We thank Drs. Robert Bonneau and Neil Christensen for helpful comments.	
This work was supported by Pennsylvania State University College of Medicine funds.

1. Isolation of T Cells from Spleen and Lymph Nodes of BDC2.5 Mice
<ol>
	<li>Use 6-week-old pre-diabetic female BDC2.5 mice as donors of diabetogenic CD4+ T cells. Mice should be diabetes-free as determined by urine glucose measurement (see below).</li>
	<li>Euthanize each mouse using CO2 asphyxiation and remove the spleen, axillary and brachial lymph nodes under sterile conditions. To remove the spleen, soak the fur with 70% ethanol, then cut and retract skin. The spleen will be visible as a dark red organ ...

<ol>
	<li>Makino, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Breeding+of+a+non-obese,+diabetic+strain+of+mice.">Breeding of a non-obese, diabetic strain of mice.</a> Jikken Dobutsu. 29, 1-13 (1980).</li><li>van Belle, T. L., Coppieters, K. T., von Herrath, M. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Type+1+diabetes:+etiology,+immunology,+and+therapeutic+strategies.">Type 1 diabetes: etiology, immunology, and therapeutic strategies.</a> Physiol. Rev. 91, 79-118 (2011).</li><li>Delovitch, T. L., Singh, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+nonobese+diabetic+mouse+as+a+model+of+autoimmune+diabetes:+immune+dysregulation+gets+the+NOD.">The nonobese diabetic mouse as a model of autoimmune diabetes: immune dysregulation gets the NOD.</a> Immunity. 7, 727-738 (1997).</li><li>Wicker, L. S., Miller, B. J., Mullen, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transfer+of+autoimmune+diabetes+mellitus+with+splenocytes+from+nonobese+diabetic+(NOD)+mice.">Transfer of autoimmune diabetes mellitus with splenocytes from nonobese diabetic (NOD) mice.</a> Diabetes. 35, 855-860 (1986).</li><li>Bendelac, A., Carnaud, C., Boitard, C., Bach, J. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Syngeneic+transfer+of+autoimmune+diabetes+from+diabetic+NOD+mice+to+healthy+neonates.+Requirement+for+both+L3T4++and+Lyt-2++T+cells.">Syngeneic transfer of autoimmune diabetes from diabetic NOD mice to healthy neonates. Requirement for both L3T4+ and Lyt-2+ T cells.</a> J. Exp. Med. 166, 823-833 (1987).</li><li>Haskins, K., McDuffie, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Acceleration+of+diabetes+in+young+NOD+mice+with+a+CD4++islet-specific+T+cell+clone.">Acceleration of diabetes in young NOD mice with a CD4+ islet-specific T cell clone.</a> Science. 249, 1433-1436 (1990).</li><li>Christianson, S. W., Shultz, L. D., Leiter, E. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adoptive+transfer+of+diabetes+into+immunodeficient+NOD-scid/scid+mice.+Relative+contributions+of+CD4++and+CD8++T-cells+from+diabetic+versus+prediabetic+NOD.NON-Thy-1a+donors.">Adoptive transfer of diabetes into immunodeficient NOD-scid/scid mice. Relative contributions of CD4+ and CD8+ T-cells from diabetic versus prediabetic NOD.NON-Thy-1a donors.</a> Diabetes. 42, 44-55 (1993).</li><li>Wicker, L. S., Todd, J. A., Peterson, L. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+control+of+autoimmune+diabetes+in+the+NOD+mouse.">Genetic control of autoimmune diabetes in the NOD mouse.</a> Annual Reviews in Immunology. 13, 179-200 (1995).</li><li>Serreze, D. V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MHC+class+I-mediated+antigen+presentation+and+induction+of+CD8++cytotoxic+T-cell+responses+in+autoimmune+diabetes-prone+NOD+mice.">MHC class I-mediated antigen presentation and induction of CD8+ cytotoxic T-cell responses in autoimmune diabetes-prone NOD mice.</a> Diabetes. 45, 902-908 (1996).</li><li>Milton, M. J., Poulin, M., Mathews, C., Piganelli, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generation,+maintenance,+and+adoptive+transfer+of+diabetogenic+T-cell+lines/clones+from+the+nonobese+diabetic+mouse.">Generation, maintenance, and adoptive transfer of diabetogenic T-cell lines/clones from the nonobese diabetic mouse.</a> Methods Mol. Med. 102, 213-225 (2004).</li><li>Kurrer, M. O., Pakala, S. V., Hanson, H. L., Katz, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Beta+cell+apoptosis+in+T+cell-mediated+autoimmune+diabetes.">Beta cell apoptosis in T cell-mediated autoimmune diabetes.</a> Proc. Natl. Acad. Sci. U.S.A. 94, 213-218 (1997).