high yield. Importantly, these allogeneic T cells had comparable functional activity to their autologous T cell counterparts in in vitro assays (tumor cell killing and cytokine release) as well as in vivo tumor models. With a relatively small bank of donors, we can provide an "off-the-shelf" CAR or TCR-T cell solution for a large proportion of the population. Conclusions. We have successfully developed a differentiated "off-the-shelf" approach, which is expected to be safe and cost-effective. It is designed to provide long-term persistence without the need for an immune suppressive regimen. This promising strategy is being applied to our T cell immuno-oncology and autoimmune research candidates. Disclosures Zhang: Intellia Therapeutics: Current Employment. Goel: Intellia Therapeutics: Current Employment. Prodeus: Intellia Therapeutics: Current Employment. Jetley: Intellia Therapeutics: Current Employment. Tan: Intellia Therapeutics: Current Employment. Averill: Intellia Therapeutics: Current Employment. Ranade: Intellia Therapeutics: Current Employment. Balwani: Intellia Therapeutics: Current Employment. Dutta: Intellia Therapeutics: Current Employment. Sharma: Intellia Therapeutics: Current Employment. Venkatesan: Intellia Therapeutics: Current Employment. Liu: Intellia Therapeutics: Current Employment. Roy: Intellia Therapeutics: Current Employment. O′Connell: Intellia Therapeutics: Current Employment. Arredouani: Intellia Therapeutics: Current Employment. Keenan: Intellia Therapeutics: Current Employment. Lescarbeau: Intellia Therapeutics: Current Employment. Schultes: Intellia Therapeutics: Current Employment.


2020 ◽  
Vol 432 (24) ◽  
pp. 166697 ◽  
Author(s):  
Yanan He ◽  
Pragati Agnihotri ◽  
Sneha Rangarajan ◽  
Yihong Chen ◽  
Melissa C. Kerzic ◽  
...  

Blood ◽  
2012 ◽  
Vol 119 (15) ◽  
pp. 3373-3374 ◽  
Author(s):  
Terrence L. Geiger

In this issue of Blood, Plesa et al demonstrate that human Foxp3+ regulatory T cells can be redirected using MHC class I–restricted T-cell receptors (TCRs), showing a surprising lack of correlation of TCR affinity and their suppressive potency.1


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3247-3247
Author(s):  
Anita N. Stumpf ◽  
Edith D. van der Meijden ◽  
Cornelis A.M. van Bergen ◽  
Roelof Willemze ◽  
J.H. Frederik Falkenburg ◽  
...  