</li><li>Amrani, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Perforin-independent+beta-cell+destruction+by+diabetogenic+CD8(+)+T+lymphocytes+in+transgenic+nonobese+diabetic+mice.">Perforin-independent beta-cell destruction by diabetogenic CD8(+) T lymphocytes in transgenic nonobese diabetic mice.</a> J. Clin. Invest. 103, 1201-1209 (1999).</li><li>Dobbs, C., Haskins, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+a+T+cell+clone+and+of+T+cells+from+a+TCR+transgenic+mouse:+TCR+transgenic+T+cells+specific+for+self-antigen+are+atypical.">Comparison of a T cell clone and of T cells from a TCR transgenic mouse: TCR transgenic T cells specific for self-antigen are atypical.</a> J. Immunol. 166, 2495-2504 (2001).</li><li>Haskins, K., Portas, M., Bradley, B., Wegmann, D., Lafferty, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=T-lymphocyte+clone+specific+for+pancreatic+islet+antigen.">T-lymphocyte clone specific for pancreatic islet antigen.</a> Diabetes. 37, 1444-1448 (1988).</li><li>Katz, J. D., Wang, B., Haskins, K., Benoist, C., Mathis, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Following+a+diabetogenic+T+cell+from+genesis+through+pathogenesis.">Following a diabetogenic T cell from genesis through pathogenesis.</a> Cell. 74, 1089-1100 (1993).</li><li>Stadinski, B. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chromogranin+A+is+an+autoantigen+in+type+1+diabetes.">Chromogranin A is an autoantigen in type 1 diabetes.</a> Nat. Immunol. 11, 225-231 (2010).</li><li>Luhder, F., Chambers, C., Allison, J. P., Benoist, C., Mathis, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pinpointing+when+T+cell+costimulatory+receptor+CTLA-4+must+be+engaged+to+dampen+diabetogenic+T+cells.">Pinpointing when T cell costimulatory receptor CTLA-4 must be engaged to dampen diabetogenic T cells.</a> Proc. Natl. Acad. Sci. U.S.A. 97, 12204-12209 (2000).</li><li>Tang, Q., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vitro-expanded+antigen-specific+regulatory+T+cells+suppress+autoimmune+diabetes.">In vitro-expanded antigen-specific regulatory T cells suppress autoimmune diabetes.</a> J. Exp. Med. 199, 1455-1465 (2004).</li><li>Calderon, B., Suri, A., Pan, X. O., Mills, J. C., Unanue, E. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=IFN-gamma-dependent+regulatory+circuits+in+immune+inflammation+highlighted+in+diabetes.">IFN-gamma-dependent regulatory circuits in immune inflammation highlighted in diabetes.</a> J. Immunol. 181, 6964-6974 (2008).</li><li>Shultz, L. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiple+defects+in+innate+and+adaptive+immunologic+function+in+NOD/LtSz-scid+mice.">Multiple defects in innate and adaptive immunologic function in NOD/LtSz-scid mice.</a> J. Immunol. 154, 180-191 (1995).</li><li>Waldner, H., Sobel, R. A., Price, N., Kuchroo, V. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+autoimmune+diabetes+locus+Idd9+regulates+development+of+type+1+diabetes+by+affecting+the+homing+of+islet-specific+T+cells.">The autoimmune diabetes locus Idd9 regulates development of type 1 diabetes by affecting the homing of islet-specific T cells.</a> J. Immunol. 176, 5455-5462 (2006).</li><li>Verdaguer, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spontaneous+autoimmune+diabetes+in+monoclonal+T+cell+nonobese+diabetic+mice.">Spontaneous autoimmune diabetes in monoclonal T cell nonobese diabetic mice.</a> J. Exp. Med. 186, 1663-1676 (1997).</li><li>Thomas, D. C., Mellanby, R. J., Phillips, J. M., Cooke, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+early+age-related+increase+in+the+frequency+of+CD4++Foxp3++cells+in+BDC2.5NOD+mice.">An early age-related increase in the frequency of CD4+ Foxp3+ cells in BDC2.5NOD mice.</a> Immunology. 121, 565-576 (2007).</li><li>Prochazka, M., Gaskins, H. R., Shultz, L. D., Leiter, E. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+nonobese+diabetic+scid+mouse:+model+for+spontaneous+thymomagenesis+associated+with+immunodeficiency.">The nonobese diabetic scid mouse: model for spontaneous thymomagenesis associated with immunodeficiency.</a> Proc. Natl. Acad. Sci. U.S.A. 89, 3290-3294 (1992).</li></ol>

All mice were housed at the Penn State College of Medicine specific pathogen-free (SPF) facility in accordance with the guidelines of the Penn State Institutional Animal Care and Use Committee.	
The authors declare that they have no competing financial interests.

T1D can be induced in recipient mice at varying efficiencies by adoptive transfer of whole spleen cells or T cell subsets from diabetic NOD mice or mice transgenic for TCRs derived from diabetogenic T cell clones. We report herein a reproducible method to induce T1D in recipient mice within two weeks at 100% incidence by transferring FACS-purified CD62L+ BDC2.5 transgenic CD4+ T cells into NOD.SCID mice.
Specific advantages of the BDC2.5 T cell transfer model described here include the very s...

The NOD mouse develops autoimmune diabetes spontaneously and has been widely used as an animal model for human T1D1,2. Pathogenesis of T1D in NOD mice is characterized by infiltration, beginning at 3-4 weeks of age, of the pancreatic islets of Langerhans by dendritic cells and macrophages, followed by T and B cells. This phase of non-destructive peri-insulitis leads to a slow, progressive destruction of insulin-producing pancreatic &beta; cells, resulting in overt diabetes by 4-6 months of age3. Transfer of splenocytes4,5, CD4+6,7 or CD8+8,9 T cells from diabetic NOD mice have been shown to mediate diabetes in immunocompromised NOD mice, indicating that islet-reactive T cells play a central role in T1D pathogenesis. Depending on the experimental conditions, diabetes developed in recipient mice slowly, over several weeks in these studies. Similarly, various T cell clones, derived by time-consuming and costly culturing of diabetogenic T cells, have been reported to mediate diabetes several weeks after transfer into recipient mice7,10. With the availability of transgenic mice expressing TCRs derived from CD4- or CD8-restricted diabetogenic T cell clones, several laboratories have subsequently shown that splenic T cells from such mice were able to transfer diabetes to recipients11-13. Specifically, BDC2.5 NOD mice are transgenic for the BDC2.5 TCR, which is specific for chromogranin A, a protein in pancreatic beta cells14-16. Transfer of in vitro-activated or un-activated whole or fractionated spleen cells from overtly diabetic or prediabetic BDC2.5 mice transferred diabetes to neonatal or immunodeficient NOD mice at varying efficiencies11,17-19.
We describe a simple method that utilizes purified transgenic CD4+ T cells from pre-diabetic BDC2.5 mice to induce T1D in recipient mice at high efficiency and consistency. Large numbers of naive, islet antigen-specific CD4+ T cells are isolated from these mice by fluorescence-activated cell sorting (FACS) for CD4+CD62L+ T cells expressing the transgenic TCR V&beta;4 chain. Purified transgenic T cells are then transferred without activation into NOD.SCID mice, which lack functional T and B cells and are insulitis- and diabetes-free20. The recipient mice are monitored for elevated concentrations of urine glucose indicating T1D, which develops rapidly within two weeks after the T cell transfer.
In contrast to other methods that transfer diabetogenic T cells with heterogenous specificities, our protocol uses FACS-sorted CD4+ T cells that almost exclusively express the diabetogenic BDC2.5 TCR. Due to their homogeneity, only small numbers of transferred T cells (~1x106 cells/mouse) are required for rapid T1D development within 2 weeks at 100% incidence. Another advantage of our protocol is that irradiation of recipient mice is not necessary as it is for some other methods. A potential limitation of this method is that it does not allow the investigation into the contribution of both CD4 and CD8 T cell subsets or specifically CD8 T cells in diabetes.
The described protocol will be useful for studying rapid T1D development, mediated by na&iuml;ve, monospecific CD4+ T cells, as well as therapeutic strategies to intervene in homing of islet antigen-specific Th cells to the target organ.