Abstract Patients with relapsed hematological malignancies after HLA-matched hematopoietic stem cell transplantation (HSCT) can be effectively treated with donor lymphocyte infusion (DLI). Donor-derived T cells mediate beneficial graft-versus-leukemia (GvL) effect but may also induce detrimental graft-versus-host disease (GvHD). These T cell responses are directed against polymorphic peptides which differ between patient and donor due to single nucleotide polymorphisms (SNPs). These so called minor histocompatibility antigens (mHag) are presented by HLA class I or II, thereby activating CD8+ and CD4+ T cells, respectively. Although a broad range of different HLA class I restricted mHags have been identified, we only recently characterized the first autosomal HLA class II restricted mHag phosphatidylinositol 4-kinase type 2 beta (LB-PI4K2B-1S; PNAS, 2008, 105 (10), p.3837). As HLA class II is predominantly expressed on hematopoietic cells, CD4+ T cells may selectively confer GvL effect without GvHD. Here, we present the molecular identification of four new autosomal HLA class II restricted mHags recognized by CD4+ T cells induced in a patient with relapsed chronic myeloid leukemia (CML) after HLAmatched HSCT who experienced long-term complete remission after DLI with only mild GvHD of the skin. By sorting activated CD4+ T cells from bone marrow mononuclear cells obtained 5 weeks after DLI, 17 highly reactive mHag specific CD4+ T cell clones were isolated. Nine of these T cell clones recognized the previously described HLADQ restricted mHag LB-PI4K2B-1S. The eight remaining T cell clones were shown to exhibit five different new specificities. To determine the recognized T cell epitopes, we used our recently described recombinant bacteria cDNA library. This method proved to be extremely efficient, since four out of five different specificities could be identified as new HLA-class II restricted autosomal mHags. The newly identified mHags were restricted by different HLA-DR molecules of the patient. Two mHags were restricted by HLA-DRB1 and were found to be encoded by the methylene-tetrahydrofolate dehydrogenase 1 (LBMTHFD1- 1Q; DRB1*0301) and lymphocyte antigen 75 (LB-LY75-1K; DRB1*1301) genes. An HLA-DRB3*0101 restricted mHag was identified as LB-PTK2B-1T, which is encoded by the protein tyrosine kinase 2 beta gene. The fourth mHag LB-MR1-1R was restricted by HLA-DRB3*0202 and encoded by the major histocompatibility complex, class I related gene. All newly identified HLA class II restricted mHags exhibit high population frequencies of 25% (LB-MR1-1R), 33% (LB-LY75-1K), 68% (LB-MTHFD1- 1Q), and 70% (LB-PTK2B-1T) and the genes encoding these mHags show selective (LY- 75) or predominant (MR1, MTHFD1, PTK2B) expression in cells of hematopoietic origin as determined by public microarray databases. All T cell clones directed against the newly identified mHags recognized high HLA class II-expressing B-cells, mature dendritic cells (DC) and in vitro cultured leukemic cells with antigen-presenting phenotype. The clone recognizing LB-MTHFD1-1Q also showed direct recognition of CD34+ CML precursor cells from the patient. In conclusion, we molecularly characterized the specificity of the CD4+ T cell response in a patient with CML after HLA-matched HSCT who went into long-term complete remission after DLI. By screening a recombinant bacteria cDNA library, four new different CD4+ T cell specificities were characterized. Our screening method and results open the possibility to identify the role of CD4+ T cells in human GvL and GvHD, and to explore the use of hematopoiesis- and HLA class II-restricted mHag specific T cells in the treatment of hematological malignancies.


1987 ◽  
Vol 166 (6) ◽  
pp. 1747-1757 ◽  
Author(s):  
S E Ratnofsky ◽  
A Peterson ◽  
J L Greenstein ◽  
S J Burakoff

In general, the human CD8 molecule is expressed on T cells specific for HLA class I molecules. Studies designed to delineate the function and to define the ligand of the CD8 molecule have been complicated by the fact that the presumptive ligand for CD8 is on the HLA class I molecule, the same molecule encoding the ligand for the antigen-specific T cell receptor. The ability to express genes in cells other than their natural host has produced a new technology with which to approach CD8 functional studies. The insertion of a cDNA clone for CD8 in a defective retroviral vector has allowed the transfer of CD8 by infection with the resulting defective retrovirus. CD8 was then expressed in an HLA class II-specific T cell, thus separating the ligand requirements of the TCR and CD8. By this approach, the human CD8 molecule was expressed in a murine T cell hybridoma specific for human class II antigens. The resulting CD8+ hybridomas demonstrated a 10-fold increase in IL-2 production over the parent cell line when stimulated with JY, a human B lymphoblastoid cell line expressing both class I and II HLA antigens, demonstrating that expression of CD8 increases T cell activation. mAbs directed against the CD8 molecule inhibited the response of CD8+ hybridomas to JY, supporting the conclusion that the CD8 molecule was fractional. The role of CD8 as a receptor for class I MHC antigens was addressed by stimulation with a cell line expressing HLA-DR antigens, but lacking the expression of HLA class I antigens (Daudi). Stimulation of the CD8+ hybridomas by Daudi did not result in increased IL-2 production. The response to Daudi was unaltered by the addition of anti-CD8 mAb, in contrast to the ability of anti-CD8 mAb to block JY stimulation. Furthermore, mAbs directed against the class I antigens present on JY cells were able to block the enhanced response of the CD8+ hybridomas to JY. These data support the hypothesis that HLA class I molecules are the ligands involved in the CD8-dependent enhancement of T cell activation.


2020 ◽  
Author(s):  
Alison Tarke ◽  
John Sidney ◽  
Conner K Kidd ◽  
Jennifer M. Dan ◽  
Sydney I. Ramirez ◽  
...  

SUMMARYT cells are involved in control of SARS-CoV-2 infection. To establish the patterns of immunodominance of different SARS-CoV-2 antigens, and precisely measure virus-specific CD4+ and CD8+ T cells, we studied epitope-specific T cell responses of approximately 100 convalescent COVID-19 cases. The SARS-CoV-2 proteome was probed using 1,925 peptides spanning the entire genome, ensuring an unbiased coverage of HLA alleles for class II responses. For HLA class I, we studied an additional 5,600 predicted binding epitopes for 28 prominent HLA class I alleles, accounting for wide global coverage. We identified several hundred HLA-restricted SARS-CoV-2-derived epitopes. Distinct patterns of immunodominance were observed, which differed for CD4+ T cells, CD8+ T cells, and antibodies. The class I and class II epitopes were combined into new epitope megapools to facilitate identification and quantification of SARS-CoV-2-specific CD4+ and CD8+ T cells.


Blood ◽  
2011 ◽  
Vol 117 (19) ◽  
pp. 5133-5141 ◽  
Author(s):  
Michael D. Stadnisky ◽  
Xuefang Xie ◽  
Ebony R. Coats ◽  
Timothy N. Bullock ◽  
Michael G. Brown

AbstractMHC class I (MHC I) is essential to NK- and T-cell effector and surveillance functions. However, it is unknown whether MHC I polymorphism influences adaptive immunity through NK cells. Previously, we found that MHC I Dk, a cognate ligand for the Ly49G2 inhibitory receptor, was essential to NK control of murine (M)CMV infection. Here we assessed the significance of NK inhibitory receptor recognition of MCMV on CD8 T cells in genetically defined MHC I Dk disparate mice. We observed that Dk-licensed Ly49G2+ NK cells stabilized and then enhanced conventional dendritic cells (cDCs) recovery after infection. Furthermore, licensed NK support of cDC recovery was essential to enhance the tempo, magnitude, and effector activity of virus-specific CD8 T cells. Minimal cDC and CD8 T-cell number differences after low-dose MCMV in Dk disparate animals further implied that licensed NK recognition of MCMV imparted qualitative cDC changes to enhance CD8 T-cell priming.


1986 ◽  
Vol 163 (3) ◽  
pp. 603-619 ◽  
Author(s):  
T Mizuochi ◽  
S Ono ◽  
T R Malek ◽  
A Singer

This study has characterized the primary T cell subpopulations that secrete IL-2 in response to recognition of either class I or class II MHC encoded determinants. The addition to culture of anti-IL-2-R mAb inhibited the consumption of IL-2 by activated lymphocytes during the response period, permitting a much more accurate assessment of the amount of IL-2 produced in the response cultures. Using this response system, we found that primary T cell populations contain two IL-2-secreting T cell subsets that express reciprocal phenotypes and different MHC recognition specificities: an L3T4+, Lyt-2- T cell subset responsive to both class I and class II MHC alloantigens, and an L3T4-Lyt-2+ T cell subset responsive only to class I MHC alloantigens. The L3T4+ T cell subset expressed a broad functional response repertoire in that L3T4+ T cells were triggered to secrete IL-2 upon recognition of unmodified self-Ia determinants, allogeneic Ia determinants, and class I alloantigens presented by self-Ia determinants. The activation of L3T4+ IL-2-secreting T cells, even those responsive to class I MHC alloantigens, could be blocked completely by anti-Ia mAbs, confirming that the L3T4+ T cell subset was in fact class II restricted. In contrast, the Lvt-2+ T cell subset expressed a narrow functional response repertoire in that they were triggered to secrete IL-2 only in response to allogeneic class I MHC determinants, and were not triggered to secrete IL-2 even in response to TNP-modified self-MHC determinants. The specificity of Lyt-2+ IL-2-secreting T cells for class I MHC allodeterminants was confirmed by the observations that: (a) their activation could be blocked completely by anti-class I mAbs, (b) they could be triggered by Ia- cell lines which expressed class I MHC alloantigens and possessed accessory function, and (c) they responded to class I MHC alloantigens but failed to respond to class II MHC alloantigens, even in the presence of exogenously added second signals that circumvented the requirement for alloantigen-bearing accessory cells. Finally, the frequency of primary Lyt-2+ T cells that secreted IL-2 in response to class I (Kbm1) MHC alloantigens was shown to be only minimally lower than that of L3T4+ T cells that secreted IL-2 in response to class II (I-Abm12) MHC alloantigens.(ABSTRACT TRUNCATED AT 400 WORDS)


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