<table border="1" fo:keep-together.within-page="always">
	<tbody>
		<tr>
			<td>Name of Reagent/Material</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr>
			<td>BDC 2.5 TCR transgenic NOD mice (NOD.Cg-Tg(Tcr&alpha;BDC 2.5, Tcr&beta;BDC 2.5)</td>
			<td>JAX</td>
			<td>004460</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>NOD.SCID mice (NOD.CB17-Prkdcscid/J)</td>
			<td>JAX</td>
			<td>001303</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Dulbecco's Modified Eagle's Medium (DMEM)</td>
			<td>Themo Scientific</td>
			<td>SH30022.01</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Bayer Diastix</td>
			<td>Fisher Scientific</td>
			<td>AM2803</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>15 ml conical tubes</td>
			<td>Falcon</td>
			<td>352095</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>50 ml conical tubes</td>
			<td>Falcon</td>
			<td>352070</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Sterile surgical tweezers</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Sterile small pair scissors</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Sterile large pair scissors</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>70 &mu;m cell strainers</td>
			<td>Fisher Scientific</td>
			<td>22363548</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>35 &mu;m cell strainer cap tubes</td>
			<td>BD Biosciences</td>
			<td>352235</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Ammonium-Chloride-Potassium (ACK) buffer</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>0.15 M NH4Cl, 1 mM KHCO3, 0.1 mM Na2EDTA, pH 7.2 in dH2O</td>
		</tr>
		<tr>
			<td>BD FACSFlowTM sheath fluid</td>
			<td>BD Biosciences</td>
			<td>342003</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>FACS staining buffer</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>PBS, 0.2 mM EDTA, 0.5% BSA/FCS, filter sterilized</td>
		</tr>
		<tr>
			<td>Phase contrast microscope</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Trypan blue</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Hemocytometer</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Anti-CD4 (APC) mAb</td>
			<td>Biolegend</td>
			<td>1005616</td>
			<td>clone RM4-5</td>
		</tr>
		<tr>
			<td>Anti-TCR V&beta;4 (FITC) mAb</td>
			<td>BD Biosciences</td>
			<td>553365</td>
			<td>clone KT4</td>
		</tr>
		<tr>
			<td>Anti-CD62L (PE) mAb</td>
			<td>BD Biosciences</td>
			<td>553151</td>
			<td>clone MEL-14</td>
		</tr>
		<tr>
			<td>Cell sorter</td>
			<td>BD Biosciences</td>
			<td>&nbsp;</td>
			<td>e.g. BD FACSAria III</td>
		</tr>
		<tr>
			<td>Heat lamp</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Mouse restrainer</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>1 ml syringes</td>
			<td>Becton Dickinson</td>
			<td>309602</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>18-1&frac12; gauge needles (sterile)</td>
			<td>Becton Dickinson</td>
			<td>305196</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>27&frac12; gauge needles (sterile)</td>
			<td>Becton Dickinson</td>
			<td>305109</td>
			<td>&nbsp;</td>
		</tr>
	</tbody>
</table>

accelerated type 1 diabetes induction in mice by adoptive transfer of diabetogenic cd4+ t cells

The nonobese diabetic (NOD) mouse spontaneously develops autoimmune diabetes after 12 weeks of age and is the most extensively studied animal model of human Type 1 diabetes (T1D). Cell transfer studies in irradiated recipient mice have established that T cells are pivotal in T1D pathogenesis in this model. We describe herein a simple method to rapidly induce T1D by adoptive transfer of purified, primary CD4+ T cells from pre-diabetic NOD mice transgenic for the islet-specific T cell receptor (TCR) BDC2.5 into NOD.SCID recipient mice. The major advantages of this technique are that isolation and adoptive transfer of diabetogenic T cells can be completed within the same day, irradiation of the recipients is not required, and a high incidence of T1D is elicited within 2 weeks after T cell transfer. Thus, studies of pathogenesis and therapeutic interventions in T1D can proceed at a faster rate than with methods that rely on heterogenous T cell populations or clones derived from diabetic NOD mice.

Our results show the isolation of transgenic BDC2.5 cells expressing CD62L, which is critical for T cells to home to secondary lymphoid organs such as pancreatic lymph nodes. Our findings further demonstrate the potent ability of this monospecific T cell population to transfer rapidly and efficiently T1D to NOD.SCID recipient mice.
Isolation of diabetogenic CD4+ T cells from BDC2.5 mice is shown in Figure 2. Approximately 5 x 107 cells from pooled spleen and lymph n...

Watch this Scientific Journal Video about Accelerated Type 1 Diabetes Induction in Mice by Adoptive Transfer of Diabetogenic CD4+ T Cells at JoVE.com

Accelerated Type 1 Diabetes Induction in Mice by Adoptive Transfer of Diabetogenic CD4+ T Cells

We provide a reproducible method to induce type 1 diabetes (T1D) in mice within two weeks by the adoptive transfer of islet antigen-specific, primary CD4+ T cells.

The nonobese diabetic (NOD) mouse spontaneously develops autoimmune diabetes after 12 weeks of age and is the most extensively studied animal model of ...

accelerated-type-1-diabetes-induction-mice-adoptive-transfer

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Immunology and Infection

16.5K visualizações.  Pennsylvania State University College of Medicine. Nós proporcionar um método reprodutível para induzir diabetes do tipo 1 (DM1) em ratinhos dentro de duas semanas pela transferência adoptiva de células T primárias de ilhéus, CD4 + específicas para o antigénio.